Musculoskeletal Disorders in the Workplace Principles and Practice 2nd Edition - nordin

372 Chapter 8d ● Treatment and indications for surgical treatment of foot and ankle injuries posterior tibial tendon ruptures or other causes of tendon FRACTURES insufficiency result in a unilateral flatfoot and highly or totally impaired independent toe rise. Fracture of the talus Clinical findings include tenderness and often swelling The talus holds a key position in the ankle joint, that of linking along the course of the tendon behind and beneath the medial the leg and the foot. It articulates to the tibia and fibula, calcaneus, malleolus. Early on, crepitus is frequently present. Passive prona- and navicular. More than 60% of the surface is covered with tion or resisted supination of the midfoot exacerbates the pain. articular cartilage, which leaves only a limited area for nutritional blood supply. Talar blood supply may be easily compromised Treatment in the acute phase includes active rest, ice, NSAIDs, with trauma and/or surgery in this region. and a medially posted orthotic. In severe cases, a short leg non–weight-bearing cast or walking boot for 2 weeks usually Apart from the common minute avulsions from the lateral relieves the pain. After careful biomechanical evaluation, part of the talar neck after lateral ankle sprains, substantial patients with flatfoot deformities need more advanced orthotic trauma is required to fracture the talus. Most commonly, a talar treatment. In chronic cases, surgical exploration is considered to neck fracture is sustained from a forceful passive dorsiflexion of address potential tenosynovitis, tendinosis, tendon tear, and steno- the ankle joint, as occurs when landing on the feet after a fall sis along the tendon course. from a height. In this situation, the anterior margin of the distal end of the tibia is thrust into the dorsal talar neck. The patient has Return to work depends on the resolution of pain. After surgery, significant ankle swelling and pain. Radiographs give details as to 2 to 4 months is often needed for healing and rehabilitation before the fracture pattern and possible subluxation or dislocations. pain-free walking is possible. Displaced fractures require reduction and rigid fixation, SUBTALAR JOINT INJURIES followed by early non–weight-bearing ROM exercises. For undis- placed fractures, 6-8 weeks of immobilization in a neutral- Subtalar joint dislocations position short leg cast is recommended. Weight bearing is delayed until radiographic union is evident. Subtalar joint dislocations or subluxations are infrequent, but when occurring they are caused by a fall from a height or a traffic accident. The prognosis after displaced unreduced fractures is poor. Substantial torsional force is required to accomplish these partial Better results are achieved after anatomic reduction and stable or total dislocations due to the pronounced inherent bony and screw fixation. Even with apparently nondisplaced fractures, how- ligamentous (medially the deltoid and laterally the calcaneofibu- ever, ankle joint arthrosis develops in one third of the patients at lar and talocalcaneal) stability of the subtalar joints. These late follow-up. injuries are classified according to the direction taken by the foot in relation to the talus, thus medial, lateral, posterior, or anterior. Return to work depends on the outcome of fracture Medial dislocation is by far the most common subtalar dislocation treatment. In successful cases, patients may return to manual labor reported, the injury mechanism being forced inversion. The condi- in 3-6 months, but nonunions and ankle joint arthrosis may lead tion is very painful to the hindfoot, and the deformity in total to life-long handicaps. dislocations is marked, with the midfoot and forefoot severely adducted. Prompt management is crucial because of potential com- Fractures of the calcaneus promise of neurovascular structures. Anteroposterior and lateral radiographs of the ankle and foot are taken without delay. As with talar fractures, substantial force is required to fracture the Fractures of the malleoli, talus, fifth metatarsal, or navicular some- calcaneus. Landing on the heel after a fall or jump from a height times accompany these injuries. An attempt at closed reduction is the most frequent injury mechanism. Partly because of the under intravenous sedation may be justified, but if not successful, associated significant swelling, a calcaneal fracture is very painful. immediate open surgical reduction must follow. Once reduced, the Initial care should always include strict elevation of the foot subtalar and talonavicular joints are typically stable, and no inter- above the heart level of the patient. Plain radiographs yield the nal fixation is needed. Postoperatively, immobilization in a short diagnosis, but further imaging using CT gives additional valuable leg non–weight-bearing cast for 3 weeks is recommended, fol- information regarding the extent of the fracture and its effect on lowed by gradual ROM exercises and progressive weight bearing. the subtalar joints. The risk of compartment syndrome in the intrinsic muscle compartments of the foot necessitates monitoring Provided that subtalar dislocations are treated promptly and the clinical course and compartment pressures and performing a reduction is successful, the prognosis is satisfactory in many fasciotomy when indicated (pressure above 35 mm Hg) to prevent patients. Severe soft tissue problems and associated fractures tend ischemic muscle injuries and clawing of the toes. to worsen the outcome. Late complications include impaired subtalar motion, arthrosis of the joints affected, and persistent The treatment of calcaneal fractures is still controversial. Because swelling and pain. In those cases, a subtalar arthrodesis is some- of the topographic complexity of the bone and the variable fracture times warranted. patterns, it is difficult to obtain comparable groups when different treatments are evaluated. A full spectrum of treatment modalities Return to work depends on the resolution of pain. After suc- ranging from reduction, surgery, or immobilization, to closed cessful closed reduction, the return to desk jobs is possible within reduction and immobilization, to open reduction and internal weeks, whereas surgical intervention often requires a rehabilita- fixation is used. At present, however, surgical treatment is increas- tion time of 2-4 months before the patients return to physically ingly favored. The main indications for surgical intervention are more demanding jobs.

Chapter 8d ● Stress fractures 373 severely disrupted posterior subtalar facets, significant upward or recurrent stress fractures, screening for endocrine and/or nutri- displacement of the calcaneal tuberosity, or valgus displacement tional dysfunction, especially in underweight persons, is indicated. of the tuberosity of the calcaneus with abutment against the lateral malleolus. Hindfoot stress fracture If a nonoperative approach is chosen, early motion is recom- Although relatively uncommon, calcaneal stress fractures have mended, whereas weight bearing is delayed for at least 8 weeks. been reported in military recruits in vigorous physical training for Operative treatment requires care by an orthopedic surgeon with more than 16 hours a day. Diffuse pain about the heel is aggra- extensive hindfoot fracture experience. vated by its compression from a medial to lateral direction. Pain is not localized only to the plantar aspect of the heel. Treatment Regardless of treatment, the long-term prognosis after calcaneal includes weight bearing with crutches as tolerated, a shock- fractures is guarded. Eighty to 90% of patients have residual absorbing heel insert, and pain control as required. At least symptoms. Typically, subtalar mobility is significantly inhibited. 8 weeks are usually required for healing. The regimen of no-weight In many cases, a permanent custom-made heel orthotic is required or partial weight bearing of these injuries makes it possible for to control pain and swelling. white-collar workers to return to their jobs within weeks, whereas the return to heavy and demanding labor may take several months. Depending on the location and extent of the injury, return to work varies but takes at least 3-6 months if repetitive weight bear- Metatarsal stress fractures ing is demanded in the job. It is sometimes impossible to return to hard work because of persistent pain during walking. Every fifth stress fracture (17-20%) in the lower extremity is located in the metatarsals, and the second ray is the most common site. STRESS FRACTURES Surgery for hallux valgus is related to stress fracture of the second metatarsal because of altered loading patterns. Hypermobility of Stress fractures of the foot and ankle a metatarsal can predispose to adjacent metatarsal stress fracture. Typical locations of metatarsal fractures are first metatarsal-medial Stress fractures of the foot and ankle, typically in the distal fibula, base, second and third-distal diaphysis, fourth-middle or distal tibia, calcaneus and navicular bone, and metatarsals, are common diaphysis, and fifth-proximal (junction metaphysis/diaphysis). in athletes and probably workers. Bone is continuously adapting Symptoms typically progress slowly in a “crescendo” effect. It can to new loading patterns. A stress or fatigue fracture is the failure take 1-2 months or more before stress fractures become visible on point in this normal adaptive process. Pain in the periosteum is plain radiographs. A bone scan, MRI, or possibly CT is the key an early warning sign of overloading. If fatigue and microdamage to early radiographic confirmation of a stress fracture. occur too rapidly, new bone cannot develop fast enough, the bone weakens, and a stress fracture may gradually develop. Metatarsal stress fractures are generally treated nonoperatively; early in nondisplaced fractures, activities are limited for 4 weeks. During gait the muscles play a major role in energy absorption. Running in 3-4 feet of water is beneficial, because the forefoot Muscle fatigue impairs shock absorption, leading to altered stress then usually is protected from heavy repetitive loading. distribution and increased compressive loads on the bone with a greater risk for stress fracture. A complementary contributing Stress fractures through the fifth metatarsal, however, need factor in the possible development of a stress fracture is biome- special attention. Nonoperative treatment implies 6-8 weeks chanical imbalance such as skeletal asymmetry and leg length of non–weight-bearing casting. Less restricted nonoperative discrepancy. A short leg is more susceptible to stress reaction treatments have shown high failure rates. An increasing number and fracture. Some anatomic abnormalities predispose to stress of investigators advocate early internal fixation because this reactions, although unpredictably. A rigid foot, for example, puts markedly decreases healing time and return to strenuous activities.4 increased stress on the metatarsals. Hard surface running places Signs of chronicity of the fracture, such as cortical thickening the second metatarsal at risk if a tight heel cord, a long second and intramedullary sclerosis, strongly indicate that only open metatarsal, or a flexible nonsupportive great toe is present also. treatment will be successful. Surgical alternatives are curettage, Other factors include exercise or prolonged walking on hard bone grafting, and cerclage fixation of the fracture; drilling of the surfaces, improperly supportive shoes, and injury to the opposite medullary canal followed by malleolar screw fixation without extremity, causing the patient to protect the injured limb by opening the fracture; or combinations of these. Postoperative placing more weight on the contralateral limb. casting time varies from 2 to 8 weeks, and the return to strenu- ous activities, or heavy labor, requires clinical and radiographic The common clinical course includes insidious onset of pain evidence of healing, most often 8-12 weeks. that initially is vague. With continued stress, pain increases and becomes more localized with possible soft tissue swelling. Clinical Hallux sesamoid stress fractures examination reveals distinct tenderness over the lesion. The early diagnosis is verified by scintigraphy or MRI followed by CT, Hallux sesamoid stress fractures are rare, much rarer than whereas plain radiographs typically become positive at 3-8 weeks. sesamoiditis, a difficult differential diagnosis. Bipartition of a Treatment consists of activity modification to the limits of comfort. sesamoid is not uncommon, so radiographic diagnosis is difficult Nongravity exercises are initiated, and casting is recommended also. Furthermore, scintigraphy in both stress fractures and only with multiple fractures, intolerable pain, or fragmentation. sesamoiditis is positive. Stress fractures, however, do not heal Healing of a properly treated stress fracture occurs in 1-4 months with immobilization or prolonged inactivity. If other causes of but could take 6 months. A useful clinical healing test is having pain can be excluded, a sesamoid stress fracture is treated with the patient hop on the affected limb without pain. In multiple excision of the bone, with usually a good outcome thereafter. It should be noted that surgical access to the lateral sesamoid is

374 Chapter 8d ● Treatment and indications for surgical treatment of foot and ankle injuries difficult and its safe removal requires significant surgical experi- Conservative treatment consists of active rest, pain control with ence in this area. NSAIDs, and usually an orthotic device (shock-absorbing heel cup or a custom-made nonrigid orthosis). Stretching exercises of the Tarsal navicular stress fracture plantar fascia and the Achilles tendon are advocated. Within a 3-month time frame this treatment is usually successful, but up to In nonathletes, navicular stress fractures are uncommon. The con- 1 year may be required in some cases. In refractory cases, a corti- dition is characterized by an insidious onset of vague arch pain, costeroid injection may be considered, but it is crucial that the cor- increased pain in the midfoot with motion, and limited dorsi- tisone is deposited deep to the plantar fascia to avoid plantar fat flexion of the ankle. Activity increases the discomfort. Typically, pad atrophy. In the few cases in which disabling symptoms persist, but not always, tenderness is localized over the navicular bone. surgical treatment such as proximal plantar fascia release is indi- Plain radiographs are most often normal, and a bone scan (or MRI) cated. The time needed for healing and rehabilitation is 2-5 months. is required for diagnosis. Plain tomography or CT also may delineate the extent of the injury. The fracture is typically sagit- Heel spurs tally oriented in the central third of the bone, due possibly to the relative avascularity of this part of the navicular. Treatment of The relation between plantar heel pain and a heel spur on radio- acutely displaced fractures calls for open reduction and internal graphs is considered to be very poor. Only half of the patients with fixation. To heal uneventfully, nondisplaced fractures should be heel pain have a spur, and of all people with a heel spur, only 10% treated with a non–weight-bearing cast for 6-8 weeks. In patients to 15% have heel pain. Indeed, a heel spur, when present, is located not casted or those given a weight-bearing cast, the complication deep to the origin of the plantar fascia, in the non–weight-bearing rate is high with delayed union, nonunion, or recurrence of substance of the flexor digitorum brevis muscle. the fracture, calling for surgical bone grafting. Postoperatively, the lower leg is immobilized in a non–weight-bearing cast until Plantar fasciitis union has occurred, which may take 2-4 months. After surgery, return to a desk job is possible within a week, whereas resump- True plantar fasciitis is an inflammation of a greater part of the tion of weight-bearing or other types of heavy work may take plantar fascia, with pain on passive dorsiflexion of the toes 3-4 months. and tenderness over the proximal area of the plantar fascia. Symptoms therefore predominate in the plantar aspect of the HEEL PAIN midfoot rather than the heel. Special orthotics designed to relieve the pressure on the plantar fascia should be used. If symp- Heel pain is a common and potentially disabling condition with toms persist in spite of adequate rest and orthotic use (at least 3- many possible causes. Distinction of these is important because 6 months), surgery such as proximal plantar fascia release should treatment and the expected outcomes differ. be considered. A thorough history of the patient’s complaints and pain and a Plantar fascia rupture and heel careful physical examination are mandatory tools in establishing spur fracture a correct diagnosis. These include an evaluation of the patient’s characterization of the pain, including onset, duration, nature, locali- Plantar fascia rupture and heel spur fracture are characterized by zation, and relation to work and/or physical activity. Alignment of pain in the same area as in heel pain syndrome, but the onset is the lower part of the leg, ankle, and foot; the ROM of the ankle sudden. Ruptures of the plantar fascia are not common, but these and subtalar joints; and the status of the longitudinal and trans- are reported most often in the literature after cortisone injection verse arches of the foot should be determined. Skin abnormalities in the plantar fascia. such as discoloration, wounds, bumps, blisters, and tender areas, including reactions to the tapping of nerve branches (Tinel’s sign), In patients with acute trauma or persistent pain, a special x-ray should be noted. projection (45 degrees medial-oblique) that can reveal a fractured spur should be taken. Treatment is primarily conservative: active Heel pain syndrome rest, NSAIDs, crutches, and very gradual resumption of weight- bearing activities over a 6- to 10-week period. If symptoms per- Pain localized over the origin of the plantar fascia on the antero- sist and nonunion is suspected, surgical removal of the detached medial calcaneal tuberosity is termed heel pain syndrome or fragment must be considered. plantar fasciitis. Preceded by overuse, the onset is insidious. The pathogenesis is believed to be traction periostitis and Fat pad atrophy microruptures of the origin of the plantar fascia. Symptoms include morning stiffness and pain that resolve during the day. The plantar fat pad of the heel is a highly structured tissue Pain increases after prolonged walking, however, and jumping designed to withstand repetitive impact loads. If the structure fails, and running can be intolerable. Palpation reveals pain in the as could happen after long-time overuse, the shock-absorbing very localized area just described that is typically not elicited capacity of the tissue markedly decreases, usually resulting in pain. with passive dorsiflexion of the toes, which causes traction on the plantar fascia. Plain radiographs are negative and may or may not show a calcaneal spur.

Chapter 8d ● Nerve injuries 375 On clinical examination, the heel pad feels softer and thinner with Classification the underlying calcaneal tuberosity readily palpable. Maximum tenderness is located centrally on the weight-bearing area of the Five degrees of nerve injury are traditionally distinguished, depend- heel, as opposed to the anteromedial tenderness location in heel ing on the severity: pain syndrome. Treatment is nonsurgical, using support with a cushioned heel cup and soft-soled shoes. Because they may aggra- I. First degree: Conduction deficit, axon intact. Prognosis is good. vate the atrophy, local cortisone injections are contraindicated. II. Second degree: Axon severed but intact endoneurium, Fat pad inflammation Wallerian degeneration. Regeneration follows the pattern of regrowth. Axon regeneration averages 1 to 2 mm/day and is Inflammation of the fat pad produces symptoms similar to those typical of a second-degree injury. of fat pad atrophy except for the lack of palpable thinning or III. Third degree: Disorganization of internal structure of the softening of the heel pad. In this situation, the supportive heel funiculi, minor perineurium changes, irregular regeneration. cup should be semirigid rather than cushioned. Prognosis is In a third-degree injury, regeneration is blocked by disorgani- usually good, but symptoms may need over 6 months to resolve zation of the Schwann’s cell tubes. As soon as it is evident completely. Again, local cortisone injections are contraindicated. that recovery is slowed or absent (Tinel’s sign along nerve route), exploration is considered. Distal tingling on percus- After a period of heel pain, return to work varies with the var- sion over a nerve marks the most distal point of regenerat- ious diagnoses as described above. Most people can work during ing sensory axons. This is very useful in mapping nerve nonsurgical treatment of heel pain, but walking should be regeneration. restricted. After surgery for heel pain (which involves mostly IV. Fourth degree: Axonal rupture, funicular and perineural dis- release of the plantar fascia), the healing and rehabilitation time ruption. The nerve trunk is intact, but nerve bundles are dis- needed to return to walking is usually around 2-4 months. organized. Spontaneous functional recovery is rare. Sometimes tenderness remains, and the rehabilitation time may V. Fifth degree: Loss of continuity of the nerve trunk. Fourth- then be prolonged. and fifth-degree injuries may not be distinguishable unless an open injury has revealed the nerve status. Although NERVE INJURIES motor nerve fibers are usually more susceptible to compres- sion and are therefore the first to fail and the last to recover, Manifestations of peripheral nerve injuries include paresis/paralysis this is not always true. Most compression neuropathies of extrinsic and intrinsic muscles, sensory defects, pain and con- recover by the sixth month; when they do not, intraneural tractures, and a risk for secondary changes such as pressure ulcers fibrosis and disorganization have occurred. Neurolysis, both and neuropathic arthropathy. In a neurologic examination of the external and internal, offers some hope of improvement. foot and ankle, careful assessment of sensory, motor, and sympa- When severe third- and fourth-degree lesions are present thetic function is important. The examination should include with no further chance of recovery, resection of the lesions evaluations of gait, heel and toe walking, and the Trendelenburg with autografting can improve the outlook, although only in sign in the hip. The presence of muscle paralysis, stiffness, selected cases. contracture, spasticity, ataxia, pain, and fixed or functional pres- ent deformity should be registered. Foot contractures are studied Entrapment neuropathies first with flexed knees, then with straightened knees to evaluate the effect of the heel cord on the deformity. Cavus, planus, varus, The pathogenesis of nerve entrapment is considered to be grad- valgus, and equinus of the whole foot and forefoot are assessed ual constriction by anatomic structures about a nerve and its together with flexibility of the arches as well as claw toes or chronic compression against a nonyielding structure. Nerve hammer toes. Skin moisture reflects sympathetic function, and entrapments usually give mixed motor and sensory symptoms, peripheral nerve disease is often accompanied by sympa- the latter of which typically come relatively late. The relationship thetic degeneration with resulting dry, thin skin. Tinel’s sign is between nerve fiber size, motor/sensory containment, and vul- closely evaluated as regards presence, intensity, and location. nerability to compression is uncertain. Many believe that sen- Documentation with drawings and photographs of areas with sory fibers are more resistant to compression than motor fibers nerve dysfunction is very helpful in the assessment and treat- are, but others disagree. Entrapment of a sensory or mixed nerve ment of nerve disorders. results in tenderness over the entrapment point. If the compres- sion has produced axonal interruption, Tinel’s sign may be elicited Causalgia, or reflex sympathetic dystrophy, is characterized at the point of compression. Electromyographic and nerve con- by overactivity of the sympathetic nervous system because of duction studies can be helpful in identifying and localizing an irritative lesions of sympathetic nerve fibers. Burning pain and entrapment lesion. dry hot skin are typical manifestations. A sympathetic nerve block often improves symptoms. Valleix phenomenon Charcot deformity is a joint deformity that can occur in con- Pain and hypersensitivity are sometimes seen proximal to a nerve junction with any neuropathy, with sensory deficit developing in compression. Blocking the nerve at the entrapment site relieves a joint subjected to loading of the body weight. This is commonly the proximal symptoms. It is postulated that compression can seen in the midfoot joints in conjunction with diabetes mellitus. result in proximal nerve hyperirritability. External decompres- sion leads to the relief of symptoms, provided that intraneural fibrosis is not established. Intraneural fibrosis is often present

376 Chapter 8d ● Treatment and indications for surgical treatment of foot and ankle injuries once motor denervation has occurred (as determined by atrophy local anesthetic relieves the symptoms, sometimes permanently, and denervation signs on electromyography). Hence, surgery and perineural cortisone may be tried as an additional nonoper- should not wait until late in the process. If intraneural fibrosis has ative measure, but occasionally pain recurs and requires surgical indeed developed, however, intraneural neurolysis under adequate decompression.10 magnification can yield some symptom improvement. Peripheral branches on the dorsum of the foot may be com- Entrapment of the common peroneal nerve pressed by tight shoes such as ski boots, cicatrix, or tarsometatarsal joint osteophytes, and produce entrapment symptoms. In these The common peroneal nerve, which transmits motor innerva- cases, preventive appropriate shoe correction is mandatory. tion to the peroneal muscles and to the extensors of the foot and Treatment with local anesthetics and sometimes a local cortisone ankle, is vulnerable to compression at the fibular head and neck. injection is usually successful. Occasionally, decompressive sur- An intraneural or extraneural ganglion (with or without connection gery, including osteophyte removal, is necessary. with the tibiofibular joint), an enlarged fabella, or a bone tumor in the proximal fibula are the most common causes of compression Entrapment of the deep peroneal nerve at this level. The deep peroneal nerve runs together with the anterior tibial The peroneus longus muscle has two heads: a superficial head artery on the anterior aspect of the ankle, beneath the extensor attaching to the head of the fibula and a deep head inserting at retinaculum, and then between the extensor hallucis longus and the fibular neck, below the nerve. After subtalar motion of the the extensor digitorum longus tendons to the dorsum of the foot. foot, the nerve slides back and forth between the two muscle A motor branch runs laterally on the mid-dorsum of the foot to heads, potentially leading to nerve compression. the extensor digitorum brevis muscle, terminating with sensory innervation of the first dorsal web space. Compression between These injuries can be part of overuse syndromes. People who the fascia and adjacent skeleton (osteophytes from the medial wear wooden shoes, walk on hard floors extensively, or make tarsometatarsal joint) leads to pain over the dorsum of the foot repeated flexion motions in their jobs may be prone to this kind with occasional radiation into the first web space, where local of injury. tenderness also is present. Tinel’s sign is sometimes positive, and hypoesthesia in the first dorsal web space may be present. Symptoms include pain and hypoesthesia in the lateral leg and During treatment, tight shoes must be avoided at least temporar- ankle, a “weak ankle” feeling, and even occasionally footdrop. ily. Surgical removal of osteophytes may be necessary, with care Objectively, there is a positive Tinel’s sign at the compression site taken to not injure the nerve.2 together with sensory deficit and peroneal weakness. In most cases, external decompression gives relief. Intraneural neurolysis Entrapment of the posterior tibial nerve is indicated when intraneural fibrosis is present. It should be noted and branches that the peroneus longus muscle is a powerful plantar flexor of the first ray; it maintains the medial longitudinal arch of the foot A mixed motor and sensory nerve, the posterior tibial nerve runs and is an important subtalar evertor. Weakness of this muscle together with the posterior tibial artery behind the flexor digito- leads to an altered distribution of the load on the foot when rum longus tendons in the distal third of the lower leg. Covered standing; more load must be borne by the second and third by the flexor retinaculum, it then courses behind and below the metatarsal heads, with potential metatarsalgia following. medial malleolus. At this point, the posterior tibial nerve gives rise to the medial calcaneal nerve, a sensory branch that pierces The lateral cutaneous nerve of the calf and the sural commu- the flexor retinaculum together with a small artery, runs directly nicating nerve, both sensory, emerge in the popliteal region from under the posterior calcaneal tubercle, and innervates the skin of the common peroneal nerve. Compression at this level leads to the heel pad. This nerve may be involved in heel pain syndrome. pain on the lateral side of the lower leg, and/or dorsolateral foot. The tibialis posterior nerve divides beneath the flexor retinaculum Local anesthesia blocks at the maximum point of tenderness usu- to form the medial plantar nerve and the lateral plantar nerve, ally relieve the pain permanently. which correspond respectively to the median and ulnar nerves of the hand. The medial plantar nerve runs under the anterior part Entrapment of the superficial peroneal nerve of the calcaneal tuberosity; gives motor branches to the abductor hallucis, flexor hallucis brevis, flexor digitorum brevis, and lum- From the division of the common peroneal nerve high in the brical muscles; and provides sensation to the medial part of the lower leg, this strictly sensory nerve travels between the anterior sole, including the medial 31/2 digits. The lateral plantar nerve intermuscular septum and the fascia of the lateral compartment also runs down along the medioplantar aspect of the calcaneal and emerges one or two nerves through the fascia at the junction tuberosity along its course to the lateral part of the plantar pedis between the middle and distal third of the lower leg. It runs sub- and the lateral 11/2 digits. Motor branches run to the adductor cutaneously in front of the lateral malleolus to innervate the major hallucis muscle, the interossei, and the small muscles on the part of the dorsum of the foot. The anatomy of the terminating lateral aspect of the foot. branches varies greatly, and they are at risk in surgery around the first metatarsal head. Transverse skin incisions on the dorsum of Although entrapment of the posterior tibial nerve at the the foot should be avoided. level of the knee or lower leg is rare, it is frequent within the fibroosseous tunnel behind and distal to the medial malleolus, The nerve can be trapped where it pierces the fascia. Recurrent where it is referred to as tarsal tunnel syndrome. This syndrome ankle sprains, causing stretching of the nerve, predispose to this is characterized by burning pain on the sole of the foot, often condition. Pain located over the lateral aspect of the calf and ankle and in the dorsolateral foot can be exacerbated by inver- sion and plantar flexion of the ankle. Objectively, local tender- ness and a positive Tinel’s sign are present. Three to 5 ml of a

Chapter 8d ● Midfoot injuries 377 accentuated by ambulation but characteristically also annoying although some prefer a transverse plantar incision near the MTP at night. Predisposing factors include chronic instability and/or joint crease. Surgery usually yields a 75% to 80% rate of good or edema, hyperpronation, and a posterior bony prominence of the excellent results. If secondary surgery is attempted, a longitudinal talus. Motor deficits and intrinsic muscle paresis/paralysis typi- plantar approach is recommended by most authors to achieve the cally come late. Tarsal tunnel syndrome is positively correlated necessary more extensive exposure. with pregnancy, as is carpal tunnel syndrome, with which this condition has many similarities. Objectively, a positive Tinel’s Entrapment of the sural nerve sign is usually present together with numbness of the sole and tenderness behind and below the medial malleolus. Delayed Entrapment of the sural nerve can occur anywhere along its nerve conduction of the medial and lateral plantar nerves further course from the popliteal fossa to the toes. Purely sensory, the supports the diagnosis. sural nerve arises from the tibial nerve 3 cm above the knee joint, runs deep to the deep fascia of the calf to the distal third of the The treatment of choice is surgical decompression, which lower leg where it becomes superficial, runs behind the lateral involves dividing the flexor retinaculum and freeing the nerve malleolus, and innervates the lateral aspect of the sole. The nerve proximally and distally. Internal neurolysis is indicated if the is often sacrificed when used for nerve grafting with minor or nerve is fibrotic. If it is symptomatic by causing compression of no subjective problems thereafter. Inadvertent traumatization, the nerve, occasionally an os trigonum is removed. however, could cause annoying discomfort. Jogger’s foot Conditions that may include local sural nerve compression include Achilles tendon peritendinitis, recurrent ankle sprains, Entrapment of the medial and/or lateral plantar nerves is occa- lateral calcaneal or subtalar joint problems, and fractures of the sionally seen as they pass under the abductor hallucis muscle. base of the fifth metatarsal. Symptoms include shooting pain “Jogger’s foot” is a medial plantar neuropraxia causing burning and paresthesias along the course of the nerve. Local tenderness heel pain, aching arch, and loss of sensation on the sole of the and a positive Tinel’s sign are characteristic. Occasionally, numb- foot behind the great toe. The entrapment site is typically the ness is noted. point where the abductor hallucis crosses the navicular tubercle. Anesthetic blocks, steroids, and antivalgus orthotics are initial Nonoperative treatment includes avoidance of external nerve treatment modalities, with surgical decompression sometimes compression as well as NSAIDs and occasionally a local block. indicated. If these measures fail, surgical decompression is advised. Morton’s neuroma Entrapment of the saphenous nerve The plantar interdigital nerves are terminal branches of the medial At foot and ankle level, entrapment of the exclusively sensory and lateral plantar nerves. Morton’s neuroma is currently believed saphenous nerve is rare. This nerve crosses over the tibia in a pos- by most investigators to be the reaction of a plantar interdigital teromedial to anterior direction 5-7 cm above the ankle joint nerve compression. The condition is characterized by metatarsal and together with the greater saphenous vein runs anterior to the pain, often poorly localized but at times clearly radiating into medial malleolus. It innervates the proximal medial part of the the toes (usually the third and fourth but possibly any or all). dorsum of the foot. Pain is aggravated by ambulation and by tight shoes. With dor- siflexion of the metatarsophalangeal (MTP) joints, the plantar Depending on the nerve involved and the type of surgery interdigital nerves and vessels are angulated over the leading performed, return to work varies. If decompression is carried out, edge of the transverse metatarsal ligament at or just proximal to the patient can return to work after a couple of weeks, even to a the bifurcation of the nerve to two adjacent toes. Irritation to the job that requires walking. Surgery that involves excision or exten- nerve results in pseudotumor formation. The third-space plantar sive release may require longer recovery, and return to work is nerve is formed from both the medial and lateral plantar nerves, then possible in 2-4 months. which possibly explains why this nerve is larger and more fixed than the other interdigital nerves and therefore more prone to MIDFOOT INJURIES compression. Other factors predisposing to this condition include cavus foot, high-heeled shoes, and weakness of the intrinsic and Midtarsal sprains peroneal muscles. The midtarsal or transverse tarsal joint, often called Chopart’s Treatment consists of shoe correction to diminish pressure on joint, that is, the talonavicular and calcaneocuboid joints, holds the metatarsal heads. In reducing MTP motion, a metatarsal bar a key position in the medial and lateral longitudinal arches. It also is often helpful. The bar should be placed posterior to (not at the acts together with the subtalar joints in inversion and eversion. level of) the metatarsal heads and preferably between the two Midtarsal sprains are potentially disabling injuries, with healing soles of the shoe. The shoe also should have a wide toe box and times often much longer than anticipated. In general, substantial a low heel. A metatarsal pad set just behind the point of tender- force is required to cause significant injury to these joints, for ness may be a successful alternative. NSAIDs and local steroid example, when the front foot is caught and the person falls and injections are advocated by some investigators. Foot exercises twists them. meant to strengthen the intrinsic, the peroneus longus, and the tibial posterior are recommended. In refractory cases, surgical A comprehensive classification system has been developed removal of the compressed part of the plantar interdigital nerve that ranges from nondisplaced ligamentous injuries, through is warranted, usually through a dorsal longitudinal approach, subluxations, to dislocations. Fractures of adjacent bones may or may not be present. Soft tissue engagement can be significant.

