348 F. Politti et al. Figure 1 Test position as the individual elevates the shoulder recording area 20 mm lateral to the midpoint of the line ipsi-lateral to the dominant arm (A) against the resistance of between the C7 spinous process and the acromion (Jensen the load cell (B). et al., 1993). A reference electrode was fastened in the C7 warrants further evaluation of the bony and soft tissue spinous process of the volunteers. structures of the cervical spine. Before beginning the recording of EMG signals, each All volunteers signed a Term of Consent as required by individual subject was asked to carry out a series of three resolution 196/96 issued by the National Health Council and maximum force elevations of the shoulder of the dominant previously approved by the Ethical Committee in Research arm, with duration of 3 s each, against the resistance from the University of Vale do Sapuca´ı e UNIVA´S. Each subject offered by the load cell (Figure 1). A 2-min rest period was was informed of the purpose and potential risks of the study given between efforts. The mean value from the three before their written voluntary consent was obtained. trials obtained against the resistance offered by the load Equipment cell, represented a subject’s 100% maximum force (Max- Myoelectric signals were obtained using an 4-channel Force) elevation of the shoulder. The two sub-maximal module (EMG System do Brazil Ltdaâ), consisting of a band force (40% and 60% MaxForce) were used in the analysis pass filter of 20e500 Hz, an amplifier gain of 1000, and activity of upper trapezium muscle in the situation pre- and a common rejection mode ratio >100 dB. All data were post-maximal clenching effort (MCE). acquired and processed using a 16-bit Analog to Digital converter (EMG System do Brazil Ltdaâ), with a sampling Initially, the data was collected as the subject trac- frequency 2 kHz. The system was composed of active tioned a load cell by elevating the shoulder at 0 upper limb bipolar electrodes displaying a pre-amplification gain of adduction, until reaching 40% and 60% of previously deter- 20Â. A channel of the acquisition system was enabled for mined MaxForce (pre-MCE). After a 10 min rest, data was the utilization of the load cell (Alfa Instrumentsâ), having collected (post-MCE) under the same sub-maximal condi- an output between 0 and 20 mV and a range up to 1 kN. tions (40% and 60% of the upper trapezium MaxForce) as the Procedure and data collection individual bit two cotton rolls (8 mm thick), positioned in Muscle activity was recorded from the upper trapezius, the first and second molar as done by Ferrario et al. (2000) selected because it can be affected by a masticatory in a similar study. dysfunction (Gola et al., 1995) and is always related to tension pain of the head and neck. The criteria for the recording of the EMG signals were always the same for all stages of the experiment. At each The bipolar surface circular electrodes (Ag/AgCl e moment (pre- and post-MCE), 40% and 60% MaxForce samples Medical Traceâ) with 10 mm diameter, were used for the were collected and maintained through visual feedback surface recording of EMG with a center to center distance provided by a line drawn on the computer screen. The of 20 mm. The electrode was positioned with the medial duration of each EMG signal sample was 5 s. In order to avoid a learning effect, the order of the sample collection (40% or 60% MaxForce) was determined by blind draw. Possible risks of bodily compensation during the traction of the load cell and of patterning in the whole experiment were prevented through training before all the tests. Of greatest concern during the experiment was that the head and neck should always be maintained in the same position, so as to avoid interference from the upper trapezius muscle in the activity. Processing and analysis of the signals Amplitude signal analysis The EMG signals was obtained during the 40% and 60% of MaxForce contractions under the conditions pre- and post- MCE. Each sample lasted 5 s with a rest interval of 2 min. The root mean square (RMS) was calculated using a 200 ms moving window. Frequency signal analysis A power spectral analysis was performed on the 5 window for upper trapezius muscle. A fast Fourier transform of 512 points (Hanning window processing) was performed on 19 consecutive, 512 ms segments, overlapping each other by half their length (256 ms), for each 5 s contraction. The Median frequency (MF) was determined from each of the 19 overlapping windows. The mean and standard deviation of the FM during each contraction were calculated for upper trapezius muscle. EMG Analysis Software, Version 1.01 (EMG System do Brasil, Ltdaâ) was used. The basic assumption for the use of spectral characteristics of the signal for inferring motor control strategies or changes in fiber membrane
Maximal clenching effort 349 Figure 2 Mean (standard deviations) of RMS of the upper Figure 3 Mean (standard deviations) of Median Frequency trapezius muscle at pre- and post-MCE conditions during the (MF) of the upper trapezius muscle during the elevation of the elevation of the shoulder at 40% and 60% of MaxForce. Not shoulder. No significant difference was found between pre- and significant difference was found between the pre- and post- post-MCE, with 40% (t Z 1.44, p Z 0.16) and 60% (t Z À0.83, MCE (Paired Student’s t-test: p > 0.05). p Z 0.41) of MaxForce (Paired Student’s t-test). properties is the scaling effect that muscle fiber conduction between the masticatory and cervical muscles (Zafar, 2000; velocity has on the power spectrum of the signal (Lindstrom Milanov et al., 2001). According to the results of this study, and Magnusson, 1977; Stulen and DeLuca, 1981). this is reflex is absent which means that MCE in centric occlusion, does not cause a widespread excitation of the Statistical analysis trapezius muscle in individuals without a history of dysfunction in the masticatory system. Similar results were Data of EMG activity from the upper trapezius muscle are also found in subjects with normal mandibular divergence presented as means and standard deviations (SD). The and lower and higher mandibular angles (Tecco et al., parametric Student t-test for paired data was used to 2007). compare the difference of the RMS amplitude and MF between pre- and post-MCE recording during elevation of However, a significantly higher EMG activity in sterno- the shoulder at 40% and 60% of MaxForce. In this explor- cleidomastoid and upper trapezius muscles has already atory study, the level of significance of each comparison been verified during maximal voluntary clenching in retru- was set to p < 0.05. The entire analysis was conducted sive occlusal position, as well as no significant differences using the software SPSSâ (Version 12.0). in EMG activity between intercuspal position, ipsi-lateral, contralateral and protrusive positions (Zuniga et al., 1995). Results The EMG pattern observed suggests that the position of the mandible can interfere in the functional link between the The values obtained in RMS demonstrated that a post- masticatory and cervical muscles. The performance of the maximal clenching effort, as contrasted with a pre-maximal upper member positioning can also be influenced by clenching effort, does not alter the amplitude of EMG signal mandibular positioning (Ferrario et al., 2003; Ciuffolo under conditions with 40% (t Z 1.0, p Z 0.32,) and 60% et al., 2005). (t Z 0.1, p Z 0.91) of MaxForce as demonstrated in Figure 2. The observations about the mandibular positioning, and The median frequency value demonstrates that MCE does the fact that the EMG signal readings were carried out only not alter motor control strategies. This result was obtained in centric occlusion, demonstrate that the methodology when comparing pre- and post-MCE conditions with 40% used in this study affected the results. (t Z 1.44, p Z 0.16) and 60% (t Z À0.83, p Z 0.41) of MaxForce in elevation of the shoulder (Figure 3). A possible functional link between the masticatory and cervical muscles is more evident in individuals with Discussion dysfunction of the masticatory system. In situations of dysfunction of the masticatory system, the trapezius Although these investigations confirm the physiological and muscle receives afferent nociceptive signal via the anatomic relationships between the masticatory system trigeminal system, remaining hyperactive while the noci- and the cervical spine (Gola et al., 1995; Zafar, 2000; ceptive stimulus lasts. Changes in shoulder position could Milanov et al., 2001), the result of this study demonstrates develop because the masticatory muscle hyperactivity that the MCE in centric occlusion does not influence the leads to cervical muscle hyperactivity, with contraction of activity of the upper trapezius muscle in individuals without the muscles responsible for shoulder elevation and protru- a history of dysfunctions in the masticatory system. sion (Mannheimer and Rosenthal, 1991). This hyperactivity, which can be related to occlusion dysfunction can also The existence of a trigemino-cervical reflex is well affect neck muscles (Ferrario et al., 2003; Ciuffolo et al., known and it may bring about the possible functional link 2005). These observations are clear indications that a modulating activity of muscles such as the trapezius can be altered by the nociceptive signal caused in the activity
350 F. Politti et al. area of the trigeminal nerve, generated by a masticatory Clark, G.T., Browne, P.A., Nakano, M., et al., 1993. Co-activation system dysfunction, as related by Gola et al. (1995). of sternocleidomastoid muscles during maximum clenching. Journal of Dental Research 72, 1499e1502. It has been demonstrated that the masseter muscle and the upper trapezius are a frequent source of pain. This Costacurta, L., 1979. Anatomia microsc´opica buco-dental humana. leads to an increase in their fatigability and a reduction in Atheneu/Universidade de Sa˜o Paulo, Sa˜o Paulo. their endurance in response to a given load (Clark et al., 1993). It has been shown that the most painful body site is Darling, D.W., Krauss, S., Clasheen-Wray, M.B., 1994. Relationship the cervical spine, followed by the scapular region and the of head posture and the rest position of the mandible. Journal temporomandibular joint (Pedroni et al., 2006). of Prosthetic Dentistry 52 (1), 111e115. These facts support the idea that nociceptive feedback from Dworkin, S.F., LeResche, L., 1992. Research diagnostic criteria for the jaw muscles may interact with systemic nociceptive mech- temporomandibular disorders: review, criteria, examinations anisms, and play a role in musculoskeletal disorders involving and specifications, critique. Journal of Craniomandibular pain distributed throughout the head, neck, and limbs. Disorders: Facial and Oral Pain 6, 301e355. However, it is possible that in situations of dysfunctions Ferrario, V.F., Sforza, C., Colombro, A., et al., 2000. A electromyo- in the masticatory system, the trapezius muscle receives graphic investigation of mastigatory muscles symmetry in normo- afferent nociceptive signals from the trigeminal system, occlusion subjects. Journal of Oral Rehabilitation 27, 33e40. staying hyperactive while the nociceptive stimulus lasts. This can be a possible cause of hyperactivity and the Ferrario, V.F., Sforza, C., Dellavia, C., et al., 2003. Evidence of an presence of a trigger point (Gola et al., 1995; Fryer and influence of asymmetrical occlusal interferences on the activity Hodgson, 2005) in this muscle, an issue that should be of the sternocleidomastoid muscle. Journal of Oral Rehabilita- investigated in future studies. tion 30, 34e40. Limitations Fryer, G., Hodgson, L., 2005. The effect of manual pressure release on myofascial trigger points in the upper trapezius muscle. The first limitation of this study is related to the sample size, Journal of Bodywork and Movement Therapies 9 (4), 248e255. which is considered too small to quantify a possible interac- tion involving the physiological and anatomic relationships Gangloff, P., Perrin, P.P., 2002. Unilateral trigeminal anaesthesia between the masticatory system and the cervical spine. modifies postural control in human subjects. Neuroscience Letters 330, 179e182. A second limitation was caused by the fact that the results pertained only to healthy individuals. If individuals with Gola, R., Chossegros, C., Orthlieb, J.D., 1995. Syndrome algo- dysfunctions in the masticatory systems were included, the