Back Pain - A Movement Problem by Josephine Key

Back Pain: A Movement Problem air into the thoracic cavity. For clarity its action will role and instead are lifted and widened by the be described as appearing to occur in two sequential continuing contraction of the costal and sternal stages. What is important to recognize is that the fibres. The inferior thorax widens in the horizontal points of stability from which the various fibres plane. Importantly this normally includes posterior can act change through the movement.100 basal expansion and not just expansion forwards into the abdomen. Thus in second stage the ribs • First stage. Provided that the spine and lower move, stabilized by the abdominal wall and a stable ribs are adequately stabilized, the crural, costal and axial spine (Fig. 6.9). Clinically it is this second sternal fibres contract and pull the dome towards stage that patients find so difficult. the pelvis. This descent becomes checked by an increase in the IAP, the abdominal contents and While the downward thrust of the diaphragm pro- abdominal muscle tone. This is often termed vides a beneficial pumping action to those organs abdominal breathing and in recumbent postures within the peritoneum, those within the pelvic when antigravity postural tone is less active, the basin warrant protection. Newton100 suggests this abdomen more visibly distends. Excess or deficient is achieved by biomechanics; the sum force of the abdominal activity compromises this action. When diaphragm contraction pushes forward and down upright and moderately active the abdominals are just below the navel, an area reinforced by the trans- constantly active in either concentric or eccentric versus abdominus. Provided that balanced neuro- mode. Thus, in stage one, the ribs and spine are muscular control regulates the lumbopelvis around stable and the abdomen moves as the diaphragm the ‘neutral’ position the pressure does not go descends (Fig. 6.9). directly into the pelvis but is shunted forward from the shape of the iliac bones. The pelvic floor mus- • Second stage. The central tendon now rests on cles and obturator membrane help regulate pressure the abdominal contents ‘held’ there by continued in the pelvic basin. If the lordosis is lost or the pelvis activity in the crural fibres and counter pressure held too far back or forward, protection of the from the abdominal muscles.23 Now it and the pelvic organs will be compromised. lumbar spine (stabilized by the lower lumbopelvic unit (LPU, see p. 110) both become the point of The respiratory wave stable support. The ribs relinquish their support In relaxed states, breathing ideally produces segmental Central tendon movement throughout the axial spine including the pelvis. This movement can be seen when observing 1 2 the prone subject. On inspiration movement com- 1+2 T12 mences at the sacrum, sequences through each seg- ment and finishes at the base of the neck. However, Rib Chaitow70 remarks that more often than not, restricted Crus spinal segments ‘rise’ simultaneously as a block, and movement of the spine occurs in two directions, cau- Vertebrae dally and cephalad from the blocked segments and often very little movement occurs above the T7/8 area. Sacrum 1 First stage Breathing is also reflected in movements of the 2 Second stage pelvis (see respiratory mechanics of the pelvis). Breathing techniques can be utilized in treatment Points of to assist in the release and reduction of activity stability levels of hyperactive muscles around the lower pole of the thorax and pelvic floor. Fig 6.9  Conceptual drawing of the apparent two stages of the diaphragm’s action (CT: central tendon; C: crus; The importance of expiration is frequently R: rib; V: vertebrae; S: sacrum). overlooked Normally, expiration is ‘passive’, longer than inspira- tion, followed by a pause and is associated with para- sympathetic activity and relaxation’110,111 Most of us 92

Salient aspects of normal function of the torso CHAPTER 6 shorten this phase. At the end of expiration the dia- gastrosoleus.113 In a MRI study, Cumpelik103 has phragm is elongated and the abdominals are in a shown that the diaphragm reacts to changes in the reciprocally more shortened position. When respira- posture of the head hands and feet. Activity of the tory demand increases, active expiration through diaphragm can be facilitated by activating reflex pos- abdominal activity becomes more predominant. In tural chain responses initiated from the hands and states of active expiration, we find the renewal of feet which also support and elongate the spine. vigorous and deep inhalation. The abdominals eccentrically lengthen and the diaphragm descends. The most important thing to appreciate about Todd 6 draws attention to the action and emergency the diaphragm is that it acts as a dynamic internal state – jumping, fighting and so on. Here the lower strut as it expands, widens and opens out the centre primary and accessory inspiratory mechanism is also body from inside. a substantial part of the power apparatus used for crouching and springing. This is reinforced by the The construct of the ‘body cylinder’ muscles of the secondary expiratory mechanisms which increase their aid to the diaphragm and is Todd6 draws our attention to the principal units of exemplified in the judo shout, etc. body weight being the head, thorax and pelvis. She says: Breath holding and paradoxical breathing The head is seen to be a trifle over a third of the breadth of the shoulders. The pelvis is When startled, frightened, or in response to ‘shocks’ approximately the width of the shoulders and emotional upsets we reflexley hold our breath. excluding the arms, and is as wide as the widest We gasp, pull in the abdomen and breathe into the part of the rib cage. The three main spinal loads, upper chest. There is a constriction around the heads chest and pelvis are of nearly the same centre body, the diaphragm cannot descend and diameter at their deepest points from front to the pelvic and vocal diaphragms also tighten.112 This back. This fact makes possible a flatter body ‘holding’ can easily become a habit. Instead of the wall both front to back than is usually imagined. abdomen expanding with inspiration it retracts and is If flat boards were placed at front and back so as known as paradoxical breathing. The person becomes to touch the head, chest and pelvis they could be an upper chest breather. This is apparent when kept approximately vertical and parallel. ‘central cinch’ behavior is operant (Ch.10). Respiratory synkinesis At the base of each mass is a diaphragm, the vocal, abdominal and pelvic. If the ‘blocks are Described by Lewit,23 respiratory synkinesis is the stacked’ such that the centre of mass of each unit close association between respiration and the motor is balanced in relation to the axis of gravity, there system in that certain movements are linked with is minimal stress in the system. The diaphragms inspiration or expiration. Locomotion and breathing are in balanced relationship to one another like a develop together – inspiration is facilitatory, exhala- series of stacked rings. tion has an inhibitory effect on muscles. Breathing is automatically involved in embellishing movements Conceptually, the torso excluding the head can of the torso. Looking up, reaching up, and trunk be seen as a slightly irregular ‘body cylinder’; the extension movements are associated with inspira- walls of which are flexible, maintained by a combi- tion. Lengthening of the spine occurs in inspiration.1 nation of spatially flexible bones, fascial sheets and Looking down; trunk flexion movements and stoop- balanced muscle activity. This principally occurs ing are associated with expiration. from the structural and functional integrity of the deep myofascial system (SLMS) and from the Lewit23 also noted Skladal’s observation that the superficial SGMS as appropriate to maintaining its diaphragm contracts when we stand on our toes, integral form in three dimensions183 while at the which led him to describe the ‘diaphragm is a respi- same time allowing adaptable shaping in movement ratory muscle with a postural function and the (Fig. 6.10). As it shifts, twists and distorts it abdominal muscles are postural muscles with a respi- remains ‘open’ in the centre. This requires balanced ratory function’. Janda knew of the strong functional activity between the flexor and extensor muscle relationship between the diaphragm and the systems and the diaphragm. Proportional activity 93

Back Pain: A Movement Problem Pole (spine) Ribs act like hoops/struts Muscular ‘cummerbund’ of Central diaphragm The diaphragm body wall connects thorax ‘ring’ opens the centre and pelvis Spine is the (like a basketball hoop) supporting ‘rod’ Pelvic diaphragm The pelvic bowl is Crura the base of the cylinder Fig 6.10  Conceptual drawing of the ‘body cylinder’ – an idealized functional torso. and correct timing of all muscles is important. The moments or shear’.39 The breath acts as the internal cylinder formed, has an internal cavity which houses antagonist, resisting the squeeze/collapse effect the organ systems. These contain a lot of fluids and from activity of the ‘outer musculature’. The head air. The diaphragm divides the cavity into caudal is an axial load centrally balanced and can be easily and cephalad chambers and regulates the pressures borne by an erect, curved and moving column’6 . . . in both. These internal pressures (intra-abdominal which contributes to the form of the ‘body cylin- and intra-thoracic) are important in helping create der’. Control of the two proximal limb girdles con- functional strength in the cylinder in much the same tribute to the stability of the ‘cylinder’ centre. An way that the carbonated gases inside a CokeW can important aspect is mutual function between the stop it being crushed.114 The maintenance of ‘the spinal flexors and extensors; between the abdom- line’ and integrity of the body cylinder is important inals and diaphragm to provide for their mutual sta- for correct functioning of the diaphragm in its cru- bility; their combined activity in providing stability cial role in breathing and spinal support and control. for psoas function;115 and similarly balance between Conversely, the diaphragm helps maintain the ‘line’ psoas and abdominals to provide stability for dia- of the outer structure from its internal support. The phragm function. When this occurs, the thoracolum- body cylinder, with its base as the pelvis, the central bar junction including the crural arch is stabilized support from the spine, cross bracing provided by from deep SLMS control instead of by superficial the ribs; and its deep system myofascial geometry, holding patterns. This is dealt with more fully in begins to show some resemblance to a tensegrity Chapters 9 and 10. structure. By nature, these are strong and light yet very flexible. They ‘transmit loads through ten- The pelvis is the tilting platform which orients sion and compression only. . . there are no bending the body cylinder. Its optimal spatial arrangement facilitates the alignment of the body cylinder and 94

Salient aspects of normal function of the torso CHAPTER 6 optimal breathing. Effective lumbopelvic control The head aligns itself over the pelvis afforded by SLMS activity in the lower pelvic unit ensures that the pelvis, the base of the cylinder can A ‘Neutral’ B Spine in C Spine in be controlled on the femoral heads and loads can more flexion more extension be transferred through the pelvis from the legs to the trunk and vice versa. Antigravity support for Fig 6.11  Schematic play with altered alignment of the the axial column comes from inside and below major body segments – the thorax and pelvis assume more and not from tensioning the outer muscles, partic- oblique relationships (B) and (C). ularly those around the central torso and the upper body. Forward bend pattern Integrated function in the SLMS helps support The line of gravity the diaphragm and resolve the problem of competi- tion between its dual roles in respiration and pos- Standing/walking tural control. The body wall is free to breathe in Sitting posture and movement. It is interesting to summa- rize the postural role of the diaphragm: Fig 6.12  Schematic drawings of the primary posturomovement patterns which are principally sagitally oriented. • Anterior support and stability of the lumbar spine • Helping control the thorax on the lumbar spine • Stabilizing the inferior thorax and the thoracolumbar junction so that the spine and ribs above are free to move • Widening and holding open the inferior thorax – the diaphragm and abdominals provide mutual stability for each other • Providing stability for the abdominals and psoas to act • Contribution to the Valsalva and dealing with short term high loading. If any of the ‘blocks’ are not centrally supported, an ‘eccentric loading’ situation is created in the spinal column, a problem dreaded by engineers for the imposed stresses this creates. Owing to the super- incumbent mass of the thorax this is probable at the thoracolumbar junction and then the pelvis and thorax don’t work in synchrony together. To counteract this, a combination of regional collapse and muscular holding patterns ensue with predict- able consequences on postural and movement con- trol breathing and balance (Fig. 6.11). The three most basic functional patterns involve the pelvis orienting the body cylinder upright in hip extension; at right angles in hip flexion when sit- ting or in variable positions during forward bending. Standing and walking are predominantly hip exten- sion patterns while sitting and bending/squat are predominantly hip flexion patterns (Fig. 6.12). While all the structures contributing to the func- tion of the body cylinder operate interdependently, the cylinder can be further conceptually viewed as consisting of upper and lower poles. The diaphragm, 95

Back Pain: A Movement Problem and its related function around the ‘solar plexus’, the base of the body cylinder – the pelvis and its serves as a ‘universal connecting principle’ uniting control both spatially and on the femoral heads upper and lower in integrated functional movement become really important. control of the whole body. Firstly the lower pole is explored. Biomechanical function Part B: The pelvic girdle Consideration of the pelvis needs to include the hips as they are both biomechanically and function- General features ally interlinked. The pelvis is like a rocking bridge. It marries a threefold function of bearing and trans- The pelvis has the job of both balancing forces and ferring the weight of the upper body, moving and providing movement. It is the power house of body orienting the body on the legs and moving the legs movement, which derives from both the small on the body. Todd6 suggests this is achieved through movements within it and the movements of it as a its arched structures. The pelvic bowl consisting of whole, all of which play a decisive role for control the sacrum and two innominates forms an arch of the legs and the spine. Continuing with the con- which acts to distribute the body load. However ceptual ‘body cylinder’, the pelvis is the base of functionally, this is in fact a double arch which the cylinder, a platform which orients the torso in behaves differently in super incumbent load transfer its two principal functional alignments to gravity – through the sacroiliac joints depending upon whether vertical and through to horizontal when forward the person is sitting or standing. bending. It acts like a gimbal to balance the torso • In standing: the forces are passed through the on the femoral heads when upright and swings and heavy lower parts of the ilia to the acetabulae where swivels on the femoral heads to initiate movements the head of the femur receives them and transmits of the body cylinder into many permutations of for- them down the leg. ward, backwards and lateral bending. There is a • In sitting: the weight, after passing into the ilia, close interrelationship between pelvic tilt, the travels through their heavy portions in line with the degree of lumbar lordosis and hip position.132 acetabulae, to the lowest point of the ischia, the Movements of the pelvis are always closed chain, tuberosities. Here the whole weight of the trunk is and simultaneously create corresponding forces balanced. and movements in the hips and lumbar spine which • Considered from the ground up, the standing need to be managed. The architecture of the joints arch is the femoro-iliosacral; the sitting is the ischio- dictates that most movement should occur in the iliosacral. hip joint while the sacroiliac and lumbar spine • These two arches are the essential weight bearing movements are only small but need to be ade- portions of the pelvis and the sacrum is the quately controlled. Segmental responses can vary keystone for both (Fig. 6.13). from minimal postural adjustments through to end range movements depending upon the particular Bracing the pelvic arches: action. The centre of gravity of the body lies within re-examining the paradigm the pelvis9,12,129 thus small alterations in its balance of sacroiliac stability can have large ramifications throughout the body. Being able to control and move the pelvis around According to Todd,6 for the pelvis to be balanced, becomes a critical component of movement control the forces acting through the arches should relate in of the axial spine and torso in general. Panjabi and the same manner to the sacral keystone whether sit- White116 have likened the forward bending spine ting or standing. The points of weight bearing, the to a cantilever bending load. To keep the stresses ischia and acetabulae are vertically aligned. The the same throughout the beam, the cross section superimposed weight of the trunk passes from the of the beam must increase as the bending moment sacrum to the hip joint and tends to spread the arch. increases. This occurs through the lumbosacral This ‘is countered by the beam-action of the pubic spine. The maximum force requirement is at the structures upon the flaring sides of the ilia, and is fixed end of the cantilever. This can be equated to 96

Salient aspects of normal function of the torso CHAPTER 6 Sacral canal Dorsal sacroiliac ligament Interosseus sacroiliac ligament Ventral sacroiliac ligament Sacroiliac joint Greater sciatic foramen Sacrospinous ligament Sacrotuberous ligament A Obturator membrane Load transference through the Ischio - ileal sacral arch, when Load transference through the sitting femoral ileo-sacral arch, when bending and standing B Fig 6.13  The two pelvic arches are the essential weight bearing portions of the pelvis with the sacrum the keystone for both. Cross section through the pelvis hip in the frontal plane (A). Schematic view showing lines of force (B). Adapted from Sobotta117, Kapandji16 and Todd.6 reinforced by the tie muscles and ligaments inside controlling the forces. Importantly, the bracing the arch’.6 Additionally, the femora act as buttresses power of the femoral shafts is lost if the thrusts of to the ilia, which in turn buttress the key stone of the the heads are too far forward as occurs when the hips arch. The obliquity of the acetabular plane looks are externally rotated. Here, the counter thrust to down, out and forward hence the thrust of the fem- the body weight is no longer directed back towards oral head is backward in and upward.132 The oblique the centre of the arch at the sacroiliac joint but for- lines of upward force directed up through the sacro- ward and medially towards the pubic rami, increasing iliac joint are tensile forces derived from the ligamen- the tendency for the pelvic ring to spread at the tous myofascial system and meet and balance the sacroiliac joints6 with associated compensatory downward compression force or weight coming movement at L5, generally into flexion. Todd says through the joints of the spine and pelvis. Balanced ‘by use of tie muscles within (my italics) the pelvic neuromyofascial mechanisms orchestrated by appro- arch, connecting lumbar vertebrae, sacrum, ilia and priate activity and timing from groups of muscles femora, we bind this arch together and only a slight and muscle systems become critically important in effort is demanded to maintain the balance.6 97