378 Chapter 8d ● Treatment and indications for surgical treatment of foot and ankle injuries In addition to plain radiographs, CTs, including three-dimensional occur but is surprisingly benign and nonsymptomatic. However, reconstructions, or MRIs are most helpful in delineating the open injuries and inadequate reduction most often lead to unsat- extent of severe injuries in this region. Undisplaced injuries are isfactory end results. normally treated nonsurgically. Because of potential instability, 6 weeks in a non–weight-bearing cast followed by 2 weeks in a MTP sprains and dislocations walking cast is recommended. During rehabilitation, a shoe with a firm sole and a longitudinal arch support should be worn. Repetitive hyperextension loads on the first MTP joint predis- Displaced fractures, subluxations, and dislocations all need to be poses to injury on the plantar aspect of the capsule around it. reduced. Occasionally, closed reduction is successful, but usually Alternatively, the dorsal aspect of the joint is sprained after a open means are required. Internal fixation is performed followed hyperflexion event. The clinical picture consists of local pain, by restricted weight-bearing casting for 3-6 weeks. tenderness, and swelling. In grade III injuries, stability is com- promised, and osteochondral damage is occasionally seen. The prognosis after midtarsal injuries is highly dependent on whether reduction is achieved. Nonreduced injuries and Treatment of MTP sprains is normally nonoperative. extensively comminuted fractures often do poorly. In these cases Ice, compression, and elevation are used acutely. Initial immobi- a future arthrodesis, with prolonged time back to work, must be lization is required with weight bearing as tolerated, but even considered. then the recovery time is often longer than 10 weeks. Whereas NSAIDs are beneficial for pain control, injections of local Tarsometatarsal injuries (Lisfranc’s joint) anesthetics or steroids are potentially aggravating to the injury and should be avoided. A plantar orthosis (steel or Orthoplast®) The second metatarsal base is the primary bony stabilizer of the limiting dorsiflexion of the first MTP joint is used during tarsometatarsal articulation, sitting in a tight mortise between the rehabilitation. Surgical capsule repair and removal of loose distal parts of the first and third cuneiforms. The cuneiforms and bodies is only occasionally indicated. Strenuous activities such the metatarsal bases are wedge shaped, being wider dorsally, and as running and jumping are resumed only after the patient thereby contribute to the metatarsal transverse arch. Motion in is asymptomatic. the joints is restricted, but together they allow some pronation and supination of the forefoot. Severe trauma to Lisfranc’s joint Forced hyperextension of the MTP joints beyond physiologic caused by direct or indirect forces on the midfoot can result in a limits may lead to rupture of the plantar plate either through the varying pattern of fractures and dislocations. Indirect forces sesamoids as fractures or proximally. The latter is irreducible along the metatarsals may result in dislocation of the joint, with because of blocking from the plantar plate. Reduction is or without fractures through the plantar aspect of the metatarsal performed with a transverse plantar incision over the prominent base. After fracture-dislocation of the Lisfranc joint complex, metatarsal head. Great care must be taken not to sever the plan- soft tissue injuries are often extensive, and because these tissues tar digital nerves. The dislocation is reduced by grabbing the torn would be further compromised, tourniquet should be avoided. end of the plantar plate and manually relocating the phalanx to its normal position. Once reduced, the joint is usually stable. Injuries to Lisfranc’s joint are notorious for missed initial Postoperatively, a cast is worn for 4 weeks with weight bearing as diagnosis and inadequate treatment. The most constant reliable tolerated. Dislocations with sesamoid fractures are usually read- radiographic sign is a slight widening between the bases of the ily reducible by closed means. first and second metatarsals, between the second and third metatarsals, or between either of the cuneiforms. Fractured frag- MTP joint dislocations of the lesser toes can typically be ments should be sought between the first and second metatarsal reduced by closed means. Once reduced, the joint is usually bases and between the medial and middle cuneiforms. For stable, and crossover taping is sufficient. adequate descriptions of radiographic findings, oblique views are necessary. Metatarsal fractures The goal of treatment is a stable anatomic reduction. Because Soft tissue coverage of the dorsum of the foot is thin, vulnerable, of interposing soft tissues or fractured fragments, reduction is and suboptimally supplied with blood. Strong ligamentous con- rarely successful by closed means. Open reduction/internal fixa- nections are present between the metatarsal necks distally and tion is recommended; transfixion is accomplished with Steinmann strong bands between the bases except the first and second, where pins or Kirschner wires (note that a standard Kirschner wire alone the soft tissue connection is located between the second base and will not hold the first metatarsal rigidly enough) or by using medial cuneiform. appropriate screws as temporary (16 weeks) internal fixation. Postoperatively, partial weight bearing for 6 weeks is recom- Common in industry, the injury often results from a direct blow mended, followed by a walking cast for 4 to 6 weeks thereafter. to the dorsum of the foot caused by a heavy object. Shoes with steel-reinforced toe boxes protect the toes but not the metatarsals. Combinations with lower leg, calcaneal, or ankle fractures are Direct force on the metatarsals usually results in transverse neck common, and, most importantly, the risk of compartment syn- fractures of the second, third, and/or fourth, whereas indirect force drome is substantial. Intracompartmental pressure measure- leads to spiral shaft fractures. The common plantar flexion-inversion ments are mandatory, and when indicated fasciotomy should be trauma results in a fifth metatarsal base fracture. After severe performed without delay. Provided that the injury is closed and injuries to the midfoot, compartment pressures in the foot should reduction/fixation is adequate, the prognosis is good. If good be carefully monitored and fasciotomy performed when indicated. primary reduction is achieved, later degenerative arthritis may

Chapter 8d ● Forefoot problems 379 Treatment of nondisplaced fractures affecting the lesser Persistent pain when pushing off is a problem for many metatarsals includes the use of a firm metatarsal pad, circumfer- patients, who therefore ask for surgery. A number of surgical pro- ential taping, and a firm boot with a crepe sole. Undisplaced cedures are available to treat hallux rigidus including: removal of fractures through the first metatarsal require a carefully molded osteochondrotic loose bodies, removal of osteophytes, wedge non–weight-bearing short leg cast for 2 weeks followed by pro- osteotomies, Keller procedure, arthrodesis, and Silastic implants. gressive weight bearing as soon as tolerated. For very demanding patients, however, arthrodesis is often pre- ferred and is the treatment of choice today. The Keller procedure In the treatment of displaced fractures, sagittal-plane displace- (extirpation of the base of the proximal phalanx) potentially ment inevitably leads to altered weight distribution across the fore- results in a short unstable great toe that would impair push-off foot and should be avoided. Normally, the load on the first ability. Silastic implants are contraindicated because of synovitis metatarsal head is twice that of any of the others (including the and even implant breakage after strenuous loading. Other interpo- fifth), and moderate frontal-plane displacements are not as critical. sition arthroplasties are currently evaluated in clinical studies. Displaced first metatarsal fractures are best treated with open Because to date there is no optimal treatment for every patient reduction and internal fixation. Chinese woven wire traps can be with hallux rigidus, individual solutions must be sought. used to distract the hallux longitudinally and aid reduction. An elastic bandage around the ankle can be used for countertraction. After surgery with arthrodesis, return to a desk job is often It is crucial to regain length. The metatarsal is then temporarily possible within a week. Return to work that involves walking transversely transfixed to the second ray. If possible, rigid inter- requires 3 to 6 months of healing and rehabilitation. nal fixation is used; if not, multiple pins are used to secure the fractures. If the fracture is open and major soft tissue problems Hallux valgus are present, wound care is possible only through the use of exter- nal fixation of the fracture. Patients with hallux valgus and bunions invariably have prona- tion deformities causing lateral pressure on the hallux. As it is With only one displaced metatarsal fracture, closed reduc- forced laterally, the medial portion of the first metatarsal head is tion is attempted. If successful, 6 weeks of non–weight-bearing uncovered and forms most of the dorsomedially directed bunion. casting follows. With multiple fractures, surgical fixation using The extensor hallucis longus tendon pull is displaced laterally, either screws and plates or intramedullary retrograde pinning is rec- further accentuating the hallux valgus deformity. The incidence ommended. Casting is unnecessary after stable internal fixation. of hallux valgus is much greater in women than in men, probably With fractures through the metatarsal neck, closed reduction partly because of the use of high-heeled and pointed-toe shoes. is virtually impossible, and fixation with Kirschner wire is com- Patients seek help because of recurrent pain/tenderness over the monly used. bunion or because of cosmetic problems and difficulties in find- ing appropriate shoes. Objectively, both the longitudinal and the Work that involves much walking after midtarsal injuries may transverse arches are insufficient. A very broad splayfoot is some- often require a long recovery time. These injuries are often either times seen. The bursa over the bunion may be intensely inflamed: missed or contribute to secondary problems, and a treatment red, hot, swollen, and very tender. The great toe is angled later- time of 3-6 months is frequently required. It is of greatest impor- ally and may even be overriding or underriding the second and tance to secure a correct diagnosis early to provide optimal treat- third toes. A hammer toe deformity of one or more of the lesser ment and facilitate early return to work. toes is often present. FOREFOOT PROBLEMS In most patients, management of hallux valgus is nonsurgical. Orthotics correcting arch insufficiency are most beneficial, and Hallux rigidus shoe modifications are in order. It is crucial to relieve pressure on the bunion; a ring-shaped pad around it is sometimes helpful. Hallux rigidus is stiffness of the hallucal MTP articulation, Indications for surgery can vary and include a valgus angle of usually secondary to arthrosis of the joint. The etiology can be more than 15 degrees, toes lying on top of each other, recurrent (1) juvenile hallux rigidus secondary to osteochondritis dissecans painful bursitis, painful calluses, or inability to wear shoes. A great of the first metatarsal head in some cases; (2) gout, especially in number of surgical procedures address bunion and the angular bilateral hallux rigidus in men; (3) posttraumatic arthrosis of the deformity. joint; and, (4) most commonly, idiopathic arthrosis of the joint, primarily in middle-aged women, with or without the presence After surgery, return to work depends on the technique used. of a hallux valgus. Radiographs reveal a crown of osteophytes on After a simple bunionectomy, it is possible to return to work the dorsal part of the metatarsal head and around the proximal within 4 to 6 weeks. If an osteotomy is carried out, return to part of the proximal phalanx. Local pain and tenderness with a walking work is not possible until a healing time of 3-5 months varying degree of ROM restriction is clinically evident. has elapsed. Treatment is initially nonoperative: rest, ice, NSAIDs, and Hammer toes shoes with stiff rocker-bottom soles. Steroid injections are often beneficial. In contrast to a true metatarsal bar, the metatarsal Characterized by hyperflexion of the proximal interphalangeal rocker bar is curved rather than flat. It should never be put prox- joints, hammer toes may develop secondary to collapse of the imal to the MTP level because it would then only accentuate the transverse arch of the forefoot. Painful corns on the dorsum of bending of the sole. A combination with moderate heel eleva- tion is often beneficial to rocker-bottom sole function.

380 Chapter 8d ● Treatment and indications for surgical treatment of foot and ankle injuries the proximal interphalangeal joints develop. If joint range of A common predisposing factor to metatarsalgia is altered forefoot motion is unaffected, conservative treatment is advocated, biomechanics, extrinsic or intrinsic, caused by the following: including an arch-correcting orthotic, adequately roomy shoes, ● High-heeled shoes, which significantly alter the load from the possibly toe manipulation to maintain mobility, and strapping of the toe in extension. hindfoot to the MTP region; ● Equinus foot, especially when caused by a tight heel cord If the toes are hyperflexed and restrict walking or if major corns and callosities are causing pain, surgery is indicated. With and/or anterior impingement of the ankle, thereby preventing established flexion contracture of the proximal interphalangeal ankle dorsiflexion; joint, excision of the distal end of the proximal phalanx is often ● Cavus foot, where support is maintained only by the metatarsal gratifying. In early stages when flexion contracture is redressable, heads and the heel (and not also by the lateral longitudinal a flexor tendon tenotomy through a minimal incision under arch), resulting in overload of the forefoot; local anesthesia usually is enough and requires no or minimal ● Irregular distribution of load between the metatarsal heads. In postoperative recovery. Return to work is often possible 1 month the static standing position, all metatarsal heads bear load, the after hammer toe surgery. first metatarsal head bearing double the load of the others. In the dynamic take-off phase of walking and running, this rela- The sesamoids tive first ray overload is even more evident. A disturbance of this load distribution between the metatarsals may be caused The sesamoids are two bones located on the plantar aspect of the by an abnormally short or hypermobile first ray or by a long hallucal MTP joint. The medial sesamoid is somewhat larger and second metatarsal. With a hypermobile first metatarsal, a signif- bears more of the load, whereas the lateral sesamoid lies toward icant part of the load is transferred to the second and third rays. the first web space. From several ossification centers, the sesamoids ossify in early childhood. Partition is common, however, with 10% In most cases, treatment is conservative. Supporting orthotics of the population having bipartite sesamoids (unilateral in 75% that relieve the overload on the metatarsal heads are often of those but bilateral in 25%; 15% having an interphalangeal beneficial. With a hypermobile first ray, a pad is tried just proxi- sesamoid as well). The sesamoids have articular facets located mal to the second and third metatarsal heads and/or underneath superiorly toward the metatarsal head. The facets are enclosed in the first ray. Stretching a tight heel cord is essential. If significant the joint capsule, and the remainder of the sesamoids is embed- discomfort persists in spite of adequate orthotics and flexibility ded in the flexor hallucis brevis tendons. The flexor hallucis treatment over a 6-month period, surgery must be considered. longus tendon passes between the sesamoids. Here soft tissue and skeletal corrections may be indicated. Injury mechanisms result from a direct blow caused by a fall Capsulitis of the second MTP joint is related to hallux valgus, from a height, typically resulting in a comminuted fracture, or a condition in which the hallux forces the second toe to sublux forced hyperextension of the hallux leading to avulsion (transverse) dorsally. Tenderness over the dorsal capsule and pain on passive fractures of the sesamoid. Such patients typically have a dislo- dorsiflexion of the second MTP joint is diagnostic. Typically, no cated first MTP joint. Stress fractures are increasingly common, interdigital pain or tenderness is present. Strapping of the second specifically in competitive athletes involved primarily in running toe in a reduced plantar-flexed position is usually helpful. Rarely or dancing. It is often very difficult to distinguish a stress fracture an extensor tenotomy, with or without capsulotomy, is required. from a bipartite sesamoid. Radiographs (anteroposterior, lateral, and axial tangentials of the sesamoids, not the entire foot) may SKIN CONDITIONS show smooth or irregular edges. A stress fracture is often unde- tectable on initial plain x-ray films. A bone scan shows increased Corns uptake in stress fractures but possibly also in sesamoiditis. To fur- ther complicate the picture, osteochondral lesions of the sesamoid Soft corns are interdigital clavi formed between toes as a result have been described also. of pressure between adjacent phalangeal condyles. Hard corns represent accumulations of keratin layers of skin, typically on the As opposed to sesamoid fractures resulting from a single trau- dorsum of the toes, to prevent ulceration of the skin from chronic matic event, sesamoid stress fractures seem to have poor healing pressure that is usually extrinsic. Relief of this pressure is the key potential. The fracture will not heal despite 6 weeks of casting to successful treatment. The corn should be softened and pared and months of activity restriction. Excision is recommended, with judiciously. Occasionally, surgical removal of intrinsic pressure is potentially good results. Successful surgery, however, requires very necessary, for example, with a prominent phalangeal condyle, a careful technique to avoid the introduction of disabling complica- hammer toe, or a hallux valgus. tions such as neuromas, hallux valgus/varus, or cock-up deformity. Calluses Metatarsalgia Calluses are hyperkeratotic lesions similar to corns that form on Metatarsalgia, or pain in the MTP region, is a condition with the plantar aspect of the foot after weight-bearing and shearing many possible causes. Hallux rigidus, sesamoiditis, stress fractures, forces. Typical lesion areas are under the metatarsal heads and and Morton’s neuralgia are discussed elsewhere in this chapter. under the heel. Underlying structural deformities such as an

Chapter 8d ● Nails 381 insufficient transverse arch, forefoot varus or valgus, a plantar- permanganate or silver nitrate. A secondary bacterial infection flexed first ray, or a long second ray are common. Local treatment may necessitate erythromycin administration. Prevention such as of calluses equals that of corns; custom-made orthotics are gener- good foot hygiene, including frequent change of socks; shoes ally needed. If these measures prove insufficient, a rare event, sur- allowing adequate aeration; and avoidance of barefoot walking gical correction of an underlying deformity must be considered. in locker rooms is essential. The diagnosis of a cutaneous lesion is sometimes difficult. NAILS Scar formation, warts, inclusion cysts, and foreign body inclu- sions all may have the appearance of a corn or a callus. A careful Ingrown toenails history, clinical examination, and occasionally soft tissue radio- graphs are needed. In doubtful cases, referral to a highly special- Ingrown toenails are common and potentially disabling. ized institution without touching the lesion is indicated. Posttraumatic nail deformation caused by injury of the nail matrix may elicit the problem. The shape of toenails is congenitally dif- Warts (Verrucae vulgares) ferent, with some types being flatter whereas others are folded. Frequently, the lateral and medial edges of a folded toenail con- A wart is the result of a papillomavirus infection that is transferred flict with the adjacent nail. The problem grows when external between individuals in showers, saunas, and locker room floors. pressure is increased from a tight sock or a shoe with a narrow The incubation period is 1-6 months. Typically located on the toe box. If the edge of the nail penetrates the skin, bacterial sole of the foot, the warts are round or oval and gray-white, have a infection and voluminous granulation tissue result. The condi- crack or a dark spot in the center, and are often tender to pressure. tion, which is most painful, typically engages the lateral aspect of They are commonly multiple. the great toe, but any toe could be affected. Primary plantar wart treatment consists of weekly paring and Prevention is essential and includes good foot hygiene, properly application of keratolytics (including 50% trichloroacetatic acid or fitting footwear, and appropriate nail trimming habits. Once a week 40% salicylic acid). Failure of this treatment to eradicate the wart the nails should be cut transversely because they may grow down may warrant the use of careful electrosurgery after infiltration of into the nail fold if cut to a rounded outline. Once established, the local anesthetic with epinephrine. We advise against excision of acute-phase infection should be drained and the area soaked in a wart by scalpel or curet because of the risk of scar formation an antiseptic solution followed by a dry cover. Surgery should be from inadvertent penetration of the basilar layer of the skin. avoided in the acute phase because of the high risk of postopera- When all else fails, x-ray therapy may be considered provided that tive infection, including potential osteomyelitis. In chronic cases, it is given by an experienced operator. Prevention is crucial, and the ingrown part of the nail, including the nail matrix of that part, the use of bath shoes in humid areas is strongly recommended. should be surgically removed. At least 3 weeks should be allowed for healing postoperatively. Blisters After surgery for ingrown toenails, return to work is possible Blisters result from shearing irritation of the skin typically caused in 3-6 weeks. These conditions are painful. by the improper fitting of shoes and/or socks. The epidermal layers split, and the cavity formed is filled with a clear fluid. Subungual hematomas (Black nail, “Tennis Treatment consists of prompt removal of extrinsic irritant and if toe,” “Soccer toe”) needed, clean aspiration of the fluid. Deroofing the blister should be avoided because the overlying skin is a good dressing and Bleeding of the nail bed can be the result of a direct blow to the helps prevent secondary infection. nail from being trodden on or from a toe box that is too narrow. The hematoma shines through the nail and renders it black or Fungal infections (Tinea pedis) dark blue. The condition may be very painful in the acute stage. The hematoma is evacuated through a small hole through the Occasionally referred to as “athlete’s foot,” fungal infections may nail made with a red-hot straightened paper clip or similar tool. develop in circumstances where foot hygiene is inadequate. The Most often painless, the procedure gives immediate relief and most common infecting organisms are Trichophyton rubrum and preserves the nail, which would otherwise fall off after 2-4 weeks Trichophyton mentagrophytes. Tinea pedis exists in both “dry” and because of disruption of its blood supply. “wet” varieties. Predominant sites of infection are the web spaces. The dry form appears as gray-white scaling of the skin, whereas Subungual exostosis in the wet vesicular form, the web space skin has a macerated appearance. Diagnosis can be made by revealing hyphae and As a result of repetitive direct blows such as a basketball player’s mycelia by light microscopic examination of scrapings from scaling forefoot repeatedly being trod upon, reactive exostosis formation and vesicle walls. may develop on the dorsal aspect of the outer phalanx of the toe underlying the nail. Intense tenderness prompts treatment, typi- Treatment of the dry form of tinea pedis consists of local anti- cally nail removal and occasionally removal of the exostosis as well. fungal spray, whereas the wet form is best treated with potassium

382 Chapter 8d ● Treatment and indications for surgical treatment of foot and ankle injuries Fissures 4. DeLee JC, Evans JP, Julian J: Stress fracture of the fifth metatarsal. Am J Sports Med 11(5):349-353, 1983. Very painful and most disabling, fissures of the weight-bearing area of the sole are correlated mainly with hyperkeratosis but are 5. Kannus P, Renström P: Treatment for acute tears of the lateral ligaments of the ankle. seen also in conjunction with psoriasis, fungal infection, obesity, J Bone Joint Surg 73A:305-312, 1991. and shoes without counters. Hyperkeratosis-related fissures are treated with topically applied salicylic acid. Steroid ointments or 6. Komprda J: Le syndrome du sinus du tarse. Ann Podol 5:11-17, 1966. creams might be added for a limited time. A concomitant fungal 7. Leach RE, Schepsis AA: Acute injury to ligaments of the ankle. In CM Evarts, ed: infection may need oral antifungal treatment. Surgery of the musculoskeletal system, Vol. 4. New York, 1990, Churchill Livingstone Fungal nail infections International, pp. 3887-3913. 8. Pettine K, Morrey B: Osteochondral fractures of the talus. J Bone Joint Surg Fungal infections of nails respond to oral antifungal treatment 69B(1):89-92, 1987. only. Treatment typically must extend beyond 3 months. Because 9. Renström P, Kannus P: Management of ankle sprains. Oper Techn Sports Med oral antifungal drugs may be liver toxic, liver function needs to 2(1):58-70, 1994. be monitored. In some instances it may be reasonable to refrain 10. Styf J: Entrapment of the superficial peroneal nerve: diagnosis & results of from treatment. decompression. J Bone Joint Surg 71B:131-135, 1989. REFERENCES SUGGESTED READINGS Coughlin MJ, Mann RA: Surgery of the foot and ankle, ed 7. St. Louis, 1999, Mosby. Greer Richardson E, ed: Orthopedic knowledge update: foot and ankle 3. Chicago, 2004, American Academy of Orthopedic Surgeons. Hansen ST: Functional reconstruction of the foot and ankle. Philadelphia, 2000, Lippincott Williams & Wilkins. 1. Allenmark C: Partial Achilles tendon tears. Clin Sports Med 11(4):759-770, 1992. 2. Baxter DE, Thigpen CM: Heal pain, operative results. Foot Ankle 5(1):16-25, 1984. 3. Broström L: Sprained ankles. V. Treatment and prognosis in recent ligament ruptures. Acta Chir Scand 132:537-550, 1966.

8eC H A P T E R In this chapter, we first describe the biomechanical demands of the foot and ankle in the workplace and specific anatomic and Adaptation of Workers physiologic deficits after foot and ankle injuries. Then we with Foot and Ankle describe how the disabilities from foot and ankle injuries may be Disorders to the reduced by various adaptation processes such as ergonomic Workplace: Case Studies modification, adaptation of work activity procedures, and the appropriate utilization of footwear and orthoses. Mooyeon Oh-Park, Dennis D. J. Kim, and Peter Sheehan The adaptation process begins by identifying the main deficits Treating injured workers is a challenging task for most clinicians, of the worker that led to the impairment and subsequent disability. especially given the fact that a significant number of workers may Evaluation of workers consists of gait examination, range of motion not be able to return to work even after successful medical or sur- (ROM) of individual joints, manual muscle testing, propriocep- gical treatment of injury. In addition, patient care is complicated tive sensation, and examination of footwear. It is important to by other factors, including the level of patient motivation to note that biomechanical derangement of the foot and ankle achieve full recovery, the system of compensation and disincen- inevitably influences knee, hip, and low back proximally because tives, and the influence of legal counsel. Despite these challenges, the foot and ankle are the terminal parts of the closed kinetic clinicians are often relied on to treat functional impairment and chain providing the base of support.32 Clinicians therefore need subsequent disabilities to achieve the goals of care for injured to evaluate the entire lower limb as one biomechanical unit. The workers: restoring function and timely returning to work after ROM of individual joints should be assessed considering the successful treatment of the underlying pathology. functional demands of the specific work activities described later in this chapter. Although extensive information regarding the treatment of foot and ankle pathologies is available in the literature, little has Footwear and orthoses play an important role in management been described about the types of measures necessary to minimize of foot and ankle disorders (Table 8e.1). When treating a working deleterious functional impairment on return to the workplace. population, clinicians should take work activities into considera- tion in prescribing footwear or orthoses because certain appliances may interfere with work activities despite providing excellent symptom relief. Solid plastic ankle foot orthoses (AFOs), for example, may relieve the pain of the worker with posttraumatic ankle arthritis but greatly interferes with work activities such as kneeling, crouching, or fast walking. In this situation, an articulated AFO with limited ROM or a leather anklet would be a better Table 8e.1 Clinical indications and function of footwear modifications Type of Clinical indications Simulated function Advantages and limitations modification Relatively costly Cushion heel Limited ROM of ankle PF Simulates PF of ankle, reduces the kinetic Relatively inexpensive Beveled heel Ankle fusion, arthritis demand on ankle dorsiflexors Rocker sole Same as cushion heel Heavy, may affect balance, requires Same as cushion heel, delays initial contact rigid sole Toe spring Limited ROM of ankle during gait DF Does not require additional Ankle fusion, arthritis Reduces dorsiflexion of 1st MTPJ, reduces modification of footwear, lightweight Hallux rigidus/limitus pressure on metatarsal head, simulates Hallux limitus DF of forefoot Caution in diabetic patients, heavy Simulates DF of forefoot Caution in diabetic patients, lightweight, can be inserted in footwear Rigid sole (steel shank) Pain or instability of midfoot Stabilizes the midfoot, reduces DF of 1st MTPJ Hallux limitus Stabilizes midfoot, reduces DF of 1st MTPJ >1/4” heel lift usually needs to be Removable rigid insole Painful instability of midfoot Accommodates ankle equinus and forefoot equinus placed on the outsole of footwear, (carbon plate) Hallux limitus footwear with high top design is Equinus deformity of forefoot preferable Heel lift Equinus deformity of ankle DF, dorsiflexion; MTPJ, metatarsophalangeal joint; PF, plantar flexion; ROM, range of motion.

384 Chapter 8e ● Adaptation of workers with foot and ankle disorders to the workplace: case studies option than a solid AFO because it allows a considerable amount Walking of motion. About 10 degrees of ankle dorsiflexion with the knee in extension Many injured workers may experience unexpected functional is required for normal walking.40 If a worker has limited ankle impairment after resuming their work activities. Work-simulation dorsiflexion secondary to contracture or pain, the tibia cannot and work-hardening sessions incorporating the adaptation process advance forward during the stance phase. Compensatory motions are often necessary to provide injured workers an opportunity to such as hyperextension of the knee, early heel rise, excessive assess their ability to return to work. pronation of the subtalar joint, or shortened step length on the contralateral side are therefore noted during gait. BIOMECHANICAL DEMANDS OF THE SPECIFIC DEFICITS AFTER FOOT FOOT AND ANKLE IN THE WORKPLACE AND ANKLE INJURIES Knowledge of biomechanical demands of the foot and ankle in After foot or ankle injuries, workers may have impairments related the workplace enables clinicians to prepare the necessary adapta- to abnormal ROM of specific joints, neurologic deficits, pain, tions when returning injured workers to their duties. edema, or any combination of these problems even after initial medical and surgical interventions. The functional impact of these Common work activities deficits is described in this section. Floor-to-waist lifting Abnormal ROM Floor-to-waist lifting in full squat position requires maximum Pain-free normal ROM of the ankle, subtalar, midtarsal, and first ankle dorsiflexion and transfer of the center of body forward, MTP joints are prerequisites for normal function of the foot and especially when lifting an object without a handle. Because workers ankle. Limited and excessive ROM of these joints interferes with with lack of ankle dorsiflexion range are unable to perform full normal gait and work activities. When excessive ROM of a certain squats, they often compensate by flexing the hip and the spine. joint is noted during evaluation, the clinician should differentiate Because of an increased lever arm between the load and the lum- the causes for excessive ROM, distinguishing a structural insta- bar spine, this lifting technique increases the demand on back bility from a compensatory response for limited ROM of the other extensors. Workers need to take special precautions to maintain joints. The pain associated with excessive ROM can be improved lumbar lordosis as much as possible during lifting to protect their by wearing footwear or orthoses designed for the control of exces- backs from injury.22 sive motion. Carrying a load Equinus of the ankle (limited ROM of ankle dorsiflexion) According to one biomechanical study, carrying a load on the side of an affected hip exerts less stress on it than carrying a load Equinus deformity of the ankle is a common abnormality after on the contralateral side.29 However, there are no studies available foot and ankle injuries. Frequently seen also in patients with regarding whether this same principle can be applied to patients spastic gastrocsoleus muscles from various neurologic disorders, with foot or ankle disorders. Carrying a load on the opposite it has a profound effect on the entire lower limb during closed side of injury theoretically increases the moment arm of the load kinetic motion. It affects proximal joints, especially driving the and may place additional stress on the affected ankle and foot. By knee joint into hyperextension during weight bearing, and distal reducing the moment arm of a load, however, carrying it on the joints, as is seen with excessive pronation of the subtalar and side of injury may change the angle of weight bearing, causing midtarsal joints.6 Long-standing excess pronation leads to painful stress on the lateral side of the ankle. Workers therefore usually arthrosis in these joints and may cause a rotatory stress to the find themselves using the side that produces fewer symptoms. knee joint at the same time. Finally, patients may compensate for the deformity by externally rotating their lower limbs, thus short- Kneeling ening the lever arm for the ground reaction force. This compen- satory gait may be necessary for the patient to accommodate the Kneeling is defined as supporting the body weight on both knees, functional deficit in the workplace, although this gait deviation a position requiring nearly full ankle plantar-flexion. Workers may cause pain or instability of the medial knee later. In this who lack full plantar-flexion range may compensate with hyper- instance, the clinician should weigh the benefit and the poten- extension of the metatarsophalangeal (MTP) joints and slight ankle tial harm of the deviation before correcting the gait.6 plantar-flexion. To manage equinus deformities, clinicians should emphasize Crouching preventive measures, including early weight bearing, preventive orthoses, and physical therapy. Physical therapy should initially In crouching with one knee up and one down, the worker needs be instituted under the supervision of a therapy team so the full ankle dorsiflexion in the forward limb. Without ankle dorsi- patient can properly learn heel cord stretching exercises before flexion, he or she can compensate with external rotation of the continuing them at home. The patient’s foot should be placed in hip and eversion of the subtalar joint. The backward limb with the knee in contact with the floor requires full plantar flexion of the ankle; otherwise, the worker can compensate with slight plantar flexion and MTP hyperextension.