dysfonctionnel de l’appareil manducateur. Masson, Paris. results could possibly have been different, which would allow for a more extensive discussion. Harryman, D.T., Sidles, J.A., Clark, J.M., et al., 1990. Translation of the humeral head on the glenoid with passive glenohumeral A third limitation might have been the collection of the motion. The Journal of Bone and Joint Surgery 72, 1334e1343. EMG signal without altering the positioning of the mandible. Future studies should be conducted with variations (inter- Harryman, D.T., Sidles, J.A., Harris, S.L., et al., 1992. Laxity at the cuspal, ipsi-lateral, contralateral, protrusive and retrusive normal glenohumeral joint: a quantitative in-vivo assessment. occlusal contact positions) regarding the positioning of the Journal of Shoulder and Elbow Surgery 1, 66e76. mandible. Hawkins, R.J., Kennedy, J.C., 1980. Impingement syndrome in Conclusions athletes. The American Journal of Sports Medicine 8, 151e157. It was possible to determine in this study that in individuals Jensen, C., Vasseljen, O., Westgaard, R.H., 1993. The influence of without a history of dysfunction of the masticatory system, electrode position on bipolar surface electromyogram record- maximum clenching effort in centric occlusion does not ings of the upper trapezius muscle. European Journal of Applied alter the electromyographic signal of the upper trapezius. Physiology 67, 266e273. This result is not sufficient to disregard a link between the masticatory system and the trapezius muscle. Lindstrom, L., Magnusson, R., 1977. Interpretation of myoelectric power spectra: a model and its applications. Proc IEEE 65, Acknowledgements 653e662. This study was partly supported by the FAPESP and CAPES/ Mannheimer, J.S., Rosenthal, R.M., 1991. Acute and chronic PROEX, Brazil. postural abnormalities as related to craniofacial pain and temporomandibular disorders. Dental Clinics of North America References 35 (1), 185e209. Ciuffolo, F., Manzoli, L., Ferritto, A.L., et al., 2005. Surface elec- Milanov, I., Bogdanova, D., Ishpekova, B., 2001. The trigeminocervical tromyographic response of the neck muscles to maximal voluntary reflex in normal subjects. Functional Neurology 16, 129e134. clenching of the teeth. Journal of Oral Rehabilitation 32, 79e84. Munhoz, W.C., Marques, A.P., Siqueira, J.T.T., 2004. Radiographic evaluation of cervical spine of subjects with temporomandibular joint internal disorder. Brazilian Oral Research 18 (4), 283e289. Neer, C.S., 1983. Impingement lesions. Clinical Orthopedics 173, 70e77. O’Driscoll, S.W., 1991. A reliable and simple test for posterior instability of the shoulder. The Journal of Bone and Joint Surgery 73B (Suppl. 1), 50. Pallegama, R.W., Ranasinghe, A.W., Weerasinghe, V.S., et al., 2004. Influence of masticatory muscle pain on electromyo- graphic activities of cervical muscles in patients with myoge- nous temporomandibular disorders. Journal of Oral Rehabilitation 31 (5), 423e429. Palmer, M.L., Epler, M.E., 1998. Fundamentals of Musculoskeletal Assessment Techniques. Lippincott Williams & Wilkins, Philadelphia. Pedroni, C.R., Oliveira, A.S., Berzin, F., 2006. Pain characteristics of temporomandibular disorder e a pilot study in patients with cervical spine dysfunction. Journal of Applied Oral Science 14 (5), 388e392.
Maximal clenching effort 351 Stulen, F.B., DeLuca, C.J., 1981. Frequency parameters of the temporomandibular joint dysfunctions patients undergoing myoelectric signal as a measure of muscle conduction anterior repositioning splint therapy. The Eruropean Journal of velocity. IEEE Transactions on Biomedical Engineering Letters Orthodontics 30 (6), 592e597. 28, 515e523. Zafar, H., 2000. Integrated jaw and neck function in man. Studies of mandibular and headeneck movements during jaw opening e Tecco, S., Caputi, S., Tete, S., et al., 2007. Electromyographic closing tasks. Swedish Dental Journal Supplement 143, activity of masticatory, neck and trunk muscles of subjects with 1e41. different mandibular divergence. The Angle Orthodontistic 77 Zuniga, C., Miralles, R., Mena, B., et al., 1995. Influence of varia- (2), 260e265. tion in jaw posture on sternocleidomastoid and trapezius elec- tromyographic activity. Cranio 13 (3), 157e162. Tecco, S., Tete, S., D’Attilio, M., et al., 2008. Surface electro- myographic patterns of masticatory, neck, and trunk muscles in
Journal of Bodywork & Movement Therapies (2010) 14, 352e360 available at www.sciencedirect.com journal homepage: www.elsevier.com/jbmt CASE SERIES Clinical and MRI findings after high dosage medical exercise therapy in patients with long lasting subacromial pain syndrome: A case series on six patients H˚avard Øster˚as a,b,*, Gunnar Myhr c, Lasse Haugerud d, Tom Arild Torstensen e a Sør-Trøndelag University College, Faculty of Health Education and Social Work, Department of Physical Therapy, Ranheimsv 10, N-7004 Trondheim, Norway b Rosenborg Sport Clinic, Lerkendal, N-7492 Trondheim, Norway c Unilabs Røntgen Trondheim, 7030 Trondheim, Norway d Moholt Physical Therapy Institute, Trondheim, Norway e Holten Institute, Lidingo¨, Sweden Received 8 January 2009; received in revised form 14 May 2009; accepted 16 June 2009 KEYWORDS Summary Background and purpose: The primary aim of this case series was to investigate Medical exercise the effect of a high dosage medical exercise therapy program on shoulder pain in patients with therapy; subacromial pain syndrome. Pain; Subjects: Six subjects were assigned to a medical exercise therapy group. Shoulder; Methods: They received three treatments a week over three months. Outcome measures were Subacromial pain descriptions of the subacromial space including supraspinatus tendon diameter, function, pain, syndrome; and active range of motion in the shoulder girdle. MRI Results: The subjects showed improvement posttest compared to pretest with respect to pain, function, range of motion, and isometric strength. An MRI demonstrated no change in tendon thickness after the treatment. Inflammatory signs such as fluid in the subacromial bursa decreased in some patients. * Corresponding author. Sør-Trøndelag University College, Faculty of Health Education and Social Work, Department of Physical Therapy, Ranheimsv 10, N-7004 Trondheim, Norway. Tel.: þ47 73 55 93 05; fax: þ47 73 55 93 51. E-mail address: [email protected] (H. Østera˚s). 1360-8592/$ - see front matter ª 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.jbmt.2009.06.004
Effects of exercise therapy in impingement patients 353 Discussion and conclusion: In patients with uncomplicated subacromial pain syndrome, high dosage medical exercise therapy might be an efficient treatment approach. The clinical effects might be explained by morphological changes in the subacromial space. ª 2009 Elsevier Ltd. All rights reserved. Introduction recruited by orthopedic surgeons in a regional hospital and by general practitioners. Ethical approval was acquired Shoulder pain is relatively common in the general pop- from the Human Review Committee and all participants ulation (Pope et al., 1997), and the longstanding painful provided written consent. Individuals between the ages of shoulder is well known to be hard to treat (Desmeules et al., 18 and 60 with a unilateral primary shoulder impingement 2003). Subacromial impingement syndrome is commonly syndrome were assigned if they had: signs of positive associated with chronic pain symptoms, but the source of impingement, a minimum of three months since the onset this pain has not been scientifically clarified (Cohen and of shoulder symptoms, not undergone previous shoulder William, 1998). Theories vary on the origin of the pain in this surgery, normal neck, elbow and thoracic spine function (no condition. Khan et al. (1999) suggest that it may come from positive neurology tests), no neurological diseases, the subacromial bursa, the rotator cuff tendons, the acro- no history of shoulder dislocation, subluxation or fracture, mion, or from a combination of pathologies in these various no vestibular or visual disturbances (which would make it tissues. In the chronic stadium, surgical treatment, such as impossible to perform the intervention), and no chiro- acromionplasty, is often instituted (Hyvonen et al., 1999). practic, osteopathic or physiotherapy sessions within the last six months prior to entering the study. Individuals were To gain a better understanding of the etiology of the pain also excluded if they had any cardiovascular, respiratory, in a patient with shoulder impingement, it may be necessary systemic, or metabolic conditions limiting exercise toler- to consider some subacromial anatomical issues. The main ance. No subjects refused to participate in the study. blood supply to the rotator cuff comes from the anterior humeral circumflex, the posterior humeral circumflex, the The subjects went through a one-day testing procedure suprascapular and the subscapular arteries (Rothman and before and after the experiment period. They were prelim- Parke, 1965). At a point approximately 1 cm from its inser- inarily informed about the length of the study and the test tion on the greater tubercle, the supraspinatus tendon is parameters that were going to be used. They were asked not hypovascular, as demonstrated by various vascular injection to perform strength training the two days before the exper- studies (Fu et al., 1991). This area is known as the ‘‘critical iments to avoid the influence of non-restituted musculature. zone’’. Adduction compounds this hypovascularity by winding the insertional end further around the humeral The averages of the subjects’ physical and physiological head. Scheib (1990) suggests that this ‘‘wringing-out’’ characteristics before the training period are presented in further diminishes the blood to the tendon. It is difficult to Tables 1 and 2. understand why the supraspinatus tendon has an area of diminished blood supply. Rathburn and MacNab (1970) Instrumentation suggest that since these are flat tendons and the blood vessels run the length of the tendons they are susceptible to Magnetic resonance imaging (MRI) was performed in traction and direct pressure. The avascular zone therefore a private radiology institute. Coronal T1dweighted turbo might result, and is not a result of degenerative changes. spin echo (TSE) and T2dweighted fat saturated TSE, transversal T2dweighted gradientecho and oblique sagittal The scientific effect of exercise treatment in patients T2dweighted fat saturated imaging sequences were per- with impingement is unclear, but exercise as treatment is formed on a Siemens 1.5 Tesla magnet (Symphony) before widely used among physiotherapists. Clinically, medical starting treatment. The coronal images were angulated exercise therapy is believed to increase local circulation in along the main direction of the superior rotator cuff this condition, though this has never been investigated. tendons. This protocol was repeated in a control MR Inconsistent findings in the literature as to the treatment examination three months later. The control MRI was per- effects of exercise therapy in subacromial pain syndrome formed one week after the end of treatment. The images might be explained by the overall low intervention dosages were evaluated in a routine clinical setting by two experi- used. The hypothesis is that there are benefits to be gained enced MR radiologists with consensus on configuration of by increasing the dosages of exercise training for patients the acromion, subacromial space reduction, degeneration with subacromial pain The primary aim of this case series in the acromioclavicular joint, lesions in the rotator cuff, was to investigate the effect of a high dosage of a medical and other soft tissue abnormalities. They agreed on each exercise therapy program on subacromial structures and finding. The subacromial space was measured in the oblique shoulder pain in patients with subacromial pain syndrome. sagittal plane at the lateral edge of the acromion, from the under surface cortical line to the cranial cortical line of the Materials and methods humeral head. The thickness of the supraspinatus tendon was measured in a coronal image located along the central Subjects. Five men and two women participated in the part of the tendon at a point one centimeter lateral to the study. One man was excluded from the study during the edge of the acromion. The measurement result was intervention period due to surgery. The participants were compared in the two MR examinations.