Back Pain: A Movement Problem Movements of the pelvis: part of a closed system; movement at one joint important initiators of spinal affects the others and their combined movements alignment and movements afford strength yet pliability to the pelvis. Grieve121 quotes a normal study on 144 male uni- There is a void in kinematics and analytical data versity students from 1936 which asserted that: regarding pelvic postures and movements.119 How- ever, the pelvis is the base of support for the spine • In standing, with the exception of flexion and and so control of it is fundamental to all control of extension, all trunk motions are associated with the lumbar spine and in many respects the spine as unpaired, antagonistic movements of the a whole. innominates Pelvic control can be distilled into: • Rotation and lateral bending of the sacrum • Intrapelvic movements occurring between the normally do not occur alone but as correlated innominates and sacrum and motions that are coincidental to antagonistic • Spatial movements of the pelvis as a whole. movements of the innominates The following impressions largely emanate from clin- ical practice with reference to available literature. • Positions of the innominates in normal standing as well as their relative mobility are affected by the Intrapelvic movements dominant eye and hand. The joints within the pelvis are the sacroiliac, The closed chain intrapelvic movements are funda- sacrococcygeal and the symphysis pubis. Frank mental to spatial control of the pelvis as a whole. movement at each joint is small. The sacroiliac They show distinct coupling patterns. To under- joint is capable of 1–4 of angular movement and stand these, it is firstly useful to look at features 1–3 mm of translation.18,120 The sacroiliac junction of the two major composite bones involved: contains the kidney shaped articulation of the joint proper, while caudally it continues as a syndesmo- The sacrum sis121,132 Steindler132 describes the innominates and sacrum as fitting into the pelvic ring under Wedged between the two innominate bones, its considerable elastic resistance, resulting in a great principle movement is sagittal rocking as follows: amount of stored up latent energy. An intrinsic equilibrium exists between the tendency for elastic • Nutation. Where the coccyx at its tip moves expansion of the bones which is checked by back and up and the top of the sacrum known as the opposing resistance of the articulation and of the base moves forward and down. Importantly, the syndesmosis of the ring. If this intrinsic equi- this is associated with an increase in the lumbar librium is destroyed by severing the pelvic ring at lordosis and the close packed most stable position of any point, e.g. by episiotomy or instability of the the sacroiliac joint. Nutation, which tightens up symphysis joint, its integral stability is lost. The most of the sacroiliac ligaments, occurs as a warped surfaces of the sacroiliac joint allow the preparatory movement to prepare the pelvis for joint to exhibit a complex rotational movement increased loading in weight bearing.122 Lumbar not unlike the lumbar facet joints, the coupled multifidus and probably iliopsoas123 directly motion of smaller magnitude, but greater force.2 influence this action with support from the lower Functionally, Grieve121 sees that the sacroiliac pelvic unit (p. 110). joint is incorporated into movement of the spine as a whole and shares in the maintenance of free • Counternutation. The reverse movement where motion from the occiput to the coccyx. Similarly, the tail bone or coccyx tucks under and the lumbar Gracovetsky considers we should see the spine as lordosis reduces. The sacroiliac joint is relatively extending from the atlas to the acetabulum.2 ‘gapped’ and less stable. The pelvic floor muscles Restated, the sacrum/coccyx are important ele- (PFM) and piriformis directly influence this action ments of the axial spine. The pelvic joints form with synergistic activity from the hip external rotators – the obturator group and gluteus maximus. When lying supine the sacrum is passively counternutated.18 On the pelvic aspect of the sacrospinous ligament10 lies the coccygeus which is part of the PFM synergy which actively pulls the coccyx and sacral apex anteriorly into counternutation,10,47 98

Salient aspects of normal function of the torso CHAPTER 6 • Sacral torsion. The sacrum can also rotate about Several important features about the innominates an oblique or diagonal axis within the constraints are worth considering: of the facets of the sacroiliac joint. According to Gracovetsky,2 these axes pass diagonally through S1 • The warped shape of the innominates means that and S3 and the determination of which is in contact rotation in one plane imparts conjunct rotations in depends upon the lordosis. Sagittal rotation of one the other planes. Conceptually the innominates innominate will pull the sacrum into torsion, have been likened to twisted discs,17 a useful particularly if rotation of the other innominate is in analogy in appreciating their movement capabilities the opposite direction. Sacral torsion is part of (Fig. 6.15.a) ‘distorsion’ in the pelvic ring (see p. 103). While not large movements, nutation and torsion of the • In the sagittal plane their anterior rotation about sacrum are functionally important and necessary for the femoral head brings the ischium back and the the effective triplanar swivel action of L5/S1, (the front of the iliac crest forward producing anterior level of the greatest rotation in the lumbar spine5) pelvic rotation. The reverse occurs in posterior and further reflected in the kinematics through the rotation (Fig. 6.15.b). rest of the lumbar spine.120 • In the frontal plane, their contribution to forming Innominate the pelvic ring limits their range of rotation compared with sagittal plane movement however The innominate consists of three fused sections, the importantly the superior (ilia) and inferior (ischia) ileum, ischium and pubis. It is irregularly shaped, poles slightly flare in and out. Slight ischial outflare constricted in the middle and expanded above and is associated with anterior sagittal rotation or tilt and below. The acetabular cavity on the lateral surface ischial inflare with posterior rotation or tilt (Fig. is approximately inferior to midway between the 6.15.c). upper and lower sections. From and through this, the pelvis swivels in multiple planes on the femoral • The inner surfaces of the innominates contribute heads (Fig. 6.14). largely to the two pelvic ‘bowls’ – the ‘superior pelvic bowl’ formed by the two iliac fossae and sacral base, and the deeper ‘inferior pelvic bowl’ formed by the lower part of the sacrum, coccyx 1st Lumbar Rib 11 Rib 11 Rib 12 spinous process Ilium Iliac crest 3rd Lumbar 5th Lumbar Ilium spinous process vertebral body Anterior superior Posterior superior Sacrum iliac spine iliac spine Ischial spine Sacrum Sacral promontory Coccyx Hip joint Coccyx Ischium Ischium Pubis Ischial tuberosity Symphyseal surface Pubis Pubic ramus Femur Medial view Lateral view Fig 6.14  Medial and lateral view of the innominate and its relationship to the sacrum and head of femur. 99

Back Pain: A Movement Problem coccyx form the bony boundaries of the roughly diamond shaped inferior pelvic opening (Fig. 6.17). • Movements of the innominates occur during both closed chain and open chain movements of the hip. Both are functionally very important yet generally poorly controlled, in particular anterior rotation in the sagittal plane. A Anterior Movements of the innominate in closed superior chain movements of the hip Ischial iliac spine tuberosity These can be felt if you lie down on the ground on your back with knees bent and feet on the floor. Place your Anterior superior finger tips on the anterior iliac crests. Locate the sit bones and ‘think’ the movements from here. Imagining iliac spine the innominates like wheels is helpful:17 Ischial • Sagittal rotation of the pelvis in supine: tuberosity • Anterior pelvic rotation. When the sit bones drop back down towards the floor, the Anterior rotation Posterior rotation anterior iliac spines correspondingly move forward. This is anterior pelvic tilt or closed B chain hip flexion. Ileal inflare, ischial outflare Ileal outflare, ischial inflare • Posterior pelvic rotation. When the sit bones is associated with anterior is associated with posterior lift, the anterior iliac spines correspondingly move back. This is posterior pelvic tilt or saggital rotation saggital rotation closed chain hip extension. C • Frontal plane rotation – Inflare/outflare of the innominates. Through rotation of the acetabulum Fig 6.15  Innominates as twisted discs (adapted from around the femoral head in the frontal plane, the ischia can move closer together ¼ ‘inflare’; or further Franklin17) in neutral (A) and showing sagittal (B) and frontal plane Superior/upper bowl movements (C). pubic rami, obturator foramina, ischia and pelvic Inferior/lower bowl floor. Narrowing of one ‘bowl’ serves to widen the Fig 6.16  Inferior & Superior pelvic ‘Bowls’. other and vice versa. The joints of the upper bowl are the SIJ ‘proper’ and symphysis pubis; the ‘joint’ of the lower bowl is the syndesmosis formed by the pelvic floor and the strong sacrospinous and sacrotuberous ligaments which counter excess nutation of the sacrum. The shape, length tension relationships and integrity of this syndesmosis is also affected by hip myomechanics. If the inferior syndesmosis is tight it will hold the sacrum counternutated and directly affect the stability and function in the SIJ (Fig. 6.16). • The pubic symphysis, pubic and ischial rami and ischial tuberosities of the innominates and the 100

Salient aspects of normal function of the torso CHAPTER 6 Median sacral crest Posterior superior iliac spine Superficial dorsal sacrococcygeal ligament Coccyx Greater sciatic Sacrotuberous ligament foramen Sacrospinous ligament Lesser sciatic Greater trochanter foramen Hip joint, articular capsule Ischial tuberosity Inguinal ligament Pubic symphysis Fig 6.17  The inferior pelvic opening viewed from behind/below with the pelvis flexed 90  on the femur. apart ¼ ‘outflare’. When the ischia move ‘in’ the ilia • The lumbar lordosis increases as the spine moves correspondingly move ‘out’ as is shown in Fig. 6.15 into extension. and vice versa. Movement of the ischia will be used as the reference point. The innominate movements • The hips move into relative flexion. carry the sacrum with them in various ways. • This pattern is fundamental to any movement The fundamental pelvic patterns which requires flexing or bending at the hips e.g. sitting or bending forward in standing. There are palpable and observable distinct patterns of kinematic coupling during sagittal closed chain • This pattern is principally achieved from synergistic pelvis on femur movements. The fundamental pelvic concentric activity of the ‘lower’ transversus patterns are physiological movements which are basic abdominis, iliacus, and multifidus with eccentric to achieving modulated posturomovement control control from the pelvic floor muscles and the of the pelvis in space and on the legs and control obturator group. Activating the ‘superior/upper pelvic of the lumbar lordosis. bowl’ serves to narrow this and open the inferior pelvic bowl’. Studies have shown that transversus activity is First fundamental pelvic pattern (FPP1) greater when the pelvis is neutral or in anterior pelvic tilt.87,98 This ‘squeeze’ action of transversus with This involves anterior pelvic tilt and ischial outflare. iliacus is important in providing pelvic stability during When the ischia widen or move apart associated closed chain hip flexion loading patterns (Fig. 6.18). actions also occur: • The ilia draw together in the front and anteriorly • This pattern underlies control of all hip flexion rotate in the sagittal plane. The superior pelvic bowl movements such as sitting, sitting to stand and narrows. return, forward bending and squatting. • The sacrum nutates and the coccyx moves away from the symphysis pubis as it ‘comes out • Clinically, it is almost a universal finding that for air’. most people have little idea or ability to perform • The dimensions of the inferior pelvic bowl and this action which is so fundamental to myo articular the pelvic floor enlarge as it ‘opens’ (Fig. 6.20.b). function of the lumbopelvic region. Instead they attempt the movement as Bartenieff noted ‘three storeys too high’28 from inappropriate SGMS activity around the thoracolumbar region. 101

Back Pain: A Movement Problem Fig 6.18  Ischial outflare: note the ‘drawing in’ of the Fig 6.19  The ischial inflare: note the flaring of the superior superior bowl. bowl. Second fundamental pelvic pattern (FPP2) • Clinically, this pattern can usually be more easily performed by most people, as they habitually FPP2 involves posterior pelvic tilt with ischial collapse in sitting and then carry the pattern inflare. When the ischia move towards one another forward when standing. Here they shift their pelvis the following also occurs: forward using the hamstrings, passively ‘hang’ on their iliofemoral ligaments and ‘hold’ with the • The ilia not only spread apart but they also obturator group while the rest of the SLMS is posteriorly rotate. The superior pelvic bowl ‘opens’ relatively inactive. It is also seen in those who are more. ‘butt grippers’.18 Intrinsic activity is usually reduced. • The sacrum counternutates and the coccyx • Control of this pattern underlies control of moves closer to the symphysis pubis. The tail bone closed chain hip extension allowing us to move is ‘tucked under’. through postural transitions and be upright • The dimensions of the inferior bowl and pelvic FPP1 and FPP2 underlie all sagittal flexion and floor or pelvic diaphragm become smaller – the extension movements of the torso over the legs. lower pelvic bowl ‘closes’ (Fig. 6.20c). Third fundamental pelvic pattern (FPP3) • The lumbar spine moves into relative flexion. FPP3 involves combined elements of FPP1 and FPP2, • The hips move into relative extension. hence is reliant upon adequate control of these. The sagittal rotation of the innominates in opposite • This pattern is fundamental to any movement directions carries the sacrum into torsion. The pel- requiring opening and extending at the hips e.g. vic ring or whole pelvis is in ‘distorsion’. sitting to stand; backward bending in standing. To clarify this, sagittal rotation of one innominate • Ischial inflare is principally achieved from creates a twist or torsion at the sacroiliac joint and concentric action of the pelvic floor muscles, the whole pelvic ring, which is greater if the other the obturator group with piriformis and even innominate is rotating in the opposite direction, gluteus maximus with eccentric control from e.g. if the right ileum is anteriorly rotating the top iliacus and transversus. Activating the lower of the sacrum is carried forward with it into nuta- pelvic bowl opens the upper bowl (Fig. 6.19). tion and also twists about an oblique axis. The joints Bendov´a et al.124 electrically stimulated the right of the right lumbosacral junction move into a ‘closing’ sided pelvic floor muscles and demonstrated medial tilting (ischial inflare) and posterior rotation of the right innominate (and posterior rotation also of the left innominate). The coccyx moved ventrocaudally. 102

Salient aspects of normal function of the torso CHAPTER 6 Coccyx Sacrum FPP3 essentially underlies all weight shift and rota- tion through the pelvis hence it is an important compo- Ano-rectal Ilium nent in unilateral weight bearing, walking and balance. triangle ‘Distorsion’ The ability of the pelvic ring to sinu- ously distort in three planes/dimensions while main- Ischial tuberosities Ischial tuberosities taining its stable integrity yet facilitating hip and Uro-genital triangle Pubic symphysis spinal movements is important in allowing the flexi- ble and adaptable transmission of the movement A Neutral C wave and loading to proceed through the pelvis – both from the upper to lower body and vice versa. IT IT Contrarotation of the innominate bones carries the sacrum into torsion and occurs in most activities PS except pure spinal flexion and extension.120 A force B Ischial outflare ‘opens’ the floor dependent oblique axis of sacral rotation is formed by the complex rotational movement between the C facets of S1 and the contralateral S3.2,147 The inno- minates and sacrum must be free enough to oscillate back and forth in this twisting movement so that the rotary movement wave can be transferred and dissipated through the pelvis from and to the hips. If not, the low/mid lumbar spine levels are forced to compensate. Gracovetsky3 has drawn attention to the impor- tance of the lumbar lordosis (and by association, sacral nutation) in effecting axial torque through the spine in walking. Intrapelvic torsion or ‘distor- sion’ and rotation of the whole pelvis in the trans- verse plane is a significant driver of axial rotation about a longitudinal axis, both important in walking, for example, and those more strenuous rotational activities such as tennis or golf. Distorsion allows IT IT Sacrum is carried into rotation on an oblique axis PS C Ischial inflare ‘closes’ the floor Fig 6.20  Schematic diagram of the inferior pelvic opening in the neutral (A), open (B) and closed positions (C). pattern – extension/side bending/rotation, while Coccyx moves those on the left are relatively ‘open – flexed, side to the left bent and rotated in the opposite direction – particu- larly if the left innominate is posteriorly rotating. Left - Innominate in This includes the right ischium abducting (outflare) posterior rotation and the left adducting (inflare) in the example above. The whole pelvic ring while stable, is distorted which Right - Innominate in we have termed ‘distorsion’ (Fig. 6.21). anterior rotation Fig 6.21  Schematic interpretation of ‘distorsion’ in the pelvic ring. 103