Chapter 8e ● Specific deficits after foot and ankle injuries 385 neutral or slightly supinated position during this exercise to avoid Figure 8e.1 Rocker sole. undesirable stretch of the midfoot instead of the heel cord. Patients therefore need to choose footwear with lower heels to To avoid its profound effect on the lower limb, equinus defor- minimize the abnormal knee flexion momentum that may cause mity can be accommodated by a heel lift inside (up to 1/4-inch painful knee conditions over time. Arthrodesis of the ankle in plan- heel lift) or outside (higher than 1/4-inch lift) the footwear. tar flexion is not recommended because of possible development Footwear with high-top design may accommodate a heel lift of of painful subtalar and midtarsal arthrosis later on.9 An ankle fused up to 3/8 inch. The heel lift should be lowered gradually to avoid in slight plantar flexion can be accommodated with footwear with development of pain in the calf or other proximal parts of the a heel lift, although there is no study available investigating the body that can occur from abruptly changing the height. long-term effect of such modifications after arthrodesis. Forefoot equinus is a deformity of the plantar-flexed forefoot Hallux limitus relative to the hindfoot that is often mistaken for the ankle equinus deformity. Etiologies of the acquired forefoot equinus include pos- Limited motion of the first MTP joint occurs after forefoot injury terior compartment syndrome, nerve injury, or surgery. Workers or arthritis secondary to a collapsed medial arch. Compensatory with forefoot equinus may complain of pain on the anterior gait patterns such as external rotation of the entire lower limb or ankle or posterior knee due to compensatory dorsiflexion of the lateral toe break during push-off are frequently observed among ankle and hyperextension of the knee on weight bearing. such workers. Rocker-sole and steel-shank footwear are com- Because the ankle is already in maximum dorsiflexion, further monly recommended for workers with painful ROM of the first stretching of the gastrocsoleus muscle may exacerbate the ankle MTP joint (Fig. 8e.1). This modification, however, makes the and knee pain further. In this instance, a heel lift in high-top footwear heavy and may not be appropriate for patients whose footwear can accommodate the deformity if surgical correction is balance is impaired by the reduced area of support. Footwear not contemplated. with a toe-spring design can be used without the additional weight of a rocker sole and usually does not affect balance. Calcaneocavus (limited ROM of ankle plantar flexion) Neurologic deficit A patient may develop limited ankle plantar flexion after rupture Weakness of ankle dorsiflexors is one of the most common neu- of an Achilles tendon, after fractures of the ankle or hindfoot, or rologic deficits affecting the foot and ankle. Various etiologies caus- as a neurologic sequelae.10,28 Management of this deformity is ing this weakness include peripheral nerve injuries, plexopathy, often much more challenging than that of equinus deformity. lumbosacral radiculopathy, and compartment syndrome as well Workers experience excessive knee flexion during weight bearing, as central nervous system disorders. Many workers with isolated resulting in increased work demand for the knee extensors. Over weakness of ankle dorsiflexors are able to return to work with proper a period of time, workers may develop painful knee conditions orthotic management even if neurologic recovery is not complete. such as patellofemoral stress syndrome. Excessive stress on the heel during the early stance phase of gait causes pain, callus, or Ankle dorsiflexors contract eccentrically during the early ulceration around it. High-top footwear with a silicone heel cup stance phase for loading of the foot and contract concentrically is often helpful to reduce the callus formation and heel pain. during the swing phase for the leg to clear the ground. Footwear with high-top designs and elevated heels reduce this biomechan- Limited ROM of ankle plantar flexion and ical demand of ankle dorsiflexors and minimize the need for dorsiflexion and ankle arthrodesis heavy bracing. High-top athletic footwear or boots with a 1/2-inch heel lift are often sufficient for workers with minimal weakness, Injury or a subsequent surgical procedure such as arthrodesis may result in marked restriction of ankle dorsiflexion and plantar flexion. As mentioned earlier, lack of ankle motion results in marked change in gait and may cause abnormal compensatory motions of the adjacent joints. Clinicians should be aware of possible modifica- tions of footwear that can compensate for lack of motion in the ankle, which in turn can improve gait and halt abnormal com- pensatory motions. A cushioned or beveled footwear heel, for example, simulates plantar flexion and thus assists initial contact and loading response of the gait. A rocker sole or a toe-spring also can be used to correct the impaired dorsiflexion of the ankle, thus improving the late stance phase of the gait. Ankle ROM abnormalities are often seen after surgical interven- tions. Ankle arthrodesis is performed for comminuted fracture, nonunion, or posttraumatic arthritis. The general recommendation for the ankle position for arthrodesis is neutral (90 degrees). Postprocedure, these patients may have abnormal flexion momen- tum of the knee when wearing footwear because most footwear have heels at least 1/2 - 3/4 inches high that tilt the tibia forward.

386 Chapter 8e ● Adaptation of workers with foot and ankle disorders to the workplace: case studies especially when early neurologic recovery is anticipated. pain relief. An orthosis controlling the ankle dorsiflexion is This approach, however, may cause development of a tight bulky and difficult to use in the workplace. heel cord over time, so workers should be educated to perform exercises to stretch it. It is not uncommon for workers to experience pain in loca- tions different from those of the injured structures. Patients with For workers with significant weakness, a posterior leaf-spring hallux limitus or plantar fasciitis may develop lateral foot pain orthosis can be used inside the footwear. Posterior leaf-spring from walking on the lateral foot to avoid weight bearing on the orthosis is a good choice because it is lightweight, flexible, and painful medial side (lateralization of pain). In other cases, the aesthetically favored by wearers. For workers with severe sensory location of the discomfort may change as the disease progresses. loss, deformity, or fluctuating edema, a conventional AFO with A patient with tibialis posterior tendon insufficiency, for example, a double upright and protective insole is recommended. may develop pain on the lateral hindfoot at a later stage as the pronation deformity progresses even though the pain was initially Workers with a combined weakness of ankle plantar flexion on the medial side. This lateralization of pain may confuse clini- and dorsiflexion generally require more restrictive orthoses. As cians attempting to diagnose and treat the primary pathology. with workers whose ankle dorsiflexion alone is weak, footwear with high-top design and elevated heel confines the ankle and Case: Burning pain around the medial ankle minimizes the need for heavy bracing. Molded ankle orthoses such as the Arizona or Baldwin AFO are available, although they A 45-year-old electrician in a large city hospital presented tend to be more costly and bulky and may require footwear in a with burning pain on the medial side of the right ankle. large size. Semisolid or solid AFOs restrict ankle motion and Pain was more prominent when standing and was relieved interfere with work activities, so clinicians should be cautious in by sitting. The patient had sustained a right Achilles ten- prescribing these restrictive orthoses for the working population. don rupture and subsequent surgery at the age of 22 from a work injury and had equinus deformity of the right foot. Significant sensory loss can occur after nerve injury or neuropa- On physical examination, Tinel’s sign was present on the thy from medical diseases such as diabetes mellitus. Compensation medial side of the ankle. An electrodiagnostic for tarsal tun- for sensory deficit is not possible, and it is more difficult to man- nel syndrome was negative. Because of the tight heel cord, age than muscle weakness. Some workers develop neuropathic significant pronation was noted on the right side on weight discomfort, balance impairment due to poor proprioceptive bearing. A tender point reproducing the symptom was feedback, or ulcerations in the foot. A lightweight AFO with a wide identified along the location of the saphenous nerve. The calf band and semirigid ankle design may provide some proprio- patient was diagnosed as having a saphenous neuroma near ceptive input from the floor to the more proximal leg for balance. the old operation scar aggravated by pronation of the foot. For ulceration of the insensate foot, attentive wound care is essential, as described in a later section. A detailed history revealed that the patient had recently changed his working boots to low-heeled athletic Foot and ankle pain footwearthat stretched the saphenous nerve due to com- pensatory pronation for his tight heel cord. The patient’s Pain is a major reason that workers cannot return to work and seek pain wassignificantly reduced by 3/8-inch heel lifts placed medical attention. When pain is the main deficit causing disabil- inside the shoes, and he subsequently returned to work ity, evaluation of injured workers is a challenging task. Workers without any further intervention. The patient was may experience persistent pain from subtle minor injuries even instructed to wear his old working boots or basketball after the obvious injuries are treated. This residual pain from sub- sneakers with elevated heels inside them. tle injury can easily be misinterpreted as a psychologic etiology, although workers are in fact suffering from real structural prob- Edema of the lower leg lems. Minor injuries can initiate symptoms in previously degener- ated yet asymptomatic structures, causing etiologic confusion for Persistent swelling of the lower leg may prevent patients from clinicians. In this section, general principles of how to approach returning to work even after initial treatment is successful. In workers with foot pain are described. Diagnosis and surgical treat- many instances, the edema is due to multiple factors, including ment of individual pathologies are not discussed in this chapter. residual inflammation, venous and lymphatic insufficiency, reduced elasticity of soft tissues, and dependent position of the legs.33 Precise history taking provides clues for the nature of pain and Provided that arterial supply is not compromised, compression guides the direction of treatment. If the pain is markedly exacer- treatment such as Unna’s paste bandage, elastic bandaging, and bated by ambulation as compared with quiet standing, proper compression stockings is the mainstay of treatment. control of the painful motion would be the main direction of management regardless of etiologies. Application of several layers In particular, Unna’s paste bandage, a zinc oxide–impregnated of Unna’s paste bandage and footwear with a rocker sole and nonelastic gauze, can be used as an effective initial treatment cushion heel may provide relative immobilization of the ankle in of edema (Fig. 8e.2). It does not yield circumferentially while the the initial phase of the treatment. This is a useful temporary trial bandage remains in contact with the skin. This causes a compres- before prescribing definitive orthosis for control of ankle motion. sion force around the leg while its contour keeps changing with ankle motion, especially during ambulation. In so doing, Pain may also present during specific ROM of joints. the bandage acts like the natural pump of the calf muscle in For example, workers with anterior impingement of the ankle experience pain from its dorsiflexion. A heel lift and rocker sole reduces the demand for ankle dorsiflexion and may provide

Chapter 8e ● Footwear at the workplace 387 Figure 8e.3 Safety shoes. Figure 8e.2 Unna’s paste boot bandage. of the plantar sole (Fig. 8e.3). Further specialized footwear is available also to protect against cutting injuries or environmental mobilizing interstitial fluid.23 The greatest advantage of the hazards related to chemicals, extreme temperature, or electricity.12 bandage is that of allowing the worker to return to standing activities while controlling the edema at the same time. Workers Each country has different standards and methods of assessing can wear regular footwear and continue to perform physical the level of protection against various hazards for safety shoes. therapy with the bandage in place. Unna’s paste bandage is also To assess the level of protection against impact to the toes, for inexpensive, readily applicable, and easily removable. During example, the American National Standard Institute standards the application, it should be cut frequently and applied evenly have a single pass-fail figure for all sizes of the footwear, whereas in contact with the skin to avoid excessive constriction that may the European standards have a sliding scale that increases with result in a local purpura or skin abrasion. To maintain its effec- footwear size. tiveness, the bandage must be kept dry in the shower. As men- tioned earlier, Unna’s paste bandage should not be applied to the Features of safety shoes patients with significant arterial insufficiency of the lower limb. The toes are most vulnerable to injuries and also the easiest to FOOTWEAR AT THE WORKPLACE protect effectively with the least ergonomic penalty. Protective toe caps are a compulsory requirement of most safety footwear Direct injuries to the foot and ankle form a substantial proportion standards. For example, European standards for personal protec- of all reported occupational accidents. In addition, many injuries tive equipment require protection against 200 Joules for the toe to other parts of the body result from slips, trips, and falls par- area12 that is achieved mostly by a carbon steel toe cap. Plastic toe tially attributable to inappropriate footwear. Patients working in caps, however, are used in environments where metal cannot be specific occupations are obligated to wear various types of safety used such as when handling munitions or inflammable chemicals. shoes for protection from environmental hazards or injuries at the workplace. The special features, advantages, and potential Protection of the plantar sole against penetration injury is pro- problems of the safety footwear used in the workplace are vided by a stainless steel plate in the outsole layer. Material that reviewed in this section. Military shoes and footwear for women resists penetration, strain, and corrosion is used to make a plate in the workplace are also described briefly. large enough to cover most of the plantar surface. Although pen- etration testing is standardized throughout the world, slight dif- Safety shoes ferences exist in the minimum permitted penetration force, which is 1100 N in Europe and 1200 N in the United States.12 Regardless of manufacturer, most safety footwear has common features such as a reinforced toe cap and steel plates for protection Specific outsole materials are used in specific footwear for slip resistance. To secure the optimal effect of slip resistance, workers need to replace the footwear on a regular basis to avoid using worn outsoles. Currently, no method of testing is available for the durability of slip resistance. Prevention of slip injuries should involve measures such as educating workers, avoiding the use of floor polish, and abrading the outsoles of new footwear.25 Heat insulation is a special feature of safety shoes to prevent injury and discomfort for the workers standing on hot surfaces such as the tar used to pave roads. The outsoles of the footwear are produced from materials with a high melting point such as vulcanized rubber marked with the code “HI” (heat insulation).

388 Chapter 8e ● Adaptation of workers with foot and ankle disorders to the workplace: case studies Potential problems of safety shoes Military shoes Wearing safety shoes may cause several problems at the expense Military shoes merit discussion because they can cause significant of protective features. One study showed that a high percentage morbidities in recruits who are expected to perform strenuous of workers (91%) complained of foot problems caused or exacer- physical feats. Recruits can develop various foot and ankle injuries bated by safety shoes.26 The common complaints were intolera- ranging from skin blisters to ligament sprains, tendonitis, and stress ble heat, inflexible soles, shoe weight, and pressure from steel fractures. Continuous efforts have been made by the researchers in toe caps. Workers wearing rubber boots in the meat packing or the field of military medicine to improve military shoes and fishing industry may develop allergic reactions to the material or reduce such injuries. develop mycotic and bacterial lesions from plantar hyperhidrosis.4 Clinicians should be aware of potential foot problems related to One study of military shoes showed that three different widths the use of safety shoes in workers with certain medical conditions. for each shoe length were necessary to accommodate the feet of Patients with diabetic neuropathy, for example, may develop military recruits.14 Interestingly, this study also showed that ulcers on the dorsum of the toes or plantar forefoot from hard choosing larger shoe sizes to accommodate the necessary width soles and steel toe caps. when appropriate widths were unavailable did not necessarily increase the incidence of overuse injuries.14 Unfortunately, there are not many choices in terms of the width and shape of safety shoes currently available. Workers with wide To reduce overuse injuries of the foot and ankle among military forefeet may settle for wearing larger sizes. In these instances, recruits, various insoles have been tried.17,41 One study indicated excessive room around the heel may cause undesirable slipping that to attenuate peak pressure during running and marching, during ambulation. To compensate, a soft heel cup can be placed Sorbothane is superior to other insole materials such as viscoelas- inside the footwear to provide a snug fit. tic polymetric, polymetric foam, and Saran.41 Once worn out, these insoles lose their shock-absorbing ability,11 but custom- Case: Toe blisters from wearing safety footwear made insoles have nevertheless been reported to decrease the incidence of stress fractures among military recruits.13,27 A 49-year-old man with a 10-year history of non–insulin- dependent diabetes mellitus presented with plantar ulcer- Additional appliances may help prevent ankle injuries or reduce ation at the right hallux (Fig. 8e.4). The patient was working the development of severe foot blisters. Ankle injuries are espe- as a housekeeper in a large municipal hospital. A few days cially common during parachute training, accounting for 30% to before presentation, the patient had noticed a blood stain 60% of all parachuting injuries. In one study, an ankle brace on his sock. He had recently changed footwear from athletic applied outside the boots significantly reduced ankle inversion walking sneakers to safety shoes with hard soles and steel injuries without increasing injuries to other parts of the body.2 toe caps that had been given to him by a colleague at work. The patient developed blisters on the plantar aspect of the Foot blisters are common and can be severe enough to require right hallux that had caused no discomfort because his medical treatment. Knapik et al21 reported that the incidence and foot was insensate from diabetic neuropathy. Treatment the severity of foot blisters can be reduced with dense wool- involved use of an Aircast walker with a thick insole and polypropylene socks combined with polyester liner as compared local relief. To prevent recurrence of the ulcerations, the with standard military issued socks during training. Two layers of patient was instructed to substitute orthopedic footwear socks probably absorb the friction better than a single layer as with soft insoles for the safety shoes. He was placed in a this principle has been practiced in various sports activities. job-retraining program also. Footwear for female workers Figure 8e.4 Ulceration on the plantar aspect of hallux after wearing safety shoes. Certain professions require female workers to wear footwear designed for the aesthetic features rather than for the health of the foot and ankle. Women’s high-heeled shoes, especially pumps, contribute to many problematic foot disorders including bunion formation, interdigital neuritis, metatarsalgia, hump pump, and tight heel cords. Most of these conditions improve with roomier footwear without extensive medical treatment. If employees are required to wear high-heeled shoes, they need to be educated to choose those with a proper wedge angle to reduce anterior slippage of the foot. Pumps without proper suspension require an extremely tight fit to prevent the foot from slipping out. High-heeled shoes with proper closure and suspen- sion such as straps or laces are preferable to pumps because they do not need to fit tightly. Another common problem women tend to develop is pain in the calf and in other parts of the body when they have changed abruptly from high- to low-heeled shoes, possibly due to biome- chanical compensation for tight heel cords.32 In such cases, a gradual change over several months to low-heeled shoes is gener- ally recommended for patients whose heel cords are tight.

Chapter 8e ● Adaptations for common conditions 389 FOOT ORTHOSES ADAPTATIONS FOR COMMON CONDITIONS Foot orthoses (FOs) were introduced in the working population Although similar principles may be applied to other types of foot not only for foot and ankle problems but also for suprapedal con- injuries, this chapter focuses on adaptation for the most common ditions such as low back pain.19 Although literature is available and troublesome conditions. regarding the application of FOs, there is no general consensus about the benefits of their use by workers. Application of generic Ankle sprain foot insoles (orthoses) without consideration of the distinct abnor- mal biomechanics of each patient did not show consistent benefit. As the most common foot and ankle injury, ankle sprain accounts for more than 70% of all ankle injuries requiring The goals of orthotic management in painful foot conditions absence from work.3 Ankle sprain is generally treated with short- are pain relief, accommodation of limited ROM, and restoring term rest, ankle bracing, and physical therapy. Edema and pain the normal alignment of the foot and ankle. Clinicians should caused by the sprain are exacerbated during standing or walking keep in mind that foot pain can be relieved even without com- and further delay return to work. Along with Unna’s paste plete restoration of the normal alignment. Successful orthotic bandage to control edema (the details of which are described treatment depends on understanding the biomechanics of the earlier), relative immobilization allows workers to resume standing foot and the suprapedal segment. Clinicians need to interrelate and walking early. the patient’s biomechanical abnormalities and the design of FOs; they may consider trying temporary insole modifications before The mainstay of physical therapy after lateral ankle sprain prescribing definitive FOs. includes strengthening of the ankle evertors in a progressive manner and stretching of the heel cord followed by propriocep- Preparatory trials tive training.24,34 Isometric strengthening of ankle evertors can be performed at the workplace by pushing the lateral side of the If a patient’s discomfort improves with the preparatory trials of foot against a stationary object such as the leg of a desk. an insole such as posting, padding, or heel lifting, the clinician can feel confident that customized FOs with these features are A lateral hindfoot wedge placed under the insole reduces beneficial. Because such FOs are highly costly and not always hindfoot inversion during the initial contact period of the gait modifiable, clinicians should be familiar with the practice of cycle. Although anklets, high-top shoes, or boots have been rec- using preparatory trials before prescribing them. Patients wearing ommended as a preventive measure, their effectiveness in pre- FOs require regular follow-up, and depending on the material venting ankle sprain is controversial.15,18,37 Because footwear with and their activity level, the FOs need to be replaced every 3 to excessively worn lateral heels increases ankle inversion, clinicians 6 months. Details of different types of FOs are described under should examine workers’ footwear as part of the evaluation. individual foot and ankle conditions below and later in this chapter. Lingering pain or instability after ankle sprain should be eval- uated for possible concurrent pathologies such as syndesmosis Pronation control lesion, pericuboidal soft tissue injuries, Lisfranc’s joint injuries, talar dome injury, peroneal tendon pathology, subtalar joint An FO for pronation control is designed to decrease rather than instability, or peroneal nerve injury. Recurrent ankle sprain should completely correct pronation.30 Because normal walking requires alert the clinician to look for underlying instability of the ankle or a certain degree of pronation, complete correction may cause subtalar joints, cavus deformity, weakness of the ankle evertors, pain in the lower limbs and back. Orthotic management for or tight heel cord.1,8 Treatment of these conditions is beyond the pronation control will not be successful if tight heel cord, a scope of this chapter. major biomechanical culprit for excessive pronation, is not addressed. Accommodation of tight heel cord with proper heel Case: Swelling and discomfort after lateral lift should be incorporated in the design of the selected FOs and ankle sprain shoes. A 43-year-old man working in a movie theater fell on the Supination control stairs and sustained lateral ankle sprain. A radiologic study excluded fracture or dislocation, and the patient was Workers with cavus foot are prone to stress fractures, heel pain, treated with ice and elastic bandage in an emergency or lateral ankle sprains. FOs are often designed to reduce ankle room. Because of persistent discomfort and swelling of the inversion and to provide shock absorption. The medial arches lateral ankle, especially during standing, the patient could of the FOs are built to accommodate the high arches of cavus feet. not return to full-time work. A short Unna’s paste bandage FOs with an excessively high medial arch, however, may increase was applied with a horseshoe pad around the lateral malle- ankle inversion injury or cause pain on the lateral foot. olus for 3 weeks, during which time the patient returned to Cautiously designed arches and appropriate lateral balancing of full-time work with a weekly change of bandage. A lateral the FOs are necessary to minimize the sliding of the foot laterally. wedge was placed in his walking athletic footwear to decrease ankle inversion.

390 Chapter 8e ● Adaptation of workers with foot and ankle disorders to the workplace: case studies Ankle arthrosis after fracture Because the initially flexible deformities frequently become rigid over time, aggressive orthotic treatment with direct control of A major complication of ankle and pilon fractures is posttraumatic the subtalar and midtarsal motion should be introduced in the arthrosis, which correlates with the severity of the original injury early stages of the condition.35,39 A plain FO with a medial and the adequacy of fracture reduction.16,36 Workers with post- wedge is usually not effective in this condition because it cannot traumatic arthrosis present with stiffness, pain, and difficulty with control the forefoot abduction or the motion of subtalar and prolonged ambulation and standing. In conjunction with footwear midtarsal joints effectively. Once the axis of the subtalar joint is that has rocker soles and cushion heels, FOs designed for limiting medially deviated as the pronation deformity progresses, a sim- the painful range of the ankle may reduce the pain significantly. ple arch support is not able to provide any corrective force to the pronating foot on weight bearing.20 The University of California A patient with a collapsed talus after a fracture may complain Biomechanical Laboratory (UCBL) supramalleolar orthosis pro- of anterior ankle pain due to anterior impingement during vides direct control of calcaneal motion, restoring proper align- dorsiflexion. In these instances, an anklet or an AFO with a heel ment of the subtalar and midtarsal joints. These orthoses can be lift (or, alternatively, high-heeled Western boots) may reduce the used in regular footwear and allow the patients to continue their impingement and provide symptom relief. Job modification and work activities (Fig. 8e.5). For the more advanced cases, a short nonsteroidal antiinflammatory medications can provide addi- rear-entry articulated AFO (Marazano AFO) has been advocated. tional benefit. Surgical treatment options are reserved for cases refractory to conservative treatment. Total ankle arthroplasty has Tight heel cord, a common sequela of this condition, contributes been recently advocated for posttraumatic arthrosis, although its also to the development of permanent deformities. Orthotic man- long-term result has not been defined. This procedure should be agement is often frustrating in patients with tight heel cord, rigid undertaken cautiously in the working population, which is typi- deformity, and arthritic changes of subtalar and midtarsal joints. cally young and engaged in a high level of physical activity. Various surgical procedures are advocated for patients with an advanced stage of the condition. If surgery is not feasible, a rigid Heel pain polypropylene AFO or Baldwin orthosis can be prescribed.5 Bulky and restrictive, these orthoses may, however, interfere with Heel pain is a common complaint of workers engaging in activi- the activities at work. ties that require prolonged standing. The etiology of heel pain can include fat pad atrophy, heel spur bursitis, plantar fasciitis, nerve Case: Insidious onset of medial hindfoot pain entrapment, Haglund deformity, and calcaneal stress fracture. in a nurse’s aide Plantar fat pad atrophy, which causes pain after standing for a period of time, is quite disabling in workers such as parking A 55-year-old woman working as a nurse’s aide developed attendants, security guards, or operating surgeons. In most patients, insidious onset of pain on the left medial aspect of the the pain usually improves with a change to footwear with soft heels hindfoot 6 months ago. She also noticed that the medial and insoles. Additional cushioning can be provided by a soft arch of her left foot was collapsing and her forefoot was heel lift such as a silicone heel cup. turning progressively outward. On physical examination, maximum tenderness was noted on the tibialis posterior In some patients, heel pain may persist despite the above tendon, and pain was precipitated by passive eversion and measures because a silicone heel cup cannot prevent the fat pad active inversion. The patient had flexible pronation defor- from spreading as it bears weight. In these instances, low-dye mity of the left foot with a slightly tight heel cord. Passive taping can be used as an additional measure to contain the fat ROM of the ankle was up to neutral. She was diagnosed pad. Plastic heel cups (Helfet) are traditionally used to prop the as having stage II tibialis posterior tendon insufficiency, heel pad. Because they are made of relatively inflexible materials, and a supramalleolar orthosis was prescribed (Fig. 8e.5). The they may cause discomfort in some patients unless a precise patient was able to work wearing the supramalleolar orthosis fitting is achieved. inside athletic footwear. A 1/4-inch heel lift was provided on the contralateral side to balance the limb length bilaterally. Plantar fasciitis is typically painful in the morning, although it can be symptomatic whenever standing. Heel lifting reduces the Midfoot arthrosis and pain discomfort, most likely by reducing tension in the plantar fascia and shifting body weight to the forefoot. The workers should The functional significance of midfoot injuries is often unrecog- stretch the plantar fascia and heel cord several times per day. nized by practitioners.7 Workers may sustain midfoot injuries Adequate stretching of the plantar fascia during the night fre- despite wearing standard safety shoes because the protective toe quently reduces the morning pain. A night splint has been recom- cap ends around the MTP joints. A device available for the pro- mended for this purpose, although it is bulky and cumbersome. tection of the dorsum of the midfoot is not favored by workers Gently wrapping the foot with an elastic bandage to keep the MTP due to the restriction of motion.12 joints in dorsiflexion seems to be one of the effective alternatives. Midfoot crush injuries with nerve damage or compartment Tibialis posterior tendon insufficiency syndrome can prolong recovery and require as long as 1 to 2 years before return to work is possible. Many of these patients are not Patients with this condition present with an initial complaint of pain in the medial hindfoot and progressive pronation deformities.

Chapter 8e ● Adaptations for common conditions 391 Figure 8e.5 Supramalleolar orthosis. Figure 8e.6 Total contact cast. capable of returning to heavy-duty industrial jobs and require under the metatarsal head may already be harboring a full-thickness vocational retraining.1 To return to work, patients often require ulceration beneath it that can lead eventually to limb loss. In rigid FOs in rocker-soled shoes to reduce the motion of the addition to treating the medical conditions, clinicians should transverse tarsal and Lisfranc’s joints. manage these workers with long-term plans such as major job modification or retraining for different vocations. Painful forefoot conditions Neuropathic ulceration Roomy footwear is the prerequisite for successful treatment of painful forefoot conditions such as interdigital neuritis, painful Neuropathic ulceration usually occurs on the plantar surface of calluses, and metatarsalgia of various etiologies. Frequently used to the foot. Off-loading plantar pressure and reducing weight bearing remedy such painful conditions, a metatarsal pad should be placed are the key components of treatment. The most effective method close to the target metatarsal head.38 According to plantar pressure of off-loading, total contact casting maintains the ambulatory recording during ambulation, the area of peak pressure of the sec- state. With such a cast, the patient with superficial noninfected ond metatarsal head moves 6 to 8 mm distally from that of the ulcers may be able to return to sedentary work (see Fig. 8e.6). standing position (unpublished data). Placed too proximally, Workers with insensate feet may not be able to tolerate safety therefore, a metatarsal pad may be ineffective in relieving pain. shoes with steel toe caps and hard soles because of the risk of ulceration. Clinicians may advise such patients to consider voca- For the plantar pain of the second MTP joint, clinicians tions that do not require safety shoes. should look for underlying biomechanical abnormalities such as subluxation of the second MTP joint or short first metatarsal or Charcot neuroarthropathy first ray insufficiency. Morton’s extension to the hallux or post- ing under the first ray is incorporated into the FO in addition to Ankle and foot injuries such as fracture, dislocation, or even metatarsal pad that be placed next to the second metatarsal shaft. minor ankle sprains in the diabetic population should be treated A spring-carbon plate effectively limits the forefoot motion and with extreme alertness because of the potential risk of Charcot can be used in conditions such as painful hallux limitus, turf toe, neuroarthropathy, the major complication that leads to amputa- or stress fracture of the metatarsals. tion of the lower limb. Beginning with intense inflammation of soft tissues, joints, and bones, Charcot neuroarthropathy eventu- Foot problems in workers ally results in fractures, dislocations, and gross deformities. It with diabetes mellitus may then cause an increase in plantar weight-bearing pressure and ulceration of the insensate foot. To prevent disastrous Complications of the foot and ankle such as Charcot neu- sequela, the patient requires a period of immobilization without roarthropathy or ulcerations in patients with diabetes mellitus weight bearing by the injured lower limb that is much longer are manageable conditions without definitive cure. The important than that of nondiabetic patients. role of the clinician is therefore prevention and early recognition of these potentially disastrous complications and long continu- Even without a history of significant trauma, unilateral swelling ous follow-up. A foot that is warm and swollen after minor of the foot should alert the clinician to possible development of trauma should alert the clinician to the possibility of early devel- Charcot neuroarthropathy. Redness, swelling, and warmth are oping Charcot neuroarthropathy. Workers with a small callus often confused with infection or cellulitis, but these diagnoses can be eliminated if there are no constitutional symptoms or open wound and the midfoot and hindfoot are involved.