354 H. Østera˚s et al. Table 1 Baseline values at inclusion of background data. Case Age/sex Height (cm) Mass (kg) Number of Durations of Subacromial 1 (M Z male, treatments symptoms (years) diameter (mm) 2 F Z female) 3 35 0,4 8 4 49/M 181 75 31 5 10 5 50/M 183 94 36 0,3 6 67/M 170 80 28 5 9 44/F 170 70 36 15 7 49/F 174 69 25 3 7 37/M 193 80 8 Pain scores weight resistance for the patient being able to do three sets of 30 repetitions. Each exercise was tested using a specific The subjective pain score was a composite score of the visual clinical test procedure developed in medical exercise analog scale (VAS). The pain responses were recorded on therapy (Torstensen, 2004). a 0e100 mm line used for each test. The extreme limits were marked with perpendicular lines using the verbal descriptors Note: An example of the exercise protocol will be found of ‘‘no pain’’ or ‘‘worst pain I can imagine’’. The subjects in Box 1. were blinded to their previous markings when follow-up measurements were taken. Measurements were expressed Thus, each patient had an individual tailored exercise in millimeters. The same rater for all subjects tested the program. The patient exercised within the comfortable active range of motion (ROM), performed in a standing range of motion with normal humeroscapular rhythm, and position with extended elbows. The subjects were asked to in the early phase the weight from the pulley apparatus was flex their shoulder as far as possible. Range of motion was used to unload some of the weight off the arm, making it noted with a digital inclinometer (Dualer, JTech Medical possible to perform the high number of repetitions in sets Industries, Salt Lake City, Utah, USA). The same procedure (three sets of 30 repetitions) with good kinetic control. As was performed measuring active abduction. Function was the patient improved, experiencing less pain, the range of measured using a functional assessment questionnaire. The motion and weight resistance were increased and the functional outcome measures included the self-completed starting position was changed according to the progression Shoulder Rating Questionnaire (SRQ) for which uniform ladder developed in medical exercise therapy (Torstensen, instructions were given. The five main components are pain 2004). The number of repetitions and sets was kept (VAS), pain in specific components, activity in daily living, constant during the treatment period, which involved three activity level in sports and leisure, and work ability. treatments a week for 12 weeks. The intervention program Psychometric properties (reliability, validity and was a combination of 20 min of global aerobic exercises responsiveness to change) of the SRQ have been previously using a stationary bike, treadmill, or step machine, and reported for patients with shoulder pathology (L’Insalata eight semiglobal and local shoulder exercises using medical et al., 1997; Williams et al., 1995). The SRQ was scored using exercise therapy equipment. All subjects used the same the method described by L’Insalata et al. (1997), resulting in eight exercises, working with all shoulder muscles. a scores rating from 17 to 90, with higher scores indicating better shoulder function with less shoulder symptoms. Remedial exercise program Experimental procedures The patients’ history and clinical tests, including muscle tests, specific joint tests and functional tests, are the basis Patient history, symptoms, and clinical findings were the for choosing the correct grading of the exercises focusing basis for choosing starting positions, range of motion, and on the appropriate weight resistance and range of motion. As an example of the test methodology a patient with 80 degrees of active flexion, 45 degrees of active abduction, Table 2 Pain (VAS), range of motion (ROM), shoulder function (SRQ) and supraspinatus tendon diameter with treatment. Case VAS ROMdflexion ROMdabduction SRQ Supraspinatus tendon diameter (mm) Pretest Posttest Pretest Posttest Pretest Posttest Pretest Posttest Pretest Posttest 1 7,2 5,0 70 170 60 170 56 80 5 5 4 4 2 7,0 2,5 120 180 100 130 47 61 6 6 6 6 3 7,5 2,0 90 170 90 160 45 79 6 6 4 4 4 4,0 0,5 120 180 80 100 67 80 5 6,0 4,5 170 180 90 90 38 58 6 4,0 1,0 180 180 180 180 45 69
Effects of exercise therapy in impingement patients 355 Box 1. Exercise protocol. For treatment purposes the patient is performs 3 sets of 30 repetitions with a 30 s break between each set, making it a total of 90 repetitions for each exercise. The test methodology is as follows: From the chosen starting position, range of motion and weight resistance the patient is asked to perform as many repetitions as possible. The patient then starts the exercise, at a speed of approximately 1 repetition every 2 s. When the patient reaches 8e9 repetitions the test is stopped and the patient is asked whether he/she feels it will be possible to complete at least 40 repetitions. Depending on the response the regime is modifieddThe response is either ‘‘yes I think I can reach 40 repetitions’’, in which case the patient continues to at least 40 repetitions. If the report is that it is too easy, the weight resistance is increased or the starting position can be changed. If however the answer is that the effort is too great or that pain in the shoulder is being provoked the weight resistance is lowered and/or the starting position and range of motion modified. When the patient reaches 40 repetitions, and starts to tire, or becomes uncoordinated, or starts to feel some pain or discomfort, the exercise is stopped, 20% is deducted from the 40, ending up with 3 sets of 30 repetitions. The goal is to involve the patient in the test making the patient understand that the goal is to find a baseline regarding range of motion and weight resistance, doing 3 sets of 30 repetitions. The exercise is then continuously monitored, increasing range of motion and weight resistance, but keeping the 3 sets of 30 repetitions constant. The grading of the exercises is a mirror image of the functional ability the patient. internal rotation to the gluteal fold, and external rotation improving, the exercises are modified accordingly, changing to 35 degrees, the exercises are tested out within these first the range of motion and then the weight resistance, so active ranges of motion. that the weight is optimal for doing the sets of 30 repeti- tions. A change in the exercise program is made at least Hence the initial starting positions of the exercise every 4th to 5th treatment. This system ensures that the program is a mirror image of the available functional level patients’ exercise is as pain free as possible. the patient has. Subjects were informed that, while the exercises might When testing out one exercise, the goal is 40 repetitions result in muscle fatigue, there should not be an increase in the and then 20% is deducted from the 40 repetitions ending up shoulder pain. It was possible to get the patient to exercise in with 32 being rounded down to 30 repetitions. the pain free range of motion with good coordination, and with the humeroscapular rhythm as close to normal as possible. To be able to do 3 sets of 30 repetitions, 30e60 s breaks are taken between each set, ending up with a total of 90 The subjects performed eight exercises, each of three repetitions. sets of 30 repetitions, three times a week for three months, making a total of 36 treatments. To be able to accomplish at least 40 repetitions, the physiotherapist (based on the clinical assessment) chooses It is possible that this high exercise dosage results in pain a range of motion, and weight resistance that is likely to modulation, stimulating the gate control mechanism in the achieve this objective. However this is trial end error and posterior horn, as well as the release of neuropeptides such each exercise is tested out the following way; as endorphins and encephalin from the pituitary gland, into the central nervous system. There was no attrition. The patient is told to complete as many repetitions as he/she can manage. Prior to the semiglobal and local exercises the experi- mental group warmed up for 15e20 min on an ergometer When the patient reaches 8e9 repetitions he/she is told cycle. Half way through the exercise program (four exer- to stop, and the following three questions are asked. cises each of three sets of 30 repetitions) the patients 1. Do you think you will be able to reach 40 repetitions, cycled for 10 min. After the last four exercises, the patients based on the starting position, range of motion, and spent another 10 min on stationary ergometer cycling. The the degree of effort you have been repeating so far?, intensity during cycle exercises was moderate to high, i.e. 2. Or, is this too easy for you to do? a heart rate frequency of 70e80% of the maximal heart 3. Or, Is this too difficult, causing an increase in rate, determined as 220 beats per minute, minus age. symptoms? All patients were treated over a three-month period with If the patient says that the loading feels acceptable to three treatments a week. For all patients a physiotherapist reach 40 repetitions, no changes are made and the patient was present in the exercise room motivating, supporting and continues the test counting 10, 11 and so forth, up to 40 re-grading the exercises according to the patients’ clinical repetitions. However if the patient says that the exercise is presentation and change in function and symptoms over the too easy, or too heavy, the exercise is modified, involving three-month treatment period. Thus, all patients received either the starting position, the range of motion, or the the same amount of attention while they were in the exercise weight resistance. Thus this is a test, within in the exercise room. The patients were treated in medical exercise therapy series, that involves the patient in the grading of the groups, where the therapist is in the exercise room, for one degree of effort, so ensuring, as best possible, a positive hour. Thus the patients were under continuous supervision experience. As the treatment proceeds, and the patient is while exercising. The variables that were continuously