Back Pain: A Movement Problem the sacrum to ‘rock n roll’ and twist initiating axial rotation from the base. Problems arise when distor- sion is reduced or becomes fixed in one direction. Contraction of one piriformis will bring the sacrum into torsion134 and counternutation. Unilateral elec- trostimulation of the pelvic floor muscles simulating unequal activity and tension between sides has demonstrated distorsion in the pelvic ring.124 ‘Distorsion’ is also involved in many lower limb movements and related change of postures, e.g. side sitting and moving to all fours and to standing. Dis- torsion is also required in large full range open chain movements of the hips – for example, anterior rota- tion of the innominate is coupled with hip extension and if the opposite is flexed, that innominate moves into posterior rotation. Inadequate control of ‘distorsion’ through the pelvis instead ends up shunting the movement into the lumbar spine and is a cause of much low back pain and self inflicted back problems through poor stretching and exer- cise programs. Movements of the innominate in open Fig 6.22  Poor control of open chain hip flexion with posterior rotation of the whole pelvis and reduced frontal plane control. chain movements of the hip rotation and reduced intrapelvic motion means that The rotation of the innominate in open chain hip this posterior rotation occurs in the whole pelvis as movement is in the opposite direction to that in it moves ‘en bloc’ (Fig. 6.22). This is common and closed chain movements of the hip. These innominate pulls the lumbar spine into early and excess flexion movements serve to augment and increase the avail- and rotation to compensate with predictable effects able range of the hip during ‘free’ hip movement. on the tissues over time. Poorly designed exercise pro- They come into play later in the range of hip move- tocols which advocate ‘knee to chest’ without regard ment when capsular and related hip structures to the hip pelvis dynamic, compound the problem. become taught. Hence ‘open’ hip flexion is associated with posterior rotation of the innominate (while in Lee18 proposes that ‘in health’ open chain or free hip ‘closed chain hip flexion the innominate anteriorly extension is associated by the innominate anteriorly rotates). Standing hip flexion towards 90 involves a rotating, a pattern that this author agrees with as it is posterior rotation of the innominate relative to the readily confirmed clinically (Fig. 6.23). Again this is sacrum. Hungerford and Gilleard,125,126 found that the reverse pattern of innominate rotation to that seen in control subjects this occurred on average around in the closed chain scenario. The presence of associated 73 of hip flexion. This is also known as the standing frontal plane innominate movements in open chain hip stork or Gillet test.18,128 movements is unclear both clinically and in studies.18 Generally most people, ‘patients’ or otherwise, display Increasing the pelvic motion on the standing leg faulty open chain hip flexion and extension. can be employed to functionally increase hip range of movement in the moving leg. For example, experi- enced dancers tend to use more anterior and posterior pelvic tilt, rather than hip flexion and extension, in order to increase the gesture leg height.127 However those who have posterior hip stiffness and/or habitually poor and compromised pelvic motor control will expectedly posteriorly rotate the innominate earlier in range during ‘open’ hip flexion. Habitual weight bearing in posterior pelvic 104

Salient aspects of normal function of the torso CHAPTER 6 Fig 6.23  Open chain hip extension with ipsilateral anterior • Posterior shift is coupled with anterior pelvic rotation. rotation of the pelvis on the femoral heads, and creates associated hip flexion and lumbar Spatial pelvic movements extension. It is dependent upon FPP1. In movement this posterior shift pattern is used These constitute movements of the pelvis as a to initiate hip flexion/trunk forward whole while also controlling intrapelvic forces and bending18,128 and other movements related to movements, particularly during weight shift. They this pattern (Fig. 6.24a).18,128 differ according to whether the weight bearing occurs through the femoral heads as in standing or • Frontal plane. The pelvis can shift to either side kneeling; or through the ischia as in sitting. and is again coupled with rotation on the femoral heads and associated changes in the alignment of the Standing spatial control hip and lumbar spine. If standing on two legs, and the pelvis shifts to the right, the pelvis assumes an Standing spatial control of the pelvis is achieved by oblique position, in this case higher on the right.23,129 spatial shifts and related rotations at the hip joint There is relative adduction of the right hip, abduction which serve to balance and tilt it on the femoral of the left and the lumbar spine assumes a relative heads. Movements vary from slight postural adjust- right side bending alignment129 and compensatory ments in order to achieve a dynamic upright equilib- adaptations will occur through the spine. It is a rium through to large movements of the body. Due common habit for people to shift their pelvis laterally to the spherical ball and socket of the hip, three- and take the weight more on one leg and ‘hang’ with dimensional, multiplanar movements are available; the weight-bearing hip in passive adduction – the however, they will be considered within the three SLMS is switched off! (Figs. 6.24b; 8.5.) principal conceptual movement planes despite the fact that functional movement is rarely ‘pure plane’. • Standing on one leg is a revealing test. This is The magnitude of movements is far greater in the sag- also known as the Gillet, stork or kinetic test.18 ittal plane than in the other two planes. Their signifi- If there is adequate control the ‘neutral’ pelvic cance and the need for greater control are apparent position is maintained in the frontal and other when standing on, or mostly on one leg. two planes. In fact, there is a slight lift of the • Sagittal plane. The pelvis can shift forwards and pelvis on the non weight bearing side and backwards in space. This is coupled with a adjustment through the spine in the frontal corresponding rotation on the femoral heads and plane (Fig. 6.24b). If control is inadequate, the consequent change in the alignment of the lumbar pelvis either drops on the non-weight bearing curve and sagittal hip position as follows: side or the person leans the trunk over the standing leg, known as the Trendelenberg • Anterior shift is coupled with posterior sign.12 Both compensations create ipsilateral rotation of the pelvis on the femoral heads and side flexion in the lumbar spine with potential creates associated hip extension and relative consequences. The ability to spatially shift and lumbar flexion. It is dependent upon FPP2. control the pelvis medially under the trunk is a This anterior shift pattern of movement is also fundamentally important action in being able used to initiate hip extension and trunk to control the lumbar spine in a reasonably extension from forward bending18,128 and neutral position during lateral weight transfer other movements related to this pattern. of the body over the standing leg. By our observations, this aligning of the axial spine over the weight bearing limb with a stable pelvis is principally achieved through inner support from the lower pelvic unit synergy (p. 110) providing stability for activity in the large SGMS pelvifemoral muscles – the adductors, hamstrings and glutei (see p. 119). • Horizontal plane. Gracovetsky3 draws attention to the importance of pelvic rotation in the horizontal plane in human gait. Rather than the legs 105

Back Pain: A Movement Problem Posterior shift with ‘Neutral’ Anterior shift with which is part of ‘distorsion’ and closed chain hip anterior rotation posterior rotation rotation and also drives the spinal rotation. This was in fact shown by Gracovetsky: it is possible to A Active ‘lift’ ‘walk’ without legs by the ischia alternately advancing.3 This is achieved through active Passive ‘hang’ ‘Neutral’ control of ‘distorsion’ the pelvis can rotate in the B transverse plane on the hips and the sacral torsion drives the spinal rotation. This movement can also be seen in sitting – weight bearing through one ischium, the other can be advanced back and forward to produce backward and forward pelvic rotation respectively. A ‘stable’ spine and leg allows the lower pelvic unit and abdominal and extensor system muscle synergies to create this rotation. Backward and forward pelvic rotation in the horizontal plane is the postural precursor to axial rotation needed in the body. This is an important movement as rotation in the lumbar spine itself is limited. This axial pelvic rotation is associated with movements in the hips but to a lesser degree in the lumbar spine. A reduced lordosis makes transverse plane pelvic rotation more difficult.130 According to Gracovetsky, those muscles which operate more or less in the transverse plane – the obturator group including pyriformis and the lower fibres of gluteus maximus could conceivably axially rotate the pelvis.131 • Forward pelvic rotation creates ipsilateral external hip rotation relative extension and abduction and contralateral hip internal rotation.132 • Backward pelvic rotation creates ipsilateral internal hip rotation relative flexion and adduction and contralateral external hip rotation132 (Fig. 6.24c). Walking is a combination of controlling subtle mul- tiplanar combinations of pelvic tilting and shifting. A reduction in the rotary range and control of the hips will reduce the transverse plane pelvic rota- tion with predictable effects through the kinetic system. Hip joint Left forward Sitting spatial control pelvic rotation Left backward The weight is taken through the ischia and thighs. C pelvic rotation Here the principal movement is tilting with shift- ing less prevalent. Sagittal tilting of the pelvis is Fig 6.24  Triplanar spatial pelvic shifts and related rotations the most dominant movement with lateral tilting in the sagittal (A), frontal (B) and horizontal planes (C). and axial rotation less so though still important. Freedom to move around on the ‘sit bones’ is criti- rotating the pelvis and carrying the ‘passenger trunk’ cal for spinal health. These tilts and to a lesser he considers that it is the spine that drives the pelvis to rotate. This author proposes that the pelvis itself is able to initiate horizontal plane rotation 106

Salient aspects of normal function of the torso CHAPTER 6 extent shifts, are all very important in initiating • Posterior pelvic tilt creates relative hip weight shift in sitting and moving from sitting to extension, lumbar flexion. In combination with stand and are instigated through the lower pelvic shifting their pelvis forward in the seat, it is unit synergy. almost universally common habit for people to passively adopt this pattern when sitting with Sagittal plane weight shift occurs through rocking unfortunate long term sequelae on their tissues – a forward and back on the ischia as the acetabulae rotate potent propagating factor in the genesis of low on the stationary femoral heads. This creates a contra- back pain. directional lumbar rhythm12 which is not obligatory. • Frontal plane or lateral tilting of the pelvis • Anterior pelvic tilt creates hip flexion with related occurs when weight is shifted laterally over one lumbar extension however flexion is also possible as ischium, the acetabulum rolling up and over the seen at the end of range when bending forward in femoral head. The base of support for the torso is sitting. Transversus abdominus and the pelvic floor one ischium and if the movement continues further muscles are more active when the spine is as in reaching to the side, may result in the femur extended.141 Multifidus is most active when the low becoming the base of support (Fig. 6.26). Note the lumbar lordosis posture is adopted133 (Fig. 6.25). oblique slope of the pelvis (pants line) and that the axial spine adjusts by laterally elongating. • Horizontal plane movement involves unweighting one ischium as above and moving it either forward or back in sagittal rotation creating ‘distorsion’ and initiating trunk rotation to orient the spine head or upper limbs (Fig. 6.27). Fig 6.25  Anterior pelvic tilt on a fixed femur allows forward Fig 6.26  Lateral weight shift initiated from the ischia. Note weight shift of the body. the elongation of the trunk on the weight bearing side. 107

Back Pain: A Movement Problem or observed to anteriorly rotate on inspiration.112 Muscular holding patterns in the pelvic floor or but- tocks will damp the response. Functional movement control of the pelvis requires adaptable control independent of the breathing cycle. The respiratory mechanics of the pelvis can be utilized in manual treatment of the pelvis. The pelvic floor or diaphragm Fig 6.27  ‘Distorsion’ in sitting. Note the position of the The boundaries of the diamond or somewhat trape- femur and the trunk rotation. zoidal shaped inferior pelvic outlet are formed by the symphysis pubis in front, the coccyx behind, Respiratory mechanics in the on each side the inferior pubic ramus and the ramus pelvis of the ischium, the ischial tuberosity and the sacro- tuberous ligament.10 An imaginary line drawn trans- The breath creates a movement wave in the spine versely in front of the ischial tuberosities divides the with a consequent oscillation of the pelvis on the region into two triangular parts. The posterior part femoral heads which varies according to the pos- contains the anus and is known as ‘the anal triangle’, ture. Clinically during deep inhalation in the prone while the anterior part is the ‘urogenital triangle’ or side lying position, the sacrum and ilia posteriorly containing the external urogenital organs (Fig. 6.20). rotate134 – the sacrum counternutates. The sacral excursion is deemed to be about 3 mm more than The pelvic diaphragm or floor is a myofascial that of the ilia.134 This is no doubt due to the hammock which spans the inferior opening (Fig. demonstrated coactivation between the diaphragm 6.28). It is composed of the composite levator ani and the PFM.92,95 Rock maintains that during inspi- and the coccygeus,10,135 collectively known as the ration the PFM activity is an eccentric contrac- pelvic floor muscles (PFM). tion.20 In the supine ‘crook’ position, the sacrum is already counternutated18 and the pelvis can be felt • The levator ani forms the greater part of the floor and morphologically can be divided into: • Pubococcygeus (from the pubis and anterior obturator fascia to the coccyx) • Iliococcygeus (from the ischial spine to the coccyx). • The coccygeus is posterosuperior to but in the same tissue plane as levator ani. It is a triangular sheet of muscle arising by its apex from the pelvic surface of the ischial spine and sacrospinous ligament and attached at its base to the margin of the coccyx and the 5th sacral segment.10 The coccygeus, levators ani and piriformes act in synergy to close the posterior triangle of the pelvic outlet10 (Fig. 6.20). The functions of the pelvic floor have been described as supportive counteracting the effects of gravity and intra-abdominal pressure; sphincteric, aiding closure of the anus vagina and urethra; and dilative during birth.136 The synergistic role the PFM share with the dia- phragm and transversus is an important one for both the generation of IAP and also in respiration, partic- ularly in cases of respiratory challenge.98 108

Salient aspects of normal function of the torso CHAPTER 6 Pubic symphysis Superior ramus of pubis Levator ani, pubococcygeus Body of pubis Anterior inferior iliac spine Ischial spine Obturator internus Coccyx Tendinous arch of levator ani Coccygeus Levator ani, iliococcygeus Sacrum Piriformis Sacroiliac joint Fig 6.28  The muscles composing the pelvic floor viewed from above. Importantly, the PFM also perform an important • Does not involve any visible movement of the dynamic role in helping modulate intrapelvic kine- pelvis or outer body matics124,137, to support posturomovement control of the spine and hips. They exert a powerful influ- • Can be felt by vaginal palpation and observed as ence upon sacro-coccygeal mobility as well as longi- movement of the perineum in a cranial direction tudinal fascial and craniosacral mobility.47 A predominance of type 1 fibres is indicative of their • Submaximal contractions can be felt in isolation. functional role in postural support. Perturbation While isolated voluntary concentric activation initi- studies of the spine show that the pelvic floor is ally provides the ‘feel’ and is targeted to sphincteric pre-activated as part of a postural control synergy closure, posturomovement activity of the floor prior to upper limb movement.94 Elevation of the should involve some intrapelvic movement as its con- pelvic floor is easier in standing than lying.138 The traction counternutates the sacrum98,124,137 and spatial position and tilt of the pelvis will affect the closes the lower pelvic opening while opening the forces imposed upon the floor and the degree of upper (Fig. 6.20). Importantly, the PFM must also its postural reflex activity. be able to eccentrically ‘let go’ (see below). In continent individuals, physiological (reactive) Synergistic activation relationships have been pelvic floor activation is automatic resulting in a shown between the PFM and the deep abdom- mid position of the floor, while voluntary activation inals;140,141 PFM and the transverse fibres of inter- results in elevation of the bladder neck.20 B´139 nal oblique81; PFM and the diaphragm.92 points out that voluntary activation is undertaken Voluntary activation of the abdominal muscles to reach the automatic response level. She describes activates the PFM prior to the abdominal action, ‘a correct pelvic floor muscle contraction’ as: indicating a pre-programmed response.140 Clinical practice suggests lower abdominal activity may be • A mass contraction of the three layer muscles more linked to greater activation in the anterior tri- producing an inward movement and squeezing angle of the floor. around the pelvic openings Clinical practice also suggests that muscles syner- gistic with PFM activity – in particular the posterior 109

Back Pain: A Movement Problem floor, are the obturator group including piriformis, ‘Fundamental pelvic patterns of gluteus maximus and hamstrings. Obtaining eccen- movement’: controlled by tric lengthening in the posterior floor40 and these synergies involving the ‘lower muscles can be difficult and contributory towards pelvic unit’ (LPU) pain in many. They literally have a ‘tight arse’. Hartley142 suggests balancing eccentric and concen- The three fundamental pelvic patterns of movement tric contractions of the PFM helps tone and provide three-dimensional modulation of the pelvic strengthen its supportive function. Competent pos- ring which we have termed ‘distorsion’. Essentially turomovement control of the pelvis thus involves they provide for lumbopelvic control and support the PFM working concentrically and eccentrically closed chain and open chain movements of the hip in cooperative synergies with those muscles that (see above). These patterns underlie all movements control closing of the superior pelvic bowl – the that the pelvis performs as it initiates and supports transversus, internal oblique, multifidus, and iliacus. movement in the spine and hips while at the same Rock20 suggests that the important eccentric control time marrying control between them. They underlie of the PFM can be activated through breathing – all weight bearing and weight shift through the pelvis ‘physiological inspiration combined with reactive on the femur and help to control the neutral lumbar eccentric contraction of the pelvic floor muscles is curve. So what muscles contribute to the synergies only possible when concentric action of all parts of that perform those movements? the thoracic diaphragm coincides with eccentric contraction of the abdominals’. ‘Lower pelvic unit’: support comes from within and below Imbalanced activity in the intrinsic PFM or extrinsic muscles acting upon the pelvis will affect These muscles all belong to the SLMS providing anti- the pelvic floor myomechanics. Spitznagle136 sug- gravity support and control (see Ch.5). Their coordi- gests that the performance of the PFM is directly nated synergistic activity provides a continuous related to the obturator internus as the origin of myofascial sleeve of deep inner support and control pubococcygeus is from its enveloping fascia.136 If from the femur through to the upper body. The mus- the fascia is taught so is the pelvic floor musculature cles belonging to the LPU are shown in Table 6.1. and if slack the muscles are likewise so. Accordingly changes in the position of the femur will affect the There is now good scientific evidence and accep- pelvic floor.124 The typical posture of children tance for inclusion of all the muscles in the left hand urgently needing to urinate and attempting to column. Some research implicates inclusion of those inhibit this, involves a postural change that com- in the right hand column. Clinical practice dictates that bines hip adduction and flexion. This action pas- all those muscles shown merit inclusion. They all play a sively pretensions the pelvic floor by elongating the obturator internus and facilitates pelvic floor muscle Table 6.1 The principal muscles of the lower pelvic unit activity, and when practiced has been shown to synergy reduce cough induced incontinence by 95%.143 If the obturators are chronically shortened as is com- Transversus abdominus Deep intersegmental muscles: mon in back pain, pelvic floor muscle function will Internal oblique À1 multifidus, interspinales be compromised. intertransversarii, rotatores lower fibres The fundamental patterns of intrapelvic con- External oblique À1 lower fibres trol ask for eccentric/concentric/ activity of the Diaphragm Iliacus PFM to open and close the pelvic diaphragm. Psoas major and minor They provide a functionally sound method for Pelvic diaphragm: Pectineus integrating pelvic floor muscle activity into the Deep hip rotators; posturomovement patterns of the pelvis. Function- levator ani. coccygeus *obturators, piriformis ally meaningful movement control always involves Multifidus À1 deep coordinated activity of all muscles in the synergy to produce an appropriate pattern of response fibres during automatic actions such as coughing or dur- ing intentional activities such as running or Quadratus lumborum jumping.144,145 À1 medial fibres 110