392 Chapter 8e ● Adaptation of workers with foot and ankle disorders to the workplace: case studies In the acute stage of Charcot neuroarthropathy, a total con- tact cast is applied for optimal immobilization; this can be changed to a custom-made AFO in later stages. A Charcot restraint orthotic walker and patellar tendon bearing AFOs are ideal to relieve weight on the lower limb, but these appliances are cumbersome and may reduce patient compliance. An orthosis of hybrid design, an AFO with a leather calf piece and double uprights attached to the shoe, can be an alternative when the patient has reached a coalescing or healing phase (Figs. 8e.7 and 8). Because treatment of diabetic neuroarthropathy is a long, tiring process, the patients should be educated to expect it. Figure 8e.7 Ankle foot orthosis with hybrid design (double uprights Case: Persistent swelling and increased with leather calf piece attached to the shoe). temperature of the foot after minor injury A 36-year-old man with a 20-year history of insulin- dependent diabetes mellitus twisted his right ankle during carpentry work and sustained a fracture at the right fifth metatarsal base. In spite of treatment with a hard-soled shoe for 3 months in another health care facility, the patient had persistent swelling and local warmth of the foot for 12 months, a history typical of Charcot neuroarthropathy. The patient was subsequently treated with a total contact cast for 11 weeks until the clinical signs of the consolidation phase appeared, followed by several months of bracing (Figs. 8e.7 and 8e.8). Partial foot amputation Workers with partial foot amputation frequently develop equinovarus deformity of the residual foot due to muscle imbal- ance between the strong plantar flexors-invertors and relatively weak dorsiflexors-evertors. Recurrent skin breakdown occurs mostly on the plantar aspect of lateral-distal stump. Stretching the gastrocsoleus muscle by exercise is not feasible in most cases due to the short lever arm of the residual foot, poor condition of the plantar skin, and long-standing contracture of the heel cord as well as the ankle capsules. Surgical correction of equinovarus deformity with an Achilles tendon lengthening, Achilles teno- tomy, or gastrocnemius recession should be implemented early. A short high-top shoe with a molded insole and rocker sole (stubby shoe) is a good choice to prevent recurrent ulceration of the residual foot, although workers may dislike its unaesthetic appearance. Workers with limited ankle ROM after partial foot amputation may use partial foot prostheses. Orthopedic footwear with a toe filler, steel shank, and rocker sole has been also recommended for these patients. Such a shoe, however, is heavy, affects the patient’s balance, and requires heel lift of the other shoe. Figure 8e.8 Ankle foot orthosis with hybrid design (double uprights Venous and lymphatic disorders with leather calf piece attached to the shoe). Complications of venous insufficiency are dependent edema on standing, recurrent ulceration of the leg, and contracture of the heel cord. Compression therapy with Unna’s paste boot or multiplayer compression bandaging followed by the application of compressive stockings is the mainstay of treatment for venous insufficiency as long as patients do not have significant

Chapter 8e ● References 393 arterial insufficiency. Patients should be educated to apply the 14. Finestone A, Shlamkovitch N, Eldad A, Karp A, Milgrom C: A prospective study of the compressive stockings and footwear in the morning, when edema effect of the appropriateness of foot-shoe fit and training shoe type on the incidence is less prominent. For workers engaging in physically demanding of overuse injuries among infantry recruits. Mil Med 157(9):489-490, 1992. jobs such as construction, surgical closure of the leg ulceration should be considered early to avoid the contracture of the heel 15. Gross MT, Liu HY: The role of ankle bracing for prevention of ankle sprain injuries. cord that may further compromise foot and ankle function.31 J Orthop Sports Phys Ther 33(10):572-577, 2003. Acquired lymphedema of the lower limb may develop in the 16. Helfet DL, Koval K, Pappas J: Intra-articular fractures of the distal tibia. Clin Orthop working population due to medical or surgical conditions. 298:221-228, 1994. Optimal control of lymphedema can be achieved by short-stretch bandaging combined with manual lymphatic drainage, compre- 17. House CM, Waterworth C, Allsopp AJ, Dixon SJ: The influence of simulated wear upon hensive decongestive therapy, and compression stockings. the ability of insoles to reduce peak pressures during running when wearing military Currently, the cost of these treatment measures is a major burden. boots. Gait Posture 16(3):297-303, 2002. CONCLUSION 18. Karlsson J, Andreasson G: The effect of external ankle support in chronic lateral ankle joint instability. Am J Sports Med 20(3):257-261, 1992. The ultimate goals of care for workers with foot and ankle injuries are restoring function and allowing a timely return to work. 19. Kelaher D, Mirka GA, Dudziak KQ: Effects of semi-rigid arch-support orthotics: an Clinicians should be knowledgeable about the details of various investigation with potential ergonomic implications. Appl Ergon 31(5):515-522, 2000. adaptation measures such as footwear and FOs with realistic expectations and goal setting. By using present technologies 20. Kirby KA, Green DR: Evaluation and nonoperative management of pes valgus. In based on sound biomechanical principles, most injured workers SJ DeValentine, ed: Foot and ankle disorders in children. New York, 1997, Churchill may be able to resume useful function and satisfactory quality of Livingstone, pp. 295-327. life. Clinicians should have a long-term plan in the early stage of management so that a major job modification or retraining can 21. Knapik JJ, Hamlet MP, Thompson KJ, Jones BH: Influence of boot-sock systems on be implemented if necessary. frequency and severity of foot blisters. Mil Med 161(10):594-598, 1996. REFERENCES 22. Lechner DE: The role of functional capacity evaluation in management of foot and ankle dysfunction. Foot Ankle Clin North Am 7(2):449-476, 2002. 1. Abidi NA: Sprains about the foot and ankle encountered in the workmans’ compensation patient. Foot Ankle Clin North Am 7:305-322, 2002. 23. Lippmann HI, Briere J-P: Physical basis of external supports in chronic venous insufficiency. Arch Phys Med Rehabil 52(12):555-559, 1971. 2. Amoroso PJ, Ryan JB, Bickley B, Leitschuh P, Taylor DC, Jones BH: Braced for impact: reducing military paratroopers’ ankle sprains using outside-the-boot brace. J Trauma 24. Lynch SA, Renstrom PA: Treatment of acute lateral ankle ligament rupture in athlete. 45(3):575-580, 1998. Sports Med 27:67-71, 1999. 3. Andersson GBJ, Cocchiarella L: Musculoskeletal impairment assessment. In: Guides 25. Manning DP, Jones C: The effect of roughness, floor polish, water, oil and ice on to the evaluation of permanent impairment, ed 5. Chicago, IL, 2000, American underfoot friction. Appl Ergon 32(2):185-196, 2001. Medical Association, pp. 523-547. 26. Marr SJ, Quine S: Shoe concerns and foot problems of wearers of safety footwear. 4. Arpini RH, Chapo RM: Dermatoses caused by footwear made of synthetic material: Occup Med 43(2):73-77, 1993. the rubber-boot syndrome. Med Cutan Ibero Lat Am 15(4):285-292, 1987. 27. Milgrom C, Giladi M, Kashtan H, et al: A prospective study of the effect of a shock- 5. Augustin JF, Lin SS, Berberian WS: Nonoperative treatment of adult acquired flat foot absorbing orthotic device on the incidence of stress fractures in military recruits. with the Arizona brace. Foot Ankle Int 8(3):491-502, 2003. Foot Ankle 6(2):101-104, 1985. 6. Boyd RM, Bogdan RJ: Sports injuries. In D Lorimer, G French, S West, eds: Neale’s 28. Myerson M, Quill GE Jr: Late complications of fractures of the calcaneus. J Bone common foot disorders. New York, 1997, Churchill Livingstone, pp. 197-226. Joint Surg 75A:331-341, 1993. 7. Burroughs KE, Reimer CD, Fields KB: Lisfranc injuries of the foot: a commonly 29. Neumann DA: An electromyographic study of the hip abductor muscles as subjects missed diagnosis. Am J Fam Phys 58:118-124, 1998. with a hip prosthesis walked with different methods of using a cane and carrying a load. Phys Ther 79(12):1163-1173, 1999. 8. Clanton TO: Instability of the subtalar joint. Orthop Clin North Am 20:583-592, 1989. 9. Coester LM, Saltzman CL, Leupold J, Pontarelli W: Long term results following ankle 30. Oh-Park M: use of athletic footwear, therapeutic shoes, and foot orthoses in physi- atric practice, state of the art reviews. Phys Med Rehabil 15(3):569-585, 2001. arthrodesis for post-traumatic arthritis. J Bone Joint Surg 83A(2):219-228, 2001. 10. Coughlin MJ: Calcaneal fractures in the industrial patient. Foot Ankle Int 21:896-905, 31. Owens JC: The postphlebitic syndrome: management by conservative means. 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Am J Sports Med 14:456-471, 1986. 35. Steb HS, Marzano R: Conservative management of posterior tibial tendon dysfunction, subtalar joint complex, and pes planus deformity. Clin Podiatr Med Surg 3:439-451, 1999. 36. Vander Griend R, Michelson JD, Bone LB: Fractures of the ankle and the distal part of the tibia. Instr Course Lect 46:311-321, 1997. 37. Verhagen EA, van Mechelen W, de Vente W: The effect of preventive measures on the incidence of ankle sprains. Clin J Sport Med 10(4):291-296, 2000. 38. Wang Y, Kim D, Oh-Park M: Plantar pressure measurement under the second metatarsal head with simple modifications of the insole in athletic footwear: a pilot study. Arch Phys Med Rehabil 82(9):poster 186, 2001. 39. Wapner KL, Chao W: Nonoperative treatment of posterior tibial tendon dysfunction. Clin Orthop 365:39-45, 1999. 40. Wernick J: Lower extremity function and normal biomechanics. In Valmassy RL, ed: Clinical biomechanics of the lower extremities. 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9C H A P T E R Functional Performance Testing Michiel Reneman and Harriët Wittink Musculoskeletal pain represents a significant burden to all sectors inability to work. Physical measurements such as tests for range of the population, with many working days lost due to back of motion and muscle strength were shown to be poorly related pain and muscle/joint pain. A study72 found that the prevalence to functional abilities and to have little value in predicting of arthritis, back pain, headache, and other musculoskeletal disability. Self-report measures of function and disability may conditions was 57% among the fully employed compared with be strongly influenced by psychosocial factors and are consid- 59% among the underemployed and with 63% among the ered subjective by definition. Self-report assessments frequently unemployed (p < 0.01). The cost due to lost productivity time do not agree with more objective measures such as observing because of these common pain conditions to employers is an the patient performing functional activities and the results of estimated $80 billion per year. Job requirements that exceed the physical examination. Medical assessment, performed by physi- worker’s physical abilities, a decline in physical abilities for instance cians, of the ability to perform work-related activities is based due to progressive musculoskeletal illness (such as arthritis), or on a more or less standardized interview and a physical examina- advancing age may lead to musculoskeletal impairments that tion. A direct comparison between expert assessments and a may cause a loss of function severe enough to render a worker direct performance evaluation has not yet been performed, likely unable to meet the physical requirements of the job. because of the poor psychometric properties of the expert assess- ments. From a need for a more objective measure of a person’s The National Institute for Occupational Safety and Health physical capacity for work, functional capacity evaluations (FCEs) report on Musculoskeletal Disorders (MSDs) and Workplace have been developed. Factors60 examined the epidemiologic evidence for a relationship between physical workplace factors and low back MSDs. Strong The introduction of FCEs cannot be tracked to a specific evidence was found for the association between back disorders, point in time; however, the practice is regarded as originating in work-related lifting and forceful movements, and whole body the United States in the 1970s. Physicians were asked to assess vibration. Evidence was found for the association between back the work ability of injured patients but were unable to do so disorders and heavy physical work (especially in combination with based on a history and physical examination only. They in turn awkward postures). For neck MSDs, there is a strong evidence for asked physical and occupational therapists to measure the patient’s an association with high levels of static contraction, prolonged ability to work. The therapists compiled existing and self- static loads, or extreme working postures involving the neck/shoul- developed tests into a battery of tests and named them FCEs. der muscles. There is evidence for an association between neck The original definition of FCE was “a systematic process of MSDs and highly repetitive work and forceful exertion. measuring and developing an individual’s capacity to depend- ably sustain performance in response to broadly defined work Acute pain complaints are usually self-limiting, but if they demands.”51 Over the past three decades FCEs have become big become chronic the consequences are serious. Musculoskeletal business as judged by the more than 1 million websites available impairments are the most common causes for occupational dis- on the Internet. ability and loss of work. The consequences in terms of the distress of patients and their families, for employers in terms of sickness Describing FCEs and their components requires a clarification absence, and for society as a whole in terms of welfare benefits, of the terminology commonly used in this area. Since the intro- lost productivity, and health care costs are enormous. It is the duction of FCEs, there has been a general inconsistency in the loss of function that creates disability. Disability is defined as the terms used to describe the evaluation itself, its procedures, and inability of the individual to meet expectations normal for one’s results. Terms such as functional capacity evaluation, functional capac- age and gender as well as one’s social and cultural environment.57 ity assessment, physical capacity evaluation, physical performance analy- sis, work capacity evaluation, work tolerance screening, and functional In recent years it has been recognized that the information ability evaluation were and still are used interchangeably, in some about a worker’s medical impairment is not a valid predictor of

398 Chapter 9 ● Functional performance testing Table 9.1 Definition of terms Terms Definition Evaluation The process of obtaining and interpreting data necessary for understanding the individual, system, or situation. This includes planning for and documenting the evaluation process, results, and recommendations, including the need for intervention and/or potential Assessment change in the intervention plan.36 Screening Testing Specific tools, instruments, or interactions used during the evaluation process with comparison of the affected body part to the norm. Capacity An assessment is a component part of the evaluation process.36 Ability Obtaining and reviewing data relevant to a potential patient to determine the need for further evaluation and intervention. Performance A standardized procedure of measurement. Performance areas The limits of the anatomic, physiologic, and psychologic systems of the person (depends on age, gender, genes, etc.). Physical capacities refer to a level of functioning, often referred to as “impairments” in the terminology of the World Health Organization’s International Classification of Functioning (ICF). Impairments may include static and dynamic muscular strength, flexibility of the joints and surrounding tissues, coordination, gait, balance, posture, and muscular and cardiovascular endurance. Capacity as modified by individual behavioral attitudes, in addition to external factors such as injury, pain, environmental and social stressors—the quality of being able to perform; a quality that permits or facilitates achievement or accomplishment. The act or process of functioning, sometimes measured by a performance scale or a performance test. Broad categories of human activity that are typically part of daily life, also called functional measures. They are activities of daily living, work and productive activities, and play or leisure activities and include sitting, standing, walking, kneeling, squatting, lifting, pushing, pulling, carrying, and manual dexterity. instances mistakenly.1 The words assessment, evaluation, testing, 2. To determine an individual’s ability to perform the demands screening, capacity, performance, ability, functional, and physical are required in relation to the work context. The perspective here used interchangeably, causing significant confusion. For clinicians is both administrative and clinical. From the administrative and researchers to understand each other, a common language viewpoint, the purpose is to ensure a safe and speedy return with clear definitions of terms is imperative (Table 9.1). to work, thereby reducing costs. From a clinical viewpoint, the purpose is to ensure that the match or mismatch between We chose to use the term functional performance evaluation the individual’s level of function and the work demands has (FPE) in this chapter, realizing that the acronym FCE is more been identified to lower the risk of further injury and to widely known in the field. The reasoning for this is that in implement appropriate work modifications if necessary. its essence the FPE is an evaluation of a person’s ability to In evaluations where return to a former job is an issue, a job perform activities. An elaboration of the differences between analysis should be performed to determine the tasks required “performance” and “capacity” is presented below. Placed into for the job. A good job analysis requires a work site visit the context of work, the FPE becomes a test to measure the during which, for instance, the frequency, duration, intensity, individual’s ability to meet or exceed the physical demands of and the distance a person must lift, bend, and reach is identi- the work, with specific reference to a job and the tasks involved fied and recorded, in addition to other factors that might affect (in turn specified into duration, load, and repetitions). the worker, such as sitting time, desk height, uneven floors, and the timing of breaks. If a job analysis cannot be done, a PURPOSES detailed quantifiable job description reflecting the critical job requirements, such as employers are required to have, is The measurement of the ability of a person to perform work- essential. The results from the FPE can then be compared with related activities can be used to serve several purposes (listed the job demands. Needless to say, the FPE tests should focus below). They may not be used for all these purposes with every on the specific tasks the worker might have difficulty with. In client but should depend on the client need, referral request, a case of preemployment testing for a potential job, a more or clinical or administrative requirements. Selection of type comprehensive and generic assessment is needed to avoid a and components of an FPE may be guided by the purpose for potential mismatch between the worker and the job demands. which it is used. A clear understanding from the referral source regarding the purpose of the FPE is essential in choosing an FPE. 3. To determine sincerity of effort and consistency of effort during assessment. Assessment results may be considered when a The purposes of FPEs are as follows38: determination regarding the level of disability is made related 1. To determine the need for intervention and treatment, and to to financial compensation. This has an administrative purpose, especially in litigious situations where assessments of function design and plan treatment. The perspective here is mainly are used for medicolegal purposes. From a clinical viewpoint, clinical to determine whether an intervention is necessary and determining sincerity or consistency of effort and underlying to design a program to improve on those activities that have causes of submaximal performance may assist in guiding the shown to be deficient.

Chapter 9 ● Purposes 399 focus of treatment. For example, an individual producing Additionally, all jobs in the U.S. economy have been classified submaximal effort may be anxious about reinjury or return to into the following five levels of exertion: sedentary, light, medium, work and may require intervention with a behavioral rather heavy, and very heavy (Table 9.2). The physical demands strength than a physical emphasis. rating reflects the estimated overall strength requirement of the 4. To document outcome, achievement of goals, and or job, expressed in terms of the letter corresponding to the partic- effectiveness of the program. The viewpoint is primarily an ular strength rating. It represents the strength and endurance administrative one, with the emphasis on demonstration of requirements, which are considered to be important for average achievement of program goals. successful work performance (see http://www.oalj.dol.gov/ 5. To determine the level of disability. This may be used for the public/dot/refrnc/dotappc.htm, accessed August 31, 2003). settlement of a workers’ compensation claim or to determine whether the disability is permanent or temporary. If disability In their systematic review of FCEs, King et al44 found little assessment is at issue, the FPE should correspond to the evidence in the literature of the inclusion of physical fitness information requested by the person determining the level of assessments in FPEs. This is in contrast to the finding that the disability.44 development of most FPEs is inspired by the DOT, in which 6. To develop and improve treatment resources for service the energy requirements of jobs are defined. The level of aerobic provision and research. fitness directly affects the amount and intensity of physical activity an individual is able to perform. Most physical activities What to measure are described in terms of their energy or metabolic cost.2,5 Physical activities are coded in metabolic equivalent (MET) Most authors agree that the test components of the FPE include intensity levels. One MET is considered a resting metabolic rate the medical history, in which the individual factors associated with obtained during quiet sitting and equals an oxygen uptake of MSDs60 such as age, gender, physical activities/fitness, strength, 3.5 ml/kg/min. The oxygen cost for physical activities ranges anthropometry (body mass index), and cigarette smoking, should from 0.9 MET for sleeping to 18 MET (running at 10.9 mph).2 be noted; physical examination to quantify physical impairment and to determine any contraindications for testing; work history; Aerobic fitness matters a great deal when performing physi- pain assessment; and a variety of work-related performance tests cally demanding work. Workers with physically demanding and self-reported functional limitations. There exists disagree- jobs include firefighters, the police and military, waste collectors, ment as to how these components should be filled.44 In the and home care workers. For instance, firefighters need to be following section the work-related performance tests and the highly aerobically fit to perform their job duties. Oxygen uptake self-reported functional limitations are discussed. during fire suppression is about 25-35 ml/kg/min (7-10 METs), which reflects how very physically demanding firefighting is. Work-related performance tests Based on this observation 38-42 ml/kg/min has been most frequently cited as the desirable VO2max level.71 This is average The contextual relationship of FPEs with work can easily be fitness for healthy males under 50 years of age, but an average understood from its original purpose. FPEs are predominantly fit female of any age would not have this aerobic capacity. If inspired by the taxonomy described in the U.S. Department of the aerobic demand of work cannot be met, premature fatigue Labor’s Dictionary of Occupational Titles (DOT). This taxon- can put a person at risk for injury. For instance, it has been shown omy, although never formally tested for its validity, has gained that inactive firefighters have a 90% greater risk of myocardial support in many countries around the world. The DOT classifi- infarction than those who are aerobically fit,58 and Linden48 cation is similar to selected domains of the International showed an inverse relationship between maximal oxygen uptake Classification of Functioning (ICF) and classifications such as a and absenteeism in custom officers. Studies investigating workers back-specific classification called the functional assessment tax- ought to describe the energy demand level of their job as set onomy.33 Among others, the DOT provides information about forth by the U.S. Department of Labor (Table 9.2). Because of the work characteristics of most jobs in the United States in terms the proven importance of aerobic fitness in the determination of of the physical demands these jobs place on the workers. The work capacity,5 aerobic testing should be part of an FPE. demand classification is based on certain principles assumed or demonstrated to be key elements in the nature of work. Self-reported functioning These key elements are defined in the DOT as the physical Historically, an assessment of functional capacity was made by demands of a specific job and are called job factors. There are 20 asking patients about their activity levels. A large variety of ques- job factors, with some of them broken into subfactors: standing, tionnaires has been developed to measure patients’ perceptions sitting, walking, lifting, carrying, pushing, pulling, climbing, of their physical activity level and disability. Studies in patients balancing, stooping, kneeling, crouching, crawling, reaching, with chronic pain, however, have identified discrepancies handling, fingering, feeling, talking, hearing, and seeing. These job between self-report of physical activity and actual level of phys- factors then express both the requirements of the job and the ical activity. In a number of these studies, the reported physical capacities a worker must have to meet or exceed those demands. activity level was clearly lower than the observed level. Objective It has been stated that the content validity of FPEs based on the measurement of functioning as by FPE therefore seems war- DOT is sufficient and that most of the commercially available ranted. When comparing the results of FPEs with the results FPEs cover many to all of these work characteristics.40 of questionnaires, it has been shown that the outcomes are substantially different and correlate moderately at best.27,47,66

400 Chapter 9 ● Functional performance testing Table 9.2 Physical demands strength rating Physical demand Occasional* 0–33% Frequent* 34–66% of Constant* 67–100% of the work day level of the work day the work day Typical energy required Sedentary 10 lbs. Negligible Negligible 1.5–2.1 METs Light 20 lbs. 2.2–3.5 METs 10 lbs. and/or walk/stand/ Negligible and/or push/pull of arm/leg Medium 21-50 lbs. 3.6–6.3 METs Heavy 50-100 lbs. push/pull of arm/leg controls controls while seated 6.4–7.5 METs Very heavy Over 100 lbs. Over 7.5 METs 10-25 lbs. 10 lbs. 25-50 lbs. 10-20 lbs. Over 50 lbs. Over 20 lbs. *Amount of force exerted to lift, carry, push, pull, or otherwise move objects, including the human body (1 lb = 0.45 kg). METs, metabolic equivalents. In one of these studies, 64 patients suffering from nonspecific Legal constraints chronic low back pain (CLBP) rated themselves on three different well-known low back–specific questionnaires as moderately to Legal constraints challenge the validity of FPEs. Various pieces of severely disabled. The questionnaires were the Roland Morris legislation, such as the Americans With Disabilities Act (1990), Disability Questionnaire,67 the Oswestry Back Pain Disability the Age Discrimination Employment Act (1967), and the Federal Scale,18 and the Quebec Back Pain Disability Scale.45 These same Uniform Guidelines of Employee Selection Procedure (1978), patients, however, were able to perform activities at a physical require that function tests not discriminate against age and intensity level consistent with moderate to heavy work (classifi- sex and that appropriate accommodation in testing is created cation DOT). Correlations between the questionnaires and the for those who have impairments. Caution should be used when FPE results were poor to moderate.66 comparing an individual’s performance with normative data, because the Americans With Disabilities Act prohibits this Another striking example of the difference between self-reports method to make decisions regarding return to work, and deny- and actual activity levels was described by Verbunt et al.78 The activ- ing a job to an individual with a disability based on data that ity levels of patients suffering from CLBP and matched healthy compares his or her functioning with that of the general pop- control subjects were measured continuously for 2 weeks using a ulation is illegal. The effects of age are confounded with work triaxial accelerometer. The results demonstrated that the mean capacity. Aerobic fitness declines with age.3 Both muscle contrac- activity levels of the patients, who had rated their disability as tile and mitochondrial protein decrease with aging in sedentary substantial, did not differ significantly from the control subjects. humans resulting in decreases in muscle strength and endurance. It is clear that instruments based on self-report or based on per- With regard to lifting, Matheson et al50 studied 531 healthy sub- formance measure different dimensions of the same construct. jects and found that age made a significant contribution to lift capacity, which continued to be significant even when resting One of the reasons for this discrepancy might be that psy- heart rate and body mass were considered, suggesting that age- chosocial factors, such as depression and disability status, appear linked decrements in aerobic capacity and musculoskeletal to have a larger effect on self-report than on performance test- strength may have a potentiating effect on decrements in lift ing.83 Unfortunately, affective states appear to influence func- capacity. Age can therefore be a justifiable reason for early retire- tional performance as well. Poorer achievement on physical ment in persons with physically demanding jobs. performance testing of patients with CLBP has been linked to fear of injury during movement, depression, pain expectations, The most important legal constraint on functional testing, pain increase during testing, and the presence of a solicitous aside from discrimination, is that it be evidence based (Daubert spouse.49,79,82,83 FPEs have been justly criticized for their lack v. Merrell Dow Pharmaceuticals, 1993). This case law requires of measurement of psychosocial variables that might influence that peer-reviewed publications in scientific journals be given testing and that may interfere with successful return to work. precedence in determining acceptability of test-based evidence. It also sets standards for legally acceptable scientific evidence. In conclusion, a performance measure should be used to Scientific peer review is essential for acceptability. Thus, when measure “a person’s ability to perform an activity.” Questionnaires big money is resting on an FCE, its credibility can be destroyed can be used to measure “a person’s self-reported ability to by the opposing attorney when the test cannot meet those perform an activity” and to measure the psychosocial factors standards.55 that might influence both self-report and performance. It is advocated to use both performance-based and self-report measures Professional practice standards to obtain a more comprehensive picture of a person’s disability. The American Psychological Association and the American CHARACTERISTICS OF AN EFFECTIVE Physical Therapy Association published professional practice FUNCTIONAL PERFORMANCE EVALUATION standards for measurement. In these models, there are five issues that must be addressed in the selection and use of any functional When developing evaluations, both legal constraints and profes- sional practice standards should be applied.

Chapter 9 ● Characteristics of an effective functional performance evaluation 401 test in a patient population. These issues, presented in hierarchical rates were 0 to 5 per 100,000 exercise tests. A survey of the order, are as follows: Veterans Affairs Health Care System exercise laboratories found ● Safety: Given the known characteristics of the patient, the an event rate of 1.2 per 10,000 tests of major cardiac events (myocardial infarction, ventricular tachycardia) and no deaths procedure should not be expected to lead to injury. during 75,828 exercise tests performed within the last year.56 ● Reliability: The test score should be dependable across evalu- In summary, it can be concluded that the risk of medical com- plications is related to the underlying disease, and it appears that ators, patients, and the date or time of test administration. the rate of death for patients, during exercise testing, is 2 to 5 per ● Validity: The interpretation of the test score should be able to 100,000 clinical exercise tests. For details on cardiovascular test- ing see http://ajrccm.atsjournals.org/cgi/content/full/167/2/211. predict or reflect the patient’s performance in a target work setting. Reliability ● Practicality: The cost of the test procedure should be reason- able and customary. Cost is measured in terms of the direct Reliability involves the extent to which an evaluation is consistent expense of the test procedure plus the amount of time required and free of error. This consistency may be over time (test-retest of the patient, plus the delay in providing the information reliability); between different raters, observers, or evaluators derived from the procedure to the referral source. (interrater reliability); between more than one identical session ● Utility: The usefulness of the procedure is the degree to which rated by the same evaluator (intrarater reliability); or between it meets the needs of the patient, referrer, and payer. equivalent parts of the same test (internal consistency). Although all types of reliability are important, establishment of test-retest Safety and interrater reliability are deemed most important in FPEs, because it ensures that any change found in the assessment is The safety of testing depends on a number of factors that the result of change in the individual and not the result of meas- include the physical health of the patient, equipment safety, a urement inconsistencies over time or between examiners. “tried and tested” protocol, and the experience of the evaluator. No testing performed on the patient should lead to reinjury A number of factors may influence the reproducibility or a new injury. Qualified professionals should administer the of results. An important factor to consider is that of a poten- FPE using a standardized protocol, both to ensure the patient’s tial learning effect and therefore the need for preliminary/ safety and to increase the reliability of the FPE. The medical familiarization testing. Patients should practice the test at least history and the physical examination to quantify physical once to prevent undue anxiety and to increase mechanical impairment together ought to determine any medical contraindi- efficiency, especially when equipment is used with which the cations for testing. Medication use should be noted because a patient is not familiar. An additional factor that may influence variety of medications (such as alpha/beta-blockers, Ca2+ channel the reproducibility of measurements is the time of testing. blockers) affects a normal exercise response and thus interferes Preferably, repeated testing should be undertaken at the same with physiologic measurement of the workload (i.e., by heart time of day, as significant diurnal variation in results has been frequency). reported.25 Furthermore, the testing protocol, procedure, and instructions to the patient must be rigidly controlled, because Safety criteria used during FPEs usually consist of the fol- these have been shown to significantly affect performance.31,73 lowing. The evaluator must know of any medical constraints Finally, disease severity (pain severity) may also affect the vari- before testing. The client should be instructed that he or she ability of some measurements during exercise42,82 and may affect may terminate testing at any point if deemed appropriate. A the interpretation of results in some patients with more severe heart rate monitor should be worn to prevent the heart rate disease. rising over a predetermined maximum. Most studies use a maximum of 85% of the client’s predicted average maximum An area that may benefit from further development is that of (220 – age). Finally, the evaluator should terminate testing when internal consistency. By examining the correlation between test the client is at risk during the evaluation. This involves a pro- items, it may be possible to streamline evaluation batteries to fessional judgment based on medical information, the client’s include only those items that assess necessary activities, rather history, the physical examination, and the performance during than duplicating items that assess the same or similar activities. the functional evaluation. No peer-reviewed data are available on how often the evaluator would terminate testing for this Reliability of evaluating work-related activities The most reason. The authors know of no reports in which new or rein- recent review of the scientific evidence of the reliability of juries during or resulting from FPEs are described. Among oth- FPEs was published in 1999.39 It was clearly demonstrated that ers, evaluators may observe quality of movement, spinal the evidence for reliability of a wide range of FPEs ranged from alignment, and body mechanics as a part of their safety deter- nonexistent to being investigated and reported in sufficient minations. With regards to the latter, the use of a squatting detail. There did not appear to be a single FPE that had been technique is usually advocated over a stooping technique. A thoroughly and comprehensively investigated for all relevant review of the biomechanical literature, however, has revealed no aspects of reliability. Since then, however, developers of FPEs significant differences in spinal compression between the two appear to have greater appreciation of the need to investigate techniques.77 and report the reliability. To the authors’ knowledge, since and including 1999, a number of papers have been published or Maximal symptom-limited aerobic testing is safe, although have been accepted for publication in peer-reviewed journals various facilities require supervision of a physician during test- (PubMed, key word: functional capacity evaluation reliability, ing. The American Heart Association analyzed eight studies related to sudden death during exercise testing.21 The reported