356 H. Østera˚s et al. regraded were range of motion and weight resistance, while shoulder pain for four months. The active range of motion the number of exercises, repetitions, sets, and time per- and function also had a marked increase. forming aerobic work, using a stationary bike, were kept constant. After each treatment the physiotherapist filled in Case 4 a compliance log for each patient. A 44-year-old female with five years of symptoms did not Case reports use her arms much at work, and was not on sick leave. She had previously been a handball player, but with no known These several case reports constitute a case series type of shoulder injuries, and she fulfilled the inclusion criteria. At research methodology. pretest she complained of shoulder pain during light upper body strength training, and she also had a certain degree of Case 1 pain at rest and in the night. The pretest MRI showed type 2 subacromial configuration, with a subacromial diameter of A 49-year-old male visited our clinic five months after he 7 mm. After 28 treatments her pain level decreased from developed shoulder pain. He had problems performing his 4.0 to only 0.5, along with an increase in overall shoulder job as a postman, due to increasing pain during the day, but function. At posttest her active shoulder range of motion he was not on sick leave. While he did not perform very was completely normal. much work above shoulder height with the affected arm, he still did much carrying and lifting during an ordinary Case 5 working day. The subacromial diameter on the affected arm was eight mm. The MRI showed an acromion type 1 and The 49-year-old woman had pain in different levels for 15 a light degree of calcification in the area 5 mm cranial to years, with no pinpointed onset, and no injury. The MRI at the supraspinatus insertion on tuberculum major. After 35 pretest showed a type 2 acromion, with an 8 mm sub- treatments the MRI did not show any changes. He had acromial diameter. Structural changes in the transition improved both function and range of motion, and the pain between muscle and tendon tissue in the supraspinatus level was decreased. were also found. At her office workplace she had a moderate degree of shoulder strain, but no specific Case 2 physical activity in her leisure time. She needed almost a month to be able to complete the recommended inter- This case is a 50-year-old male working with a moderate vention level due to pain, but she was able to train the last degree of physical strain on the upper body, but not with two thirds of the medical exercise treatment period as work over shoulder height. As in case 1, this man did not prescribed. After 36 treatments the MRI found normaliza- perform any specific kind of physical activity in addition to tion in the tissue changes found in the supraspinatus at his work. His shoulder pain had developed gradually, pretest, and no extra-tendinous oedema in the same area. starting approximately five years ago. There was no obvious Her range of motion did not change, but she had less pain reason for the initial pain. The MRI at pretest showed a type and increased function. 1 acromion, no calcification, 10 mm subacromial diameter, but a light degree of liquid between lateral parts of the Case 6 supraspinatus tendon and the deltoid muscle. A small benign subcortical cyst in ventral parts of the tuberculum This 37-year-old male with three years of shoulder pain also major was also found at pretest. After 31 treatments over had some pain in the other shoulder, but he fulfilled the 12 weeks the radiologist found a normalization of the inclusion criteria. He worked as a physiotherapist, but did not supraspinatus tendon and no cyst. The patient had marked do heavy work due to shoulder strain. However, he had been pain relief; from 7.0 to 2.5 on the VAS, along with increased an active cross-country skier, and he was still performing function and range of motion. upper body physical activities on a daily basis. The initial MRI showed acromion type 2, with an 8 mm subacromial diam- Case 3 eter. After 25 treatments 12 weeks later, a thin layer between the supraspinatus tendon and the deltoid muscle A 67-year-old male was seen four months after the initial disappeared, corresponding to a pain relief from 4.0 to 1.0 on shoulder symptoms. He had worked as a bureaucrat his entire the VAS. His function also improved. The range of motion was career, and had never done strenuous overhead physical not affected in the beginning. He was able to increase the activities, and had no known shoulder or arm injury. His frequency of his cross-country skiing, but at posttest he still acromion configuration was type 2, with a subacromial had increased shoulder pain through strength training in diameter of 9 mm. The MRI showed a light degree of tendi- a more than 90-degree flexion or abduction. nosis in both the supraspinatus and the subscapularis tendons. Despite failing standardized protocols describing Each participant’s compliance categorization was quantification tendinosis in these areas, the MRI at posttest, determined by averaging the compliance reported on four with the same radiologist and corresponding MRI procedure, compliance logs. The compliance level was 83%%, with the showed less tendinosis after 36 treatments. He was the number of sessions expected at the outset. The results from patient in the present study that improved most with respect the testing of active range of motion in the shoulder girdle to pain, from 7.5 to 2.0 on the VAS. However, he had only had are presented in Table 2, which showed an increase in both active abduction and flexion in all subjects from pretest to posttest. The results from the MRI are illustrated in Figures 1e3.
Effects of exercise therapy in impingement patients 357 Figure 1 Longitudinal rupture of the supraspinatus tendon at the musculotendinous junction. 1A and 1B: Pretreatment coronal and sagittal T2 weighted fat saturated images shows irregular signal and high-signal intensity oedema in the superficial part of the tendon (arrow). 1C and 1D: The same images after treatment. The tendon is normal. Four subjects had type 2 acromial configuration and three referred to surgical treatment and was therefore had type 1 according to the Bigliani classification (1986). excluded from the study group. The subacromial diameter was unchanged from pretest Discussion to posttest images for all subjects. In this case series, we found reduced pain, improved active The thickness of the supraspinatus tendon pretest and range of motion and function, in a group of patients with posttest is given in Table 1. shoulder impingement syndrome treated with high dosage exercise therapy. The thickness changed in three patients, two increased by 1 mm and one decreased by 1 mm. In five of the six patients, the subjective qualitative evaluation of the MRI findings suggests a normalization of In addition to the measurement values that were found the subacromial soft tissue structures. Due to the low during the MRI, some qualitative soft tissue findings number of subjects, we do not know whether the high changed during the study period. They included dosage medical exercise therapy correlates with the reduced fluid in the subdeltoid bursa in four cases and specific soft tissue findings on the MRI. increased fluid in one case. The shape of the acromion has been classified into three A partial intratendinous longitudinal rupture normal- anatomical types by Bigliani et al. (1986). ized during the study, see Figure 1a and b. 1. In type 1, the acromial under the surface has a flat A small intrasubstance rupture in the supraspinatus shape. tendon was not visible on the follow up in one patient. A calcified tendinosis remained unchanged in one case. One patient with extensive osteoarthritis of the acro- mioclavicular joint, bursitis of the subdeltoid bursa and penetrating rupture of the supraspinatus tendon was
358 H. Østera˚s et al. Figure 2 The standard measurement of tendon thickness. 2A: Distance from the tip of acromion. 2B: The measurement. 2. In type 2 the acromial shape is gently curved with the in the 4e7 mm range. Intraobserver variability may have majority of the inferior cortex parallel to the curva- been a source of error. The small change in diameter ture of the humerus head in the oblique sagittal cannot be related to treatment. We would expect a treat- plane. ment effect on tendon inflammation to lead to a decrease in thickness. Some of the qualitative differences seen in the 3. The type 3 acromial shape has an anterior hook that soft tissue structures may be related to a decrease in local abruptly narrows the anterior acromiohumeral distance inflammation, e g. decrease in bursal fluid. It is difficult to (Crues and Fareed, 1991). Type 3 acromion has been decide if this is a real treatment response or just a repara- found to predispose for impingement syndrome and tive response over time, because of a change in physical might be associated with rotator cuff tears in the activity patterns, regardless of the treatment. ‘‘critical zone’’ (Wolin and Tarbet, 1997). The present study used a high number of repetitions in In the present study, the number of subjects is too small the treatment program. In vitro studies of shoulders have to suggest a correlation between acromial shape and demonstrated an avascular zone in the supraspinatus symptoms, which might be of interest in subjects who are tendon, located approximately one cm proximal to the candidates for surgery. insertion of the tuberculum majus (Wolin and Tarbet, 1997; Shoulder pain and the shoulder impingement syndrome Figure 3 The acromion shape extrapolated from Bigliani are third in frequency of visits to general practitioners, only et al. (1986). Sagittal fat saturated T2 weighted image shows less frequent than headaches and backaches (Bland et al., the Type 2 acromion with the surface parallel to the head of 1977). The shoulder impingement syndrome is the most the humerus. common shoulder problem seen in sports medicine. This syndrome may be caused by repetitive overhead use of the arm causing microtrauma to the subacromial tissues. These microtraumas provoke a local inflammatory response, partial tearing, and thickening of the rotator cuff. The subacromial bursa may also become irritated with resultant thickening of its wall, accumulation of fluid, and adhesion formation (Jackson and Graf, 1985). Correct rehabilitation is the key to successful conservative treatment. Nirschl (1989) suggests that intrinsic muscle contractile tension overload is the major factor in rotator cuff tendinosis rather than primary impingement. This, according to him, is why stage 1 and 2 lesions respond positively to exercise therapy. The qualitative MRI evaluation of soft tissue changes in patients with shoulder pain is subjective. Subtle differ- ences in tendon signal intensity and small intrinsic or surface ruptures may be difficult to detect in the first place. Changes between two consecutive studies may be more difficult to objectify. The same problem is apparent when measuring thickness of tendon plates that normally is