Salient aspects of normal function of the torso CHAPTER 6 Diaphragm Quadratus lumborum muscle Multifidus and other deep intersegmental Psoas muscle intrinsic muscles Iliacus muscle Transverse and lower oblique muscle Obturator internus muscle Pelvic floor muscles, obturators and piriformis Deep hip rotators Pectineus muscle Fig 6.29  Schematic drawing of the muscles contributing to the LPU which provides both an inner framework of deep anterior support to the column and ‘hoop support’ to the column and pelvis, functionally connecting the thorax, pelvis and hips. role in lumbopelvic control. Referring again to the body lower transversus, internal oblique and iliacus in cylinder construct, it can be seen that LPU provides concert with the others in the synergy. Breathing both a framework of deep anterior support of ‘the col- is facilitated. umn’ as well as providing an ‘inner hoop support’ which connects and integrates function between the Richardson et al86,87 advocate maintaining a neu- thorax, lumbar spine, pelvis and hips. Importantly this tral spine and ‘drawing in the lower abdomen’ or integrated support comes from within and below abdominal hollowing to activate the deep musculo- (Fig. 6.29 also Fig. 6.34). What is quite extraordinary fascial corset. The problem is that in the clinical is that to date, two of the most important muscles in setting, despite careful prompts and supervision, for the synergy responsible for effective load transfer many this predictably tends to activate the upper through the pelvis, the psoas and particularly iliacus, abdominals, create a flexion moment of the lumbar have been largely unrecognized and ignored by the con- spine, posterior pelvic tilt and breath holding as it is temporary scientific community. Poor old iliacus! It an ‘action that doesn’t go anywhere’ (Fig. 6.30). has been quietly getting on and doing such a good job Patients generally cannot create a ‘neutral spine’ – or otherwise. Maybe it’s a case of out of sight out and ‘holding patterns’ are already a problem for the of mind. Its role deserves more attention. Likewise patient. Rather, activation of the LPU and the rein- the obturator group serve an important function. troduction of important components of useful func- tional patterns of movement help appropriate control Activation of the lower pelvic unit involves focus- of lumbopelvic alignment and ‘stability’. At the same ing movement from the sit bones and tail bone – time activity in the diaphragm is facilitated as well as initiation from ‘down in the basement of control’. helping to achieve the ‘hip hinge’ control advocated Drawing the sit bones apart equates with drawing by McGill8 when forward bending. the anterior iliac spines closer together in the frontal plane. This can be felt to beautifully activate the The functional role of the LPU synergy can be summarized as contributing to: 111

Back Pain: A Movement Problem Fig 6.30  The patient thought she was activating which acting at the sacrum, causes the innominate transversus; however, note the tendency to axial ‘total flexion to posteriorly rotate through the acetabular axis. This pattern’ behavior including posterior pelvic tilt. backward tilt of the pelvis accentuates the sacral nutation. These forces are resisted by a counterbalan- • Providing basic antigravity support of the cing tensile stress in the anterior sacroiliac, and segments including equilibrium especially the sacrospinous and sacrotuberous liga- • Adaptive postural presetting of the pelvis to ments.16,146 According to DonTigny,147 a force support trunk movements dependent transverse axis is established through the • The respiratory and postural role of the breathing sacrum but not necessarily through the sacroiliac mechanisms joints. This axis of rotation is approximately through • The generation of IAP for spinal support the S3. In fact however, this analysis relates more to • Provision of the basic movement patterns of the the forces involved as there is little movement, any pelvis hip and lumbar spine tendency being resisted by the powerful ligaments. • Control of forces from legs to pelvis and torso to The sacroiliac joint is ‘wound up’ through this self pelvis and load transfer through the pelvis locking and so is stabilized within the pelvic rim • Initiating movement from the pelvis on the femur (Fig. 6.31). If the pelvis posturally shifts forward, • Connecting function between the upper and lower this mechanism is compromised. body. Line of gravity While providing fundamental support, LPU activity will obviously also involve other muscles depending Body weight upon postural, kinematic and force requirements. S1 P W G N Pelvic tilt – balancing the pelvis Sacrospinous on the legs ligament Sacroiliac joint ‘self-locking’ when Sacrotuberous upright ligament When standing, in the ‘ideal normal alignment’, the W Weight of the trunk GRF weight of the trunk acts as a compression force trans- G Ground reaction force mitted down through the vertebral bodies. This acts N Sacrum nutates upon the superior surface of the sacrum and tends P Innominate posteriorly to rotate it forward into nutation. At the same time the ground reaction force transmitted up through rotates on the femoral heads the femora to the hip joints which are more anterior, forms with the body weight, a rotary force couple Fig 6.31  Intrinsic ‘self locking’ and stability of the sacroiliac joint is influenced by gravitational lines of force. 112

Salient aspects of normal function of the torso CHAPTER 6 Dynamic control of Sagittal pelvic tilt: the inferior pelvis forward at the ischia. They ‘are the important primary role of the deep possibly more important as postural muscles than as intrinsic force couple – iliopsoas and prime movers. . . acting as adjustable ligaments of the obturator group (with the hamstrings) joint in all positions.’10 For ease they will be collec- tively termed the obturator group. They all attach In the sagittal plane pelvic equilibrium is labile.132 to the greater trochanter. Piriformis arises from Gravity practically always produces moments of the saccrum and is the most superiorly placed. rotation which have to be neutralized by neuromus- The rest arise from the ischium and the mem- cular control of these forces. Nine deep muscles brane and rim of the obturator foramen. These provide sophisticated diagonal pulls and essentially six primary outward rotators form a functional balance and adjust the pelvis with the spine on the muscle ‘fan’, each pulling at a slightly different hips and maintain hip range of motion – psoas, ilia- angle to rotate the femur28 and importantly, con- cus, and pectineus in the front, with the piriformis, trol the pelvis on the ‘stable’ femur. obturators internus and externus, the superior and inferior gamelli and quadratus femoris forming the Returning to the static standing construct; ideally, posterior part of the force couple.1,6,28,148 Collec- the line of gravity passes anterior to the sacroiliac joints tively, the posterior group are commonly termed but posterior to the axis of the hip joints, tending ‘the external rotators of the hip’16 or ‘the deep to create an extension moment at the hip, as the six’ which understates their important action on pelvis posteriorly tilts on the femoral heads.9 The the pelvis when the femur is ‘fixed’ (Fig. 6.32). As three strong ligaments at the front of the hip joint they are spatially positioned under the axis of the resist this force – passive reliance on them is a common hip joint they have an important role in ‘swinging’ postural habit. Dynamic control, that is, of anterior pelvic tilt at the hip is achieved by co-active control from iliacus and psoas. This has been demonstrated Sacrum Pelvic bone Lesser sciatic foramen Sacrospinous ligament Greater sciatic foramen Sacrotuberous ligament Piriformis Obturator internus Superior gemellus Ischial tuberosity Obturator externus Inferior gemellus Fig 6.32  The ‘obturator group’ of muscles. Quadratus femoris 113

Back Pain: A Movement Problem Ilio-psoas group, anterior superior to hip Centre of gravity Rectus femoris Obturator group, posterio inferior to hip Hamstrings SLMS muscles A Line of gravity SGMS muscles B Axial flexor & extensor systems Fig 6.33  The pelvic ‘gimbals’ is dynamically balanced between iliacus/psoas and obturator/hamstring groups activity (A). Schematic view (B). by EMG in standing,149,150 standing on one leg, and in their point of intersection would fall at the gravity sitting.151 With pectineus, Todd6 likens their activity line i.e. midway between the axis of the spine and to anterior tension members countering the posterior the legs (Fig. 6.33). Bartenieff148 considers that compression forces at the back. Their activity also thrusts the pelvis back in space. when hamstrings action is not appropriately In a dynamically balanced pelvis, activity incorporated into pelvic-femoral rhythm by the between the obturator group and iliopsoas forms two diagonal planes of force through the pelvis synergistic activity of the deep external rotators which should be equal and opposite. The iliopsoas is supero-anterior, tipping the superior pelvic the hamstrings they simply act as extensors of bowl forward. The obturators and piriformis with the hamstrings are inferoposterior tipping the the knee. Some see that all the deep external inferior pelvic bowl forward. If they are overac- rotators contribute to posterior tilt,1,6 while tive, the pelvis is held in posterior tilt and the lat- eral bracing action of the hips affording stability others see that ‘some’ accompany forward tilt to the SIJ is reduced (see Aspects of normal neu- initiated by iliopsoas103,148 (assumedly obturator romuscular behavior around the spine, above). When both groups are in a balanced relationship, externus). When iliopsoas is not used appropri- ately the rectus femoris and rectus abdominus are overused.148 Rolf1 notes that psoas, iliacus, obturator internus and piriformis form a continuous steadying prever- tebral web which connects the base of the thorax, lumbar spine, sacrum and pelvis to the legs. The 114

Salient aspects of normal function of the torso CHAPTER 6 piriformis inserting onto the greater trochanter determines balance between the hip, pelvis and from behind, establishes the anterioposterior posi- lumbar spine. This prevertebral support network tion of the sacrum and so balance between sacrum prevents undue anterior displacement of the spine and ileum and sacrum and lumbar spine and thus and relieves the burden of the post vertebral exten- forms the foundation for iliacus-psoas; the iliacus- sors and helps support the thoracic structure of the psoas attaching to the lesser trochanter in front body1 (Fig. 6.34). Caval opening Central tendon of diaphragm Diaphragm Esophageal opening Right crus of diaphragm Left crus of diaphragm Median arcuate ligament Aortic opening Medial arcuate ligament Lateral arcuate ligament Quadratus lumborum Transversus abdominis Transversus abdominis Internal oblique Psoas major External oblique Psoas minor Sacrum Iliacus Anterior superior iliac spine Inguinal ligament Piriformis Coccygeus Ischial spine Levator ani Pubic symphysis Pubic tubercle Fig 6.34  Much of the LPU involves a prevertebral and intrapelvic web of support. 115

Back Pain: A Movement Problem Essentially, dynamic pelvic control involves the The deep intrinsic pelvic force couple is also very various LPU elements (obturator and iliopsoas important in controlling sagittal movements further groups and the PFM) working in harmony with the away from the gravity line in sitting and standing. large SGMS – hamstrings, gluteus maximus and DonTigny notes when bending forward the line of adductors to provide the lowest component of both gravity moves forward of the acetabular axis and mobility and balanced ‘grounding’ for the lower the sacroiliac joints are more vulnerable.147 He body.28 recommends a strong abdominal contraction pro- vides a self bracing of the joints affording protection Control of pelvic tilt is achieved from during this maneuver. However, clinically activating cooperative interplay between abdominals ‘alone’ is more likely to create a flexion SLMS and SGMS moment and ‘cause a pathological release of the self bracing position’.147 Rather, if the pelvis spatially While convention acknowledges that pelvic rota- shifts posteriorly while anteriorly rotating, abdomi- tion known as tilt affects lumbar posture, it is gen- nal activity in coactivation with the extensors, con- erally hard to find descriptions in the literature of trols the ‘body cylinder’ which is carried forward the principal muscle force couples which are in a more kinematically sound way. Inner support deemed responsible for controlling it. Clearly con- from the LPU allows force couple synergies to cre- trol of pelvic tilt involves complicated synergies ate anterior rotation of the pelvis with principal involving both the deep and superficial systems. contribution from concentric activity of the iliacus While certain movement educators have been and psoas149,150 as well as lower transversus, inter- aware of the important contribution of the deep nal oblique and multifidus, and corresponding intrinsic force couples in controlling sagittal pelvic eccentric play out from the PFM, obturator group tilt in both posture and movement1,6,28,148 (see aided and abetted by the hamstrings and gluteus above), the medical model appears to only primar- maximus. The return occurs via posterior rotation ily consider the static force couples created by the of the pelvis from principal concentric gluteus max- large superficial muscles in the SGMS e.g. the imus, hamstrings, PFM and obturator group activity Kendall’s129 description: and eccentric abdominal, iliacus and psoas activity. • Posterior tilt is achieved from the downward Prominent buttocks are one of the most characteris- pull of gluteus maximus and hamstrings and the tic features of the muscular system in man asso- upward pull of the anterior abdominals – rectus and ciated with the frequent need to bring the trunk external oblique. upright.10 • Anterior tilt occurs through upward pull of the spinal extensors and the downward pull of the hip Balanced control of both the obturator and iliop- flexors – rectus femoris, tensor fascia lata, sartorius soas groups gives a free swinging pelvic base for and the iliopsoas. quick postural adjustments and the ability to readily squat and return. The control of sagittal tilt is also Often only the superior effectors are mentioned involved in forward weight shift in sitting, moving such as the abdominals create posterior tilt.152 from sitting to stand and lowering to sit and many other actions. However, clinical practice frequently A dynamic well balanced pelvis requires bal- reveals imbalanced and defective use and control anced length/tension relationships between all of this force couple with altered length tension rela- muscles attaching to it both inferiorly and superi- tionships in the muscles. orly from both the deep and superficial systems. Imbalance between the axial flexors and extensors Influence of the thorax on sagittal has a significant influence on pelvic tilt control. pelvic tilt The large common tendon of the erector spinae attaches to the sacrum and pelvis, hence their Harrison et al.153 showed that when ‘normal’ sub- overactivity, unmatched by the abdominals can jects stood with an unrestrained pelvis and per- anteriorly rotate the pelvis.12 In addition, congru- formed a primary forward and backward ent activity between iliacus/psoas and the abdom- translation of the thoracic cage, large changes in inals is particularly important in providing the sagittal lumbar posture and pelvic tilt were pro- anterior tensile support. duced as well as changes in the thoracic kyphosis. 116

Salient aspects of normal function of the torso CHAPTER 6 Anterior thoracic translation caused the pelvis to The ‘ischial swing’ anteriorly tilt by 15, while posterior translation tilted the pelvis posteriorly by nearly 16. Well developed spatial control of the pelvis as a whole is characterized by the ischia being able to Frontal plane pelvic tilt: the freely swing in the sagittal and frontal planes. Control important contribution of obturator- of this is critical to effective sagittal weight shift and iliacus concentric/eccentric activity frontal plane weight transfer onto one leg where the ipsilateral ischium swings medially as the leg comes Iliacus lines the superior pelvic bowl while obtura- under the pelvis or the pelvis moves over the leg. tor internus piriformis and the PFM line the inferior pelvic bowl. The control if ischial inflare/outflare The further functional roles occurs from coactivity in the LPU with balanced of iliacus and psoas activity between iliacus/transversus superiorly and the obturators/PFM inferiorly. This internal control The iliopsoas muscles have been long considered by from LPU synergies provides intrapelvic stability certain practitioners as perhaps the most important and a firm base of support for the pulls of the larger muscles in determining upright posture.1,6 Rolf1 muscles balancing the pelvis as a whole over the considers psoas’ function is unique in unifying the standing leg (Fig. 6.35). The adductors appear syn- torso and thigh and no other myofascial element ergistic with transversus and iliacus in creating can substitute satisfactorily. ischial outflare, while the abductors are synergistic with inflare. (See further functional roles of iliacus, Their actions are usually described together and psoas adductors below) conventionally as: hip flexion, bending the trunk and pelvis forward as in rising from lying to sitting; Iliac crest 5th lumbar vertebra Sacroiliac joint Psoas minor Sacrum Superior anterior iliac spine Piriformis Psoas major Iliacus Coccygeus Sacrotuberous ligament Pecten of pubis Ischial tuberosity Tendinous arch Pubic symphysis Obturator internus Fig 6.35  Schematic inner view of the superior and inferior innominate bowls. 117