402 Chapter 9 ● Functional performance testing 1999-2003). Reports containing new data of different aspects Validity of reliability were identified about the following FPEs: ● Baltimore Therapeutic Equipment Primus FPE: Test-retest Validity is usually considered to be the extent to which an instru- ment measures what it is intended to measure. The validity of a reliability of handgrip and lifting of 30 healthy subjects was test refers to the appropriateness, meaningfulness, and usefulness good, both for strength and for endurance protocols.47 The of the specific inferences made from the test results. Validity reliability of three other tests was also studied, with similar depends on the purpose of the assessment and therefore the test results, but it may be questioned whether tests of isolated objectives. It is not a universal characteristic of an assessment. wrist flexion and extension and elbow flexion should be No single measure is sufficient from which to determine an considered as functional. assessment’s validity. These aspects imply that multiple studies ● Ergos Work Simulator: Test-retest reliability of seven upper of the various forms of validity are required and that validity extremity items were tested on 12 healthy subjects, indicating must be evaluated within the context of the test’s intended good reliability.10 Similar to the Baltimore Therapeutic purpose and a specific population. Several forms of validity are Equipment Primus FPE, it may be questioned whether some relevant to FPEs: face, content, criterion-related (concurrent and of the tests studied should be considered as “functional” predictive), and construct validity (Table 9.3). activities. ● Functional Range of Motion Assembly Test: Test-retest relia- Sincerity of effort A confusing and inappropriate use of the bility of three items was tested on 51 healthy adults. Results term validity occurs in some work-related assessments. The terms indicate moderate to good reliability.52 validity profile, valid, conditionally valid, conditionally invalid, and ● Isernhagen Work Systems FPE: Five separate reports of invalid effort are used by some FPEs. These terms do not refer interrater and intrarater as well as test-retest reliability of the to the validity of the instrument or test battery results but material handling items indicate good overall reliability in rather to the level of effort exerted by the client performing the healthy subjects and patients.24,30,41,61,63 Test-retest reliability assessment. They are used to describe the level or sincerity of of two tests measuring maximum holding times of static postures effort exerted by a client and are not related to the measurement indicated good reliability in healthy young adults.64 Test-retest concept of validity. The reader should be aware of this use of reliability of almost all items of the Isernhagen Work Systems the term and note that there is no scientific justification for the FPE, tested on 30 patients with CLBP, indicated a wide range use of the term validity profile as that term relates to functional of reliability, varying from unacceptable to good.12 testing.40 This subject of effort levels, sincerity of effort, and ● Physical Work Performance Evaluation: Test-retest reliability pain behaviors is one of great importance for any form of of nine main items of this FPE was tested on 24 subjects with performance testing, including FPEs. stable physical injuries (mainly back disorders). The results indicate moderate to substantial reliability of the items tested.76 The term capacity connotes the maximum ability of the evaluee, beyond the level of tolerance that is being measured.50 Although many FPEs have still not demonstrated reliability Capacity is the evaluee’s potential, determined by physiologic in peer-reviewed journals, the developments are positive. A factors.80 The use of the term capacity is somewhat misleading, number of studies are performed with reasonable to good because capacity is rarely measured in a performance task, unless scientific scrutiny, using both injured and uninjured samples, by the evaluee is highly motivated and trained to perform that different researchers independent from each other. The studies particular task. Examples of maximum task performance are demonstrate that performance-based measurements, such as found when experienced athletes compete. When the evaluee is FPEs, can be used to reliably evaluate a person’s functional an injured worker, the functional capacity is usually inferred capacity. They also demonstrate that although reliable at from evaluation of task performance. Even when the evaluation the group level, the performances of injured individuals (with task is designed to measure the evaluee’s maximum performance CLBP) may vary substantially between occasions.12 It appears level, this is achieved rarely. that this variance can in large part be attributed to the variance in patient performances rather than measurement inconsisten- The maximum level of performance that can be measured cies over time or between raters.30 Further research is needed, is the portion of capacity the evaluee is willing to muster. Thus, however, to confirm this suggestion. Most of the recently the performance of the individual depends both on his or her published studies have used the IWS FPE. This may be positive abilities to perform and his or her motivation to perform. Two for the body of knowledge of the Isernhagen Work Systems items are of paramount importance in this: (1) how can capacity FPE but not to the field of FPEs as a whole, because it is cur- and performance be differentiated when evaluating an individual rently not known if, or to what extent, the knowledge gained (are the results reflective of maximal or submaximal physical from one FPE can be generalized to other FPEs. abilities) and (2) what factors determine the motivation of a patient to perform? Neither question can be answered with Reliability of evaluation aerobic capacity The intraindividual scientific certainty at this time. day-to-day variation in measuring aerobic fitness (VO2max) is between 4% and 6% in persons with no known cardiovascular Methods that are being used to differentiate between a maxi- disease,69 but the variation is larger in persons with known mal and a submaximal performance (also referred to as sincerity chronic obstructive pulmonary disease (6-10%).13 There is no of effort) are Waddell’s nonorganic signs, descriptions of pain information on the reliability of maximal symptom limited behavior and symptom magnification, coefficients of variation, cardiopulmonary testing in persons with musculoskeletal pain. correlations between musculoskeletal evaluation and function, grip measurements, and the relations between heart rate and pain intensity. Despite the widespread use of these methods, up to 1998 little had been published to address their reliability and

Chapter 9 ● Characteristics of an effective functional performance evaluation 403 Table 9.3 Definitions of validity40 Face validity When a work-related assessment appears to measure what it intends to measure and it is considered a plausible method to do so. Content validity The degree to which test items represent the performance domain the test is intended to measure. Content validity is usually Criterion validity determined by a panel of experts who examine the relationship between test objectives and test items or by knowledge of the normal practices used. Concurrent validity The systematic demonstration of the extent to which test performance is related to some other valued measure of performance Predictive validity or external criterion. It is composed of concurrent and predictive validity and is considered to be the most practical approach to Construct validity validity testing and the most objective. Examines the correlation between two or more measures given to the same subjects at approximately the same time so that both reflect the same incident of behavior. Compares a subject’s performance at the initial time of testing with performance obtained at a future date with another highly valued measure or “gold standard.” For work-related FPEs a client’s success when returning to work is a highly valued criterion. The extent to which a test can be shown to measure a hypothetical construct. For example, a work-related assessment may be considered to have some support for construct validity if it is able to differentiate between clients who are able to lift safely and those who do not, where the construct being measured is safe lifting ability (also called discriminant validity). Known Groups Method is the most general type of evidence and involves the ability of the test results to discriminate between groups which are known to be different (e.g., different diagnostic groups; different age groups; different occupational groups) in a theoretically appropriate manner. Correlation with other tests involves the examination of the degree of convergence and/or divergence with other tests that are presumed to measure the same or different constructs or traits. FPEs, functional performance evaluations. validity specific to the FPE setting.46 Two studies published since pain and work injury management, it is advocated to use the then have tested strategies to differentiate between maximal and services of a clinical psychologist or a behavioral therapist submaximal performance in a lifting test. Both studies report to assess these aspects in conjunction with the evaluation of the promising results with regards to the sensitivity and the speci- functional capacity. Their assessments, however, should meet the ficity of their methods to differentiate between maximal or same criteria of reliability and validity as any other assessment submaximal effort levels.19,43 Both studies used healthy subjects, and should not rely on self-reports or clinical expertise only. which may not be representative for patients with musculoskele- tal injuries. Additionally, both studies dichotomized between Validity of evaluating work-related activities The last review maximal and submaximal, suggesting a greater difference than of the scientific evidence of the validity of FPEs was published presented in daily practice. There are large differences with the in 1999.40 It was demonstrated that the evidence for validity group labeled as “submaximal,” because all subjects performing of a wide range of FPEs ranged from nonexistent to being between 10% and 90% of their maximum would fall into that investigated and reported in sufficient detail. Very few FPEs were category. The challenge for future developments in this area is to able to demonstrate adequate validity in more than one area or develop and test methods to differentiate between all levels of with more than one study. Since then, as was the case with the effort (from light to maximum), not only on healthy subjects but reliability, developers of FPEs appear to have greater appre- on relevant patient groups as well. Until then, clinicians should ciation of the need to investigate and report the validity. To our remain careful in classifying their patients’ performance levels. knowledge, since and including 1999, several articles have been published or have been accepted for publication in peer reviewed The second question deals with factors determining the journals (Pubmed, key word: functional capacity evaluation motivation of a patient to perform during an FPE. Watson80 validity, 1999-2003). Reports containing new data about differ- developed a model in which task performance during a per- ent aspects of the validity were identified for the following FPEs: formance evaluation of patients with chronic pain is explained. ● Baltimore Therapeutic Equipment Work Simulator: Real and Other than physiologic factors, the following nonphysiologic factors are postulated in the model: task familiarity and learning, simulated lifting tasks were compared. The results suggest self-efficacy, pain self-efficacy, fear avoidance beliefs, current the Baltimore Therapeutic Equipment Work Simulator pain level, and outcome expectancy. Based on these factors, a overestimates real lifting endurance performance in healthy patient may be motivated to perform to maximum capacity or men. Lower physiologic stresses during the simulated task to terminate an activity before reaching maximum. It is impor- suggest a significant difference between the real and simulated tant to not only assess the extent to which a client is willing to loads.75 perform to his or her physical maximum, but also the reason(s) ● DOT Residual Functional Capacity battery: Stooping, climb- why he or she performs as such. This assessment may require ing, balancing, crouching, feeling shapes, handling left and knowledge beyond the professional capabilities of functional right, lifting, and carrying appear to have construct validity capacity evaluators, often physical or occupational therapists. in chronic pain patients. In a sample of 155 chronic pain Consistent with all major standards and guidelines of chronic patients, the DOT Residual Functional Capacity battery

404 Chapter 9 ● Functional performance testing could not predict employment levels. However, if a patient positive as well. A number of studies concerning different passes certain items of the FPE and has a pain level less than aspects of validity are published. As was the case with reliability, 5.4 (scale, 0-10), that patient has a 75% chance of being most of the recently published studies concern the Isernhagen employed at 30 months after treatment at the pain facility. It Work Systems FPE. Again, this may be positive for the body of was concluded that some DOT Residual Functional Capacity knowledge of the Isernhagen Work Systems FPE but not to the battery job factors demonstrate a predictive validity in the field of FPEs as a whole, because it is currently not known if, “real work world.”20 A study on functional capacity and psy- or to what extent, the knowledge gained from one FPE can be chologic measures concluded that psychologic variables were generalized to other FPEs. One study in which upper lifting related to measures of functional capacity measured at the performance was tested according to two FPE protocols admission stage of a rehabilitation program and that psycho- revealed significant differences in results.37 This indicates that logic measures at admission were not good predictors of later differences in operational definitions of the activity tested, for functional capacity measures. Additionally, functional capac- example lifting height and repetitions, really do matter. Even ity measures were identified as important predictors of follow- though the amount of evidence is limited, it is suggested that up employment outcome, but return to work could not be generalization between FPEs should not be made unless great predicted without taking pain into account.16 care is used. ● Functional Assessment Screening Test: Some evidence was described to confirm criterion validity because performance In conclusion, the following can be derived from previous40 of patients with CLBP was inversely related to self-reported and the above-mentioned publications. The construct validity depression, disability, and different dimensions of pain of FPEs based on the DOT classification is confirmed with experience.68 The strength of the relationships, however, was regards to the choice of activities that make up the evaluation. not reported. It has been demonstrated clearly that the results of functional ● Gibson Approach to FPE: An expert review performed by capacity measurements differ substantially from results of self- five occupational therapists supported the content validity reports. Psychologic factors are known to influence test results, of aspects of this FPE.26 but the extent to which they do, however, remains unclear and ● Isernhagen Work Systems FCE: In a large cohort of patients warrants future research. The predictive power of FPEs with (n = 650; diagnoses not specified) studied retrospectively, regards to their ability to predict safe and lasting return to work gender and time off work were found to be the strongest has not been clearly demonstrated and the results of different predictors of whether or not the patients returned to work, studies appear to conflict. with performance on a lifting task adding little but signifi- cantly to the prediction. Of those who did return to work, the It may be questioned whether FPEs will ever be found valid performances on two lifting tasks were related to the level of for the prediction of a safe and lasting return to work. The work they returned to.52 A study that examined the ability of construct of “workability” is widely regarded as a multidimen- this FPE to predict a timely return to work in a workers’ com- sional construct. Whether a patient successfully returns to work pensation environment by a worker suffering from low back or not depends on more than functional capacity by itself. It is pain found that better performance on FPE was weakly asso- paramount that an instrument measuring a single dimension ciated with faster recovery; however, the amount of variation cannot be expected to assess a multidimensional construct. It explained was small.28,29 One task in the FPE was as predictive is therefore by definition incorrect to suggest or to claim that as the entire protocol. Another study that examined the abil- the results of an FPE should be able to predict a person’s work ity of this FPE to predict sustained recovery in a workers’ ability or, even more complex, a successful return to work. compensation environment by a worker suffering from low At best, one may expect from an FPE, in conjunction with back pain found that better FPE performance as indicated by endurance testing, to measure an individual’s functional ability a lower number of failed tasks was associated with higher risk to perform work-related activities. This should be seen as one of of recurrence. The validity of the FPE’s purported ability to the prerequisites for a successful return to work. Seen in this light, identify claimants who are “safe” to return to work is sus- the role of the physical domain may prove to be a modest one. pect.28,29 Two separate studies confirm the concurrent and the construct validity of this FPE, as it relates poorly to moder- Validity of testing aerobic capacity The gold standard for ately to different forms of self-reported disability.28,29,66 A determining absolute VO2max in an individual is by metabolic moderate relation between FPE performance and pain inten- measurement system analysis of O2 and CO2 gas in expired sity was found,28,29,65 and the relation between FPE perform- air at regular intervals and attainment of a maximum heart rate ance and kinesophobia was found to be nonexistent.65 of at least 90% of age predicted maximum (220 – age), a plateau- Self-reports of function or prediction of function was poorly ing of VO2 and respiratory exchange ratio (RER) >1.0.4,6,74 In nor- related to actual function on tests measuring maximum hold- mal subjects, the highest VO2max is obtained with treadmill ing times of maintaining postures.62 Yet another study found testing due to the quantity of the muscle mass involved, fol- preliminary evidence in support of the ecologic validity of lowed by bicycle testing. VO2max achieved by bicycle testing is this FPE; test results were not relevantly influenced by differ- reported to be 5-15% lower than with treadmill testing in normal ences in test conditions.64 subjects.34,35 Astrand and Rodahl5 report a 5-7% difference in maximal oxygen uptake between treadmill and bicycle testing in Although many FPEs have still not demonstrated aspects of well-trained subjects. Predicted VO2max ml/kg/min estimated their validity in peer-reviewed journals, the developments are from arm exercise testing is 60-70% of leg exercise in normal subjects. Normal females reach 65-75% of male VO2max.6 The lower oxygen uptake capacity in women may have to do with their

Chapter 9 ● Characteristics of an effective functional performance evaluation 405 lower hemoglobin concentration and higher body fat content. In 41% and overestimate predicted VO2max by as much as 38%. both genders, oxygen uptake peaks at 18-20 years of age, followed On average, an error of 20% should be taken into account. by a gradual decline with age. At the age of 65, the mean value Similarly, estimating aerobic fitness in METs from a Bruce tread- is about 70% of what it is for a 25-year-old individual. mill test, by comparing the level reached by the patient with established MET norms for that level, results in significant Not much is known about the validity of exercise testing in underestimation and overestimation of individual fitness levels patients with chronic pain, because historically exercise testing ranging from 25% to 33%.84 It is important to understand that was mostly used in athletes, healthy subjects, or subjects with the most accurate, and therefore valid, way to measure VO2max in cardiac and pulmonary problems. One study81 compared tread- a single individual is through direct measurement of maximal mill, bicycle, and upper extremity ergometry (UBE) exercise test- oxygen uptake. When determining fitness for duty it is extremely ing in a small (n = 30) sample of patients with CLBP. Indirect important to “get it right” as a person’s health and safety might calorimetry was used to determine oxygen uptake, and a three- be at stake, not to mention his or her job security. lead electrocardiogram was used to determine heart rates at each minute of testing. Subjects were encouraged to “do as much Aerobic fitness has construct validity in physically demanding as you can.” The researchers used the modified Bruce treadmill work. A vast body of knowledge has been accumulated on the test, the Astrand-Rhyming bicycle test, and a UBE test. The test- energy cost of physical work. In general, a person can carry on ing response for patients with CLBP was remarkably similar to all day without fatigue if the workload is less than 40% of the that of normal subjects. Significantly higher heart rates, peak individual’s maximal aerobic fitness. Ergo, the less fit a worker is, VO2, and predicted VO2max ml/kg/min were achieved by the the less load this person can tolerate (or tolerate the same load modified Bruce treadmill test than with the bicycle or UBE tests, for a shorter amount of time). Pohjonen59 investigated the effect despite pain, consistent with normal subjects. Also, peak and of aerobic capacity of home care workers on their ability to work predicted VO2max showed gender differences consistent with and found that poor average maximal oxygen consumption published results for normal subjects, supporting criterion (l.min-1; odds ratio, 3.1) indicated a high risk for reduction in validity of aerobic testing in patients with CLBP by treadmill, work ability, supporting the content validity of aerobic fitness. bicycle, or UBE. Further criterion validity for treadmill testing in A combination of back strength and aerobic fitness explained patients with CLBP was supported by the finding that prediction 31- 41% of the total variance of lifting ability in healthy equations for estimated maximum oxygen consumption females.53 No such data are yet available on persons with MSDs. (VO2max) in patients with CLBP equal those in healthy sedentary men and active women.54 The predictive validity of aerobic fitness is mixed. As stated before, inactive firefighters have a greater risk of myocardial The treadmill is the most commonly used mode of testing infarction than those who are aerobically fit.58 Low cardiovascu- and is the apparatus of choice in the laboratory because exercise lar fitness level was a risk factor for disabling back pain in a intensity is easily determined and regulated. Most clinics have prospective longitudinal study among aerospace manufacturing access to a treadmill, making this a practical test. Determining workers.8 In their landmark article, Cady et al15 reported that aerobic uptake by indirect calorimetric measurement is time the frequency of injuries among firefighters was 10 times higher consuming and costly, however, and therefore not always of for the least-fit group than for the most-fit group (n = 266 in practical use in the clinic. A variety of (submaximal) tests has the least-fit group, n = 259 in the most-fit group). The cost been developed estimating aerobic capacity when direct meas- per claim for the 19 injured men from the least-fit group was urement is not possible. These tests usually involve running/ 13% more than for the 36 injured men from the middle-fitness walking for a given time or distance, such as the 12-minute group. Unfortunately, fitness levels were a composite of strength, walk/run test, the shuttle test, and various step tests.70 Longer flexibility, and aerobic fitness, and it is unclear which compo- distances and shorter test times are associated with higher levels nent of the fitness score was most important to the outcome. of aerobic fitness. Other tests estimate VO2max by submaximal Similar composite measures of fitness were identified as risk testing and extrapolation to maximal heart rate by treadmill factors for training injuries in the military.9 Boyce et al,11 how- walking or bicycling against a predetermined load with measure- ever, reported that only 7% of absenteeism could be explained ment of heart rates.3,7,14,23 These tests were mostly developed for by age, sex, and physical fitness among 514 police officers testing aerobic fitness in healthy people and were validated by 35 years or older. comparing actual measured VO2max with predicted VO2 or to the test performance. The validity of a number of these tests was Practicality established for patients with cardiac or pulmonary problems,17,32 but little has been done to validate these tests in patients with Full-length FPEs usually require 4 to 6 hours of both the chronic pain. In one study,84 30 patients with CLBP underwent patient’s and the evaluator’s time. Some FPEs divide this time bicycle ergometer testing using the Astrand-Rhyming method. over consecutive days to evaluate the effects of the evaluation of Predicted VO2max was calculated, both by using the nomogram the first day, whereas other FPEs take up to a total of 22 hours and by extrapolating VO2 values obtained by indirect calorime- to perform, divided over multiple days. It has been suggested try. The predicted VO2max values derived from the nomogram that FPEs should shorten the time needed to collect data to were age corrected as suggested by Astrand and Rodahl.5 There meet consumer demand.44 This suggestion seems reasonable; were no significant differences between the nomogram and the length or comprehensiveness of the FPE should be tailored calorimetric predicted VO2max values (p > 0.59) for the sample. to the purpose of the evaluation, and the results of recent stud- Individual predicted values by the nomogram method, however, ies suggest that is quite possible to do so. A shortened version were shown to underestimate predicted VO2max by as much as has been suggested as a screen to filter out those individuals who self-limit their performances due to pain behaviors.68 The need

406 Chapter 9 ● Functional performance testing for a 2-day evaluation for patients with CLBP could not be 3. Astrand I: Aerobic work capacity in men and women with special reference to age. confirmed.61 Most recently, a strategy has been described to Acta Physiol Scand 49:1-92, 1960. develop a job-specific FPE derived from a full-length protocol, reducing evaluation time from 6 to 1.5 hours.22 Additionally, 4. Astrand I, Astrand PO, Rodahl K: Maximal heart rate during work in older men. research is warranted to streamline evaluation batteries to J Appl Physiol 14:562-566, 1959. include only those items that assess necessary activities rather than duplicating items that assess the same or similar activities. It 5. Astrand P, Rodahl K: Textbook of work physiology, physiological bases of exercise, has not been shown that longer FPEs are superior to short FPEs. ed 3. New York, 1986, McGraw-Hill Book Company. Utility 6. Astrand PO: Experimental studies of physical work capacity in relation to sex and age, 23-95. Dissertation. Copenhagen, 1952, Munkgaard. An FPE needs to have utility. There should be a justifiable reason to perform an FPE; otherwise, such a test adds to the 7. Astrand PO, Ryhming I: A nomogram for calculation of aerobic capacity (physical health care burden unnecessarily. To be of value the test must fitness) from pulse rate during submaximal work. J Appl Physiol 7:218, 1954. help the individual, physician, health care personnel, payer, and employer to determine the individual’s physical ability. It 8. Battie MC, Bigos SJ, Fisher LD, et al: A prospective study of the role of cardiovascular should be able to identify an injured worker’s ability to return risk factors and fitness in industrial back pain complaints. Spine 14:141-147, 1989. to his or her usual work or be able to determine a person’s fitness for duty in case of a preemployment assessment. It can 9. Bell NS, Mangione TW, Hemenway D, Amoroso PJ, Jones BH: High injury rates among also be used as a preprogram measure in functional restoration female army trainees: a function of gender? Am J Prev Med 18:141-146, 2000. or work-hardening programs to identify rehabilitation needs and targets and to serve as an outcome measure postprogram. 10. Boadella JM, Sluiter JK, Frings-Dresen MHW: Reliability of upper extremity tests Finally, an FPE should be able to identify persons with symptom measured by the Ergos™ Work Simulator: a pilot study. J Occup Rehabil 13(4): magnification or malingering. 219-232, 2003. CONCLUSION 11. Boyce RW, Jones GR, Hiatt AR: Physical fitness capacity and absenteeism of police officers. J Occup Med 33:1137-1143, 1991. The results of performance-based evaluations of work-related activities are distinctly different from other types of evaluations. 12. Brouwer S, Dijkstra PU, Reneman MF, Groothoff JW, Schellekens JMH, Göeken LNH: They are, however, still not always incorporated into standard- Test-retest reliability of a modified Isernhagen Work Systems functional capacity eval- ized assessment batteries. The reasoning for this is unknown. uation in patients with chronic low back pain. J Occup Rehabil 13(4):207-218, 2003. It is speculated that disadvantages believed to accompany FPEs, one of which being the duration of the evaluation (several 13. Brown SE, Fischer CE, Stansbury DW, Light RW: Reproducibility of VO2max in patients hours), weigh heavily in the decision-making process. FPEs with chronic air-flow obstruction. Am Rev Respir Dis 131:435-438, 1985. may thus be impractical and expensive. Additionally, the psy- chometric properties of FPEs have been critically reviewed in 14. Bruce R, Kusumi F, Hosmer D: Maximal oxygen intake and nomographic assessment the past. The results of these reviews have repeatedly shown that of functional aerobic impairment in cardiovascular disease. Am Heart J 85:546-562, FPEs lack foundation regarding reliability and validity. Recent 1973. scientific developments of some FPEs have been presented here. The results should force the general opinion into a more 15. Cady LD, Bischoff DP, O’Connell ER, Thomas PC, Allan JH: Strength and fitness and optimistic direction. subsequent back injuries in firefighters. J Occup Med 21:269-272, 1979. The strength of assessing the functional domain by means of 16. Cutler RB, Fishbain DA, Steele-Rosomoff R, Rosomoff HL: Relationships between a reliable and valid FPE may be to confirm or refute a patient’s functional capacity measures and baseline psychological measures in chronic pain belief that his or her capacities are insufficient to perform patients. J Occup Rehabil 13(4):249-258, 2003. work. From a cognitive-behavioral perspective, such a belief to be proven false through an FPE is beneficial, because it confronts 17. Demers C, McKelvie RS: Reliability, validity, and responsiveness of the six-minute the patient with maladaptive behaviors and belief systems. The walk test in patients with heart failure. Am Heart J 142:698-703, 2001. effect of such a confrontation may allow for introduction of different, more effective, and efficient interventions directed 18. Fairbank J, Couper J, Davies J, O’Brien J: The Oswestry Low Back Pain Disability toward a safe and lasting return to work. Questionnaire. Physiotherapy 66:271-273, 1980. REFERENCES 19. Fishbain DA, Abdel-Moty E, Cutler RB, Rosomoff HL, Steele-Rosomoff R: Detection of a “faked” strength task effort in volunteers using a computerized exercise testing 1. Abdel-Moty E, Compton R, Steele-Rosomoff R, et al: Process analysis of functional system. Am J Phys Med Rehabil 78:222-227, 1999. capacity assessment. J Back Musculoskel Rehabil 6:223-236, 1996. 20. Fishbain DA, Cutler RB, Rosomoff H, Khalil T, Abdel-Moty E, Steele-Rosomoff R: 2. Ainsworth BE, Haskell WL, Leon AS, et al: Compendium of physical activities: Validity of the dictionary of occupational titles residual functional capacity battery. classification of energy costs of human physical activities. Med Sci Sports Exerc Clin J Pain 15:102-110, 1999. 25:71-80, 1993. 21. Fletcher GF, Balady G, Froelicher VF, Hartley LH, Haskell WL, Pollock ML: Exercise standards: a statement for healthcare professionals from the American Heart Association. Circulation 91:580-615, 1995. 22. Frings-Dresen MHW, Sluiter JK: Development of a job-specific FCE protocol: the work demands of hospital nurses as an example. J Occup Rehabil 13(4):233-248, 2003. 23. Froehlicher V, Thompson A, Davis G, Triebwasser J: Prediction of maximal oxygen consumption: comparison of the Bruce and Balke treadmill protocols. Chest 68:331-336, 1975. 24. Gardener L, McKenna K: Reliability of occupational therapists in determining safe, maximal lifting capacity. Aust Occup Ther J 46:119, 1999. 25. Garrard CS, Emmons C: The reproducibility of the respiratory responses to maximum exercise. Respiration 49:94-100, 1986. 26. Gibson L, Strong J: Expert review of an approach to functional capacity evaluation. Work 19:231-242, 2002. 27. Gross DP, Battie MC: The construct validity of a kinesiophysical functional capacity evaluation administered within a workers’ compensation environment. J Occup Rehabil 13(4):287-295, 2003. 28. Gross DP, Battie MC: The prognostic value of functional capacity evaluation in patients with chronic low back pain. Part 1. Timely return to work. Spine 29(8):914-919, 2004. 29. Gross DP, Battie MC: The prognostic value of functional capacity evaluation in patients with chronic low back pain. Part 2. Sustained recovery. Spine 29(8): 920-924, 2004. 30. Gross DP, Battie MC: Reliability of safe maximum lifting determinations of a functional capacity evaluation. Phys Ther 82:364-371, 2002. 31. Guyatt GH, Pugsley SO, Sullivan MJ, et al: Effect of encouragement on walking test performance. Thorax 39:818-822, 1984. 32. Guyatt GH, Sullivan MJ, Thompson PJ, et al: The 6-minute walk: a new measure of exercise capacity in patients with chronic heart failure. Can Med Assoc J 132: 919-923, 1985. 33. Halpern M: Functional assessment taxonomy relevant to low-back impairments. J Occup Rehabil 11:201-215, 2001. 34. Hermansen L, Ekblom B, Saltin B: Cardiac output during submaximal and maximal treadmill and bicycle exercise. J Appl Physiol 29:82-86, 1970.