Effects of exercise therapy in impingement patients 359 Figure 4 Standing unloaded shoulder flexion 3 Â 30 repetitions, 3 kg. Hawkins and Abrams, 1987). This avascular zone may be Khan et al., 1998). Adding to the problem of making a true a predisposing factor in tendon degeneration and tendonitis and correct tissue-at-fault diagnosis, health professionals with pain and reduced function (Lyons and Orwin, 1998). generally find it difficult to agree on a common diagnosis and treatment for patients who have a painful shoulder A positive effect from the medical exercise therapy (Bamji et al., 1996). might be an increase in revascularization and regeneration of the rotator cuff tendons through a biomechanical stim- To avoid these problems the basis for choosing exercises ulus from performing dynamic exercises with a concentric and their grading in medical exercise therapy is strictly and eccentric phase (Torstensen, 2004; Torstensen et al., based on the patient presentation. This includes the 1994). This fits well with the move from tendinitis to ten- patient history, the patient’s pain reaction, and such clin- dinosis (Khan et al., 2002). In patients with tendinosis of ical findings as active and passive range of motion, palpa- the Achilles tendon, a vasculo-neural growth in the tendon tion, isometric tests, provocation tests, impingement tests, has been registered and may be a possible explanation for and so on, and not on structural changes of tissues. Another pain in patients with longstanding Achilles tendinosis factor that clinicians must take into account is the fact that (Alfredson et al., 2003; O¨hberg, 2003). O¨hberg (2003) has the more complex and chronic a shoulder problem is, the also documented that eccentric training resulted in more complex and diverse the pain mechanisms, the more a decrease in the neovascularization of the tendon and that futile the effort is to direct treatment at a ‘‘specific’’ the tendon infrastructure changed from having ultrasono- target tissue. The exercise therapy in this trial did not have graphically hypoechoic areas and irregular fiber structure in the ‘‘single-bullet-therapy’’ effect, as, for example, a normal tendon. Even though the function of the shoulder a cortisone injection; rather the total exercise dosage has is different compared to the lower leg, there are relevant the effect of a shotgun hitting all structures in the shoulder, clinical and functional similarities. A case study by Tor- shoulder girdle and the arm. stensen et al. (1994) showed that a supraspinatus tendon (tendinosis) regenerated after HD medical exercise In a systematic review by Michener et al. (2004) on the therapy. More research is needed into any positive effects effectiveness of rehabilitation for patients with sub- on tissue structures that are causing shoulder pain. acromial impingement syndrome they concluded that therapeutic exercise was the most thoroughly investigated Pain source? Even after eliminating shoulder pain caused form of rehabilitation. Controlled trials indicate that by structures in the neck and thoracic area, it is still diffi- therapeutic exercise is more effective in reducing pain and cult to pinpoint exactly which structure in the shoulder is improving functional loss than a placebo in both short- and causing the subacromial pain. When the pain is caused by long-term follow up (Brox et al., 1993; Brox et al., 1999), structures within the shoulder joint, there is a very low and more effective than no intervention in short-term correlation between structural changes in soft tissues in the follow up (Ludewig and Borstad, 2003). Given the evidence shoulder and the pain experience (Needell et al., 1996; from the last systematic review by Michener et al. (2004),
360 H. Østera˚s et al. therapeutic exercise is indicated as an effective interven- Crues III, J.V., Fareed, D.O., 1991. Magnetic resonance imaging of tion for patients with subacromial impingement syndrome shoulder impingement. Top Magn. Imaging. 3, 39e49. as opposed to no treatment or placebo treatment. However, the interventions were vaguely described, making Desmeules, F., Cote, C.H., Fremont, P., 2003. Therapeutic exercise the exercise techniques difficult to replicate. It is also and orthopedic therapy for impingement syndrome: a system- unclear what the optimal exercise regimen is or the atic review. Clin. J. Sport Med. 13, 176e182. frequency and intensity of an exercise program. Dualer IQ. J Tech Medical Industries, Salt Lake City, Utah, USA. One shortcoming in the present case series is the Fu, F.H., Harner, C.D., Klein, A.H., 1991. Shoulder impingement differences in the number of sessions attended (Table 1). Further research with a time-series analysis could shed syndrome. Clin. Orthop. 269, 162e173. some light on this discussion of dosage. It would be inter- Hawkins, R.J., Abrams, J.S., 1987. Impingement syndrome in the esting and useful to compare symptomatic with asymp- tomatic subjects in a future study. Further research in this absence of rotator cuff tear (stages 1 and 2). Orthop. Clin. area should address a larger group of patients in random- North Am. 18, 373e382. ized clinical trials. Imaging methods such as diagnostic Hyvonen, P., Lohi, S., Jalovaara, P., 1999. Open acromionplasty ultrasound should also be included. Randomized clinical does not prevent the progression of an impingement syndrome trials should also be used to further investigate the thera- to a tear. J. Bone Joint Surg. Br. 8, 813e816. peutic effects of different exercise therapy regimens in Jackson, D., Graf, B., 1985. Decompression of the coracohumeral patients with longstanding subacromial pain. arch. In: Jackson, D. (Ed.), Shoulder Surgery in the Athlete. Aspen Publications, Rockville, MD, pp. 51e63. Conclusion Khan, K.M., Tress, B.W., Hare, W.S.C., Wark, J.D., 1998. Treat the patient, not the x-ray: advances in diagnostic imaging do not replace The primary purpose of this clinical trial was to investigate the need for clinical interpretation. Clin. J. Sports Med. 8, 1e4. whether there might be pain, active ROM or morphological Khan, K.M., Cook, J.L., Bonar, F., Hardcourt, P., A˚strøm, M., 1999. changes after medical exercise regimens in non-operated Histopathology of common tendinopathies. Sports Med. 27, patients with subacromial pain syndrome. The subjects 188e201. showed clinically improved results after twelve weeks of Khan, K.M., Cook, J.L., Kannus, P., et al., 2002. Time to abandon medical exercise training for overall pain and function, the ‘‘tendinitis’’ myth. Painful, overuse tendon conditions have though further research is needed for this to be more a non-inflammatory pathology. BMJ 324, 627e628. conclusive. In patients with uncomplicated subacromial L’Insalata, J.C., Warren, R.F., Cohen, S.B., et al., 1997. A self- pain syndrome, medical exercise therapy might be an administered questionnaire for shoulder assessment of symptoms efficient treatment approach Figure 4a and 4b. and function of the shoulder. J. B. Joint Surg. Am. 79, 738e748. Lyons, P.M., Orwin, J.F., 1998. Rotator cuff tendinopathy and Acknowledgement subacromial impingement syndrome. Med. Sci. Sports Exerc. 30 (4), 12e17. The authors received no funding in the writing or prepa- Ludewig, P.M., Borstad, J.D., 2003. Effects of a home exercise ration of this manuscript and have no conflicts of interest. programme on shoulder pain and functional status in construction workers. Occup. Environ. Med. 60 (11), 841e849. References Michener, L.A., Walsworth, M.K., Burnet, E.N., 2004. Effectiveness of rehabilitation for patients with subacromial impingement Alfredson, H., O¨hberg, L., Forsgren, S., 2003. 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A software programmer and sportsman with low back pain and sciatica. In: Jones, M.A., Rivett, D.A. (Eds.), Clinical Brox, J.I., Gjengedal, E., Uppheim, G., et al., 1999. Arthroscopic Reasoning for Manual Therapists. Elsevier Ltd, London, pp. 275e311. surgery versus supervised exercises in patients with rotator cuff Torstensen, T.A., Meen, H.D., Stiris, M., 1994. The effect of disease (stage II impingement syndrome): a prospective, medical exercise therapy on a patient with chronic supra- randomized, controlled study in 125 patients with a 2 1/2-year spinatus tendinitis. Diagnostic ultrasound e tissue regeneration: follow-up. J Shoulder Elbow Surg. 8 (2), 102e111. a case study. JOSPT 20 (6), 319e327. Wolin, P.M., Tarbet, J.A., 1997. Rotator cuff injury: addressing Cohen, R., William, G., 1998. Impingement syndrome and rotator cuff overhead use. Phys. Sports. Med. 25 (6). disease as repetitive motion disorder. Clin. Orthop. 351, 95e100. 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Journal of Bodywork & Movement Therapies (2010) 14, 361e366 available at www.sciencedirect.com journal homepage: www.elsevier.com/jbmt PHYSIOLOGY Effect of low back pain on postural stability in younger women: Influence of visual deprivation Luana Mann a, Julio F. Kleinpaul a, Antˆonio Renato Pereira Moro a, Carlos Bolli Mota b, Felipe P. Carpes c,* a Laboratory of Biomechanics, Federal University of Santa Catarina e Floriano´polis, SC, Brazil b Laboratory of Biomechanics, Federal University of Santa Maria e Santa Maria, RS, Brazil c Exercise Research Laboratory, Federal University of Rio Grande do Sul e Porto Alegre, RS, Brazil Received 24 October 2008; received in revised form 19 June 2009; accepted 26 June 2009 KEYWORDS Summary This study investigated the effect of low back pain (LBP) on body balance during Body balance; normal and visual deprivation during standing in a LBP group (10 women) and a control group Pain; (10 women). A 3-D force plate was used to measure the center of pressure (COP) anteroposterior Sensory feedback; and mediolateral displacements, and resultant velocity. ANOVA was used to compare situations. Visual information; LPB group presented higher amplitudes of COP for anterioposterior direction (p < 0.01) in condi- Motor control; tions of open (3.07 Æ 0.53 cm) and closed eyes (3.70 Æ 0.71 cm) than healthy women Lumbar spine; (1.39 Æ 0.17 cm and 1.75 Æ 0.36 cm, for open and closed eyes, respectively). Similar results Postural balance were found for COP involving mediolateralsway. The resultant COP velocity was larger for LBP group (p < 0.05) when visual information was removed (3.03 Æ 0.68 m/s and 3.63 Æ 1.33 m/s for LBP and healthy women, respectively). LBP influenced the stability of young women during quiet standing, and the visual deprivation appears to reinforce LBP effects. ª 2009 Elsevier Ltd. All rights reserved. Introduction relationship between the center of mass projection and the area of support (Winter et al., 1998). The postural stability The ability to control of body balance during standing is usually is described by changes in the center of pressure e dependent on the activity of central nervous system (CNS). COP e excursion (Winter et al., 1998). The CNS regulates The CNS plays a fundamental role for generation and the body stability while standing or during locomotion regulation of proper muscle activity to control the mainly by means of afferent information from the visual system (Mergner et al., 2005), proprioceptors organs (Bove * Corresponding author. Tel.: þ55 51 3308 5859; fax: þ55 51 3308 et al., 2003; Tresch, 2007), cutaneous inflow (Kavounoudias 5842. et al., 1998), and changes in vestibular input (Bacsi and Colebatch, 2005). E-mail address: [email protected] (F.P. Carpes). 1360-8592/$ - see front matter ª 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.jbmt.2009.06.007