Back Pain: A Movement Problem and possible ‘important activities’ in balancing the Neutral position Psoas major trunk in sitting.10 Bogduk et al.154 proposed that Eccentric adductors Iliacus the upper fascicles of psoas tend to extend the upper lumbar spine and the lower fascicles tend to Concentric flex the lower lumbar spine; otherwise it is a hip abductors flexor. A postural stabilizing role for psoas is gaining support.130,155,156,157 McGill describes psoas’ spinal Head of stabilizing role as resisting the forces or torques cre- femur ated on the spine as a result of limb movement, in particular hip flexion.8 As far as the sacroiliac joint is concerned, Steindler132 has been the only source found in the literature to consider that the ‘mighty mass (of the sacrospinalis as well as) the iliopsoas protects the joint before it really comes to ligamen- tous strain’. This is particularly so with the back in motion where the iliacus and psoas help control the momentum of the back and forward pelvic swing incidental to locomotion. Clinical practice supports agreement with all of these roles and suggests more. Iliacus’ architecture allows the top of the pelvis to be pulled forward47 hence it plays a substantial role in initiating anterior pelvic rotation during actions such as forward bending in standing. At the same time psoas is syn- ergistically acting to control spinal intersegmental alignment – the pelvis flexes on the hip while the low back is controlled in variable extension. If the hip does not act as the fulcrum of the movement, the back is used instead with predictable conse- quences over time. If there is under use of iliopsoas in the flexion and support phase when walking, the obturators and piriformis compensate, become overactive, increasing hip external rotation and the stress through L4/5.28 Frontal plane control Fig 6.36  Conceptual view of frontal plane pelvic rotation in lateral weight transfer and proposed line of pull of psoas and In concert with psoas, iliacus conceivably also plays iliacus. a crucial role in lateral weight shift and load trans- ference through the pelvis when upright (see ‘Fron- attachments and serve to provide an internal tensile tal plane pelvic tilt. . .’ above). The leg can be support over the anterior SIJ, actively binding the brought under the body or the body over the leg. joint surfaces together. At the same time the lum- It has been proposed that the SIJ is vulnerable to bar segments are adaptively aligned and stabilized shear loading stress.158 However, as has been over the weight bearing leg. Clinically it appears pointed out by Gracovetsky,2 the joint surfaces are that the ipsilateral psoas is eccentrically active to warped and highly organized toward their functional ‘lengthen the side’ ipsilaterally while the contralat- role. He points out that the inferior part of the SIJ eral psoas is concentrically active to help control on the ileum is in fact a warped ledge which is part adaptive change in the spine. In similar vein, of an arch and is well suited to weight bearing. Con- Sims159 cites a proposal by Bombelli that in single ceivably, when the pelvis rotates in the frontal plane leg stance iliacus and the abductors balance the pel- over the femoral head, as seen in Figure 6.36, the vis whilst psoas and the contralateral quadratus active line of pull of the fibres of psoas and iliacus lumborum position the centre of gravity over the are almost vertical between their top and bottom 118

Salient aspects of normal function of the torso CHAPTER 6 centre of rotation of the femoral head. Psoas is thus ramus from the symphysis in front to the lateral an important medial stabilizer of the hip157 and con- inferior ischial tuberosity below the hamstrings tributing to the force couple synergy are the hip insertion posteriorly, they must surely play a large abductors helping to hold the ileum ‘over’ the leg role in balancing the pelvis on the femur and helping while the adductors also provide important eccen- stabilize the inferior bowl. Their muscle mass is tric control and stability of the pelvis on the leg. enormous yet ‘extensive or forcible action of the femur is not a common action’.10 While in symmet- In walking, iliacus and psoas provide a complex rical easy standing their activity is minimal or oscillating role between stability and mobility one absent10 it is reasoned they come into their own limb supporting, the other swinging while at the when weight bearing on one leg. Hungerford same time controlling the alignment and balance of et al.161 describe their early EMG onset when the pelvis with the spine on the legs. An eccentric standing on one leg. On a stable femur their closed contraction occurring before a concentric contrac- chain function probably involves helping to balance tion enables the muscle to perform more positive the ‘ischial swing’ in both the sagittal and frontal work with increased power.67 This enhanced per- planes. Also, actions where the pelvis opens away formance is attributed to the ability of the muscle from the stable leg involve reversed origin and to store energy during the stretch (eccentric con- insertion eccentric control from the adductors traction) and subsequently use some of this energy and internal hip rotators. during the concentric contraction. Todd6 suggests that because iliacus and psoas are contracting before Kendall129 draws attention to their internal they receive the load in either stance or swing rotary action because they insert onto the femur phase, they not only assist as shock absorbers but anterior to the mechanical axis. Those which insert rebounders providing an energy efficient spring in posterior to the mechanical axis will act as lateral the step. rotators (Fig. 6.37). What is the role of the In the frontal plane they balance activity in the adductors in pelvic glutei and tensor fascia lata and provide invaluable myomechanics? eccentric control as the pelvis rotates over the fem- oral head during lateral weight shift (see ‘Further The functional role of the adductors has in general functional roles of iliacus and psoas’ above). On a received relatively scant attention. Kendall et al.129 fixed femur in synergy with iliacus and transversus describe their actions as adduction of the hip joint; their action abducts the ischium and inferior pubic and together with pectineus, the longus and brevis ramus which is counterbalanced by PFM and obtu- flex the hip joint. The anterior fibres of the massive rator group activity to provide stability of the infe- adductor magnus may assist in hip flexion while the rior pelvic syndesmosis and stability of the pelvic posterior fibres may assist in hip extension.10,129 ring. They have also been assigned an essential synergistic role in the complex patterns of gait and controllers Lee18 notes their role in regional stabilization of of posture.10,160 Janda160 showed they were active the pelvis between the thorax and legs as part of during flexion and extension of the hip and knee the ‘anterior oblique sling’ of the global system. tested in prone, supine and sitting and particularly against resistance, demonstrating their proximal Hip rotator balance: important postural stabilizing role. He points out that their for both hip and pelvic excitation level is relatively low; they also have with myomechanics one of the shortest chronaxies of the lower limb muscles; and in cerebral palsy adductor hyper spas- The deep rotators form a fan around the innominate ticity develops mainly after verticalization of the as they encase the femoral head and variously insert child. The magnus and longus are probably medial onto the femur each pulling at a slightly different rotators of the thigh.10 angle. The ‘deep’ internal rotators are the iliopsoas1, gluteus medius and minimus which are anterior and Given their combined proximal attachment cov- superior to the hip joint – the only exception being ers the entire lateral surface of the inferior pubic the adductors. The deep external rotators – the obturators, the gamelli, piriformis and quadratus 119

Back Pain: A Movement Problem Mechanical axis chain hip movements.28,148 More commonly the superficial gluteus maximus is used for external rota- tion of the leg rather than the deep rotators.28,145 Most people don’t appreciate the fact that the gluteals are rotators and are often tight. Rolf1 considered iliopsoas the prime internal rotator which counters principal external rotation from piriformis, and balance between them with obturator internus is important in providing the pre- vertebral support for the spine which then relieves the load on the spinal extensors. Superficially, balance in the fascia lata is achieved from balanced activity between the anteriorly placed tensor fascia lata which is also an internal rotator and the posterior gluteus maximus which is also a lateral rotator (Fig. 6.54). Hip rotator imbalance alters the freedom of the innominate to rotate in the sagittal and frontal planes and so disturbs pelvic myomechanics. When the internal rotators are tighter, innominate movement into posterior rotation and ischial inflare is reduced. When the external rotators are tighter, innominate movement into anterior rotation and ischial outflare is reduced. Clinically, Gluteus medius (cut) Fig 6.37  Rotary action of the adductors acting around the Gluteus maximus mechanical axis. (cut) femoris are posterior and lie level with or below the Gluteus Ilium hip joint. As their fibres are roughly horizontal they minimis can directly modify the plane of movement of the Sacrum pelvic basin and transmit tension to the pelvic Iliacus and bones1. The internal rotators are the ‘upper storey’ psoas major Piriformis while the external rotators are the ‘lower storey’28 Coccyx (Fig. 6.38). Hip external rotation is associated with elements of posterior pelvic tilt/hip extension, Obturator internus abduction and closing the pelvic floor while internal and others in the rotation is synergistic with hip adduction, flexion/ obturator group anterior pelvic tilt and opening of the pelvic floor. Femur These are certainly not obligatory responses. Full use of the deep hip rotators particularly the external Anterior Posterior rotators allows better range and freedom of open Fig 6.38  The lateral view of the pelvis showing the ‘deep rotator fan’ of the hip. 120

Salient aspects of normal function of the torso CHAPTER 6 it is more common for people with back pain to has become a major trend in rehabilitation despite have more difficulty with various combinations meager research.167 of closed chain hip flexion, internal rotation and adduction and so related opening of the inferior Current models about back pain have proposed pelvic bowl becomes restricted. This limits clos- ‘instability’ of the spine as a cause. This led to think- ing of the superior bowl and control of the lumbar ing that in order to make the spine more stable, the lordosis. abdominals needed to be strong so as to ‘not let the spine move’. It appears there has been misinterpre- Role of superficial muscle tation of some of the research. The Queensland slings group of Hodges and co workers have done nice research showing that in one of the abdominal mus- Various synergistic muscle slings in the SGMS act- cles – transversus, activity is reduced and delayed in ing through fascial sheets have been proposed to people with back pain.86,87 In the normal state its provide regional stabilization of the pelvis between activity is automatic and occurs in conjunction with the thorax and legs.18,152,162,163,164 other muscles such as the pelvic floor, diaphragm and multifidus as part of a postural reflex synergy The posterior longitudinal sling connects the per- prior to an actual movement occurring. While voli- oneii, biceps femoris, sacrotuberous ligament, the tional activation of a single muscle may initially deep lamina of the thoracodorsal fascia and the ‘help get the feel’ of the desired action, its syner- erector spinae.18 gistic activity in functionally relevant postur- omovement patterns needs to be learnt. The anterior oblique sling connects the external Hodges168 makes it clear that control of the spine oblique, through the anterior abdominal fascia, to should be dynamic – that stability is controlled the opposite internal oblique, the transversus abdo- mobility. However, some of the confusion may minus and the adductors. also have arisen from the researcher’s protocols which recommended the ‘abdominal hollowing The posterior oblique sling connects the latissi- exercise’ (AHE)86,87,169 as a means of initially mus dorsi, through the thoracolumbar fascia to the gaining simultaneous contraction of the deep mus- contralateral gluteus maximus. Bogduk165 however, cle synergy. While a specific and controllable considers the contribution of latissimus dorsi to maneuver, it is not a particularly functional move- sacroiliac stability to be ‘trivial’. ment and certain subgroups of patients (see Ch. 9) will have great difficulty achieving the correct action. The lateral sling contains the tensor fascia lata, Asking for an action such as ‘narrowing the waist and gluteus medius and minimus and the lateral stabili- inwardly drawing in the abdomen’,170 tends to limit zers of the thoracopelvic region.18 diaphragm activity, increases the tendency for central ‘holding patterns’ and encourages more of a ‘functional In similar vein, Myers166 describes functional disconnect’ around the central torso; often doing little myofascial synergies in terms of superficial front that it sets out to achieve. Beith171 found that in and back lines, spiral lines, lateral lines and func- a group of physiotherapy students, only 20% could tional lines. All of these superficial system synergies consistently isolate the deep abdominals (IO) from undoubtedly play a role in the panorama of move- external oblique in 4-point kneeling and prone raising ment control. However, it is suggested that without the question as to whether elimination of EO activity adequate preceding and more integrated tonic activ- during the AHE is always possible, desirable or neces- ity in the SLMS, their ability to provide effective sary. However, interventions by ‘significantly experi- control will be suboptimal. enced’ therapists who have adopted this protocol with other associated re-educative exercise172 have What is core control? shown positive outcomes. No one concept has been so misunderstood, confused McGilll8,59 repudiates the adoption of what he and abused and as that of ‘core control’. The term has calls ‘single muscle strategies’ and doesn’t believe unfortunately become synonymous with the abdomi- that AHE ensures stability. In order that the spine nal muscles – the need for ‘strong abs’ and ‘holding in’ can withstand steady state loading as well as sud- and ‘pulling in your stomach’. Further, the idea of den unexpected complex loads, McGill173 advo- ‘core strengthening’ has evolved which overempha- cates abdominal bracing involving activation of sizes development of the superficial abdominals and 121

Back Pain: A Movement Problem the whole lateral abdominal wall and training Functional role of the ‘patterns of stabilization’8 as the most effective abdominal group of muscles means of achieving core control. He advises that high levels of co-contraction are not required – A big ‘tummy’ is common these days and prompts 5% during normal ADL and up to 10% during the belief that doing abdominal exercises will fix rigorous activity. it. However, this is usually more the result of pos- tural collapse, ‘middle aged spread’ and obesity. Abdominal bracing does provide an immediate ‘Curls’ and ‘crunches’ will often aggravate rather stiffening of greater magnitude than hollowing.174 than help the problem. The role of the abdominals However, creating too much stiffness is as much is complex. of a problem as too little stiffness. There is often too much bracing from hyperactivity of the ‘The abdominals’ consist of four muscles – the abdominal or mistaken ‘core’ muscles185 in cer- rectus abdominus suspended within the fascial tain groups of people with back pain. Clinical sheet of the anterior abdominal wall, and the three experience suggests that for many, both AHE anterolateral muscles arranged in three layers, each and abdominal bracing represent patterns of layer having a different fibres direction, creating a activity that are just too close to their habitual pattern of cross bracing as they form the anterolat- ‘central cinch’ or holding patterns (see Ch.9), eral wall of the body, connecting the thorax to the the action occurring ‘too high’ and so compromis- pelvis. They are not just flexors which curl the ing the breathing pattern. The first sign of defec- trunk forward; they have differing yet synergistic tive core control is defective breathing.103 Core roles. As a group they support the abdominal control is control of the LPU at the core of the viscera, flex side bend and rotate the trunk, and body’s centre of weight. It involves the coordi- contribute to the breathing mechanism and the sta- nated activity of whole synergies of muscles in bility of the spine through the generation of IAP. the control of the pelvis which is and supports Importantly, they have a postural role and control the core and breathing. Feldenkrais175 comments the relationship between the thorax and pelvis and ‘the dependence of proper breathing on the cor- the alignment of the axial spine. They help to con- rect holding of the pelvis was also recognized trol forces acting upon both the spine and the pel- by the Yogi long ago’. The ‘core’ is also the centre vis. Beith and Harrison177 report finding reflex of weight shift. The LPU synergy, particularly facilitation in all four oblique muscles in response iliacus and transversus stabilizes the pelvis so it to stretch in one suggesting close synergies between can rotate on the femoral heads through all the obliques in providing stability to the vertebral degrees of freedom in all parts of available range. column. What is often not appreciated is that the Bartenieff,148 a physiotherapist and dance move- architecture of the obliques and transversus is such ment educator talked of the importance of gaining that different regions of the one muscle show dif- function in this region which she termed ‘the dead ferent morphology and perform different functions seven inches’ so prevalent in most American’s bod- which become important to understand when con- ies.28 Control from the internal core helps minimize sidering axial alignment and control. overdependence on the external muscles. Movement at the core is basic to expressive and dynamic move- The deepest layer, the transversus abdominis ment and can be seen in terms of opening and clos- (Tr A), interdigitates with the diaphragm thus its ing; expanding and condensing; concaving and function is closely intertwined with the breathing convexing.28,176 Movement at the core also begins mechanism and the generation of IAP.92 Its with the breath. attachments to the lower six ribs and the pelvic rim, and fibrous attachments to large aponeurotic When working for ‘core control’, which move- and fascial sheaths front and back, respectively, ment patterns and synergies are chosen becomes mean that it acts like an inner sleeve of support the art of the prescribing practitioner. Understand- helping control the thorax over the pelvis. It ten- ing ‘what’s wrong’ informs the choice. Most impor- sions the front and back ‘fascial plates,’ providing tantly, the person needs to establish and maintain postural support and stability to both the lumbar proper diaphragmatic breathing through the move- spine and ribs so the diaphragm can effectively ment. Movements which focus on the correct acti- contract. Studies have confirmed its postural role vation of the LPU will generally achieve these and implicate separate CNS regulation to that of features. 122