Chapter 9 ● References 407 35. Hermansen L, Saltin B: Oxygen uptake during maximal treadmill and bicycle exercise. 62. Reneman MF, Dijkstra SJ, Jorritsma W, Muskee C, Schiphorst Preuper HR, Goeken LN: J Appl Physiol 26:31-37, 1969. Assessment and treatment of chronic work-related pain disorders in an outpatient university rehabilitation setting in The Netherlands. Work 16:23-30, 2001. 36. Hinojosa J, Kramer P: Occupational therapy evaluation of clients: obtaining and interpreting data. Bethesda, MD, 1998, American Occupational Therapy Association. 63. Reneman MF, Jaegers SM, Westmaas M, Goeken LN: The reliability of determining effort level of lifting and carrying in a functional capacity evaluation. Work 18:23-27, 37. Ijmker S, Gerrits EHJ, Reneman MF: Upper lifting performance of healthy young adults 2002. in functional capacity evaluations: a comparison of two protocols. J Occup Rehabil 13(4):297-305, 2003. 64. Reneman MF, Joling CI, Soer EL, Goeken LN: Functional capacity evaluation: ecological validity of three static endurance tests. Work 16:227-234, 2001. 38. Innes E, Straker L: A clinician’s guide to work-related assessments. 1. Purposes and problems. Work 11:183-189, 1998. 65. Reneman MF, Jorritsma W, Dijkstra PU: The relationship between kinesiophobia and performance in a functional capacity evaluation. J Occup Rehabil 13(4):277-285, 39. Innes E, Straker L: Reliability of work-related assessments. Work 13:107-124, 1999. 2003. 40. Innes E, Straker L: Validity of work-related assessments. Work 13:125-152, 1999. 41. Isernhagen SJ, Hart DL, Matheson LM: Reliability of independent observer judgments 66. Reneman MF, Jorritsma W, Schellekens JM, Goeken LN: Concurrent validity of questionnaire and performance-based disability measurements in patients with of level of lift effort in a kinesiophysical functional capacity evaluation. Work 12: chronic nonspecific low back pain. J Occup Rehabil 12:119-129, 2002. 145-150, 1999. 42. Janicki JS, Gupta S, Ferris ST, McElroy PA: Long-term reproducibility of respiratory gas 67. Roland M, Morris R: A study of the natural history of back pain. Part I. Development exchange measurements during exercise in patients with stable cardiac failure. Chest of a reliable and sensitive measure of disability in low-back pain. Spine 8:141-144, 97:12-17, 1990. 1983. 43. Jay MA, Lamb JM, Watson RL, et al: Sensitivity and specificity of the indicators of sin- cere effort of the EPIC lift capacity test on a previously injured population. Spine 68. Ruan CM, Haig AJ, Geisser ME, Yamakawa K, Buchholz RL: Functional capacity 25:1405-1412, 2000. evaluations in persons with spinal disorders: predicting poor outcomes on the 44. King PM, Tuckwell N, Barrett TE: A critical review of functional capacity evaluations. Functional Assessment Screening Test (FAST). J Occup Rehabil 11:119-132, Phys Ther 78:852-866, 1998. 2001. 45. Kopec JA, Esdaile JM, Abrahamowicz M, et al: The Quebec Back Pain Disability Scale: conceptualization and development. J Clin Epidemiol 49:151-161, 1996. 69. Shephard RJ: Tests of maximum oxygen intake: a critical review. Sports Med 46. Lechner DE: Functional capacity evaluation. In PM King, ed: Sourcebook of 1:99-124, 1984. occupational rehabilitation. NY, Springer-Verlag 1998. 47. Lee CE, Simmonds MJ, Novy DM, Jones S: Self-reports and clinician-measured 70. Siconolfi SF, Garber CE, Lasater TM, Carleton RA: A simple, valid step test for estimat- physical function among patients with low back pain: a comparison. Arch Phys Med ing maximal oxygen uptake in epidemiologic studies. Am J Epidemiol 121:382-390, Rehabil 82:227-231, 2001. 1985. 48. Linden V: Absence from work and physical fitness. Br J Ind Med 26:50-53, 1969. 49. Lousberg R, Schmidt AJ, Groenman NH: The relationship between spouse solicitousness 71. Sothmann MS, Saupe K, Jasenof D, Blaney J: Heart rate response of firefighters and pain behavior: searching for more experimental evidence. Pain 51:75-79, 1992. to actual emergencies: implications for cardiorespiratory fitness. J Occup Med 50. Matheson LM, Mooney V, Grant J, Leggett S, Kenny K: Standardized evaluation of 34:797-800, 1992. work capacity. J Back Musculoskel Rehabil 6:249-264, 1996. 51. Matheson LN: Work capacity evaluation for occupational therapists. 1982, 72. Stewart W, Ricci J, Chee E, Lipton R: Work-related cost of pain in the US: results Rehabilitation Institute of Southern California. from the American Productivity Audit. IASP/10th World Congress on Pain, Abstract 52. Matheson LN, Isernhagen SJ, Hart DL: Relationships among lifting ability, grip force, 697-P331, 2002. and return to work. Phys Ther 82:249-256, 2002. 53. Matheson LN, Leggett S, Mooney V, Schneider K, Mayer J: The contribution of aerobic 73. Swinburn CR, Wakefield JM, Jones PW: Performance, ventilation, and oxygen con- fitness and back strength to lift capacity. Spine 27:1208-1212, 2002. sumption in three different types of exercise test in patients with chronic obstructive 54. Mitchell RI, Carmen GM: Results of a multicentre trial using an intensive active lung disease. Thorax 40:581-586, 1985. exercise program for the treatment of acute soft tissue and back injuries. Spine 15:514-521, 1990. 74. Taylor HL, Buskirk E, Henschel A: Maximal oxygen intake as an objective measure 55. Mooney V: Functional capacity evaluation. Orthopedics 25(10):1094-1099, 2002. of cardiorespiratory performance. J Appl Physiol 8:73-80, 1955. 56. Myers J, Voodi L, Umann T, Froelicher VF: A survey of exercise testing: methods, utilization, interpretation, and safety in the VAHCS. J Cardiopulm Rehab 20: 75. Ting W, Wessel J, Brintnell S, Maikala R, Bhambhani Y: Validity of the Baltimore thera- 251-258, 2000. peutic equipment work simulator in the measurement of lifting endurance in healthy 57. Nagi S: Disability concepts revisited: implications for prevention. Disability in men. Am J Occup Ther 55:184-190, 2001. America: toward a new agenda toward prevention. Committee on a National Agenda for the Prevention of Disabilities, Division of Health Promotion and Disease Prevention, 76. Tuckwell NL, Straker L, Barrett TE: Test-retest reliability on nine tasks of the Physical Institute of Medicine. Washington DC, 1991, National Academy Press, pp. 309-327. Work Performance Evaluation. Work 19:243-253, 2002. 58. Peate WF, Lundergan L, Johnson JJ: Fitness self-perception and VO2max in firefighters. J Occup Environ Med 44:546-550, 2002. 77. van Dieen JH, Hoozemans MJ, Toussaint HM: Stoop or squat: a review of biomechanical 59. Pohjonen T: Age-related physical fitness and the predictive values of fitness tests for studies on lifting technique. Clin Biomech 14:696, 1999. work ability in home care work. J Occup Environ Med 43:723-730, 2001. 60. Putz-Anderson V, Bernard BP, Burt SE, et al: Musculoskeletal disorders (MSDs) and 78. Verbunt JA, Westerterp KR, van der Heijden GJ, Seelen HA, Vlaeyen JW, Knottnerus JA: workplace factors: a critical review of epidemiologic evidence for work-related Physical activity in daily life in patients with chronic low back pain. Arch Phys Med musculoskeletal disorders of the neck, upper extremity, and low back, DHHS Rehabil 82:726-730, 2001. (NIOSH) Publication No. 97-141. Cincinnati, OH, 1997, U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and 79. Vlaeyen JW, Linton SJ: Fear-avoidance and its consequences in chronic Prevention, National Institute for Occupational Safety and Health. musculoskeletal pain: a state of the art. Pain 85:317-332, 2000. 61. Reneman MF, Dijkstra PU, Westmaas M, Goeken LN: Test-retest reliability of lifting and carrying in a 2-day functional capacity evaluation. J Occup Rehabil 12:269-275, 2002. 80. Watson PJ: Non-physiological determinants of physical performance in musculoskeletal pain. In M Max, ed: Pain 1999—an updated review, ed 1. Refresher course syllabus. Seattle, 1999, IASP Press, pp. 153-158. 81. Wittink H, Michel TH, Kulich R, et al: Aerobic fitness testing in patients with chronic low back pain: which test is best? Spine 25:1704-1710, 2000. 82. Wittink H, Rogers W, Gascon C, Sukiennik A, Cynn D, Carr DB: Relative contribution of mental health and exercise-related pain increment to treadmill test intolerance in patients with chronic low back pain. Spine 26:2368-2374, 2001. 83. Wittink H, Rogers W, Sukiennik A, Carr DB: Physical functioning: self-report and performance measures are related but distinct. Spine 28(20):2407-2413, 2003. 84. Wittink HM: Physical fitness, function and physical therapy in patients with pain: clinical measures of aerobic fitness and performance in patients with chronic low back pain In M Max, ed: Pain 1999—an updated review, ed 1. Refresher course syllabus. Seattle, 1999, IASP Press, pp. 137-145.

10C H A P T E R The Physician’s Role in Disability Evaluation Robert H. Haralson III Throughout history most social systems have been forced to deal not even been the subject of significant research. To some extent, with the problems of a population containing individuals who therefore, physicians asked to perform this task must do so based have been injured, who are suffering from chronic disease, or on personal opinion, great variability in experience, and usually who simply through aging have a reduced ability to perform the poorly thought out legislation or social contracts. daily activities required for survival both at work and at home. In nonindustrialized societies, the physical disabilities associated ETHICS ASSOCIATED WITH DISABILITY with aging are often perceived as being accompanied by increased EVALUATION wisdom and experience. Older members of these societies thus become the teachers and decision makers for the communities. Physicians required to determine a degree of impairment and the Those individuals with minor restrictions in ability are given tasks ability or inability of an individual to perform specific tasks must around the home in the preparation of tools or food and the care deal with a number of ethical dilemmas not commonly consid- of children. Because of a lack of medical and health resources, the ered in clinical practice. In comparison with disability evalua- severely disabled inevitably succumb to infection or malnutrition tion, basic clinical practice is relatively simple. Most physicians and, occasionally in certain societies, some form of ritual suicide. perceive their ethical duties as to care for and to relieve patient symptoms or illnesses by whatever means they can, without any In modern industrialized nations, on the other hand, those consideration of the social position of their patients or the pres- individuals who are disabled have access to a wide variety of sures exerted from outside authorities. The welfare of the patient health care facilities and social resources that attempt to reinte- is inherent in the Hippocratic Oath. The contract for services is grate them into the community. To avoid abuse of these benefits, between the doctor and the patient. mechanisms have been developed to assess degrees of disability and assign responsibility for its cause. Rapid growth in the cost of When a physician is required to change roles and issue opin- these benefits has led to an increasing emphasis on the effects of ions on legal matters, one of two things happens. If their opinions chronic illness and injury on life-style and work capacity. will impact their own patients’ ability to obtain compensation or Extensive legislation has established rules for the provision of to work in particular occupations, physicians naturally are biased benefits to those unfortunate enough to have reduced capacity as in favor of each patient’s position in the matter. Failure to take a a result of chronic illness or injury. Such legislation includes patient’s position could seriously jeopardize the patient-doctor workers’ compensation,30 Social Security,35 and the Americans relationship and adversely impact the ability to manage the with Disabilities Act. Furthermore, multiple private and industrial patient’s health care needs. On the other hand, an inability to jus- programs and insurance policies have been established to assist tify a particular position that the patient may hold strongly can individuals who are ill, injured, or otherwise disabled. seriously jeopardize the physician’s credibility within a workers’ compensation or other health care delivery system. Studies by In almost every determination of disability or ability, legisla- Brand and Lehmann8 demonstrate that many treating orthope- tion or private contract requires the input of at least one and often dists are willing to exaggerate a situation to benefit the patient’s several licensed health care practitioners. The basic assumption is position in third-party actions. that the individual who is most competent and best trained to determine the ability of other members of society to perform If physicians are functioning as independent medical examiners, specific duties is the medical physician. This decision has been their ethics are subject to pressure from the referring source. based not on any well thought out or scientifically investigated Inevitably an independent medical examiner receives a referral competence but instead has fallen on the physician by default. because of disagreement between the insurance carrier or agency Unfortunately, the skills necessary to perform this social function and the patient or treating physician. Regardless of the honesty are not as a rule taught in medical school and until recently have

410 Chapter 10 ● The physician’s role in disability evaluation of the independent medical examiner, insurance carriers tend to status, the point at which administrative rules concerning disabil- refer insured persons to physicians with track records who are ity begin to take effect. It is virtually impossible for an accurate likely to support their positions. Further difficulty arises in that permanent disability evaluation to be made before declaration of patients tend to distrust independent medical examiners and the point of maximum medical benefit. Within some jurisdic- may attempt to justify their perceived positions through embel- tions with a time limit, however, it is occasionally necessary to lishment and other forms of exaggerated behavior. Although the render an opinion before maximum medical improvement is criteria of Waddell and associates37 can be used to identify cer- reached. In those situations, commonly involving an arthritic tain of these factors, the assessing physician may lose sympathy joint that will ultimately lead to total replacement, the physician for such an individual regardless of an underlying disability that should state the disability at that time but indicate that improve- may be camouflaged by this behavior. Physicians must be care- ment or worsening is possible. In some cases the physician may ful to remember that some patients who exaggerate can also have include an estimate of future impairment. real pathology. In our system, patients are paid to be sick, and the sicker they are, the more they are paid. Patients who learn to Although there is no universal rule, it is reasonable to assume act sick cannot get well.18 In that situation, it is a natural human that the time of maximum medical benefit or permanent and sta- response to advocate for one’s position. tionary status is the point at which the patient has shown no sig- nificant change for a number of weeks and it is unlikely that future Hadler17,19 seriously questioned the ethics of any physician who medical treatment will improve the medical status or level of dis- performs disability evaluations, arguing that the notion of impair- ability. The American Medical Association (AMA) guides2 define ment rating is fatally flawed and should be discarded completely. maximum medical improvement as the time from which the patient He believes that diminished work capacity as a result of muscu- is unlikely to experience significant improvement within 1 year. loskeletal disorders, the most common cause of disputed disability, is overwhelmed by psychologic and sociopolitical confounders and Residual subjective complaints cannot be determined in the medical setting. The marked variation in medical opinion as to the nature and extent of disability given Once it is determined that the patient has reached permanent similar clinical findings tends to support this view. Further support and stationary status, most agencies request a statement regard- comes from the work of Waddell et al,36 Bigos et al,5,6 and Deyo ing the ongoing symptoms. The discussion of subjective com- and Diehl,14 which demonstrates that the greatest predictors of dis- plaints includes a list of the specific body parts or functions that ability from low back pain are psychosocial rather than pathophys- are affected and the manner in which they compromise the iologic. Other studies demonstrated that by far most factors patient’s functional ability in both work and recreation. This can predicting return to work are psychosocial rather than physical. often be obtained by simply asking the patient to list all symp- toms and discuss how they affect all activities. It is useful to note Treating physicians, most of whom have not had specific how patients perceive not only their disabilities but also what training in impairment evaluations, are least prepared to render they consider to be their abilities for specific functions. objective ones. Data show that surgeons who perform large numbers of cardiovascular operations and total joint replace- Residual objective findings ments achieve better outcomes; data suggest also that physicians who perform large numbers of independent medical evaluations Inevitably, the physician is asked to list the abnormalities found are more accurate and consistent. Training and practice improve on physical examination as well as any and all abnormal labora- outcomes in impairment evaluations just as they do in surgical tory and imaging findings. In certain disability evaluation sys- procedures. Just as patient treatment relies on scientific rather tems such as Social Security, a simple listing of the objective than anecdotal data, so-called evidenced-based medicine applied findings is all that is necessary.10 Other systems, such as the AMA to impairment or return-to-work determinations results in opin- guides,2 require not only lists of objective findings but also sever- ions that are fairer to the employee, employer, and insurer. ity classifications of loss of range of motion (ROM), sensation, strength, or coordination. MEDICAL OPINIONS REQUIRED DURING DISABILITY EVALUATION Another decision often required in this setting is a statement as to whether the subjective complaints are consistent with and The physician faced with a demand for a disability evaluation confirmed by the objective findings. Signs of nonorganic clini- must reach a number of conclusions and provide opinions on cal patterns, such as those developed by Waddell et al37 for low the topics explained on the next few pages. Not all disability back pain, may be requested by name or by insinuation. schemes require that the physician address each issue. Furthermore, specific requirements or definitions inherent in the Diagnosis administrative procedure of a specific disability system might not be included in this outline. Date of permanent and stationary status Although many disability evaluation systems require a diagnosis, it shows little correlation with the amount of impairment and, Either a treating or an assessing physician must determine the point for that matter, disability. Many workers function quite well of maximum medical improvement or permanent and stationary with significant impairments, including amputations of upper and lower extremities, whereas others are totally disabled by less

Chapter 10 ● Medical opinions required during disability evaluation 411 significant impairments. Disability is more closely tied to psy- employees back to work early for fear that the requirements chosocial issues than to diagnosis. With regard to the spine, might cause the condition to recur or delay the recovery; physicians should remember that in the absence of obvious employers fear that it will lead to another claim. Data show that radiculopathy, examination of a patient with acute neck or back the chances of significant recurrent injury after an episode of pain rarely identifies the pain generator or yields a specific diag- acute low back pain are in the range of 1.7 times the incidence nosis. A diagnosis of back sprain implies tearing of ligaments, a in workers with no previous back pain. The incidence of back condition that probably rarely exists. Examiners are encouraged injury claims in the normal population is 3 per 100 workers, so to use more generic terms such as back pain or lumbago. that of recurrent claims in workers with previous back injuries is 5.1 per 100, an increase of 2 per 100. The cost of these additional Making a specific diagnosis in an extremity is usually much claims is miniscule compared with that of leaving all 100 workers easier than in the spine, but even here “pain only” syndromes off work for extended periods of time.36 Data on return to work can be a problem. The examiner should follow the International after myocardial infarction are similar.22 Classification of Diseases coding rules and diagnose only to the point at which the specificity is certain.24 The main determinant of an employee’s decision to return to work is tolerance of mild discomfort and inconvenience. Are the Return-to-work determinations rewards greater for returning to work than for being absent? Some employees fear returning to work; many know of an Determining when a patient should return to work is now one of acquaintance who is chronically disabled by back pain. Many the most controversial requirements of treating and evaluating employees need convincing that by benefiting their health and physicians. It has been commonplace for physicians to take well-being, return to work is in their best interest, as proven by workers off work for extended periods of time for conditions that numerous studies.23 Although the pursuit of pain relief decreases should not prevent some kind of work activity. Mounting evi- function and increases pain, the pursuit of increased function dence shows that the longer a patient is off work for whatever decreases pain. reason, the less likely that he or she will ever return. Several stud- ies demonstrated significant increases in morbidity and mortal- One difficulty in this setting is to differentiate the capabilities ity in people who are no longer working.16 Very few conditions of a normal healthy person of similar age, sex, education, and would in and of themselves prevent a worker from being at work. body build. These can often be inferred by National Institute for One is coma; another is lower extremity injures in which the use Occupational Safety and Health or other standards.31 It then of ambulatory aids is precluded by concomitant upper extremity becomes necessary to determine how a particular individual injuries. It has been stated that if an employee can commute and being evaluated differs from normal and how this variance be at work, there is no reason for absence.34 Data indicate that in affects the ability to do specific work. Nowhere in medical or the long run it is less expensive for the employer to have an even in specialty training does this determination approach a sci- employee at work doing nothing than for the employee to stay ence, but two references give some reasonable guidelines for at home where deconditioning continues; if the employee can return to work: the Official Disability Guidelines13 is categorized by actually do meaningful work or even attend rehabilitation, the diagnosis and The Medical Disability Advisor32 is categorized by rewards are even greater. With proper accommodations, early diagnosis and procedure. A study by Buchbinder et al9 showed return to work should be the norm, but many companies still do that merely educating patients about how returning to work was not have programs to allow it. This is especially true of the most in their best interest significantly reduced their time off. common condition to cause loss of work, acute back pain.15 Work and activity ability Return-to-work decisions are based on three concepts: capac- ity, risk, and tolerance. Capacity is what a patient can do at a par- In addition to determining if and when an employee may return ticular time. Very few people function at full capacity, which can to work, physicians are often asked to prescribe activity limita- be increased by conditioning and training. It is therefore current tions. The Occupational Safety and Health Administration guide- ability that is being assessed, a difficult task because it requires lines are very restrictive and do not reflect the science. Bigos,4 the the cooperation of the patient. The standard method is func- lead author of the AHCPR (Agency for Health Care Policy and tional capacity evaluation, implying that one can assess the job Research) clinical practice guidelines for low back problems in requirements, perform a functional capacity evaluation, and adults, indicated that government personnel changed the physicians’ match the two. It has not been shown, however, that functional recommendations regarding weight restrictions. Mounting evidence capacity evaluations are valid for assessing abilities with regard to indicates that the restrictions physicians habitually place on workers low back pain, for example. Functional capacity evaluations are are overstated.11 With respect to acute low back pain, Malmivaara more useful in limited situations: jobs involving only simple et al27 wrote the “Activity Paradigm,” the principle of which is to motions by the extremities where testing simulates the require- return to activity as normal as possible as soon as possible. Although ments and infrequent near maximal lifting where isometric some other conditions obviously require temporary limitations of strength approximates. Although many rating physicians still use activities, workers should be reintroduced to the work force as early functional capacity evaluations in any situation because they are as possible and to normal activity if at all possible. This is benefi- helpful to corroborate clinical impressions, results must be inter- cial for their physical rehabilitation as well as for their psyches. preted in the context of their lack of proven scientific validity. There is little evidence, for instance, that patients need restric- Risk of reinjury or worsening of a condition greatly concerns tions after recovering from episodes of acute back pain. Although physicians and employers. Physicians are reluctant to send the most common restriction is lifting, little evidence has shown

412 Chapter 10 ● The physician’s role in disability evaluation that lifting in and of itself causes back pain. Most back injuries, impairment rating before the injury in question, accurate appor- in fact, are associated with light loads. Studies do not show that tionment is very difficult, if not impossible. lifting follows the dose-response curve in which the more one lifts, the more it hurts. When proper lifting techniques are used If the physician can reconstruct an impairment scenario that and the load lifted does not correlate with injury, twisting during existed before the present condition, however, apportionment lifting is more likely to aggravate back pain. may be possible. If a worker previously had a lumbar radiculopa- thy treated with surgery that relieved pain, for instance, then he Causation or she would be rated as a lumbar category III and at a 10% impairment. If radiculopathy recurred in the same spinal area, Although causation is more a legal doctrine than a medical one, whether or not the condition required surgery, the worker would examining physicians are often asked to render their opinions. In now be rated by the ROM method. Subtracting the 10% cate- medical school we are taught to take a history from the patient and gory III rating from the ROM rating would allow the rater to to rely on it when forming opinions. When a patient indicates that apportion the remainder to the new injury.2 Though the two a pain started at a certain time and in association with a certain methods of rating are not totally compatible, this is one way of activity, it is not the examiner’s duty to investigate whether he or estimating apportionment. she is telling the truth. Physicians are asked to judge if the injury described by the patient could have reasonably caused the condi- Ongoing and future medical tion. In many extremity injuries, objective findings on physical care requirements examination and imaging studies make the etiology obvious, but if the claimant complains of back pain or one of the other pain- At times physicians are asked to estimate future medical costs, a only conditions like carpal tunnel syndrome or lateral epicondyli- very difficult task because costs include not only physician fees tis, deciding causation is more difficult. Back pain is ubiquitous: but also hospital charges, which can be variable and are usually About 80% of humans experience it at some time during their significantly higher. In addition, predictions about future med- lives. Degenerative disk disease is present in essentially every ical care are inexact because of the variation in the type of treat- human after age 50. Thirty percent of magnetic resonance images ments suggested by different physicians. The care of back pain is in patients with no back pain are read as positive for ruptured a prime example. The incidence of back surgery in different parts disk.7 Identical twin studies have shown no difference in the of the country varies significantly, and the inference is that some amount of degenerative disk disease in hard-working and seden- physicians are more likely than others to opt for surgical treat- tary twins, suggesting that it is mostly hereditary.3 It is therefore ment. Like return to work after a back injury, future medical care difficult to attribute much of the back pain we see to industrial of back pain, moreover, is steeped with psychosocial issues. injuries, but in today’s legal climate if a worker states his or her Predicting the rate at which damaged joints will lead to total back pain started on the job, it is assumed to be compensable replacement is inexact also, because psychosocial issues may unless proved otherwise. Although we do have scientific infor- influence the treatment chosen. Despite the difficulties, physi- mation on injury response, it is difficult to attribute back pain to cians must make estimates in some cases and should reflect the a particular injury when the onset of pain was more than 24 to inaccuracy of such endeavors in their reports. 48 hours afterward. In addition, there is mounting scientific evi- dence that carpal tunnel syndrome is rarely entirely secondary to PRINCIPLES OF IMPAIRMENT work tasks.12 DETERMINATION Apportionment The workers’ compensation system is administered by each state, each of which requires use of its own method of evaluating per- Physicians are often asked to render an opinion as to how much manent impairment. The standard text for determining perma- impairment is due to a particular injury and how much was pre- nent impairment is the AMA Guides to the Evaluation of Permanent existing, because the legal and insurance industries assume they Impairment,2 which is required or recommended by some 40 states. are trained to do so. Unless an impairment evaluation has Some states name a specified edition, whereas others require the occurred before the injury in question, however, this is a very dif- use of the “most current” version: Texas, for instance, recently ficult task. In fact, it is mostly guesswork on the part of the exam- switched from the third to the fourth edition, and in 2004 ining physician, one that may not be appropriate. Sometimes the California began using the fifth edition. Some states have a physician should decline to offer an opinion and state that it is hybrid system; for instance, West Virginia uses the fifth edition medically impossible to apportion. This is true especially in a but will not allow use of the ROM system to evaluate spinal dis- claimant with a work-related back injury, preexisting degenera- orders. A few states have developed their own unique systems, tive disk disease, and previous episodes of back pain not associ- and at least one state allows the physician to use any method he ated with work or in one who has had multiple work-related back or she wishes. injuries. In the absence of any objective changes in anatomic structures that are caused by the injury in question, the only dif- The AMA guides are just that, not an authority engraved in ference is the amount of pain the claimant is experiencing, which stone. Some conditions such as shoulder disorders are not cov- cannot be quantified or qualified. In the absence of a formal ered well. A patient with a rotator cuff tear that was successfully repaired with a full ROM probably has some residual impair- ment but would be classified as not impaired according to the

Chapter 10 ● Using the AMA guides for rating impairment 413 ROM method. It is therefore permissible to depart from the rating to determine disability and monetary award, the AMA AMA guides if the reasons are set out in the report. Another guides suggest that this is inappropriate. example is cervical category IV, where a patient with an arthrode- sis of one level for radiculopathy is assigned at least 25% impair- The AMA guides attempt to provide a method of rating ment when in fact this standard treatment for disk pathology in impairments that allows multiple physicians to arrive at similar the cervical spine seldom results in much disability. ratings. Response to treatment and several of the Waddell signs are examples. Physicians performing impairment ratings using The question of who should perform the evaluation is contro- the AMA guides must thoroughly understand the entire text, versial. Some believe that it should be the treating physician who especially Chapters 1 and 2. It is insufficient merely to turn to a should know the most about the examinee. Data suggest, how- picture of an anatomic part and read an impairment rating from ever, that an independent physician who has never treated the the adjacent chart or table. There may be several appropriate patient is more objective.20 Physicians are taught in medical ways to rate a patient, and the rater must decide which one is school to advocate for their patients, a precondition for good most accurate for the particular case. doctor-patient relationships. This requirement places the treating physician in a difficult position, especially if the outcome of Differences between the fourth treatment has been less than satisfactory. and fifth editions Although activity is very complicated and often not intuitive, There are several differences between the fourth and fifth few physicians have had any formal training in impairment eval- editions of the AMA guides. The biggest difference in the spine uation. Such an evaluation does, however, require the skill of a section is that in the fourth edition, the impairment was calcu- physician who is performing a complete and accurate history lated for the injury, not for the result of treatment. This meant and physical examination and interpreting objective and subjec- that findings that occurred any time during the patient’s course tive findings. Physicians must learn to objectify subjective find- were enough to place a patient in a category and the results of ings.21 Patients in the workers’ compensation setting tend to treatment made no difference. In the fifth edition, treatment is exaggerate their symptoms, a natural human response to a system considered, and to be significant, findings must be present at the in which the payment level corresponds to that of an illness. The time of the examination. In addition, in the fourth edition there examining physician must be adept at sorting out contradictory was no way in the diagnosis-related estimate (DRE) method to findings so that the impairment evaluation is fair to all parties. consider arthrodesis, but in the fifth edition it is included in the Over-interpretation of subjective findings may lead to an inordi- definition of loss of structural integrity. Finally, the ratings in the nately high rating, but care must be taken not to underrate only DRE method include a 3% range: The physician is allowed to because a few nonphysiologic signs are present. Some claimants increase the rating up to 3% if there are ongoing objective signs who have learned to exaggerate as part of illness behavior may of continuing problems. The rating should not be increased only have real pathology. because of a pain complaint. The differences between the fourth and fifth editions with respect to the upper and lower extremities It is incumbent on all evaluating physicians to become adept are minimal. A very helpful addition to the lower extremity in impairment evaluations; several training alternatives are avail- section is the matrix on page 526 that assists in the decision as to able. The American Academy of Disability Evaluating Physicians1 when to combine the different methods of evaluating the lower holds several courses on impairment evaluations per year through- extremity. out the country, as does the American Board of Independent Medical Examiners; both organizations offer a certifying exami- Pain nation. Several specialty societies have begun to include impair- ment evaluation on their curricula, and a number of states Chapter 1 of the AMA guides states that “physicians recognize the require continuing medical education in evaluations to be able local and distant pain that normally accompanies many disorders. to perform them. These states either provide the continuing Impairment ratings in the AMA guides already have accounted for medical education themselves or arrange with one of several commonly associated pain, including that which may be experi- organizations to teach the subject. enced in areas distant to the specific site of pathology.”2 Because a 3% range is already included in the spine DRE ratings, Robinson USING THE AMA GUIDES FOR RATING et al33 argued that it is never appropriate to “double dip” and add IMPAIRMENT ratings for pain to ratings in the spine chapter. On the other hand, if an examinee has pain defined as “ratable” according to the AMA Because the use of the AMA guides is required or suggested in guides, then one can use the pain chapter (Chapter 18) to award most states and may serve as a template in jurisdictions that do not up to an additional 3% impairment. require its use, and because the musculoskeletal system is the most commonly used section, it is appropriate in this text to have a brief Spine impairments discussion of some of its principles. Physicians must understand the difference between impairment and disability. Impairment is In both editions, the DRE is the method required to rate all defined as loss of function of a body part. Disability includes patients who have sustained an injury to the spine, except for a impairment, motivation, education, socioeconomic status, and several other parameters that are difficult to measure. The AMA guides rate impairment, not disability. Although some jurisdic- tions use a mathematical formula that includes the impairment

414 Chapter 10 ● The physician’s role in disability evaluation few conditions in the fifth edition for which the ROM method is be combined with other methods of assessing impairment in the used. In most cases, disk pathology is assumed to be secondary to upper extremity. an injury. For cases of recurrent radiculopathy in the same spinal area, fractures at multiple levels in the area, or multilevel loss of Normally only one method is used, but if more than one accu- structural integrity (multilevel spinal arthrodesis), the ROM rate method is available to assess impairment, it may be appropri- method is used. This practice has led to inordinately high ratings ate to use them all and award the highest value. Occasionally, for patients who have undergone one-level diskectomy and methods are appropriately combined when the impairment is not fusion for disk pathology in the cervical spine. Recurrent injuries adequately estimated by one. An example would be a distal elbow not involving radiculopathy should not be rated by the ROM fracture that injured the ulnar nerve. The elbow injury would method. If it is followed, the AMA guides require the use of an appropriately be rated by ROM measurements, but these would inclinometer rather than a goniometer for measuring the motion. not include residual impairment from the ulnar nerve injury, The rating physician should be aware that the ROM method which would require the use of the peripheral nerve ratings. Total requires the inclusion of all three of its components: ROM upper extremity rating would then be calculated by combining (Table 15-7) and any neurologic component from Tables 15-17 the two. Values for fingers should be converted to the hand, the or 15-18 if appropriate. These ratings are combined using the hand to the upper extremity, and the upper extremity to the body Combined Values Tables at the back of the book. Controversy as a whole using Tables 16-1 to 16-3. exists about the accuracy of spinal ROM measurements and the relationship of loss of ROM to impairment and/or disabil- Carpal tunnel syndrome rating uses the neurologic method. ity, but at this time the ROM method is still used in certain Sensory and motor deficits are determined and graded using default conditions.25,26,28-29 Tables 16-10 and 16-11, although the two-point discrimination method or the Semms-Weinstein monofilaments may help the Spinal injuries that involve injuries to the spinal cord or evaluator grade the sensory component. Grading motor loss usu- cauda equina are rated using Table 15-6, which combines seven ally does not require formal strength testing but may be helpful tables from the neurologic chapter. Values from each table are in verifying the validity of the examination. combined with each other and then that value is combined with a rating from DRE categories II through V. The rating from the Evaluating physicians are strongly encouraged to use the DRE method awards impairment for the local condition (frac- charts on pages 436 and 437. These charts guide the user through ture or radiculopathy), whereas Table 15-6 does so for the cord the complicated upper extremity process and give specific damage. instructions about adding versus combining values. Upper extremity impairments Lower extremity impairments The function of most of the upper extremity is to move the hand Unlike the upper extremity, the function of the lower extremity in a position to perform a task. As a result, ROM measurements is to provide a stable platform for standing or ambulation. are of paramount importance; a reasonable way to assess impair- Though important, ROM is therefore less so than in the upper ment; and the mainstay of rating the shoulder, elbow, and wrist. extremity, so several other assessment methods are available. The hand itself is rated by combining values for amputation, sen- Table 17-2 is a guide to when these methods should or should not sory deficits (based on the two-point discrimination method), be combined. Strength loss, muscle atrophy, and gait derange- and loss of motion. Because there is usually no motor loss in ment are usually used when there is no other good way to rate hand injuries below the wrist, strength measurements are seldom the patient. Limb length discrepancy, on the other hand, may be necessary. combined with several other methods. In some situations, loss of ROM is the best way to assess impairment even in the lower Nerve injuries are rated by estimating the magnitude of sen- extremity. Impairments for loss of motion in each direction are sory and motor deficits using the appropriate tables and then added in each joint. For instance, impairment in the hip would multiplying that figure by the maximum loss for each named be calculated by adding impairments for all six motions. nerve, branch of the cervical plexus, or nerve root. Vascular deficits are rated using a specific table. A number of “other” con- The impairment for complete ankylosis of a joint is calculated ditions such as synovial hypertrophy, joint malalignment, and by assessing impairment for ankylosis in optimum position and joint instability are rated by estimating the magnitude of the par- then adding impairments for malposition, if present. In the hip, ticular problem using Tables 16-9 through 16-24 and multiplying for instance, this would mean a possible addition of five more by the maximum value for each particular joint from Table 16-18. estimates (there are no tables for ankylosis in extension). The sum Recurrent dislocation of the shoulder has its own table in which total of all impairments in a badly deformed hip may be more rating is based on frequency. than 100%, in which case the whole person impairment is the 40% assigned to the lower extremity because the extremity impair- If there is no other method to assess impairment of the upper ment cannot be more than 100% of a part. A rating method extremity accurately, one may use loss of strength. Tables in the unique to the lower extremity is that for narrowing of a joint sec- AMA guides estimate normal grip strength by occupation and ondary to arthritis: To calculate impairment, narrowing on x-ray age as well as by normal pinch strength. By subtracting the examination is compared with standard measurements for nor- patient’s strength from the “normal” strength and dividing by mal joint space. the “normal” strength, one calculates the loss of strength index. Table 16-34 then estimates impairment. This method should not The AMA guides contains a large section of diagnosis-based estimates, including total joints, malaligned fractures, and liga- mentous instabilities. Total joints are rated based on a point