362 L. Mann et al. When some restriction occurs, such as absence of visual Methods feedback while standing with the eyes closed, the stability is expected to decrease (Schieppati et al., 1999). Elite Subjects gymnast athletes evaluated during bipedal, unipedal and handstand postures in different levels of complexity pre- Institutional approval for all phases of this study was sented not only direct effect of visual deprivation on the obtained from the Committee of Ethics in Research with stability evaluated by COP surface and COP mean velocity, Humans of the Institution where this study was developed but also, for example, the influence of the segment’s (IRB number 23081.001276/2007-32). Subjects signed orientation (Asseman et al., 2005). Visual deprivation can a consent form affirming voluntary participation in the also increase instability in dancers (Hugel et al., 1999). This study. The subjects were divided into two groups. The supports the concept that visual information can influence experimental group (LBP) comprised 10 women reporting postural stability mainly by changing the interaction with chronic nonspecific LBP for more than three months the environment. (mean Æ standard-deviation age of 20.7 Æ 2.1 years old, body weight of 57.6 Æ 0.6 kg, and height of 1.65 Æ 0.04 m). Fear or apprehension, for instance, while standing on The LBP group was paired to a control group (healthy) platforms of various heights (0.8, 1.6, and 3.2 m) resulted in without any LBP episode and without history of lumbar increased COP variation depending on the degree of fear of surgery, spine abnormalities, neuromuscular, joint and falling and anxiety detected (Davis et al., 2008). Additionally, reflex deficits, cauda equina, carcinoma, pregnancy, or subjects evaluated under a similar protocol also presented radicular symptoms observed during functional evaluation. changes in H-reflex that could not be explained by the back- These 10 healthy women presented mean Æ standard- ground muscle activation, but were dependent on pre- deviation age of 20.2 Æ 1.7 years old, body weight of synaptic inhibitory mechanisms anxiety-related (Sibley et al., 56.7 Æ 0.2 kg, and height of 1.66 Æ 0.03 m. 2007). The authors suggested this theoretical mechanism is also possible due to pain. Indeed, young-trained gymnasts of The inclusion in the LBP group was based on LBP uni- or normal weight and anxiety-free but with low back pain (LBP) bilaterally with nonspecific origin for more than three presented increased variability of center of pressure (Harringe months, which was confirmed by use of functional tests et al., 2008). The authors investigated whether athletes previously described in the literature for the low back training and competing with LBP would change their strategies (Gross et al., 1996). The subjects of both the groups had not for postural control. The anteroposterior COP excursion while been involved with regular physical activity during the six standing with eyes closed on a foam surface was greater in LBP months prior to evaluation. subjects compared to subjects with lower extremity injury (Harringe et al., 2008). Pain evaluation LBP affects the ability to control standing posture LBP was rated by each subjects by means of a visual analog (Brumagne et al., 2008a, b). Studies suggest LBP as a public scale from 0 to 10, where 0 represented ‘no pain’, and 10 health problem with prevalence up to 20% in USA and up to represented ‘unbearable pain’. The pain grade also sug- 40% in European countries (Van Tulder, 1996). Nonspecific LBP gested 0e2 as ‘light pain’, from 3 to 5 ‘light to moderate has been considered resultant of articular and/or muscular pain’, from 6 to 7 ‘moderate to intense pain’, and from 8 to imbalances of the lumbo-pelvic complex (Vogt, 2003) and is 10 ‘unbearable pain’ (Bird and Dickson, 2001). more frequent for women (Clarke and Buckley, 1980; Ander- sen et al., 2006). Among the factors underlying LBP are Body balance biomechanical assessment decrease of agility, coordination and postural control (Alar- anta et al., 1994). The low muscular conditioning of muscles The biomechanical assessment of body balance followed the of the trunk and lumbo-pelvic complex has also been sug- protocol described in a recent publication (Carpes et al., gested as influencing the hip strategy for control of body 2008). The changes in center of pressure (COP) displacement balance in LBP subjects (Carpes et al., 2008). were measured using a biomechanical 3-D force plate (Advanced Mechanical Technology, Inc., Watertown, MA, As a corollary, LBP is known to negatively influence the USA) placed in the center of a quiet environment and cali- proprioceptive capacity (Mientjes and Frank, 1999; Bru- brated as described by the manufacturer recommendations. magne et al., 2008a), which probably leads to increased The force plate was embedded at the level of the laboratory dependence on the visual system (Brumagne et al., 2000, floor, and the room presented no visual or auditory distrac- 2008a). This would be related to similar pre-synaptic tions. The subjects had their feet positioning marked on the inhibitory mechanisms similar those observed in fear/ force plate surface in the first trial, and each individual used anxiety situations (Sibley et al., 2007; Davis et al., 2008). In this template for all the subsequent trials. this regard, under both quiet stance and dynamic condi- tions, vision cannot be readily replaced by other sensory Subjects were oriented to stand quietly barefoot sepa- inputs in normal subjects (Schmid et al., 2007). If so, the rated at a comfortable width (about shoulder-width apart) ability to control the body balance in nonspecific LBP with their arms resting at their sides. The trials had a duration subjects, deprived of vision, should result only from non- of 30 s with the subjects maintaining a static posture, and visual sensory feedback. Thus, visual deprivation in LBP were repeated three times randomly with closed eyes (CE) or patients may result in more remarkable effects on body opened eyes (OE) in an attempt to minimize variability. The balance than would be the case for healthy subjects. The eyes closed characterized the visual deprivation, which was purpose of this study was to investigate the effects of vision observed by the researcher to make sure that subjects deprivation on the body balance of younger women reporting nonspecific LBP.
Effect of low back pain on postural stability COPml (cm) 8 363 CE remained with the eyes closed during the trials. The COP was OE ¢ used to express the neuromuscular responses to postural * stability due to changes of the position of center of gravity 6 (Winter, 1990). Data regarding body balance were acquired in * the same way for the two groups. 4 The testing protocol was conducted in a quiet room with 2 data being collected at sampling rate of 100 Hz via personal computer using specific software (data acquisition and off-- 0 LBP line analysis) of the biomechanical force plate (NetForce, Healthy Advanced Mechanical Technology, Inc., Watertown, MA, USA). From COP data, the anterioposterior displacement Figure 2 Center of pressure displacement in mediolateral (COPap), mediolateral displacement (COPml) and resultant direction (COPml, in cm) for the two groups (healthy and low velocity (COPvel) were considered for discussion. back pain e LBP) in the situations of closed (CE) and opened eyes (OE). For LBP subjects, the COPml was higher in the closed Statistical procedures eyes situation (¢, F Z 9.33; p Z 0.007), and COPml was higher than found for healthy subjects for both closed and opened Data were organized for mean and standard-deviation for eyes situation (*, F Z 23.9 and F Z 97.6, respectively, for each situation and group. The data normality was p < 0.001). confirmed by means of Shapiro-Wilk’s test. The homoge- neity of variances was verified using Hartley’s test. The displacement in both situations (see Figure 1). COPap was comparison between situations within and between groups statistically higher for the subjects, for CE (F Z 59.6; was accomplished by means of a two-way mixed model p < 0.001) and OE (F Z 91.35; p < 0.001). COPap was higher (between-within) ANOVA. Post-hoc Tukey’s test was applied in the situation of closed eyes for healthy (F Z 7.85; where main interactions were found. All statistical proce- p < 0.05) and LBP subjects (F Z 5.04; p < 0.05). COPml dures were conducted using the SPSS 11.5 for Windowsâ (Figure 2) did not differ between situation of closed and (Statistical Package for Social Sciences, Chicago, IL, USA). The significance level was set at 0.05. opened eyes for the healthy subjects (F Z 0.92; p Z 0.350). For low back subjects, the COPml was higher than found for Results healthy subjects for both closed and opened eyes situation The LBP group presented scores of 6 Æ 2 concerning the (F Z 23.9 and F Z 97.6, respectively, for p < 0.001). Closed pain ratio grade, which denotes moderate to intense pain. eyes situation elicited higher COPml than while standing The Figures 1e3 depict the findings of the present investi- with eyes open (F Z 9.33; p Z 0.007). gation. The overall results were consistent with significant effects of LBP and visual deprivation on body balance. The The COPvel (see Figure 3) depicts the velocity of changes visual deprivation was related to increase COPap magni- in resultant COP position for the different groups and tudes for both groups. LBP subjects presented higher COPap situations. COPvel was not influenced by the visual condition 8 ¢ in healthy subjects (F Z 0.01; p Z 0.91 for closed eyes, and CE F Z 1.28; p Z 0.27 for opened eyes). For opened eyes OE * 8 * 6 * CE OE 4¢ COPap (cm) 6 COP vel (m/s) 24 0 2 Healthy LBP Figure 1 Center of pressure displacement in anteroposterior 0 LBP direction (COPap, in cm) for the two groups (healthy and low Healthy back pain e LBP) in the situations of closed (CE) and opened Figure 3 Center of pressure resultant displacement velocity eyes (OE). COPap was statistically higher for the LBP subjects, (COPvel) for the two groups (healthy and low back pain e LBP) for CE (¢, F Z 59.6; p < 0.001) and OE (¢, F Z 91.35; in the situations of closed (CE) and opened eyes (OE). Closed p < 0.001). COPap was higher in the situation of closed eyes for eyes situation present statistically significant difference healthy (*, F Z 7.85; p < 0.05) and LBP subjects (*, F Z 5.04; between the groups (*, F Z 7.24; p Z 0.015). p < 0.05).