Salient aspects of normal function of the torso CHAPTER 6 Linea alba Rectus abdominis Arcuate line Fascia transversalis Fig 6.39  Transversus abdominis. the rest of the group.96,178 Urquhart179 described • The lateral fibres can depress and approximate three different regions (Fig. 6.39): the thorax and pelvis anteriorly and laterally. • The upper anterior fibres showed the least tonic Clinically, these fibres are frequently tight. activity The external oblique (EO) forms the superficial • The middle region was most associated with layer. Its fibre arrangement essentially comprises two respiratory activity sets of ‘functional slings’ with potentially different pos- turomovement behavioral characteristics (Fig. 6.41). • The inferior region showed more tonic postural activity. Clinically, this region plays a very important • The upper anterior fibres from ribs 5–8 pass forward and inferiorly to attach to the anterior role in the synergies responsible for the control of aponeuroses and can depress the thorax and flex the pelvic ring myomechanics and its control on the femur. thoracolumbar spine. Activation of the lower and middle regions was • The lower lateral fibres from ribs 9–12 pass down and independent of the upper region.180 The postural forward. Those from the 9th rib go to the pubis and send fascial expansions towards the adductor origins; those responses also varied according to body position from the 10th rib to the inguinal ligament16 and anterior with recruitment delayed in sitting compared to half of the ileum as do the rest of the fibres.10 This sling standing.181 can16 flex the spine with more influence on the lumbar spine and posterior pelvic tilt.129 If the pelvis is held The internal oblique (IO) constitutes the middle stable these fibres ‘help to draw the posterior rib cage layer. Its fibre arrangement also delineates three dif- towards the anterior iliac crest and in so doing tend to fering regions129 and functional roles (Fig. 6.40): extend not flex the thoracic spine’.129 These fibres thus • The lower anterior fibres in conjunction with help to maintain a good alignment of the thorax in transversus support the abdominal viscera and have an relation to the pelvis as they counter the flexion important role in approximating the anterior ilia182 moment of the upper anterior fibres. • The upper anterior fibres assist in breathing, depress the thorax, and approximate the pelvis and thorax, flexing the spine129 123

Back Pain: A Movement Problem Linea alba Fig 6.40  Internal oblique. Pectoralis major Serratus anterior Latissimus Lower lateral fibres Linea alba dorsi of external oblique Upper anterior Lower fibres lateral fibres Anterior fascial aponeurosis Fig 6.41  External oblique. 124

Salient aspects of normal function of the torso CHAPTER 6 Rectus abdominis activity is more straightforward on the sides of the coccyx. This author considers in approximating the pelvis and thorax and flexing that control of this lateral movement is important the spine. Examining abdominal wall activity during in ‘lengthening the sides’, a significant factor in ‘belly dancing’, Moreside et al.183 recently demon- controlling lateral weight shift onto one leg. strated significantly different activation levels between upper and lower rectus and that the obli- In concert with transversus and rectus, the com- ques tend to work in synergy with the lower rectus bined upper portions of the obliques often termed more than the upper during various pelvis move- ‘the upper abdominals’ contribute more to breathing ments with minimal thorax motion. and controlling the alignment of the thorax on the lumbar spine. Their combined lower portions – the Kendall129 notes that during the trunk curl sit up, ‘lower abdominals’ are more responsible for the con- the lower lateral fibres of external oblique are elon- trol of intrapelvic and spatial movements of the gated. Doing a lot of these, results in ‘stretch weak- pelvis including tilting and the alignment of the pelvis ness’ of this sling and hypertrophy of the anterior and lumbar spine. sling as well as the internal oblique and rectus. This results in altered alignment in standing; either the Norris187 draws attention to the antagonistic activ- pelvis tips anteriorly as in a kyphosis lordosis pos- ity of the abdominal group where during maximal ture or anteriorly shifts with posterior deviation of trunk extension abdominal activity can vary between the thorax in the ‘sway back’ posture. When the 32% and 68% of the activity in longissimus.188 pelvis hangs or is shunted forward there is little demand for postural activity in the anterior abdom- Problems for the spine ensue when abdominal inal wall. This is also related to corresponding short- activity is increased, decreased or imbalanced. Some ness of the lateral IO in both situations.129 muscles or parts become overactive and short while others become underactive and ‘weak’. This affects Importantly if the posterolateral sling of EO is weak, their ability to control the relationship between pelvis with associated deficient activity from the LPU syn- and thorax amongst other things. The work of Hodges ergy, marked difficulty in supine leg loading tests will et al.189 has shown that transversus activity is com- be apparent. It is suggested that it is this mechanism monly decreased and delayed in people with back which is operant during a positive active straight leg pain. Activity in the other three may also be decreased raise test (ASLR) described by Mens184 and is not nec- so that the whole abdominal wall is lax. Clinically how- essarily reflective of specific SIJ dysfunction. This also ever, while transversus is generally underactive, there explains the increased SGMS fixing around the lower may be increased activity in all or some of the others thorax and decreased diaphragmatic descent described in the group – mostly the obliques.53 Hence we have by O’Sullivan et al.185 during this test. the situation of not only imbalance between the deep and superficial layers, but potentially between the When both obliques are acting together in syn- obliques themselves, and/or between rectus and the ergy, besides flexing, side bending and rotating the obliques, reflecting changes in function. thorax and pelvis on one another, they help control sagittal plane alignment, bringing the thorax back In addition, it is common to find differences in when the pelvic position is controlled or ‘fixed’ or the activity levels between the ‘upper abdominals’ the pelvis forward and up when the thorax is stable. and the ‘lower abdominals’. Kendall129 noted Important to control of sagittal alignment is control uppers ‘strong’ and lowers ‘weak’ was the most of lateral movements. Gracovetsky131 considers the prevalent finding, followed by uppers and lowers lateral bending motion of the torso is an archetypal both weak and this certainly accords with clinical and important movement pattern principally con- practice findings. McGill describes the obliques as trolled by the obliques and iliocostalis. Rather than having regional neuromuscular compartments and functional separation between the upper and lower specific muscles, it has been suggested that myofas- regions8 and has recently shown the same in rec- cial aggregations form specific meridians166 which tus.183 As mentioned previously, when supine, if create functional ‘contractile fields’186 to produce the uppers are stronger the person can curl the movement. Beach186 further suggests that head, neck trunk but will have difficulty controlling the pelvis and torso side bending is achieved through a ‘lateral in leg loading actions. contractile field’ linked to sense organs in the head. Consisting of non-anatomically defined lateral tissues Controlling the pelvis is an important compo- (including hundreds of muscles), the field extends nent when working for abdominal control and gen- from the eyes and ears to the pelvic floor to insert erally poorly understood. ‘Posterior pelvic tilting’ is an exercise frequently practiced with little 125

Back Pain: A Movement Problem understanding of ‘function’ or regard to its appropri- Simple mechanics informs that in ‘stoop lifting’ ate use. It is a good example of an exercise passed with no dynamic leg action and the spine in flexion, on by tradition with little scientific evidence to increased load is taken on the passive structures and support its effectiveness.190 It is usually easy for if repeated enough, cumulative damage is likely. most people including those with weak abdominals or a weak lateral EO to do this action! The neutral Consequently, ‘squat lifting’ has generally been lordosis is lost in posterior tilt and the facet joints seen as ‘the correct method’ and advocated in are in end range flexion. This habitual pattern gen- industry training despite it being a somewhat erally does not need reinforcing. It is possible to unphysiological action. Because the emphasis has posteriorly tilt the pelvis through its inferior pole been on knee flexion rather than the hip, being less at the hip via the obturators, piriformis and ham- stable and more awkward for most, it has a high strings without much EO activity at all. It is impor- energetic cost, and is biomechanically hard on the tant that when working to improve EO activity knees and thus understandably compliance levels that the pelvis is stabilized in neutral with the help are generally low. Studies in repetitive lifting of the LPU, so that the action of EO on the thorax revealed subjects who began in squat reverted to can be appropriately worked for. Importantly, stoop as they became fatigued.193,194 Most people, intrapelvic and spatial control of the pelvis is including manual workers, habitually adopt stoop heavily reliant upon the ‘lower abdominals’ syner- despite instruction to the contrary.191 It is sug- gistically coactivating with various pelvi-femoral gested that this is probably because it is a ‘pattern muscles to provide appropriate control of pelvic of movement that they know’, related in part to force couples. The control of anterior pelvic rota- habitual standing and sitting postures where com- tion is particularly important and universally defi- monly, posterior rotation of the pelvis is consis- cient which explains the ubiquitous ‘tummy’ over tently adopted. In 1999, Van Die¨en et al.195 the lower abdomen. extensively reviewed the biomechanical evidence and concluded that there was no justification for The prescription of therapeutic exercises which advocating squat technique. appropriately redress the underlying muscle imbal- ances in the abdominal wall is an art. Different peo- Studies on self selected or freestyle lifting techni- ple need different solutions. A gung ho, recipe ques have revealed the postures typically adopted are based approach does little except to compound intermediate between stoop and squat, hence semi- much prevailing dysfunction. squat techniques are receiving more interest. Described as ‘moderate range of flexion at both knees and trunk, it The bending and lifting allows a pattern of inter-joint coordination which debate – stoop or squat or appears to be functional in reducing muscular effort’.196 something else? Review of the literature is fascinating in that for The recognition that many work-related back pain an action that requires initiation and control from incidents result from bending and lifting has engen- the pelvis, this is rarely mentioned or factored into dered much research and debate on the mechanism the research design, instead the focus largely being of injury and the ‘best lifting style’– stoop or squat. on the effect different knee positions have on the Stoop has been defined as ‘knees straight, back back. A recent study disallowed subjects any forward bent; and squat as ‘knees bent back straight’.191 trunk inclination when squatting! Hardly a functional What is interesting is that neither definition men- pattern and not surprisingly, the knee was working tions the hip dynamics yet McClure et al.192 overtime.197 Locking the knees in stoop limits pelvic showed that normally return from forward bending rotation. The degree of knee flexion in squat is initially occurs in the hip. McGill8,59 notes, it is unphysiological as it places such high loads on them. the kinematic motion patterns together with the No wonder ‘the evidence’ is equivocal. muscle activation patterns that heavily influence the loads the spine bears. Poor patterns of move- Pattern of forward bending – ment and motor control errors can induce injury lumbopelvic rhythm or pelvi-femoral when bending to pick up a pencil.8 rhythm? While the interest has been in lifting, the pattern of forward bending not only underlies lifting but also 126

Salient aspects of normal function of the torso CHAPTER 6 many repetitive low load ADL activities such as Line of gravity emptying the dishwasher and gardening. Some of Extensors the confusion and clinical myths about forward IAP Flexors bending patterns probably stems from some text book descriptions of lumbopelvic rhythm. These describe the first 60 or so of trunk flexion occur- ring in the lumbar spine and any further flexion occurs in the hip.5 McGill8 rightly refutes this as ‘fiction’ and instead proposes the ‘hip hinge’ in for- ward bending, citing Olympic weightlifters lock the lumbar spine close to neutral and rotate almost entirely around the hips. Hence it makes sense to adopt the term ‘pelvi-femoral rhythm’.148 Spine in forward bending pattern resembles a cantilever Panjabi and White198 describe the spine in forward Fig 6.42  An effective ‘body cylinder’ provides both internal bending as behaving like a cantilever – where one and three dimensional support to the spine in forward end of a long structure is fixed and its other free bending rendering the torso an adaptable cantilever. The end is ‘loaded’. The ‘fixed’ end is obviously the centre of mass is supported over the base. stronger, heavier and centrally placed base of the spine within the pelvis which itself has been be stronger when the fulcrum for forward bending described as a cantilever.6 was at the hips.200 However, achieving this pelvic control is elusive for most as it isn’t an action they A simple cantilever, as Norris187 points out, is habitually use. It cannot happen if the knees are externally supported and subject to bending load. extended. However, flexing the knees does not nec- If the spine is construed as an arch it becomes more essarily solve the problem either, as a common strat- intrinsically stable. This stability is reliant upon the egy is to attempt the ‘squat’ with knee flexion and musculature to modulate the lordosis and provide posterior pelvic rotation thus pulling the lumbar IAP and so keep the thrust line within the arch. spine into more flexion! Habitual postural and move- When the thrust line moves outside the arch it ment patterns result in many subjects being disin- becomes unstable. Coactivation and balanced activ- clined to load the lower limb in flexion: the pelvis ity between the flexors and extensors and the LPU in hip flexion/ anterior pelvic rotation with knee optimizes both IAP and alignment of the ‘body cyl- flexion and dorsiflexion. inder’ functionally rendering it an effective cantile- ver’ during forward bending (Fig. 6.42). Functional forward bend pattern: semi-squat involving ‘pelvic swing Maneuvering the base of the cantilever is the and shift patterns’ task and this is the job of the pelvis. It should be able to swing freely between the leg axis and the It is proposed that obtaining effective pelvic action in spinal axis and as it does so, it carries the ‘body cyl- semi squat is dependent upon the initiation and sup- inder’ forward into bending and return/lifting. port of the LPU synergy through the movement Effective pelvic actions allow the body cylinder to (see Dynamic control of sagittal ‘Pelvic tilt’ above). flexibly maintain its integral shape including the Reliant on active ‘grounding’ through the feet, the lumbar lordosis. The bulk of the movement occurs at the large ball and socket hip joints. Gracovetsky et al.199 suggest that for every angle of forward flexion there is a unique degree of lordosis that will minimize and equalize the compressive stresses within the spine and at the same time will be asso- ciated with minimum muscle activity. Isometric trunk extension–flexion testing has been shown to 127

Back Pain: A Movement Problem kinematics in biomechanically sound forward bending and psoas, transversus and multifidus work con- and lifting patterns involve three distinct phrases in centrically and eccentric control comes from the the movement which are led by the ischia. obturator group, PFM, gluteus maximus and ham- strings acting to ‘brake’ the movement as the Forward bend upper body is lowered. It is important to appreci- ate that control of this force couple is only achieved Forward bend is accomplished by the ischia assum- when there is coactivation between the anterior hip ing the following pattern: and trunk flexors and the posterior hip and trunk • Shifting posteriorly in space and reaching extensors where the pelvis can be ‘driven back’ backwards from the feet and spatially controlled in order to • Lifting so the pelvis anteriorly rotates take advantage of the extensor mechanism in the • Widening into ischial outflare. lower limb (See Ch. 4 & Fig. 6.54) Thinking about ‘pushing the ischia back’ in order to ‘come forward’ This is an extension of FPP1 and the pattern of is useful in overcoming the habit of simply hanging movement involves posterior shift with anterior pel- forward (Fig. 6.44). vic rotation, hip flexion and lumbosacral extension. The hip flexion provides the majority of the move- Lifting ment while the spine elongates through the move- ment and is free to perform the fine tuning and The return movement continues to involve the fun- small adjustments needed for the arms to engage damental control from the LPU, which now brings and carry the load (Fig. 6.43). This involves the the ischia into the following pattern: LPU in dynamic synergism with the body cylinder which in this action also resembles a 1st class lever. • Shifting forward in space The fulcrum of the movement is the hip as the ace- • Dropping down so that the pelvis posteriorly rotates tabulum rotates around the femoral head. The spine • Narrowing into ischial inflare. and hips work together and Gracovetsky considers that both the erector spinae and psoas are important This occurs in synergism with strong concentric in control of the lordosis.131 Incidentally, this pat- activity of the hip/pelvic extensors201 to ‘drop’ the tern of movement is also involved in forward weight effort arm, extend the hip and raise the body cylin- shift in sitting, moving from sitting to stand and der. Co-activation from the anterior hip flexors is lowering to sit and squatting as well as in many still important as they eccentrically work and pro- other actions. vide stability and control of the pelvis while the extensors ‘lift’ it. The magnitude of the load dic- Raising the effort arm – the ischia – is achieved tates the level of activity of the muscles in the walls from dynamic synergism between the LPU and of the body cylinder including the generation of more superficial muscles. In particular iliacus appropriate levels of IAP. Fig 6.43  ‘Drilling’ the ‘pelvic swing and shift patterns’ for The inferior pelvis is the generator and leads control of the forward bend pattern; the hands help focus the movement via swings and shifts. It can only leading from the ischia. Note the grounding of the feet helps do this if the ankles and knees are simultaneously drive the ischia back and up where the tailbone can involved in the pattern. According to Pope, Bor- lengthen and the torso is well aligned. elli, the father of biomechanics understood that the levers of the musculoskeletal system magnify motion rather than force.202 The movement role of the short stocky lever, the ischia while seem- ingly not large has an enormous effect on pelvic myomechanics when upright and through move- ment (Fig. 6.44). The hamstrings play an impor- tant role in bending and lifting, dynamically eccentrically/concentrically adjusting all through the movement to drive the ischia back/up and down/forward. Defective control of eccentric lengthening of the obturator group and the hamstrings is the progenitor 128