Chapter 10 ● References 415 system that reflects the function of each. Total ankles have not decision whether to award a monetary settlement to the claimant. been addressed. Meniscal pathology is rated depending on the The adjudicatory process involves either an administrative law treatment. Partial excision is rated less than total. Because it was judge or a jury. In addition, many times the evaluating physician not common at the time the fifth edition was published, meniscal is required to give a deposition or even testify in court. Because transplant is not mentioned but is now receiving more attention. close adherence to the AMA guides increases the likelihood that Most patients have some narrowing of the joint, and in these the rating will be given weight, it is important to use the prepared situations combining values for the narrowing and for partial report charts, especially in the upper extremity. meniscectomy seems appropriate. The administrative system believes that physicians have all the Peripheral nerve injuries are rated similarly to those in the answers when it comes to impairment, apportionment, and causa- upper extremity, with Tables 16-10 and 16-11 being used to grade tion, and obviously this is not true. In doubtful cases, the physician the deficits. Skin loss in the lower extremity can cause significant should not attempt to make estimates or statements that are not impairment in certain locations such as the ischial tuberosity and justifiable. Apportioning in a patient who never had an impairment the bottom of the foot, and there are methods for rating for those rating before an injury may be impossible, and again this may be conditions. As in the upper extremity, vascular lesions are rated more of an administrative decision than a medical one. The inde- by a separate table. pendent physician should remain neutral and advocate neither for the patient nor for the insurance company or attorney. Fair and ADMINISTRATIVE CONSIDERATIONS accurate impairment ratings are as much an obligation to physi- cians as treatment itself, and we as independent physicians must The final decision about whether an individual is eligible for be as diligent in performing them as we are in caring for patients. benefits under a disability system is in all cases either legal or administrative. Physicians performing disability evaluation must REFERENCES recognize that they are simply providing information and opin- ions upon which administrative or legal decisions can be made; 1. American Academy of Disability Evaluating Physicians: www.aadep.org. it is not unusual for medical perception of the amount of impair- 2. American Medical Association: Guides to the evaluation of permanent impairment, ment to translate financially into either considerably more or less disability. Each piece of legislation concerning disability and ed 5. Chicago, 2001, The Association. every administrative policy or contract includes very complex 3. Battié MC, Videman T, Gibbons LE, Fisher LD, Manninen H, Gill K: Determination methods of translating a physician’s medical report into specific numbers used to distribute benefits. The Social Security system of lumbar disc degeneration: a study relating lifetime exposure and magnetic and many disability policies, for example, are all-or-none deci- resonance imaging studies in identical twins. Spine 20(24):2601-2612, 1995. sions: An individual is declared either disabled or capable of 4. Bigos S: Personal communication. returning to work. 5. Bigos SJ, Battié MC, Spengler DM, et al: A longitudinal study of work perceptions and psychosocial factors affecting the report of back injury. Spine 16:1-6, 1991. CONCLUSION 6. Bigos SJ, Spengler DM, Martin NA, et al: Back injuries in industry: a retrospective study. III. Employee-related factors. Spine 11:252-256, 1986. Rating physical impairment of the musculoskeletal system is an 7. Boden SD, Davis DO, Dina TS, et al: Abnormal magnetic-resonance imaging of the entrenched part of the workers’ compensation system in the lumbar spine in asymptomatic individuals. J Bone Joint Surg Am 72:403-408, 1990. United States as well as in many other third-party conflicts. 8. Brand RA, Lehmann TR: Low-back impairment rating practices of orthopedic sur- Assessing impairment and disability is an inexact science at best. geons. Spine 8:75-78, 1983. Because many findings require interpretation and the evaluator 9. Buchbinder R, Jolley D, Wyatt M: Effect of media campaign on back pain beliefs must differentiate between those that are objective, subjective, or and its potential influence on management of low back pain in general practice. subjective but able to be “objectified,” assessment requires the Spine 26:2535-2542, 2001. knowledge, expertise, and skill of a physician. Because impair- 10. Carey TS, Hadler NM, Gillings D, et al: Medical disability assessment of the back pain ment evaluation is rarely taught in medical school or residency, patient for the Social Security Administration: the weighting of presenting clinical it is unfortunately incumbent on the evaluator to undergo the features. J Clin Epidemiol 41:691-697, 1988. necessary training. It is unfair to all stakeholders not to provide 11. Carragee EJ, Helms E, O’Sullivan GS: Are postoperative activity restrictions a fair and accurate rating. necessary after posterior lumbar discectomy? A prospective study of outcomes in 50 consecutive cases. Spine 21(16):1893-1897, 1996. The AMA guides attempt to provide a method whereby sev- 12. Carrico HL: Virginia declares carpal tunnel not a job injury. Occup Health Manage eral physicians can come to similar conclusions using the same July:79-80, 1996. facts. Unfortunately, this is frequently not the case, because 13. Denniston P, ed: Official disability guidelines 2001, ed 6. Corpus Christi, TX, 2001, many impairment ratings are done by physicians who do not Work Loss Data Institute. bother to understand the entire volume and the multiple ways in 14. Deyo RA, Diehl AK: Psychosocial predictors of disability in patients with low back which a patient can be evaluated. Obviously, these physicians see pain. J Rheumatol 15:1557-1564, 1988. a picture of the anatomic part to be rated and never stray from 15. Feldman JB: The prevention of occupational low back pain disability: Evidenced-based that page. Physicians are also at cross-purposes with attorneys. reviews point in a new direction. J Surg Orthop Adv 13(1):1-13, 2004. The evaluating physician must remember that the impairment 16. Gerdtham U, Johannesson M: A note on the effect of unemployment on mortality. rating is only one part of an administrative process resulting in a J Health Econ 22:505-518, 2003. 17. Hadler NM: Backache and humanism. In J Frymoyer, ed: The adult spine: principles and practice. New York, 1991, Raven Press. 18. Hadler NM: If you have to prove you are ill, you can’t get well: the object lesson of fibromyalgia. Spine 21:2397-2400, 1996. 19. Hadler NM: Insurance against work incapacity from spinal disorders. In J Frymoyer, ed: The adult spine: principles and practice. New York, 1991, Raven Press. 20. Hales RE, Yudofsky SC: The American Psychiatric Publishing textbook of clinical psychiatry, ed 4. 2002, American Psychiatric Publishing. 21. Haralson RH, Brigham CR: Objectifying the spinal impairment examination: fifth edition approaches. The guides newsletter, Nov/Dec 2001, American Medical Association. 22. Hurst W: The Heart, ed 9. New York, 1998, McGraw-Hill.

416 Chapter 10 ● The physician’s role in disability evaluation 23. Indahl A, Haldorsen EH, Reikeras O, Ursin H: Five year follow-up of a controlled 30. Minnesota Medical Association: Worker’s compensation permanent partial disability clinical trial using light mobilization and an informative approach to low back pain. schedule. Minneapolis, 1984, The Association. Spine 1(23):2625, 1998. 31. National Institute for Occupational Safety and Health: A work practice guide for 24. International classification of diseases, ed 9 revision, clinical modification. Los manual lifting. Report 81-122. Cincinnati, OH, 1981, U.S. Department of Health and Angeles, 2004, Practice Management Information Corporation. Human Services. 25. Keeley J, Mayer TG, Cox R, Gatchel RJ, Smith J, Mooney V, et al.: Quantification of 32. Reed P: The medical disability advisor, ed 4. Boulder, CO, 2001, Reed Group. lumbar function. Part 5. Reliability of range of motion measures in the sagittal plane 33. Robinson J, Turk DC, Loeser JD: Pain evaluation: fifth edition approaches. The Guides and an in vivo torso rotation measurement technique. Spine 11:31-35, 1986. Newsletter, Jan/Feb, 2002. 26. Lowery WD, Horn TJ, Boden SD, Wiesel SW: Impairment evaluation based on spinal 34. Smith G: Personal communication. range of motion in normal subjects. J Spinal Dis 5:398-402, 1992. 35. Social Security Administration: Disability evaluation under Social Security: a hand- 27. Malmivaara A, Hakkinen U, Aro T, et al: The treatment of acute low back pain—bed book for physicians. HEW Publication (SSA) 79-10089. Washington, DC, 1975, The rest, exercises, or ordinary activity? N Engl J Med 332(6):351-355, 1995. Administration. 36. Waddell G, Main CJ, Morris EW, et al: Chronic low back pain, psychological distress 28. Mayer T, Kondraske G, Beals S, Gatchel R: Spinal range of motion: accuracy and and illness behavior. Spine 9:209-213, 1984. sources of error with inclinometric measurement. Spine 22:1976-1984, 1997. 37. Waddell G, McCulloch JA, Kummel E, Venner RM: Nonorganic physical signs in low back pain. Spine 5(2):117-125, 1980. 29. Mayer TG, Tencer AF, Kristoferson S, et al: Use of noninvasive techniques for quantification of spinal range of motion in normal subjects and chronic low back dysfunction patients. Spine 9:588-595, 1984.

Index A American National Standards Institute Ankle—Cont’d (ANSI), 216 plantar flexion and dorsiflexion of, Abduction, hip, 291–292, 292f limited ROM with, after foot Ability(ies) American Physical Therapy Association, 400 and ankle injuries, 385 American Psychological Association, 400 ROM of, 345–347, 346f defined, 398t American Society for the Surgery of the Hand, sprains of evaluation of, 395–416 diagnosis and treatment of, 367–368 Accessory handles, 258, 259f 228, 230 workplace adaptation of workers with, 389 Accommodation of work populations, American Society of Hand Clinicians, 230 workplace-related, 353–355, 354f, 355f Americans with Disabilities Act, 400, 409 ankle instability after, 354, 354f process for, 195, 195f Amputation, foot, partial, in diabetics, 392 grading of, 353 Acetaminophen, for arthritis of knee, 304 Analgesia/analgesics, opioid, for hip pain, 301 impingement lesion, 355 Achilles tendon overuse injuries, diagnosis and Analytic epidemiology, 5–9, 6f–8f, 8t osteochondral lesions of talus, 355, 355t persistently painful, 353–354 treatment of, 370–371 case-control study, 7, 7f tear of peroneus longus or brevis tendon, Acromioclavicular joint cohort study, 6–7, 6f 354–355, 355f cross-sectional study, 7–8, 8f, 8t treatment of, 353 articulation of, 155 randomized trials, 8–9, 8f tendon injuries around, diagnosis and fracture-dislocations of, 189–190 Anatomic variation as factor in internal joint treatment of, 370–372 Active range of motion (AROM), neck injuries workplace-related injuries of, 352–356 forces for hip and knee, 279 fractures, 352–353, 352f in workers and, 55, 57–58, 58f Anatomic/biomechanical abnormalities, sprains, 353–355, 354f, 355f. See also Ankle, Activities of daily living (ADLs) sprains of sports-related foot and ankle joint forces during, hip and knee, injuries due to, 334–335, 335f Ankle foot orthoses (AFOs), 383, 386, 391, 392f 281–284, 283f Anesthesia/anesthetics Ankle joint, 342 local injection, in elbow evaluation, 180 in wrist and hand evaluation, 233 in shoulder instability examination, 187–188 movement transfer of, 345 Activity ability, in disability evaluation, Ankle, 329–393. See also Foot and ankle rotational axis of, 345 disorders; Foot and ankle injuries Ankle joint complex motion, 345–347, 346f 411–412 arthrodesis of, indications for, 385 restraints of, 347 Acute herniated disk, 75–77, 76f, 77t, 78f arthrology of, 342–343 rotational axis and movement transfer of ankle arthrosis of treatment of, 77, 78f after fracture, workplace adaptation of joint, 345 Adaptation, workplace, 87–93. See also workers with, 390 ANSI. See American National Standards diagnosis and treatment of, 369–370 Workplace adaptation biomechanical demands of, in workplace, 384 Institute (ANSI) Adduction, hip, 291–292, 292f biomechanics of, 343–345, 346f Antalgic gait pattern, 290 Adhesive capsulitis, 190–191 calcaneocavus of, abnormal ROM of, after Anterior atlantodens interval, 82 ADLs. See Activities of daily living (ADLs) foot and ankle injuries, 385 Anterior drawer test, 295–296, 296f Adson’s test, 65 chronic pain of, diagnosis and treatment of, Anterior instability, of shoulder, evaluation of, Adson’s maneuver, 65, 172 368–370 Aerobic capacity testing, FPE validity in, equinus of, after foot and ankle injuries, 171, 171f 384–385 Anterior talofibular ligament (ATFL), 404–405 fractures of, workplace-related, occult fractures, AFOs. See Ankle foot orthoses (AFOs) 355–356, 356f function of, 367 Age impingement lesion of, anterolateral, Anthropometric considerations, in workplace workplace-related, 355 as factor in internal joint forces for hip and instability of adaptation for shoulder disorders, knee, 277–279, 278f after sprain, 354, 354f 204–206, 205f, 206f chronic, 367 Antidepressant(s), for low back pain, 131 as factor in MSDs, 269 lateral, impingement syndrome of, diagnosis Antifatigue mats Age Discrimination Employment Act (1967), 400 and treatment of, 369 contaminants effects on, 319–320 Agency for Health Care Policy and Research loose bodies in, diagnosis and treatment for jobs requiring prolonged standing, of, 369 319–320 (AHCPR), 56, 411 medial, burning pain around, case Anti-inflammatory drugs, nonsteroidal (NSAIDs) AMA. See American Medical Association (AMA) study, 386 for hip arthritis, 299 American Academy of Disability Evaluating overuse injuries of, diagnosis and treatment of, for low back pain, 129 370–372 Apley test, 295, 295f Physicians, 413 Apple Computers QuickTime, 201 American Academy of Orthopaedic Apportionment, in disability evaluation, 412 Surgeons, 228 American College of Occupational and Environmental Medicine, Occupational Medicine Practice Guidelines of, 299, 301 American Heart Association, 401 American Medical Association (AMA), 115, 410 Guides to the Evaluation of Permanent Impairment of, 412–415

418 Index Arch(es), foot, 343, 344f Biopsychosocial model, of work-related MSDs, Carpet installers Arm rests, in workplace adaptation for shoulder 13–14, 14f injury/disease prevention plan for, 315–319, 316f–318f disorders, 207 Black nail, 381 lower extremity trauma in, case study, AROM. See Active range of motion (AROM) Blister(s) 311–314, 312f–314f Arthritis NIOSH ALert for, 318, 319 of foot, 381 of hip, treatment of, 299, 301f of toe, safety footwear and, case study, Carrying load of knee, treatment of, 304–305, 305f, 306f low back pain associated with, work of lower extremity, 270 388, 388f adaptations for, 138–139, 140f, 141f rheumatoid. See Rheumatoid arthritis Body link sizes, as fractions of total stature, in workplace, 384 Arthrodesis(es), indications for, 385 Arthrology, of foot and ankle, 342–343 197, 197t Cartesian coordinate system, 254, 254f Arthroscopy Body masses, for males and females ages 18 and Case-control study, in analytic | in hip evaluation, 297 in knee evaluation, 297 over, 197, 198t epidemiology, 7, 7f Arthrosis, ankle Body segment distance, from proximal joint Causalgia, 375 after fracture, workplace adaptation of Causation, in disability evaluation, 412 center of gravity, 197, 197t CBT. See Cognitive behavioral therapy (CBT) workers with, 390 Body segment weights, as percentage of total Cervical degenerative disk disease, 77–79, diagnosis and treatment of, 369–370 Articulation(s), elbow, 163–164, 163f body mass, 197, 197t 80f, 81f ASO brace, 353 Body supports, in workplace adaptation for spondylitic myelopathy, 78–79, 80f, 81f Assessment, defined, 398t spondylosis, 77–78 ATFL. See Anterior talofibular ligament (ATFL) shoulder disorders, 207 Cervical spine “Athlete’s foot,” 381 Bone(s) biomechanics of, 41–54 Atrophy disorders of. See also specific disorders, deltoid, 168, 168f cuneiform, 341–342, 341f of fat pad, diagnosis and treatment of, 374–375 of foot, 341–342, 341f e.g., Neck sprain shoulder-related, 168–169, 168f tarsal, of midfoot fractures, acute herniated disk, 75–77, 76f, 77t, 78f Avascular necrosis, of hip, treatment of, 301, 302f cervical degenerative disk disease, 77–79, Axial compression test, 64 workplace-related, 360 Bone and Joint Decade (2000–2010) 80f, 81f B hyperextension injuries, 82–83 initiative, 97 neck sprain, 75 Babinski’s sign, 60, 64f Bone scans, in neck injury evaluation rheumatoid arthritis, 79, 81–82, 82f Back, lower, 95–144 spondylosis, 77–78 Back pain in workers, 69 treatment of, 73–86 Bouchard’s nodes, 245 problems related to Brace(s), ASO, 353 algorithm for, 83–86, 84f, 85t described, 97 Brachial plexus, 59 whiplash injury, 82–83 disability due to, 103–104, 104f Brachioradialis reflex, inverted, 62 lower, biomechanics of, 46, 49f–53f, 53t, epidemiologic studies of, 97–99, 98f Bristow procedure, for shoulder implications of, 104–105 54, 54t incidence of, 99–100, 99f instability, 188 upper, occiput/C2, biomechanics of, 42, occupational and other relevant Bureau of Labor Statistics, 309, 351 exposures, 97–98 Bursitis 44f–48f, 44t, 45t prevalence of, 99–100, 99f CFL. See Calcaneofibular ligament (CFL) lower extremity, 269–270 Charcot deformity, 375 risk factors for, 100–102 trochanteric, treatment of, 301 Charcot neuroarthropathy, in diabetics, structural pathology and, 100–101 tissue injury and, 100–101 C 391–392, 392f work-related, reporting of, 102–103 Chopart’s joint, 342, 377 Baltimore Therapeutic Equipment CAI. See Chronic ankle instability (CAI) Chronic ankle instability (CAI), sports-related Calcaneofibular ligament (CFL), Primus FPE, 402 foot and ankle injuries due to, 335 Baltimore Therapeutic Equipment Work function of, 367 Chronic regional pain syndrome, workplace- Calcaneous, 341, 341f Simulator, 403 related, 365 Bankart procedure, for shoulder instability, 188 abnormal ROM of, after foot and ankle “Claims processor” job, for identifying Barium swallow, in neck injury evaluation in injuries, 385 and controlling shoulder and neck workers, 69 fractures of stressors, sample documentation and “Belly press,” 170 diagnosis and treatment of, 372–373 analysis of, 88t Bennett Hand-Tool Dexterity Test, 234 workplace-related, 356–359, 357f, 358f Clavicle, fracture-dislocations of, 189 Best Evidence Synthesis on Traumatic Mild Clinical Guidelines for the Management of Callus(es), of foot, 380–381 Acute Low Back Pain, 14 Injury, 26 CAM walker boot, 358 Clonus, 60 Biomechanic(s) Canon, W., 13 Cochrane review of multidisciplinary Capacity, defined, 398t, 402 biopsychosocial rehabilitation, 129 of cervical and thoracic spine, 41–54. See also Capsulitis, adhesive, 190–191 Cognitive behavioral therapy (CBT), for NSLBP, Cervical spine; Thoracic spine Carpal ganglia, 246, 246f 127f, 128 Carpal joint, force through, 223–224, 223f Cohort study, in analytic epidemiology, of elbow, 162–166 Carpal tunnel syndrome (CTS), 211–218, 6–7, 6f of neck, 41–42, 41f–44f Common peroneal nerve, entrapment of shoulder, 155–162 238–239 of, 376 described, 238 Complex regional pain syndrome diagnosis of, 238–239 (CRPS), 247 treatment of, 239 Carpal Tunnel Syndrome Questionnaire, 228 Carpet installation clinical responses to, biomechanical basis for, case study, 311–314, 312f–314f “stretcher adapter” in, 318–319

Index 419 Computed tomography (CT) defined, 397 Dynamic work, low back pain associated with, in elbow evaluation, 179, 180f evaluation of. See Disability evaluation work adaptations for, 138–143, 139f–142f in hip evaluation, 296 low back pain–related, 136 in low back pain evaluation, 119f, 120 Disability evaluation carrying, 138–139, 140f, 141f in neck injury evaluation, 67–68, 67f, 68f ethics associated with, 409–410 lifting and lowering, 139–143, 141f, 142f in shoulder evaluation, 175 impairment determination in pushing and pulling, 138, 139f Dynamometric devices, isokinetic and isoinertia, Concurrent validity, defined, 403t AMA guides in Confidence limits, in statistical analysis, 9–10 differences between fourth and fifth in low back pain evaluation, 122 Confounding, 5–6 editions, 413 lower extremity impairments, 414–415 E defined, 5 pain, 413 Constraint(s) spine impairments, 413–414 Economic issues, in low back pain, 114–115 upper extremity impairments, 414 Edema of elbow, 164–165 of glenohumeral joint, 158–161, 160f principles of, 412–415 of lower leg, after foot and ankle injuries, Construct validity, defined, 403t rating of, AMA guides in, 413–415 386–387, 387f Contaminant(s), impact on antifatigue properties medical opinions required during, 410–412 apportionment, 412 in wrist and hand evaluation, 228–229, 229f of floor mats, 319–320 causation, 412 Elbow Content validity, defined, 403t date of permanent and stationary Copenhagen Neck Functional Disability articulations of, 163–164, 163f status, 410 biomechanics of, 162–166 Scale, 66 diagnosis, 410–411 Corns, 380 ongoing and future medical care anatomic considerations in, 162–164, Corticosteroids, for low back pain, 131 163f, 164t Cox proportionate hazards model, 9 requirements, 412 Crawford Small Parts Test, 234 residual objective findings, 410 constraints, 164–165 Criterion validity, defined, 403t residual subjective complaints, 410 developments in, 165 Cross-sectional study, in analytic epidemiology, return-to-work determinations, 411 future directions in, 165 work and activity ability, 411–412 kinematics, 164 7–8, 8f, 8t for neck injuries in workers, 55, 55t kinetics, 165 Crouching, in workplace, 384 physician’s role in, 409–416 disorders of, 149–154. See also Elbow disorders CRPS. See Complex regional pain syndrome administrative considerations, 415 evaluation of, 176–180 Disease stage, as factor in internal joint forces CT in, 179, 180f (CRPS) diagnostic blocks in, 180 Crush injury, of foot, workplace-related, 365 for hip and knee, 279, 279f diagnostic testing in, 178–180, 179f, 180f CT. See Computed tomography (CT) DISI. See Dorsal intercalated segmental EMG in, 179–180 CTS. See Carpal tunnel syndrome (CTS) local anesthetic block in, 180 Cuboid, 341f, 342 instability (DISI) MRI in, 179 Cumulative Load Theory, of musculoskeletal Disk(s), herniated, acute, 75–77, 76f, 77t, 78f nerve conduction studies in, 179–180 Disk degeneration patient history in, 176–177 injury causality, 135 physical examination in, 176f, 177–178, 177f Cuneiform bones, 341–342, 341f hereditary influences on, 101 radiography in, 178–179, 179f Cutting tools, 252–253, 253f, 254t occupational influences on, 101–102 technetium bone scanning in, 180 Cyst(s) Diskcriminator, 231 muscles of, 164, 164t Diskography, in low back pain evaluation, 122 stiffness of, 176 mucous, of wrist and hand, 246–247 Dislocation(s) tennis, 149 retinacular, 246 foot, workplace-related, 362–364, 362f–364f resistant, 152 of MTP joint, treatment of, 378 Elbow disorders, 149–154 D shoulder-related, 189–190 classification of, 149 subtalar joint, diagnosis and treatment entrapment neuropathies, 152, 177 DASH (disabilities of the arm, shoulder, and epidemiology of, 149–150, 150t hand) test, 228 of, 372 individual factors for, 151 Distal interphalangeal joint, in newspaper workers, 150, 150t de Quervain disease, 237, 237f, 245, 245f occupational risk groups for, 149–150, 150t Deep peroneal nerve, entrapment of, 376 osteoarthritis of, 246 pathomechanisms of, 151–152 Degenerative joint disease, of shoulder, 191 Distal radius fracture, 242–243, 243f prevention of, 152 Deltoid atrophy, 168, 168f Distraction test, 64 risk factors for, 150–151 Dermatome testing, in neck injury evaluation in Dorsal intercalated segmental instability social factors for, 151 tendinopathy, 177 workers, 59, 59f (DISI), 224 work-related factors for, 150–151 Descriptive epidemiology, 4–5 “Dose-response” relationship, described, 87 Electrodiagnostic studies, in neck injury Dexterity, in wrist and hand evaluation, DOT. See Dictionary of Occupational Titles evaluation in workers, 69–71, 72t 233–234, 233f, 234f (DOT) Electromyography (EMG) Diabetes mellitus, foot problems in workers DOT Residual Functional Capacity battery, in elbow evaluation, 179–180 with, 391–392, 391f, 392f 403–404 in low back pain evaluation, 122 Diagnostic blocks about elbow, in elbow Down syndrome, 4 in neck injury evaluation, 70 DRE method. See Diagnosis-related estimate in shoulder evaluation, 176 evaluation, 180 surface, in analysis of job task demands, Dictionary of Occupational Titles (DOT), of (DRE) method “Dropping sign,” 170 202–203 U.S. Department of Labor, 399, 400t duToit capsulorrhaphy procedure, for shoulder “Elevated arm stress test,” 65 Differential Fatigue Theory, of musculoskeletal instability, 188 injury causality, 135 Dynamic forces, 260–262, 260f–262f Digital flexor tendon sheath, 237, 238f Disability(ies) back pain–related, 103–104, 104f

420 Index Embase, 25 Fasciitis, plantar Foot—Cont’d EMG. See Electromyography (EMG) diagnosis and treatment of, 374 nerve injuries, 364 Entrapment neuropathies workplace adaptation of workers with, 390 sprains, 362–364, 362f–364f TMT joint injuries, 362–363, 362f, 363f about elbow, 177 Fat pad common peroneal nerve, 376 atrophy of, diagnosis and treatment of, Foot and ankle disorders, 329–393. See also Foot deep peroneal nerve, 376 374–375 and ankle injuries elbow and shoulder disorders and, 152 inflammation of, diagnosis and of foot and ankle, 375–377 treatment of, 375 blisters, 381 jogger’s foot, 377 calluses, 380–381 Morton’s neuroma, 377 Fatigue corns, 380 posterior tibial nerve and branches, 376–377 MSDs due to, prevention of, 197–198 diagnosis and treatment of, 367–382 saphenous nerve, 377 muscular, as factor in elbow and shoulder superficial peroneal nerve, 376 disorders, 152 ankle pain, chronic, 368–370 sural nerve, 377 work-related conditions affecting, 195–200. See ankle sprains, 367–368 Valleix phenomenon, 375–376 also Exposure-response relationship forefoot problems, 379–380 Epidemiologic concepts fractures, 372–374 analytic epidemiology, 5–9, 6f–8f, 8t. FCEs. See Functional capacity evaluations midfoot injuries, 377–379 (FCEs) nerve injuries, 375–377 See also Analytic epidemiology subtalar joint injuries, 372 descriptive epidemiology, 4–5 Federal Rules of Evidence, 56 tendon injuries around ankle, 370–372 measures of disorder frequency in, 3–4 Federal Uniform Guidelines of Employee epidemiology of, 331–339 in MSDs, 3–11 military-related injuries, 332–333, 333f statistical issues, 9–11, 10f, 11t Selection Procedure (1978), 400 sports-related injuries, 333–337, 334t, 335f, Epidemiology Finger(s) analytic, 5–9, 6f–8f, 8t. See also Analytic 336f. See also Sports, foot and ankle joint injuries of, 242 injuries related to epidemiology trigger, 237–238, 238f studies of, methodology of, 331 defined, 97 Finger escape sign, 62 work-related injuries, 331–332 descriptive, 4–5 Finkelstein test, 245 fungal infections, 381 Equipment Fissure(s), toenail-related, 382 skin conditions, 380–381 described, 89 Flexibility, lack of, sports-related foot and ankle toenail-related, 381–382 work-related, in analysis of job warts, 381 injuries due to, 335 workplace adaptation of workers with, task demands, 202 Flexor hallucis longus tendon overuse problems, 383–393 Ergonomics ankle arthrosis after fracture, 390 diagnosis and treatment of, 371 ankle sprain, 389 for NSLBP, 128–129 Floor-to-waist lifting, in workplace, 384 for common conditions, 389–393, 391f, 392f in shoulder disorder prevention, 162 Foot, 329–393. See also Foot and ankle disorders; diabetics, 391–392, 391f, 392f Ergos Work Simulator, 402 foot orthoses, 389 Estimates, in statistical analysis, 9–10 Foot and ankle injuries footwear, 383–384, 383t, 387–388, 387f, 388f Ethics, disability evaluation-related, 409–410 amputation of, partial, in diabetics, 392 forefoot pain–related, 391 European Guidelines 2005, 128, 129 anatomy of, 341–342, 341f heel pain, 390 Evaluation, defined, 398t arches of, 343, 344f midfoot arthrosis and pain, 390–391 Event-based observations, time-based arthology of, 342–343 tibialis posterior tendon insufficiency, “athlete’s,” 381 390, 391f observations vs., in analysis of job task biomechanic(s) of, 343–345, 346f venous and lymphatic disorders, 392–393 demands, 203 biomechanical demands of, in workplace, 384 workplace-related, 351–366. See also Ankle, Evidence-based medicine (EBM) techniques, in bones of, 341–342, 341f workplace-related injuries of; Foot, neck injury evaluation in workers, 56 external forces acting on, 347 workplace-related injuries of Exercise, for NSLBP, 127f, 128 fractures of, 356–362, 357f–359f, 361 approach to patient with, 351–352 Exercise laboratories, of Veterans Affairs Health epidemiology of, 351 Care System, 401 workplace-related, 356–362 prevalence of, 351 Exostosis, subungual, 381 calcaneus fractures, 356–359, 357f, 358f return to work after, 365 Experimental study designs, clinical trials, metatarsal fractures, 360–360f types of, 352–365 8–9, 8f midfoot fractures, tarsal bones of, 360 Foot and ankle injuries. See also Foot and ankle Exposure-response relationship, 195–200, 195f, phalangeal fractures, 361–362 disorders 196f, 197t, 198t, 199f, 200f, 200t sesamoid fractures, 360–361, 361f deficits after, 384–387, 385f, 387f biomechanics of, 196–197, 196f, 197t, 198t talus fractures, 359–360, 359f abnormal ROM, 384–385, 385F described, 195–196, 195f edema of lower leg, 386–387, 387f limitations in, 197 ground reaction forces and pressure foot and ankle pain, 386 worker capacity and, 198–200, 199t, 200f, distribution on, 344f, 348 neurologic deficit, 385–386 200t, 201f Foot and ankle movement, measurement Extensor lag, defined, 294, 294f internal forces acting on, 344f, 347–348 of, 343–345. See also Ankle joint External forces, acting on foot, 347 jogger’s, 377 complex motion Extremity(ies), lower, 265–416. See also Ankle; osteology of, 341–342, 341f clinical and functional assessment in, 343 Foot; Hip; Knee; Lower extremity plantar surface of, neuropathic ulcerations on, three-dimensional assessment in, 343–345 Foot and ankle pain, after foot and ankle F in diabetics, 391, 391f injuries, 386 shoe selection considerations for, Face validity, defined, 403t 348–349, 348f workplace-related injuries of, 356–365 CRPS, 365 crush injuries, 365 dislocations, 362–364, 362f–364f fractures, 356–362, 357f–359f, 361f. See also Foot, fractures of MTP joint injuries, 363–364, 364f