364 L. Mann et al. condition, no difference was found between healthy and support the deficit in hip strategy in LPB subjects. This low back pain subjects (F Z 4.26; p Z 0.054). Closed eyes relates to the number of degrees of freedom considering situation present statistically significant difference the anteroposterior oscillation when compared to the between the groups (F Z 7.24; p Z 0.015). mediolateral direction that is mainly controlled by the hip strategy (Mochizuki et al., 2006). Discussion A hip strategy for postural control involves action of Vision is the sensory input of highest confidence for the CNS muscles across the trunk and hip with horizontal shear in postural stabilization (Latash, 1997). Postural control forces as results of torque produced at the hip joint, rather involves information processing from sensory stimuli than ankle joint to maintain the body stability. On the other deriving from the visual, vestibular and somatosensorial hand, an ankle strategy concerns action of muscles across systems in an integrated way to accurately regulate body the ankle joint producing torques that shift the center of positioning and center of mass movements (Oie et al., 2002; vertical foot pressure to maintain the center of mass over Della Volpe et al., 2006). If one or more of these systems the base of support provided by the contact of feet with the fail, or the sensoy information is not correctly processed, ground (Henry et al., 2006). the risk of a fall or instability increases (Horak and Mac- pherson, 1996). LBP can alter the sensory input to postural Indeed, LBP subjects present deficits in the sense of control (Graven-Nielsen et al., 1997; Gill and Callaghan, position for the region of the hip (Gill and Callaghan, 1998; 1998). It may be related to increased pre-synaptic inhibi- Brumagne et al., 2000, 2008a), and which evokes an ankle tion of afferent muscles (Sibley et al., 2007) in this case due strategy to maintain the standing posture (Brumagne et al., to pain, or for chronic LBP subjects could suggest an 2004). The influence of muscle fatigue due to change in adaptation of cortical processing of proprioceptive infor- trunk position combined with pain may lead to increased mation (Rossi et al., 2003). Additionally, the deficit in instability in low back subjects, including subjects with recovery from perturbations is suggested to be dependent chronic pain. on reduced proprioceptive information, which would elicit increased visual dependence (Nies and Sinnott, 1991; Our results are also consistent with a posture of trunk Mientjes and Frank, 1999; Brumagne et al., 2008a). shift forward in LBP subjects, as elicited by the greater COPap displacement (Brumagne et al., 2008a; Popa et al., In this regard, for normal subjects under both quiet 2007). According to Brumagne et al. (2008a) increased stance and dynamic conditions, vision cannot be readily forward trunk inclination resultant from anticipation of replaced by other sensory inputs (Schmid et al., 2007). postural instability may play a key role in the recurrence of Gymnasts performing specific movements in bipedal, uni- LBP. This effect could be similar those resulting from fear pedal and handstand postures were not only affected by and/or anxiety involving postural control while standing on visual deprivation, but also by visual deprivation combined platforms of different heights (Davis et al., 2008) when with orientation (Asseman et al., 2005). Visual deprivation changes in H-reflex not explained by the muscle activity was suggested as affecting postural control in dancers (Hugel may also arise (Sibley et al., 2007). The present results and et al., 1999). LBP is known to decrease proprioceptive the results from previous studies have implications for the capacity (Mientjes and Frank, 1999; Brumagne et al., 2008a), postural control in older subjects with LBP or hemiplegic which may lead to increased dependence on the visual subjects, as previous suggested (Sibley et al., 2007). system in an attempt to improve the interaction with the environment, providing stability (Gautier et al., 2007; Bru- Considering LBP as the only factor contributing to magne et al., 2000, 2008a). changes in postural control, changes in normal standing posture leads to increased activation of back muscles Therefore, the main purpose of this study was to assess (Brumagne et al., 2008a), and therefore an increased the body balance in young women, both healthy and with LBP, fatigue rate (Vogt, 2003). These changes in the pattern of with and without visual information. Our results are back muscle activation have been suggested as a strategy consistent with increased dependence on visual informa- to limit spine movements regardless of the pain intensity tion in LBP subjects (Mientjes and Frank, 1999; Radebold (Nies and Sinnott, 1991; Mientjes and Frank, 1999; Bru- et al., 2001; Brumagne et al., 2008a; Mok et al., 2004; Nies magne et al., 2008a). and Sinnott, 1991; Speers et al., 2002). Subjects presented LBP ratio classified as moderate to intense. Visual depri- Our results for COPvel are consistent with LBP leading to vation was induced by standing posture while keeping the decrease of spine mobility (Thomas et al., 1998) and eyes closed. The results support the influence of LBP in increased reaction time for a stimulus in the spine general variables of body balance (Della Volpe et al., 2006; (Jayaraman et al., 1994). It negatively affected postural Brumagne et al., 2008a; Harringe et al., 2008). Addition- control likely due to alterations in muscle recruitment ally, we found visual deprivation increasing postural insta- (Wegener et al., 1997; Bouisset et al., 2002). In the situa- bility more significantly (higher magnitudes of COP tion of visual deprivation, the subjects with LBP present displacements) for those with LBP. greater instability; with sensory-motor information insuffi- cient to correct and avoid postural imbalances (i.e. spinal Among the factors for reduced postural control in LBP and cerebral reflexes, motor cortex processing and senso- subjects is the limited ability for use of a hip strategy due rimotor pathways) (for a review see Ebenbichler et al., to reduced force and flexibility of the lumbo-pelvic region 2001). (Carpes et al., 2008; Brumagne et al., 2008b). Our results eliciting higher variability in mediolateral direction, Our results demonstrated that LBP subjects deprived of visual information present increased postural instability compared to healthy subjects while standing in the erect posture (Figure 3). This suggests that even the COP is not significantly dependent on visual information during dynamic
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Journal of Bodywork & Movement Therapies (2010) 14, 367e374 available at www.sciencedirect.com journal homepage: www.elsevier.com/jbmt HEAD POSTURE Influence of forward head posture on scapular upward rotators during isometric shoulder flexion Jong-Hyuck Weon a, Jae-Seop Oh b, Heon-Seock Cynn c, Yong-Wook Kim d, Oh-Yun Kwon e,*, Chung-Hwi Yi e a Department of Rehabilitation Therapy, Wonju Christian Hospital, Wonju College of Medicine, Yonsei University, Wonju, Republic of Korea b Department of Physical Therapy, College of Biomedical and Engineering, Inje University, Gimhae, Republic of Korea c Department of Physical Therapy, Hanseo University, Seosan, Republic of Korea d Department of Physical Therapy, College of Alternative Medicine, Jeonju University, Jeonju, Republic of Korea e Department of Physical Therapy, College of Health Science, Yonsei University, Republic of Korea Received 30 December 2008; received in revised form 25 June 2009; accepted 26 June 2009 KEYWORDS Summary We assessed the effects of forward head posture in the sitting position on the activity Electromyography; of the scapular upward rotators during loaded isometric shoulder flexion in the sagittal plane. Forward head posture; Scapular upward rotator Healthy volunteers (n Z 21; 11 men, 10 women) with no history of pathology participated in the study. Subjects were instructed to perform isometric shoulder flexion with the right upper extremity in both the forward head posture (FHP) and neutral head posture (NHP) while sitting. Surface electromyography (EMG) was recorded from the upper trapezius, lower trapezius, and serratus anterior muscles. Dependent variables were examined by 2 (posture) Â 3 (muscle) repeated measures analysis of variance. Significantly increased EMG activity in the upper trape- zius and lower trapezius and significantly decreased EMG activity in the serratus anterior were found during loaded isometric shoulder flexion with FHP. Thus, FHP may contribute to work- related neck and shoulder pain during loaded shoulder flexion while sitting. These results suggest that maintaining NHP is advantageous in reducing sustained upper and lower trapezius activity and enhancing serratus anterior activity as compared with FHP during loaded shoulder flexion. ª 2009 Elsevier Ltd. All rights reserved. * Corresponding author. Department of Rehabilitation Therapy, Introduction The Graduate School, Yonsei University, 234 Maji-li, Hungob-myon, Wonju, Kangwon-do 220-710, Republic of Korea. Tel.: þ82 33 760 Work-related neck and shoulder pain are frequently repor- 2429; fax: þ82 33 763 2496. ted in the workplace. Haughiee et al. (1995) found that forward head posture (FHP) is associated with neck and E-mail address: [email protected] (O.-Y. Kwon). 1360-8592/$ - see front matter ª 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.jbmt.2009.06.006
368 J.-H. Weon et al. shoulder pain. In addition, Chiu et al. (2002) found that Methods approximately 60% of individuals with neck pain had FHP. Several variables have been identified as risk factors for the Subjects development of shoulder pain, including highly abnormal sustained posture of the cervical spine, repetitive use of the Healthy subjects (n Z 21; 11 men, 10 women) were arm, and work with the arm in an elevated position. Lifting recruited from the Department of Physical Therapy, Yonsei and overhead work in the sagittal plane are often performed University. The subjects had a mean age of 21.3 (Æ3.1) in construction and assembly line workplaces for loading and years, a mean weight of 72.4 (Æ2.2) kg, and a mean height unloading, and FHP is the typically assumed posture during of 174.6 (Æ5.3) cm. Exclusion criteria were past or present much work in construction and on assembly lines. Greenfield neurological, musculoskeletal, or cardiopulmonary diseases et al. (1995) reported that patients diagnosed with shoulder that could interfere with shoulder flexion in the sitting overuse demonstrated increased FHP in comparison with position. healthy subjects. Before the study, the principal investigator explained all Musculoskeletal pain occurs due to changes in muscle procedures to the subjects in detail. All subjects signed an length when assuming a poor posture for a prolonged period informed consent form, which was approved by the Yonsei and performing repetitive movements (Bergqvist et al., University College of Health Science Human Studies 1995). Spinal alignment is thought to affect scapular posi- Committee. A power analysis determined that 12 subjects tion and shoulder girdle function. Faulty cervical spinal were required to obtain a power of 0.8 at a < 0.05. This alignment, such as FHP, is usually associated with short- analysis was based on an estimated effect size (5% MVIC ening of the posterior neck extensor muscles and tightening difference) derived from previous literatures (Perry, 1992; of the anterior neck muscles, as well as the shoulder McLean and Urquhart, 2002). Perry (1992) has stated that muscles, affecting scapular position and kinematics 5% MVIC was an appropriate threshold for determining the (Kebaetse et al., 1999). FHP is also considered to be an onset and termination of muscle activity during gait cycle. etiological factor in the pathogenesis of subacromial And 5% MVIC was used as threshold to measure the level of impingement syndrome. Postural deviations observed in upper trapezius muscle load in computer and production FHP involve a downwardly rotated, anteriorly tilted, and workers (McLean and Urquhart, 2002). Thus, we estimated protracted scapula leading to increased compression in the the effect size by 5% MVIC. The proposed effect size may subacromial space during arm elevation (Lewis et al., have been inflated because it was not derived from pilot 2005). Although there is evidence for an association data; therefore, 21 subjects were tested. between abnormal sustained forward posture of the cervical spine and the development of shoulder pain, there Equipments is a lack of evidence addressing the issue of how posture of the cervical spine contributes to shoulder pain. A biome- Electromyographic (EMG) data were collected using a Bio- chanical mechanism that may explain this association pac MP100WSW and a Bagnoli EMG System. Skin preparation involves altered scapular and humeral kinematics, of electrode sites involved shaving and cleaning with secondary to scapular upward rotator muscle imbalance. rubbing alcohol, as described by Cram et al. (1998). Disposable AgeAgCl surface electrodes were positioned at To prevent shoulder pain associated with abnormal an interelectrode distance of 2 cm. The reference elec- neck posture, many researchers have stressed trode was attached to the styloid process of the right ulna. maintenance of a neutral head posture (NHP) during arm EMG data were collected for the following muscles on the movement and functional activity (Edmondston et al., right side: upper trapezius (2 cm lateral to the midpoint of 2007; McLean, 2005). Many studies have been performed a line drawn between the C7 spinous process and the to determine the effects of head, thorax, and shoulder posterolateral acromion), lower trapezius (placed on an position on shoulder and scapular kinematics and the oblique vertical angle with one electrode superior and one strength of the shoulders and hands. Ludewig and Cook inferior to a point 5 cm inferomedial from the root of the (1996) investigated the effects of head position on scap- spine of the scapula), and serratus anterior (placed verti- ular orientation and muscle activity during shoulder cally along the mid-axillary line at rib levels 6e8) (Cram elevation in the scapular plane without an applied load. et al., 1998; Nieminen et al., 1993). Each pair of electrodes However, to our knowledge there have been no previous was aligned along the line of underlying muscle fibers. studies of the effects of head position on muscle activity of the scapular upward rotators during loaded shoulder EMG data were sampled at 1000 Hz. The EMG signals flexion in the sagittal plane. It is generally believed that were amplified and digitized using AcqKnowledge 3.7.2 FHP is a contributor to the development of chronic neck, software. Band-pass (20e450 Hz) and band-stop filters shoulder, and even jaw pain (Haughie et al., 1995). (60 Hz) were used. The raw data were processed into root However, there is confusion in the literature regarding the mean square (RMS) data using a moving window of 250 ms impact of head posture on upper quadrant pain. We and converted to ASCII files for analysis. For normalization, hypothesized that FHP during loaded isometric shoulder 5-s reference contraction data were recorded while flexion would alter the muscular activation pattern of subjects performed three trials of maximal voluntary scapular upward rotator muscles. We assessed the effects isometric contraction (MVIC) in the manual muscle testing of FHP on electromyographic activity of the upper trape- position, as recommended by Kendall et al. (2005). A 1-min zius, lower trapezius, and serratus anterior muscles during rest period was provided between trials. The mean RMS was loaded isometric shoulder flexion (30, 60, 90, 120) in calculated for each muscle. The EMG signals collected the sagittal plane.