Salient aspects of normal function of the torso CHAPTER 6 Hip joint Piriformis Extensor system Coccyx Sacrum Obturator group Ischial tuberosity Hamstrings and obturator group need to Flexor system eccentrically lengthen to allow ischial lift Abdominal cavity and ‘brake’ the forward bending of the body Eccentric hamstring activity helps lift the ischia Femur in forward bending; concentric hamstring lowers the ischium in the lifting/return phase Note: Coactivation of the hamstrings with the quadriceps also helps control extension of the knee Fig 6.44  Control of the ‘ischial swing’ is fundamental to raising and lowering the ‘effort arm’ in manoeuvring the ‘body cylinder’ in forward bending/lifting. of many lumbopelvic pain symptoms and directly action. It can only do this if there is co-activation related to hamstrings ‘tears’. Some studies have from the LPU especially the lower abdominals and demonstrated flexion–relaxation in the hamstrings iliopsoas. Comparing trunk extension strength in at the end of forward bending.203 McGorry found kneeling and standing, Gallagher205 found a reduc- that it varied204 between individuals and in restrained tion in kneeling which he attributed to a reduced or free standing postures. In the extension/lifting capability to rotate the pelvis due to a disruption of phase, hamstrings were recruited first indicating that the biomechanical linkage of the leg structures. pelvic motion leads the movement of trunk exten- While this is no doubt true, the kinematic pattern sion. If the legs operate as dynamic supports to assist also involves a conjunct posterior spatial shift, and lowering and raising the sit-bones the hamstrings his testing device prevented this. Bringing the pelvis should be either eccentrically or concentrically con- back keeps the centre of mass more within the base tracting throughout the movement. When the pelvis of support (see Ch.4, ‘Basic concepts in postur- is allowed to shift backwards this facilitates this omovement analysis’). 129

Back Pain: A Movement Problem Locking the knees locks ‘Anatomical vs functional actions of muscles’). Had the pelvis they allowed the dynamic action described above, it is suggested the outcome would have been more The base of support – the feet with the ankles and favorable (see ‘The extensor mechanism’ p. 142). knees – form an important part of the kinetic move- ment chain helping the pelvis to appropriately shift in The importance of the feet space in order to present the torso to the task at hand. They must be free to dynamically adjust. Locking the Being ‘on your legs’ and the important contribution of knees significantly limits the important contribution the feet in providing a flexible and dynamic base of sup- of the pelvis and robs the large joints of a job they are port for posturomovement function is generally over- well suited to do. One of the few lifting studies to fac- looked. Importantly, receptors in the feet are tor the effect of pelvic tilt on lumbar posture during responsible for activation of significant reflex responses lifting191 reported some increase in anterior shear underlying postural stabilization and breathing.103 and compression in lordosis and maximum segmental flexion moment in kyphosis. This led them to recom- Functionally, their motion and muscular control mend the ‘freestyle’ posture – that of moderate flex- relates to three events: shock absorption, weight ion, as the safe lifting posture of choice. However, bearing stability and propulsion.206 The three foot subjects were asked to keep their knees straight, articulations which have a major functional signifi- significantly limiting the adaptive capability of the cance in walking are the subtalar, midtarsal and pelvis and the distribution of load sharing through metatarsalphalangeal joints.206 The 26 bones vari- the lower limb and increasing the load on the lumbar ously contribute to the three arches of the foot: spine. The two joint muscles acting over the hip and the inner and outer longitudinal and transverse knee provide effective load sharing (see Ch. 4 arches. These transmit weight as well as distribute it (Fig. 6.45). The medial ‘unit’ accepts the weight I II III IV IV III II I V V Cuneiform bones Cuboid bone Cuneiform bones Navicular bone Navicular bone Talus Talus Calcaneus Lateral longitudinal arch Medial longitudinal arch Dorsal aspect Plantar aspect Fig 6.45  The structural organisation of the bones of the foot reflects its functional role. 130

Salient aspects of normal function of the torso CHAPTER 6 of the leg while lateral portion function is probably hallux valgus. Many of those waddling around with more in lifting and balancing.1 A strong myofascial foot orthotics would be better served in bare feet matrix of tough connective tissue, tendons and and addressing the disturbances obviously present small intrinsic foot muscles arranged in four layers in the pelvi-femoral myomechanics. supports the arches and gives spring and resiliency to the foot for support. In concert with the action Part C: Upper pole of the of the calf muscles they also bring the joints of the body cylinder – the thorax, feet into their close packed positions so that the shoulder girdle, head and foot is converted to a semi rigid lever for effective neck push off.10 The foot oscillates between yielding to the ground and pushing away from it. The thorax provides the base of support for the head and neck and the shoulder girdle. They all The feet are richly supplied with somatosensory operate as an interdependent system, each element inputs – proprioceptive, cutaneous and joint recep- reciprocally influencing all the other elements. Rolf1 tors, all contributing important information towards maintained that the ‘pattern of the upper pole’ is postural control of the body in general.103 In neutral determined by three factors: standing the line of gravity falls anterior to the ankle • The position of the thoracic spine with respect to joint, hence the soleus exhibits continuous postural the line of gravity activity.10 Balance requires the ability to transfer • The balance of the shoulder girdle as it distributes weight through the feet articulations forwards and the physical work of the body. This girdle is more backwards and mediolaterally hence full mobility in vulnerable to deformation than the pelvic girdle. the hips and knees and ankles is also necessary to • The alignment of the cervical spine with respect allow this. The arrangement of the intrinsic muscles to the gravity line is particularly important as resembles that in the hand hence the foot is capable it balances the head containing the prime sensing of conforming to all manner of surfaces. Clinically, organs. actively ‘fanning the toes’ and/or ‘grasping’ with the The shoulder girdle determines the position and com- feet (and/or hands) directly facilitates a reflex reaction petence of the thoracic and cervical spines and the in the postural mechanism including better activation head. The alignment of the spine dictates the place- of the LPU and the diaphragm103 (see Fig. 13.105). ment of the girdle. Each component is explored. However, many are functionally ‘dead on their Thorax legs’. Described as ‘sensory deprivation chambers’207 the shoes we wear not only deprive us of the rich The rib cage is part of the spine’s structure; a sensory bombardment that feeds and nourishes the roughly ovoid shaped cage formed by the manu- CNS but also multiple unexpected surface changes brium/sternum in front, 12 pairs of ribs and their and movements which help maintain the pliability adjacent vertebra. The vertebrae provide the point and dexterousness of the feet. When the feet are of stability for rib movements while at the same active and well ‘grounded’ the SLMS is better acti- time embellishing rib movement – movement of vated and the kinetic movement chain up the legs one involves the other. and through the pelvis can be more effective. In this way the feet utilize the ground reaction force and assist The thorax is capable of expansion in all dimen- the ‘push up’ against gravity. The feet affect how the sions, in particular the bottom half which is more flex- pelvis can spatially shift208 and functionally there is a ible than the top. The upper opening or outlet is less strong link between heel pressure and the movement than half the width of the capacious inferior outlet. control of the ischial tuberosities and the eccentric Its structure is resilient enough to provide protection and concentric control of the hamstrings as the pelvis for the vital organs yet flexible enough to contribute is moved over the leg. Pressure through the ball of the towards movement control of the whole body. It also foot also has kinetic links to activation of ilio-psoas.28 has the potential to be deformable. The control of the pelvis is also reflected in the feet such that Rolf termed them ‘tattletales’. In par- ticular, imbalance in the deep intrinsic inferior pel- vic force couple with obturator group dominance creates external rotation at the hips, pronated feet, collapse of the medial longitudinal arch and possibly 131

Back Pain: A Movement Problem Biomechanics upper limb girdle to the body. With C7 this also forms the cervicothoracic transitional zone. The thoracic spine is mechanically stiffer and less mobile than the other regions.5 In general, 2. Vertebrosternal region: includes T3–7; ribs structural and kinematic data about the thorax 3–7 and the sternum into which they insert. The are limited.,209,210 Coupling patterns between axis of the costovertebral and costotransverse in rotation and lateral bending has caused the most general lies closer to the frontal plane hence when interest.5 In the upper part they are strongly cou- the rib rotates and elevates in a ‘pump handle’ pled though not as much as in the cervical spine5 action, the anteroposterior dimension of the thorax and less distinct in the middle and lower regions, is increased. This part of the cage is more flexible although variability, and predominantly ipsilateral than that above though less than that below. With coupling in the middle and lower regions has been the arm by the side, the glenohumeral joint is lies found.211 Arm elevation produces distinct ipsilat- approximately adjacent to the lateral 3rd 4th and 5th eral coupling and associated extension in the upper ribs. thoracic spine.212 3. Vertebrochondral region: T8–10; ribs 8–10 The variability is no doubt due to the influence which share a common cartilaginous insertion of different myofascial-rib states; vertebral move- which blends with that of the 7th costal cartilage. ment is affected by the freedom or otherwise in The axis of the posterior costovertebral and the ribs. transverse joint largely lies more in the sagittal plane hence elevation of the rib creates a ‘bucket Regions handle’ action which increases the transverse diameter of the thorax. This represents the most Different morphological characteristics of the ver- deformable part of the cage. Harrison et al.153 tebrae and ribs have led to different regions being showed that translating the thorax anteriorly/ described in the literature. While there is no clear posteriorly changed the kyphosis and 60% of the distinction, undoubtedly differing biomechanics movement occurred in this region. serve different functions. • Three vertebral regions have been described: T1–4; Kapandji16 notes that in the midzone of the T4–8; T8–12.5,211 thorax, the costovertebral joints lie between • Stokes218 also notes three vertebral regions the sagittal and frontal planes hence elevation though different: the transitional cervicothoracic of the ribs increases both the anteroposterior and thoracolumbar regions and an intermediate and transverse diameters of the thorax here zone – T3. (Fig. 6.46) • Lee209 delineates four regions which in functional terms make sense to consider, below. 4. Thoracolumbar junction: T10/11/12/L1/2; ribs 11 & 12 which are ‘floating’, acting like 1. Vertebromanubrial region: consists of T1 large transverse processes, they help ‘feather’ &2; 1st and 2nd ribs and the manubrium into the transition between the thorax and the which they insert. The first and second ribs don’t relatively mobile lumbar spine. They also provide have a lot of movement and represent a firm collar important attachment points for numerous or ring forming the upper thoracic outlet – ‘the muscles – the diaphragm, transversus, quadratus upper ring’. This provides a stable point of lumborum to name a few. This region is the attachment for the scalenii and point of inflection between the thoracic sternocleidomastoid to help in balancing the head kyphosis and the lumbar lordosis.24 The vertebrae and neck; a point for lifting and opening the provide an important transition between the manubrium sternum, as well as assisting in lifting primary movement of rotation in the thorax and the top of thorax in high demand breathing. The flexion/extension in the lumbar spine. The clavicle also attaches to the manubrium and orientation of the vertebral facets through this represents the only joint directly connecting the region gradually changes from nearly coronal in the thoracic spine nearly sagittal in the lumbar spine. The first sites of ossification in the spine consistently occur in the bodies of these levels.24 This and their resistance to 132

Salient aspects of normal function of the torso CHAPTER 6 Axis of movement between the costovertebral and costotransverse joint ( ) determins rib swivel direction Inferior Superior Action: Action: Widening Increases antero-posterior dimension Bucket handle action of the rib as it rotates on the costovertebral joints Fig 6.46  Movements of the ribs during inspiration vary in different regions. Adapted from Kapandji16 rotation/torsional stresses and extension afforded Scaffolding of the upper pole of by the facets24 indicate its significance as a stable the body cylinder supported by the SLMS load bearing region. When laterally translating Acting like struts, each rib or ‘hoop’ is connected by the thorax relative to a fixed pelvis, Harrison the intercostals arranged in two layers, their fibres et al.215 found lateral flexion was the largest at running in diagonally opposite directions. Through fascial connections they become contiguous with L1 and decreased from L1 to L5, but the segmental rotation angles for lateral flexion were largest at L3/4 (6.2), then L4/5 (5.7) and L2/3 (3.9) 133

Back Pain: A Movement Problem transversus, the diaphragm, and psoas through to between 35 and 70 mm. This involves lengthening the pelvis and so on, providing a continuous deep one side and shortening the other. ‘Lengthening sleeve of neuromyofascial support. The line of their the sides’ is an important component function in fibres is also continued through the obliques and the body cylinder including weight shift, breathing further with the interdigitations of serratus and and reaching. rhomboids and so on. Posteriorly the deep para- spinal intrinsic muscles control segmental move- Achieving a balanced neutral is also important ment. This myofascial cross bracing supports the where symmetry is fundamental. When disturbed, structure in such a way that it can be likened to a the thorax is shifted laterally and a scoliosis ensues. tensegrity structure – malleable, light yet strong This may be structural – complex bio and myome- and dissipating forces through tension and compres- chanically and more so if a double rather than a sin- sion.39,213 Forces are transferred globally across the gle curve. More clinically common, is the functional entire structure. In addition, ‘a tensegrity mast like scoliosis or lateral list of the thorax on the pelvis. the spine, functions whether vertically or horizontal The literature is replete with motherhood state- and can accept loads in any position’.213 Studies on ments about this condition yet nowhere could this deep muscle control of the thoracic spine are few. author find a myofascial descriptor as to its genesis. Lee et al.214 found differential activity between Greive216 suggests that iliopsoas may be implicated the deep and superficial paraspinal muscles during in pelvic torsion and this generally accompanies an trunk rotation in sitting. Multifidus activity while acute list. Kendall129 suggests ‘lateral trunk muscles’ variable, was not necessarily direction dependent, are involved. Clinical practice delineates ilio-psoas, and varied in different regions of the spine probably quadratus lumborum, serratus posterior inferior, reflecting regional biomechanical differences. the lateral abdominals and lateral latissimus dorsi can all be implicated in this changed alignment The ribs and their related fascia also provide (Fig. 6.47). attachment points for many of the large muscles attaching the shoulder girdle to the thorax and also Myofascial geometry helps ‘shore the pelvic girdle to the thorax. The fibre direction up’ the thoracolumbar junction at in many of these is also diagonal and serves to extend a potential cost and reinforce the dynamic bracing afford by the deep system muscles in a continuous myofascial While significant control between the thorax and pel- ‘wrapping’. The cage itself needs to be both mobile vis is afforded by the large thoracopelvic muscles – and stable as a whole as well as within it, in order that the erector spinae, anterolateral abdominals, psoas it can provide an effective and adaptable stable base quadratus lumborum and latissimus dorsi, clinically of support from which these limb girdle muscles it becomes apparent that the junction is further can act. Unequal length tension relationships in any reinforced by a fan shaped myofascial arrangement one of these can ‘cause distortions to occur through- over the junction which terminates around L2–3 out the structure in all three axes’.213 This jeopar- (Fig. 6.48). dizes not only the alignment of the axial spine but also the intrinsic shape of the cage and its spatial Anteriorly, the diaphragm attaches between T12 relationship to the head and the pelvis. and L3 (on the right and L2 on the left) and extends laterally and anterosuperiorly to encircle the base of An examination of significant aspects of the myo- the inferior thoracic opening. It can be considered fascial architecture of the thorax helps understand its analogous to a basketball hoop on a pole. While psoas alignment and control as part of the body cylinder. attaches to all lumbar levels and T12, Bogduk et al.154 proposed that its lower fascicles tend to flex the lower Alignment and control of the thorax lumbar levels and the upper fascicles extend the over the pelvis upper segments. Penning156 argues that this differen- tial action between fascicles serves to stabilize the Frontal plane spine. If spinal alignment is altered, their angle of pull will change and their action may become provocative. An important movement of the thorax is lateral trans- lation necessary for effective weight shift and pos- Posteriorly, the lowest point of origin of spinalis tural adjustment through the torso. Harrison is L3.16 Serratus posterior inferior attaches from et al.215 have shown that this can be significant, T11 to L2 or L310 and passes up to the lower four 134

Salient aspects of normal function of the torso CHAPTER 6 Trapezius Sternocleidomastoid Spine of scapula Clavicle Deltoid Infraspinatus Pectoralis major Teres minor Biceps brachii Long head of triceps brachii Serratus anterior Teres major Short head of triceps brachii External oblique Brachialis Umbilicus Sheath of rectus abdominis Latissimus dorsi Anterior superior iliac spine External oblique abdominal muscle aponeurosis Lumbar triangle Tensor fasciae latae Thoracolumbar fascia Sartorius Posterior superior iliac spine Gluteal fascia Gluteus maximus Fig 6.47  The lateral wall of the body. ribs which also receive attachments from the lateral Sagittal alignment of the thorax abdominals and latissimus, which itself is attached to L3. In relative terms, segments T12–L3 enjoy The line of gravity passes through the upper and more myofascial stability and the lumbar segments lower thoracic junctions and anterior to the apex below are potentially vulnerable in altered postur- of the kyphosis.24 The attendant axial load tends omovement control. to increase the thoracic curve210 – and will certainly 135