Index 421 Foot arch supports, 349 Functional performance evaluation Hand tools Foot orthoses (FOs), at workplace, 389 (FPE)—Cont’d biomechanical aspects of, 249–265 Footwear. See Shoe(s) manual screwdrivers, 249–251, 249f, 251f Force(s) professional practice standards for, 400–406, Phillips head screws, 251f, 252, 252t 403t pliers and cutting tools, 252–253, 253f, 254t external, acting on foot, 347 power tools, 249, 253–262. See also Power internal, acting on foot, 344f, 347–348 practicality, 405–406 hand tools measurement of, in analysis of job task reliability, 401–402 recommendations, 263 safety, 401 screwdriver blades and screw heads, 251–252, demands, 202 utility, 406 251f, 252f, 252t prediction of, in analysis of job task demands, validity, 402–405, 403t. See also Validity, of slotted screws, 251–252, 252f, 252t Torx head screws, 251f, 252, 252t 203–204 FPE manual, 249 Forearm rests, in workplace adaptation for purposes of, 398–400, 400t self-reported functioning, 399–400 Hand-arm vibration syndrome, 213, 239–240 shoulder disorders, 207 test components of, 399 Handle force model, dynamics of, Forefoot validity of, legal constraints challenging, 400 of work-related activities, reliability of, 401–402 261–262, 261f painful, conditions of, workplace adaptation of work-related performance tests, 399 Hawkins impingement test, 171 workers with, 391 Functional performance testing, 397–407. See also Hazard, defined, 9 Heel pain problems related to, 379–380 Functional performance evaluation (FPE) FOs. See Foot orthoses (FOs) Functional Range of Motion Assembly Test, 402 diagnosis and treatment of, 374–375 FPE. See Functional performance Functional spinal unit (FSU), 107–110, 108f, workplace adaptation of workers with, 390 Heel pain syndrome, diagnosis and evaluation (FPE) 109f, 109t Fracture(s) anterior portion of, 107, 108f, 109t treatment of, 374 ligaments in, 109–110 Heel spur(s), diagnosis and treatment of, 374 about ankle, workplace-related, 352–353, 352f posterior portion of, 107–109, 109f Heel spur fracture, diagnosis and treatment of, 374 ankle arthrosis after, workplace adaptation of Fungal infections Hematoma(s), subungual, 381 of foot, 381 Heredity, as factor in lower extremity workers with, 390 of toenails, 382 calcaneal F-wave response tests, 71, 72t osteoarthritis, 270 Herniated disk, acute, 75–77, 76f, 77t, 78f diagnosis and treatment of, 372–373 G workplace-related, 356–359, 357f, 358f treatment of, 77, 78f distal radius, 242–243, 243f Gamekeeper’s thumb, 242, 242f Herniation(s), soft disk, types of, 75, 76f foot and ankle, diagnosis and treatment of, Ganglion(a) Hindfoot, stress fracture of, 373 Hip, 267–327 372–373 retinacular, volar, 246 heel spur, diagnosis and treatment of, 374 wrist and hand, 246–247, 246f abduction of, 291–292, 292f hip, treatment of, 299, 300f adduction of, 291–292, 292f Massoneuve, 353 carpal ganglia, 246, 246f arthritis of, treatment of, 299, 301f metatarsal mucous cysts, 246–247 avascular necrosis of, treatment of, 301, 302f retinacular cysts, 246 biomechanics of, 273–287 diagnosis and treatment of, 378–379 ulnar tunnel, 239 workplace-related, 360–360f Gender, as factor in internal joint forces for hip kinematics, 273–274, 274t occult, of ankle, workplace-related, kinetics, 274–277, 275f and knee, 277–279, 278f reducing internal joint load, 277–285, 355–356, 356f Gibson Approach to FPE, 404 phalangeal, workplace-related, 361–362 Glenohumeral joint, biomechanics of, 158–162, 278f–285f. See also Internal joint forces, scaphoid, 243–244, 243f on hip and knee sesamoid, workplace-related, 360–361, 361f 159f, 160f, 161t, 162f clinical evaluation of, 289–297 shoulder-related, 189–190 animal models, 162 CT in, 296 stress, of foot and ankle, diagnosis and constraints, 158–161, 160f imaging in, 296 disability prevention through ergonomics, 162 MRI in, 296, 301 treatment of, 373–374 kinematics, 158, 159f patient history in, 289, 289t talar kinetics, 161 physical examination in, 289–292, 290f–292f mechanical properties of articular cartilage and radiography in, 296, 299, 300f diagnosis and treatment of, 372 fractures of, treatment of, 299, 300f workplace-related, 359–360, 359f ligaments, 161–162, 161t, 162f kinematics of, 273–274, 274t tarsal navicular, stress, 374 Glenohumeral ligaments, 160–161, 160f kinetics of, 274–277, 275f tibial pilon, 352 Goniometer(s), in low back pain evaluation, 122 osteoarthritis of, 270–271 wrist and hand, 242–244, 243f Grip and release test, 62 treatment of, 299, 301f distal radius, 242–243, 243f Guides to the Evaluation of Permanent Impairment, osteonecrosis of, treatment of, 301, 302f metacarpals, 244 pain of phalanges, 244 of AMA, 412–415 severe, treatment of, 299, 301 scaphoid, 243–244, 243f treatment of, 301 Frozen shoulder, 190–191 H range of motion of, 290–291, 291f FSU. See Functional spinal unit (FSU) rotation of, 290–291, 291f Functional assessment, of wrist and hand, Hallux limitus, 385, 385f sprains and strains of, treatment of, 301 Hallux rigidus, 379 trochanteric bursitis of, treatment of, 301 232–234 Hallux seseamoid stress fractures, 373–374 work-related problems of, treatment of, Functional Assessment Screening Test, 404 Hallux valgus, 379 299–301, 300f–302f Functional capacity evaluations (FCEs), Hammer toes, 379–380 Hand, 209–263. See also Wrist and hand 397–398. See also Functional performance evaluation (FPE) Functional performance evaluation (FPE), 397–407 of aerobic capacity, reliability of, 402 characteristics of, 400–406, 403t

422 Index Hip extension, 291, 292f ISO. See International Standards Knee—Cont’d Hippocratic Oath, 409 Organization (ISO) treatment of, 304–305, 305f, 306f Hoffman’s sign, 60, 64f Holding work, low back pain associated with, Israeli Defense Forces Medical Corps, 332 pain of anterior, treatment of, 306 work adaptations for, 137, 138f J nonspecific, treatment of, 306 Homer syndrome, 82 “Horn blower’s” sign, 170, 170f Job documentation, 200 sprains of, treatment of, 303–304, 303f, 304f Humerus, proximal, fracture-dislocations of, 190 Job rotation, 137 tendinitis of, treatment of, 305–306 Hyperextension injuries, 82–83 Job stresses, physical, in analysis of job task varus/valgus deformity of, 292, 292f work-related problems of, treatment of, treatment of, 83 demands, 202–204, 203f. See also Physical Hypothenar hammer syndrome, 213 job stresses, in analysis of job task 301–306, 303f–306f demands Knee injuries I Job task demands analysis of, 200–204, 202t acute, workplace-related, chronic pain, Imaging physical job stresses in, 202–204, 203f. See discomfort, and work restrictions due to, in hip evaluation, 296 also Physical job stresses, in analysis of case study, 320–325, 321t, 324t in knee evaluation, 296–297 job task demands interviews, 202 ligamentous, treatment of, 303–304, 303f, 304f Impairment evaluation, for neck injuries in job documentation, 200 meniscal, treatment of, 301–303, 303f workers, 55 measurements of work station and Knee joint stability, testing of, 295–296, 295f, equipment, 202 Impingement lesion, anterolateral, of ankle, observations, 200–201 296f workplace-related, 355 video recordings, 201–202 Kneeling, in workplace, 384 Jogger’s foot, 377 Impingement syndrome, 185–187 Joint(s) L of lateral ankle, diagnosis and treatment foot and ankle, 342–343. See also specific joint of, 369 wrist and hand, constraint and stability of, 219 Laboratory studies, in neck injury evaluation in Joint forces, wrist and hand, 221–223, 223f workers, 71 Incidence, defined, 25 Joint loads, estimation of, 198, 200 Incidence rate, defined, 4 Lachman test, 295–296, 296f Industrial back “injury” incident reports and K Lateral cord of brachial plexus, 59 Lateral elbow syndrome, 149 claims filing, 102–103 Kienböck disease, 223 Lateral humeral epicondylalgia, 149 Industrial Commission of Ohio, 311 Kinematics Leg(s), lower, edema of, after foot and ankle Inflammation, of fat pad, diagnosis and elbow, 164 injuries, 386–387, 387f treatment of, 375 glenohumeral, 158, 159f Legend of variable notation, 255t Information processing, in wrist and hand hip, 273–274, 274t Lesion(s). See specific types, e.g., Osteochondral knee, 273, 273t evaluation, 232–233 spine, 110, 110f, 111f lesions Ingrown toenails, 381 Kinetics Lhermitte’s sign, 60, 81 In-line power drivers, 256f, 257–258 elbow, 165 Liberty Mutual Insurance Company, 136 Instability glenohumeral, 161 Liberty Mutual Insurance Company database, 100 hip and knee, 274–277, 275f Lidocaine injection tests, in shoulder evaluation, anterior, of shoulder, 171, 171f spine, 110–112, 111f, 112f shoulder, 185–189. See also Shoulder(s), Knee, 267–327 175, 176f analytical joint models of, 275–277, 275f, 276f Lifting, floor-to-waist, in workplace, 384 instability of biomechanics of, 273–287 Lifting and lowering, low back pain associated Internal joint forces kinematics, 273, 273t with, work adaptations for, 139–143, on foot, 344f, 347–348 kinetics, 274–277, 275f 141f, 142f on hip and knee, 277–285, 278f–285f reducing internal joint load, 277–285, Ligament(s) glenohumeral, 160–161, 160f during ADLs, 281–284, 283f 278f–285f. See also Internal joint forces, spine, 109–110 squatting, 281–283, 283f on hip and knee wrist and hand, constraint of, 219 stair climbing, 283–284 clinical evaluation of, 289–297 Lisfranc’s joint, 342 walking, 283–284 arthroscopy in, 297 injuries of, diagnosis and treatment of, 378 MRI in, 297 Local anesthetic injection, in elbow factors affecting, 277–279, 278f, 279f patient history in, 289, 289t evaluation, 180 reduction of, 280–281, 280f–282f physical examination in, 292–296, 292f–296f Local ischemia, 152 radiography in, 296 Loge of Guyon, 239 lever arm reduction in, 280, 280f, 281f jobs requiring use of, injury/disease prevention Long-tract signs, in neck injury evaluation in synergic movement and muscular plan for, 315–319, 316f–318f workers, 60, 62, 64f, 65f joint forces on, in vivo direct measurement Low back, 95–144 coactivation in, 280–281, 282f of, 277 Low back pain task variables in, 284–285, 285f kinematics of, 273, 273t causes of, 135–136 in vivo direct measurement of, kinetics of, 274–277, 275f theories of, 135–136 osteoarthritis of, 271 vs. exacerbation, 98–99 hip and knee, 277 chronic, treatment of International Classification of Diseases, 149, 411 manipulation in, 129 International Standards Organization multimodal programs in, 129, 130t control of, 135–136 (ISO), 216 costs related to, 136 Interphalangeal joint, proximal, osteoarthritis of, differential diagnosis of, 122–123 245–246 Interview(s) patient, in neck injury evaluation in workers, 56 worker and supervisor, 202 Ischemia, local, 152 Isernhagen Work Systems FCE, 404 Isernhagen Work Systems FPE, 402

Index 423 Low back pain—Cont’d Lower extremity disorders Metatarsal fractures disabilities due to, 136 age-related, 269 diagnosis and treatment of, 378–379 duration of, treatment goals related to, 126 rating of, AMA guides in, 414–415 stress fractures, 373 epidemiology of, 97–106 workplace-related, 309–327 workplace-related, 360–360f evaluation of adaptations recommended for, 315–325, blue flags in, 115 316f–318f, 321t, 324t Metatarsalgia, 380 CT in, 119f, 120 in carpet installers, 311–314, 312f–314f Metatarsophalangeal (MTP) joint, 342–343 diskography in, 122 injury/disease prevention plan for, Metatarsophalangeal (MTP) joint injuries EMG in, 122 315–319, 316f–318f initial, 113–124 industry-specific data, 309 sprains and dislocations, treatment of, 378 laboratory studies in, 122 knee injury, chronic pain, discomfort, and workplace-related, 363–364, 364f mechanical testing in, 122 work restrictions due to, case study, Michigan Hand Questionnaire, 228 MRI in, 120–121, 120f, 121f 320–325, 321t, 324t Midfoot, arthrosis and pain of, workplace myelography in, 117f, 120 prevalence of, 309 patient history in, 113–115, 113t vascular problems, 314–315 adaptation of workers with, 390–391 physical examination in, 115–118, Midfoot injuries, 377–379 116f–118f Lowering, low back pain associated with, Midtarsal sprains, 377–378 patient on side, 118 work adaptations for, 139–143, Military shoes, at workplace, 388 patient prone, 118 141f, 142f Military-related foot and ankle injuries, patient sitting, 116, 116f patient standing, 115–116 Lunotriquetral interval injury, 241 332–333, 333f patient supine, 116–118, 117f, 118f Lymphatic disorders, foot and ankle–related, Minnesota Manual Dexterity Test, 234, 234f radiography in, 119–120 Moberg Pick Up test, 233 radionuclide bone scan in, 121 workplace adaptation of workers with, Moment(s), reduction of, 280–281, 280f–282f red flags in, 113–115, 113t 392–393 Monofilament(s), Semms-Weinstein, 231, 414 specialized examinations in, 117f–121f, Morton’s neuroma, 377 119–122 M MOS 36-Item Short Form Health Survey ultrasonography in, 121–122 yellow flags in, 114–115 Magnetic resonance imaging (MRI) (SF-36), 66 nature of, 135 in elbow evaluation, 179 Motion, wrist and hand, 219–220 nonspecific, 125 in hip evaluation, 296, 301 Motor strength examination, in neck potentially serious conditions related to, in knee evaluation, 297 red flags for, 113–115, 113t in low back pain evaluation, 120–121, injury evaluation in workers, prevalence of, 136 120f, 121f 59–60, 60f–62f, 60t problems related to, extent of, 136 in neck injury evaluation, 68, 68f–70f MRI. See Magnetic resonance imaging (MRI) psychosocial and economic issues in shoulder evaluation, 174–175, 175f MSDs. See Musculoskeletal disorders (MSDs) associated with, 114 MTP joint injuries. See Metatarsophalangeal specific, 125 Maine-Seattle back pain disability (MTP) joint injuries treatment of, 125–134 questionnaire, 9 Mucous cysts, of wrist and hand, 246–247 antidepressants in, 131 Multivariate Interaction Theory, of complications of, 132 Manipulation, for chronic low back pain, 129 musculoskeletal injury causality, 136 corticosteroids in, 131 Manual hand tools, 249–253, 249f, 251f–253f, Muscle(s) models for, 125 elbow, 164, 164t muscle relaxants in, 129, 131 252t, 254t mechanical failure of, 152 NSAIDs in, 129 Manual screwdrivers, 249–251, 249f, 251f nerve and main root supply of, 71, 72t occupational health guidelines in, 125 shoulder, 157–158, 157t opioids in, 131 handle diameter of, 250–251, 251f wrist and hand, 221–223, 223f patient expectations in, 125–126 handle length of, 249–250, 249f Muscle grading, 170, 170t surgical, 131–132 Massoneuve fractures, 353 Muscle performance testing, in wrist and hand workplace adaptation for, 135–144 Mat(s), antifatigue evaluation, 229–230, 230f dynamic work, 138–143, 139f–142f. contaminants effects on, 319–320 Muscle relaxants, for low back pain, 129, 131 See also Dynamic work, low back for jobs requiring prolonged standing, Muscular fatigue, as factor in elbow and pain associated with, work shoulder disorders, 152 adaptations for 319–320 Musculoskeletal disorders (MSDs) holding work, 137, 138f Maximum voluntary contraction (MVC), 150 age as factor in, 269 seated work, 137 McGill Pain Profile, 227 epidemiologic concepts in, 3–11. See also static work, 136–137 McGill Pain Questionnaire, 232 Epidemiologic concepts McGregor line, 82 frequency of, measures of, 3–4 Lower back, 95–144. See also under Low back McMurray test, 294, 294f of hand and wrist, 211–218, 211f, 212f, 214t, pain Mechanical assists, in workplace adaptation for 215t. See also Wrist and hand disorders localized fatigue and, prevention of, 197–198 Lower extremity, 265–416. See also Ankle; Foot; shoulder disorders, 206–207 of lower extremity, workplace-related, 309–314, Hip; Knee Mechanical testing, in low back pain 310f, 312f–314f of neck, in workers, evaluation of, 55–72. epidemiology of, 269–272, 269t, 270t evaluation, 122 See also Neck, evaluation of definitions associated with, 269 Medial cord of brachial plexus, 59 occupational, defined, 269 occupational illness, 269 Medical history, as factor in internal joint psychologic and psychosocial factors occupational injuries, 269 associated with, 14–15 forces for hip and knee, 279, 279f psychosocial aspects of, 13–18. See also Medical Outcomes Study, 66 Psychosocial factors, MSDs and MEDLINE, 25 psychosocial interventions for, 16–17, 17f Meniscal injuries, treatment of, 301–303, 303f Metabolic equivalent intensity levels, 399 Metacarpal(s), fractures of, 244 Metatarsal(s), 341f, 342

424 Index Musculoskeletal disorders (MSDs)—Cont’d Neck—Cont’d Neurologic deficits, after foot and risk factors for, work-related conditions physical examination in, 57–59, 58f ankle injuries, 385–386 affecting, 195–200. See also Exposure- PROM in, 58 response relationship radiography in, 66–67, 66f, 67f Neurologic examination, in neck injury in workers, neck pain associated with, 25–40. red flags in, 57, 57t evaluation in workers, 59–65, 59f–65f, See also Neck pain, in workers, ROM in, 57–59, 58f 60t, 63t. See also Neck, evaluation of, epidemiology of Spurling’s test in, 59 neurologic examination in SSEPs in, 71 Musculoskeletal pain, prevalence of, 397 standard examination in, 55 Neuroma(s), Morton’s, 377 MVC. See Maximum voluntary contraction Neuropathic ulcerations, on plantar surface of MSDs of, in workers, evaluation of, 55–72. (MVC) See also Neck, evaluation of foot in diabetics, 391, 391f %MVC. See Percentages of maximum voluntary New Zealand Guidelines, 14 Neck Disability Index, 66 Newspaper workers, elbow problems in, contraction (%MVC) Neck pain Myelography 150, 150t anatomy related to, 73–75, 74f, 75f Newton’s Third Law, 196, 196f in low back pain evaluation, 117f, 120 causes of, 73, 73t NHANES I study, 270, 271 in neck injury evaluation, 68–69, 71f defined, 25 Nine Hole Peg Test, 233, 233f, 234 Myelopathy, spondylosis with, 78–79, 80f, 81f factors associated with, 27, 28t, 29 NIOSH. See National Institute for Occupational Myeloradiculopathy, 78 in workers Safety and Health (NIOSH) N epidemiology of, review of, 25–40 NIOSH Alert, for carpet installers, 318, 319 article selection in, 26 Nonspecific low back pain (NSLBP), 125 National Academy of Sciences, 213 critical review of literature in, 26 National Center for Health Statistics, statures data synthesis in, 26 acute literature search in, 25–26 prognosis of, 126 and body masses for males and females methods in, 25–26 self-care for, 126 ages 18 and over, 197, 198t purpose of, 25 treatment of, evidence for, 126 National Institute for Occupational Safety and relevance of, 35 Health (NIOSH), 139 results of, 26–35, 27f, 28t, 30t–34t natural history of, 126 National Institute for Occupational Safety and selection and critical appraisal of articles recurrence of, 126 Health (NIOSH) Report on in, 26–27, 27f subacute, treatment of Musculoskeletal Disorders (MSDs) and Workplace Factors, 397 incidence of, 29, 30t–31t blue flags in, 127 Navicular, 341, 341f prevalence of, 27, 28t interventions in, 127–129, 127f Neck, 23–93 risk factors for, 29, 30t–31t yellow flags in, 127 anatomy of, 73–75, 74f, 75f specific occupational groups, 29, treatment of, 127–128, 127f biomechanics of, 41–42, 41f–44f CBT in, 127f, 128 disorders of, workplace adaptation to, 87–93. 32t–34t, 35 combination therapy in, 128 See also Workplace adaptation, to MSDs, factors associated with, 29, 32t–34t ergonomic intervention in, 128–129 neck-related disorders incidence of, 29, 35, 36t–37t exercise in, 127f, 128 evaluation of, 55–72 prevalence of, 29, 32t–34t Nordic Health Questionnaire, 203 AROM in, 57–58, 58f risk factors for, 35, 36t–37t Northwick Park Neck Pain Questionnaire, 66 barium swallow in, 69 Neck Pain and Disability Scale, 66 NSAIDs. See Anti-inflammatory drugs, bone scans in, 69 Neck sprain, 74f, 75, 75f CT in, 67–68, 67f, 68f prognosis for patients with, 75 nonsteroidal (NSAIDs) disability examination in, 55, 55t treatment of, 75 NSLBP. See Nonspecific low back pain (NSLBP) electrodiagnostic studies in, 69–71, 72t Neck stressors, identification and control of, EMG in, 70 O evidence-based medicine in, 56 sample documentation and analysis of imaging studies of spine in, 66–69, 66f–71f “claims processor” job in, 88t Observation(s), of workers performances, impact-related, 65–66, 66t Neck-related pain syndromes, causes of, 73, 73t 200–201 impairment evaluation in, 55 Neer “impingement sign,” 171, 171f laboratory screening in, 71 Neer procedure, for shoulder instability, 188 Occlusion of superficial palmar branch of ulnar MRI in, 68, 68f–70f Nerve(s). See specific nerve, e.g., Saphenous nerve artery, 213 myelography in, 68–69, 71f Nerve conduction studies nerve conduction studies in, 71, 72t in elbow evaluation, 179–180 Occult fractures, of ankle, workplace-related, neurologic examination in, 59–65, 59f–65f, in neck injury evaluation, 71, 72t 355–356, 356f 60t, 63t in shoulder evaluation, 176 long-tract signs, 60, 62, 64f, 65f Nerve entrapments, lower extremity, 270 Occupational illness. See also specific illness motor strength examination, 59–60, Nerve injuries defined, 269 60f–62f, 60t degrees of, 375 reflex examination, 60, 62, 63f–65f, 63t of foot and ankle, 375–377 Occupational injuries, defined, 269 sensory examination and dermatome classification of, 375 Occupational Medicine Practice Guidelines, of testing, 59, 59f entrapment neuropathies, 375–377 specialized physical tests, 64–65, 65f workplace-related, 364 American College of Occupational and palpation in, 59 Neural network technique analysis of Environmental Medicine, 299, 301 patient history in, 56–57, 57t motion patterns, in low back pain Occupational MSDs, defined, 269 patient interview in, 56 evaluation, 122 Occupational Safety and Health Administration Neuroarthropathy, Charcot, in diabetics, (OSHA), 3, 4, 211, 411 391–392, 392f O’Connor Finger Dexterity Test, 233–234 O’Connor Tweezer Dexterity Test, 233, 234 Official Disability Guidelines, 411 O*NET, of U.S. Department of Labor, 234 Opioid(s) for hip pain, 301 for low back pain, 131 Oppenheim’s sign, 60

Index 425 Orthosis(es) Peroneus longus tendon, tear of, workplace- Proximal interphalangeal joint, osteoarthritis of, ankle foot, 383, 386, 391, 392f related, 354–355, 355f 245–246 cervical (Philadelphia collar), 82 foot, at workplace, 389 Phalangeal fractures, workplace-related, 361–362 Psychologic factors, musculoskeletal disorders sports-related foot and ankle injuries due to, Phalanges, 341f, 342 and, 14–15 336–337, 336f supramalleolar, UCBL, 390, 391f fractures of, 244 Psychophysical responses, in analysis of job task Phalen’s test, 239 demands, 203, 203f OSHA. See Occupational Safety and Health Phillips head screws, 251f, 252, 252t Administration (OSHA) Physical capacity evaluation, in wrist and hand Psychosocial factors in low back pain, 114–115 Osteoarthritis evaluation, 234 MSDs and, 14–15 hip, 270–271 Physical job stresses, in analysis of job task relationship between, 15–16 imaging of, 296 work-related, 13–18 treatment of, 299, 301f demands, 202–204, 203f biopsychosocial model, 13–14, 14f knee, 271 event-based vs. time-based observations, 203 described, 15–16 treatment of, 304–305, 305f, 306f measurement of posture and force, 202 evidence for, 17–18, 17f lower extremity, 270–271, 270t prediction of posture and forces in, 203–204 heredity as factor in, 270 psychophysical responses, 203, 203f Psychosocial interventions, for MSDs, prevalence of, 270, 270t surface EMG, 202–203 16–17, 17f wrist and hand, 213, 244–246, 244f, 245f Physical Work Performance Evaluation, 402 Physician(s), role in disability evaluation, Pulling, low back pain associated with, work Osteochondral lesions, of talus adaptations for, 138, 139f diagnosis and treatment of, 368 409–416 workplace-related, 355, 355t Pistol-grip power drivers, 255–257, Purdue Pegboard Test, 233, 234, 234f Pushing and pulling, low back pain associated Osteonecrosis, of hip, treatment of, 301, 302f 256f, 257f, 257t Oswestry, 9 Plain radiographs. See Radiography with, work adaptations for, 138, 139f Overexertion theory, of musculoskeletal injury Plantar fascia rupture, diagnosis and Putti-Platt procedure, for shoulder causality, 135 treatment of, 374 instability, 188 Overuse injuries, ankle-related, diagnosis and Plantar fasciitis Q treatment of, 370–372 diagnosis and treatment of, 374 workplace adaptation of workers with, 390 Q-angle, 279 P Playing surfaces, sports-related foot and ankle Quebec Back Pain Disability Scale, 9 Quebec Task Force classification, 122 Pain injuries due to, 337 Quebec Task Force on Whiplash-Associated anterior knee, treatment of, 306 Plier(s), 252–253, 253f, 254t back. See Back pain “Popeye” muscle, 172 Disorders, 26 foot and ankle, after foot and ankle injuries, 386 Posterior atlantodens interval, 82 QuickTime, 201 heel Posterior cord of brachial plexus, 59 diagnosis and treatment of, 374–375 Posterior talofibular ligament, function of, 367 R workplace adaptation of workers with, 390 Posterior tibial nerve, entrapment of, 376–377 low back. See Low back pain Posttraumatic injury, wrist and hand, 224, 224f Radial tunnel syndrome, 152 musculoskeletal, prevalence of, 397 Posture Radiograph(s), in neck injury evaluation in neck, in workers, epidemiology of, 25–40. See also Neck pain, in workers, measurement of, in analysis of job task workers, 66–67, 66f, 67f epidemiology of demands, 202 Radiography “patellofemoral,” treatment of, 306 rating of, AMA guides in, 413 prediction of, in analysis of job task demands, in elbow evaluation, 178–179, 179f wrist and hand, 232 203–204 in hip evaluation, 296, 299, 300f in knee evaluation, 296 “Painful arc,” 171 Power hand tools, 249, 253–262 in low back pain evaluation, 119–120 Passive range of motion (PROM), in neck injury accessory handles and torque reaction arms, in shoulder evaluation, 172–174, 173f, 174f 258, 259f Radiohumeral joint, articulation of, 164 evaluation in workers, 58 dynamic forces with, 260–262, 260f–262f Radionuclide bone scan, in low back pain “Patellofemoral pain,” treatment of, 306 handle force model, dynamics of, 261–262, 261f Patient Specific Functional Scale, 66 in-line power drivers, 256f, 257–258 evaluation, 121 Patient-rated Wrist Evaluation Questionnaire, 228 pistol-grip power drivers, 255–257, Radioulnar joint, articulation of, 164 Pectoralis reflex, 62, 65f 256f, 257f, 257t Ranawat measurement, 82 Percentages of maximum voluntary right-angle power drivers, 254f, 257, 258f Randomized control trials, in analytic static forces with, 254–258, 254f, 255t, contraction (%MVC), 198 256f–258f, 257t epidemiology, 8–9, 8f Performance, defined, 398t tool counterbalancers, 259–260 Range of motion (ROM) Performance areas, defined, 398t tool torque buildup model, 260f, 2602–261 Peroneal nerve abnormal, after foot and ankle injuries, Practicality, of FPE, 405–406 384–385, 385F common, entrapment of, 376 Predictive validity, defined, 403t deep, entrapment of, 376 Prevalence, defined, 25 ankle plantar flexion and dorsiflexion, 385 superficial, entrapment of, 376 Prevalence rate, defined, 4 calcaneocavus, 385 Peroneal tendon injuries, diagnosis and “Preventing Knee Injuries and Disorders in equinus of ankle, 384–385 hallux limitus, 385, 385f treatment of, 371 Carpet Layers,” 318 ankle, 345–347, 346f Peroneus brevis tendon, tear of, workplace- Prognostic study, in analytic epidemiology, hip, 290–291, 291f knee, 294, 294f related, 354–355, 355f 6–7, 6f in neck injury evaluation in workers, 55, PROM. See Passive range of motion (PROM) Pronator reflex, 64 57–59, 58f Proximal humerus, fracture-dislocations of, 190 wrist and hand, 228 Rate(s), defined, 3–4