Back Pain: A Movement Problem Spinalis thoracis Lateral fibres of Diaphragm Longissimus thoracis latissimus dorsi Psoas major and internal oblique Rib 9 Serratus posterior inferior Rib 12 Spinous process of lumbar 3 Anterior view Posterior view Fig 6.48  Clinically an often dense myofascial fan acts to hyperstabilize the thoracolumbar region and lower pole of the thorax. do so in the case of poor postural and movement integrating upper and lower limb function, and control in the thorax. The thoracic curve varies in contributing to lower limb girdle control. its magnitude217 and is deemed to increase with age.209,210 Importantly, in normal studies, rotation was found to be greatest in the mid-thoracic region The sagittal alignment of the thorax over the pel- around T6–7.16,210,218 Anterior and posterior disc vis is dependent upon the alignment and movement postural loads have been shown to be balanced at capability within it which deserves attention. T8/9.217 Upper and lower poles of the thorax The lower section, being relatively more mobile, is more vulnerable to potential deformation from The T6/7/8 region is interesting. The midpoint of myofascial imbalance. This will affect the myome- the thoracic spine is T6/7 which is roughly the chanics of the whole thorax and the body cylinder apex of the thoracic curve. Anteriorly rib 6 has a as a whole. Harrison et al.153 showed that during direct connection to the sternum. Rib 7 shares its A/P sagittal translation of the thoracic cage, 60% insertion with ribs 8–10. The sternum or breast of this occurred between T8–12. plate acts as an anterior strut providing more sta- bility to the upper pole of the thorax. This creates Myofascial control of sagittal thorax the possibility for a functional ‘hinge’ between the alignment more mobile lower pole and the more structurally reinforced upper pole of the thorax – the ‘dorsal This basically depends upon balance between the hinge’.41 This is particularly likely to occur into flexor and extensor systems. This comprises balance flexion. The predominant pump handle A/P rib of the thorax as a whole over the pelvis and between action in the upper pole and predominant bucket its upper and lower poles. Imbalance in the upper handle lateral rib excursion probably further rein- pole will be reflected in the lower pole and vice versa forces this. • Balance in the upper pole is essentially represented by: The more stable upper pole is more directly related to head neck and shoulder function and it • balance between the cervicothoracic flexors is here that the major part of the axioscapulohum- and extensors and eral muscles attach. The lower pole being more mobile is more involved with primary breathing, • balance between the shoulder girdle flexors/ controlling the alignment of the body wall, protractors anteriorly, and synergistic activity between the shoulder girdle retractors and depressors posteriorly – middle and lower 136

Salient aspects of normal function of the torso CHAPTER 6 trapezius and rhomboids. Janda53 referred to Frontal plane these collectively as the ‘lower scapular stabilizers’. Normal quiet inspiration involves a lateral expansion of the lower pole of the thorax and a widening of • Balance of the lower pole is between the the waist. abdominals anterolaterally and the spinal extensors, serratus posterior inferior and Shoulder girdle latissimus dorsi posterolaterally (Fig. 6.47). Importantly, the ability to spatially move the The function of the shoulder girdle will in large thorax forward and back with respect to the pelvis part determine the competency and kind control requires adequate spatial pelvic control in order in the upper thorax and its effect upon the rest that it can provide a stable base of support for the of the spine. In fact, people with spinal pain action. always show defective control of their major ball and socket joints – the hip and the shoulder. Note that while there is the tendency for a structural Rather than a comprehensive treatise on the and functional ‘hinge’ in the mid thorax, nature has shoulder, examination of the function of the cleverly transitioned the attachment of the anterior shoulder girdle as it relates to torso control will shoulder muscles. The pectorals extend from the be considered. second rib to the cartilage of the 6th or 7th rib10 and serratus anterior is generally considered to extend The shoulder girdle consisting of the clavicle, to rib 9,129,219 though can be between the 8th and the scapula and head of the humerus rotating in the 10th rib.10 The upper attachments of the abdominals spherical glenoid, allows large multiplanar freedoms extend as high as the 5th rib. There is a direct fascial link of movement as well as the provision for weight between the sternocleidomastoid, pectoralis major and bearing. The girdle is suspended on top of the tho- the rectus sheath of the abdominals.10 rax rather like an oxen yolk, its only bony attach- ment via the connection of the clavicle with the Posteriorly, trapezius extends from the occiput to sternum (Fig. 6.49). The clavicle acts like a strut T12 but may not extend below T8.10 The rhomboids or ‘yard arm,’ holding the girdle away from the ribs together attach to the spinous processes of C7 to so that the arm hangs free of the body.6 The scapu- down to T5.10 Rolf1 considered rhomboids central to lae slide and rotate on the chest wall pivoting activity of the shoulder girdle. around the lateral end of the clavicle in order to ori- ent the arm. Movement of one is always reflected in Changes in the shape of the thorax the other. during inspiration Effective control of the claviscapular unit pro- Sagittal plane vides a spatially appropriate and stable platform of control to support function of the arm and hand. Many conventional texts such as Kapandji16 Like the axial column, arm use occurs as either open describe the pattern of inspiration as one of rais- or closed kinetic chain movements and always ing the cage both superiorly and inferiorly and involves muscle activation patterns throughout the increasing the anteroposterior diameter of the torso as well as a degree of weight shift both within upper thorax. However, well informed clinical the thorax and over the base of support. Arm move- practice220 dictates that this pattern equates to ments into elevation irrespective of the plane of high load auxiliary breathing using the accessory motion produce small but arguably important seg- breathing muscles to lift the thorax – not a desir- mental thoracic spinal motion.221 This is signifi- able state of affairs in the usual low load state. cantly greater into side flexion and rotation with Instead, the primary action should be one of a unilateral movements, whereas bilateral arm use lateral expansion of the lower ribcage with an produces a small extension displacement in the anterior expansion of the anterior thorax and upper thoracic spine and more significant extension upper abdomen balancing posterolateral expan- in the lower thoracic spine.221 Axial muscles attach- sion. Importantly, all breathing aficionados70,110 ing to the scapular and humerus span every verte- recommend no lifting of the cage as a whole – a bral level from the occiput to the sacrum and pattern associated with stress, tension and hyper- surround the chest wall as they unite the girdle to ventilation syndrome. 137

Back Pain: A Movement Problem Rib I Thoracic vertebra I Scapula Acromion Head of humerus Humerus Coracoid process Clavicle Sternum Fig 6.49  Viewed from above, the shoulder girdle resembles a ‘yoke’ suspended over the thorax. the spine and torso. Hence movement of the arms • Elevation and depression has a significant effect upon the alignment and con- • Retraction or adduction and protraction or trol of the axial spine as a whole. abduction • Downward or upward rotation. The position of the sternum and the rest of the thorax with respect to the line of gravity directly Functional movement control comprises varying influence the position of the girdle. When combinations of these movements. Like the pelvis, dropped and recessed, the clavicles downwardly the scapula is the bridge marrying movement rotate carrying the scapula-arm so that the girdle between the limb and the torso. If the arm is fixed hangs forward, down and narrows, occasioning or stable, the scapula rotates around the head of the increased holding from the suspensory muscles humerus. If the scapula is fixed, the humeral head above. When lifted and open, the clavicles poste- rotates in the glenoid. riorly rotate, the scapula drops back and the shoulders widen. However, it is critically important that the thorax and the shoulder girdle are able to move Similar to the pelvis, appropriate spatial position- independently of one another – the ribs moving ing of the clavi-scapular position facilitates gleno- under the shoulder girdle or the girdle moving humeral movements and balanced rotator cuff over and around the thoracic cage. The scapula action in centering the humeral head during move- can be required to perform a concurrent dual ment. Ingenious scapular positioning can also func- role of controlling both stability and mobility in tionally increase gleno-humeral advantage and ‘reach’. movement. Weight shift when on all fours is an example. Movements of the girdle Myofascial balance in the shoulder Essentially movements of the clavi-scapular unit girdle ensures optimal shoulder produce simultaneous movements in the sternocla- and thorax function vicular, acromioclavicular and scapulothoracic ‘joint’ with conjunct rotations occurring in the glenohum- Its tenuous bony attachment to the skeleton and eral joint. All glenohumeral movements consist of relatively shallow glenoid fossa means that function- rotations in the various planes which are associated ally, the shoulder girdle is a compromise between with spin slide and roll in the joint. Claviscapu- mobility and stability. Accordingly, it is highly lothoracic movements constitute movements of dependent upon dynamic stability provided by the whole girdle and principally consist of: 138

Salient aspects of normal function of the torso CHAPTER 6 balanced myofascial control. Balance needs to occur are able to contribute to various combinations and in all three planes of movement. For example, a modulation of movement direction. If the action winged scapula occurs with serratus anterior weak- of any of the spokes is impaired by unequal pulls, ness; however, more often than not, this is indica- the whole mechanism suffers. Depending upon the tive of disorganized spatial control of the whole ‘fixed point’– either the thorax/scapula or the girdle, part of which is due to serratus not eccentri- humerus, the muscles contribute to both open and cally lengthening. closed kinetic chain movement control similar to that seen in the pelvis. ‘Open chain’ movements It is useful to view the girdle in the different are those where the arm moves around the stable planes in order to fully appreciate its potential thorax/scapula; in ‘closed chain’ movements, the dysfunction: thorax/scapula moves around the stable limb. Note movement occurs variably between the humerus, Sagittal plane view scapula and chest wall. The scope of upper limb activities varies from Balance in the muscle activation patterns and strong lifting, throwing carrying, pulling and pushing length tension relationships between antagonistic to fine movements of the hands. The manner in groups need to be considered as follows: which the axioscapulohumeral muscles are arranged around the body wall allows lines of pull in all • Protraction / retraction of the girdle planes and forces can be transmitted throughout the body. Their form resembles the spokes of a • Anterior group – collectively, the upper wheel, which functionally converge at the shoulder, anterior chest muscles – serratus anterior and the conceptual ‘hub’6 (Fig. 6.50). Rather than pure the pectorals flex and protract the girdle on plane movements, adjacent muscles in the ‘wheel’ the thorax. With the girdle fixed or stabilized they depress the sternum and flex the thorax. Anterior girdle fixing can also be used as a Elevation Extension - elevation Levator scapulae Flexion - elevation Upper trapezius Spine of scapular Middle Clavicle trapezius Teres Pectoralis Infraspinatus major and minor Rhomboids Extension T7 Flexion Lower Sternum trapezius acts as a strut T12 Depression - extension Serratus anterior Flexion - depression Latissimus dorsi Depression Fig 6.50  Schematic lateral view of the thorax and the myofascial ‘wheel’ of the axioscapulohumeral muscles acting upon the glenohumeral ‘hub’ after Todd.6 139

Back Pain: A Movement Problem strategy to assist in labored breathing whereby Rhomboids serratus and pectorals act to lift the ribs. Middle trapezius • Posterior group – rhomboids, middle and lower trapezius retract and anchor the girdle Lower trapezius to the dorsal spine. With the girdle fixed or stabilized they assist in opening and lifting Fig 6.51  The forces exerted by the inferomedial scapula the sternum forward and extending the stabilizers. thoracic spine. Similarly, adduction of the arm causes abduction of If the anterior group is more dominant, the girdle is the scapula. Also, during glenohumeral abduction, if forward and the upper pole of the thorax is more teres doesn’t adequately lengthen and medial flexed. stabilization is inadequate the scapula is again pulled • Elevation / depression of the girdle into abduction. • Upward and downward scapula rotation. • Superior group – the upper trapezius and Upward rotation of the scapula provides the levator scapulae with some contribution from essential platform for arm elevation. It is achieved rhomboids12 lift the girdle. If the girdle is by a force couple between all three parts of fixed or stabilized they are synergistic in trapezius and the lower fibres of serratus acting to dropping the trunk between the girdles as in pull the inferior angle laterally while tipping the lowering oneself from sitting to the floor superior angle medially and hence the glenoid up. through the arms. Downward rotation is achieved through eccentric lengthening of the same synergy plus rhomboids and • Inferior group – the serratus, pectorals, latissimus activity. The upper/lower and medio/ latissimus dorsi and lower trapezius depress lateral contributions to the force couple need to be the girdle. Subclavius also contributes. When balanced. If the upper anterior unit is dominant, the the girdle is fixed as in weightbearing through girdle becomes hitched and protracted. the arms the body can be lifted through the girdles as in lifting your bottom off the seat. Transverse plane • Activity of the anterior depressors – the Forward and backward movements of one clavis- serratus, pectorals and subclavius needs to be capular unit produce a rotary torque in the trans- matched by activity in the posterior depressors, verse plane on the ‘upper ring’ – called forward and the lower trapezius and latissimus, otherwise the backward shoulder rotation. Essentially protraction girdle is protracted and depressed and the thorax is flexed. Coronal plane Given that the majority of modern man’s arm use is forward, the medial scapula stabilizers – the rhom- boids and middle and lower trapezius with synergistic activity in the adjacent paraspinal muscles need to pro- vide effective eccentric and concentric control in order to balance the anterior load on the girdle (Fig. 6.51). Balance needs to occur in the three prime move- ment directions: • Superior/inferior. Upper trapezius, levator scapulae rhomboids activity balanced with middle and lower trapezius and latissimus. • Medio/lateral. Rhomboids major and minor need to be balanced with serratus anterior and pectoralis minor and also pectoralis major acting through the humerus. Rolf1 also draws attention to balance between rhomboids and teres. If teres is dominant scapula retraction is attempted by teres. 140

Salient aspects of normal function of the torso CHAPTER 6 and retraction, the upper ribs and vertebrae vari- splenius, levator scapulae, trapezius and scalenes ably move either with221 or independent of the variously attaching to the manubrium clavicle, girdle. When accepted by the brain, the head scapula or vertebrae. They act like guy ropes turns ipsilaterally, the girdle movement thus initi- and their balance is critical. However, with poor ating and embellishing cervical movement ease deep system control and the collapse down and and range. When resisted, for example when forward of the thorax and shoulder girdle, looking at a good sort as you reach behind, the they tend to become over active, hold the head head remains in neutral rotation. This is an forward, and shorten and extend the neck and important postural setting action supporting head head. rotation and arm actions. During walking, the transverse plane girdle rotation initiates the pen- Competent inferior axial support includes com- dular arm swing which reduces the energy cost petent diaphragmatic control otherwise the acces- in walking. sory breathing muscles are called into chronic • Backward shoulder rotation (BSR). It is over activity with predictable consequences on important that this is primarily initiated from the the neck. medial and lower scapular stabilizers and not teres and infraspinatus. Serratus eccentrically The cervicocranial junction – the first two ver- lengthens. tebrae are connected to each other and the skull • Forward shoulder rotation (FSR). This is by a complex chain of joints with three axes and primarily initiated from serratus rather than from three degrees of freedom.16 The region allows pectorals, while rhomboids and middle and lower the greatest triplanar mobility of any part of the traps lengthen. Cervicothoracic junction and spine.12 Optimal alignment and control of the shoulder function are intimately related. rest of the axial column allows their important contribution to nodding and rotating the head. Cervical spine and head Movements of the eyes are closely linked with facilitating head movements, generally in the When the axial skeleton is balanced the head is bal- same direction, though this is not obligatory and anced and vice versa. The pelvis at the base is the contradirectional head and eye movements are key which determines the support and control of also possible. Steindler132 draws attention to the the rest of the axial spine and thorax. With well bal- increased functional range of rotation afforded anced support from below, the head and neck are by the eyes being able to rotate 45 on each side. balanced over the thorax and are free to easily lift, When the head is carried forward, movement of rotate and oscillate to orient the prime sense organs the upper movement unit is hindered, and will which drive motor function. The head apparently need to occur elsewhere. The mid cervical levels weighs some 3–4 kilos. If poorly balanced, chronic risk becoming sites of relative flexibility when muscle activity and tension patterns are needed to movement does not occur as it should in the ‘hold’ the head up. Mobility in the upper thoracic upper and lower cervical junctions. motion segments is important in facilitating move- ments of the cervical spine.210 Part D: Functional interrelationship between The cervicothoracic junction represents a criti- the upper and lower body cal crossroads of functional cooperation between cylinder the thorax, cervical spine and shoulder. The postural fate of the neck is dependent upon the It is considered that the function of the two limb organization of the shoulder girdle1 and in partic- girdles determines the motor competency of the ular the related position of the ‘top two rings’ whole body.1 Inadequate proximal girdle function of the thorax; the 1st and 2nd ribs with their creates problems for the spine.148 ‘In the primary vertebra behind and manubrium–sternum ante- patterns of movement the thorax and pelvis work riorly. Lift of the anterior strut enables a neutral together and the breathing rhythms adjust to the cervical spine largely maintained by principal coordinated whole, the shoulders and the arms fol- activity from the SLMS. Superficial system low the dictates of the head’.6 support is provided by the sternocleidomastoid 141