Influence of forward head posture 369 during each degree of shoulder flexion are expressed as testing all subjects were familiarized with shoulder flexion percentages of the calculated mean RMS of MVIC (%MVIC). in the sagittal plane with a 2-kg dumbbell. All subjects were comfortable, with standardized position and movement at Procedure the time of data collection. Each subject was required to assume an upright position, Statistical analysis sitting comfortably in a low-backed wooden chair. The height of the chair backrest was low enough (lower thoracic The data are expressed as the means Æ standard deviation. level) to allow movement of the scapula in all subjects. We A 2 Â 3 repeated measures ANOVA with one within-subject performed this test on the right side to minimize artifacts factor (posture) and one within-subject factor (muscle) was from the electrocardiographic signal. While sitting in used to determine the main effects and interaction effects a chair, the subject was asked to raise the right upper at each degree of flexion, with the significance level set at extremity in the sagittal plane (30, 60, 90, 120) in both a Z 0.05. If statistical significance were found for a main the NHP and FHP in random order. Surface EMG was effect of muscle, multiple comparisons were performed recorded from the upper trapezius, lower trapezius, and using paired t-tests with the appropriate Bonferroni serratus anterior muscles (Figure. 1). A plumb line hanging adjustment. from the ceiling was used to determine the subjects’ posture. In NHP, each subject’s external auditory meatus, Results acromion, and greater trochanter were aligned with a base plumb line that was perpendicular to ground level. In FHP, There were significant posture-by-muscle interactions for the subject was instructed to position his or her head EMG activity at 30, 60, 90, and 120 loaded isometric anteriorly in a horizontal plane allowing the tragus to be shoulder flexion. There was a significant main effect of aligned to a target plumb line, which was placed 5 cm posture for the EMG activity in 30, 60, 90, and 120 loaded anterior to the base plumb line. An inclinometer was used isometric shoulder flexion. There was also a significant main to determine when the shoulder was at 30, 60, 90, or effect of muscle on EMG activity in 30, 60, 90, and 120 120 flexion. A horizontal bar was placed at this level and loaded isometric shoulder flexion (Table 1). Multiple provided feedback to the subject when instructed to flex comparisons among the three muscles are presented in Table his/her right shoulder with a 2-kg dumbbell in the hand 2. A significant posture-by-muscle interactions were further until the upper aspect of the right wrist touched the bar analyzed conducting separate repeated measures ANOVA for and to hold the position without elbow flexion for 5 s. The three 2 Â 2 subtables in each shoulder flexion angle. There EMG signal was recorded during this 5-s isometric contrac- were significant interaction effects except for the interac- tion period. A 2-min rest period was provided between tion effects between upper trapezius and lower trapezius in measurements to minimize muscle fatigue and the mean 90 and 120 (Table 3). RMS of three trials was determined for comparison. Prior to Figure 1 Loaded isometric shoulder flexion at 90 shoulder flexion. (A) Neutral head position. (B) Forward head position.
370 J.-H. Weon et al. Table 1 Summary of analyses of the EMG data. trapezius was significantly different at 30 and 60 shoulder flexion (Padj < 0.017). Degree of Effect F value p-Value flexion Discussion 30 Posture F1,20 Z 29.702 .000 Pain and stiffness in the shoulder and posterior neck lead to an inability to work or carry out household and leisure Muscle F2,40 Z 16.815 .000 activities, burdening both patients and society (Nie et al., 2005). Postural neck pain is usually associated with sus- Posture  muscle F2,40 Z 35.685 .000 tained static loading of the cervical spine and shoulder girdle, induced by faulty posture and incorrect movement 60 Posture F1,20 Z 39.502 .000 patterns. Although many previous studies have examined the relationship between FHP and pain, our study is the first Muscle F2,40 Z 21.982 .000 to determine the effects of FHP on the upper trapezius, lower trapezius, and serratus anterior muscle EMG activity Posture  muscle F2,40 Z 26.309 .000 related to scapular upward rotation during loaded isometric shoulder flexion in the sagittal plane. In the present study, 90 Posture F1,20 Z 37.885 .000 the activities of the upper trapezius and lower trapezius were increased significantly, while that of the serratus Muscle F2,40 Z 7.567 .002 anterior was decreased significantly in FHP in comparison with those in NHP during all degrees of loaded isometric Posture  muscle F2,40 Z 30.383 .000 shoulder flexion. 120 Posture F1,20 Z 20.744 .000 There are several potential mechanisms that may Muscle F2,40 Z 8.452 .001 explain our results. First, FHP may alter the length and Posture  muscle F2,40 Z 31.629 .000 tension of the levator scapula muscle during scapular upward rotation. Significantly increased levator scapulae Results of post hoc paired t-tests revealed that EMG activity was reported previously in FHP vs. NHP (McLean, 2005). The upper trapezius is an agonist muscle for upward activity in the upper trapezius and lower trapezius was rotation of the scapulae, and the levator scapula is an antagonist for scapular upward rotation. Thus, increased significantly increased and EMG activity in the serratus tension of the levator scapula will prevent scapular upward rotation. To overcome this increased levator scapula anterior was significantly decreased during loaded tension, it is believed that the upper and lower trapezius isometric shoulder flexion with FHP in 30, 60, 90, and should be activated to a greater extent in FHP than in NHP. 120 (P < 0.05) (Figure 2). Second, scapular or thoracoscapular position could be changed during the FHP condition. Clinicians have postu- Results of post hoc paired t-test for multiple compari- lated that abnormal cervical spine alignment alters the sons between muscles are presented in Figure 3. In NHP, Table 3 Summary of interaction comparisons. there were significant differences in EMG activity between serratus anterior and upper trapezius all shoulder flexion positions, and significant differences in EMG activity between upper trapezius and lower trapezius were found at 30, 60, and 90 shoulder flexion (Padj < 0.017). A significant difference in EMG activity between serratus anterior and lower trapezius was revealed at 90 and 120 shoulder flexion in NHP (Padj < 0.017). In FHP, the EMG activity between serratus anterior and upper trapezius was significantly different at 60 shoulder flexion, the EMG activity between upper trapezius and lower trapezius was significantly different at 30, 60 and 90 shoulder flexion, and the EMG activity between serratus anterior and lower Degree Interaction F p- of value Value flexion Table 2 Multiple comparisons between muscles. Degree of Muscle comparison p-Value 30 Posture  muscle (UT vs LT) F1,20 Z 16.656 .001 flexion Posture  muscle (UT vs SA) F1,20 Z 32.240 .000 Posture  muscle (LT vs SA) F1,20 Z 52.740 .000 30 Upper trapezius vs lower trapezius .000 Upper trapezius vs serratus anterior .002 60 Posture  muscle (UT vs LT) F1,20 Z 39.502 .016 Lower trapezius vs serratus anterior .016 Posture  muscle (UT vs SA) F2,40 Z 21.982 .000 Posture  muscle (LT vs SA) F2,40 Z 26.309 .000 60 Upper trapezius vs lower trapezius .000 Upper trapezius vs serratus anterior .000 90 Posture  muscle (UT vs LT) F1,20 Z 37.885 .400 Lower trapezius vs serratus anterior .010 Posture  muscle (UT vs SA) F2,40 Z 7.567 .000 Posture  muscle (LT vs SA) F2,40 Z 30.383 .000 90 Upper trapezius vs lower trapezius .008 Upper trapezius vs serratus anterior .003 120 Posture  muscle (UT vs LT) F1,20 Z 20.744 .155 Lower trapezius vs serratus anterior .929 Posture  muscle (UT vs SA) F2,40 Z 8.452 .001 Posture  muscle (LT vs SA) F2,40 Z 31.629 .000 120 Upper trapezius vs lower trapezius .548 Upper trapezius vs serratus anterior .002 NHP, neural head posture; FHP, forward head posture; SA, Lower trapezius vs serratus anterior .001 serratus anterior; UT, upper trapezius; LT, lower trapezius.
Influence of forward head posture 371 40 * 30 degrees 60 degrees 30 * * 40 * * * 30 %MVIC 20 20 %MVIC 10 10 0 UT LT 0 UT LT SA Muscle SA Muscle 90 degrees 70 * 120 degrees * 60 * * * 60 * LT 50 50 40 UT 30 Muscle %MVIC 40 20%MVIC 10 30 0 20 SA 10 NHP FHP 0 UT LT SA Muscle Figure 2 Comparison of the EMG activity between NHP and FHP in 30, 60, 90, and 120 loaded isometric shoulder flexion. Abbreviation: NHP, neural head posture; FHP, forward head posture; SA, serratus anterior; UT, upper trapezius; LT, lower trapezius. *P < 0.05. resting position of the scapula (Greenfield et al., 1995). anterior according to head position (0, 25, 50) during Previous studies have shown that sitting posture and humeral elevation in the scapular plane, without an applied thoracic spine position affect scapular kinematics (Finley load. In our study, however, EMG activities of the upper and and Lee, 2003; Kebaetse et al., 1999). Ludewig and Cook lower trapezius and serratus anterior were significantly (1996) reported that the scapular upward rotation and different between NHP and FHP. The different findings of posterior tilting were significantly decreased in the 20 the present study may have been due to the pattern of arm flexed head position during humeral elevation without load. elevation (i.e., the plane of arm elevation or external load Although we did not measure scapular kinematics directly application) affecting the scapular movement pattern. In in this study, the FHP-related altered scapular position may our study, subjects were asked to elevate their arm in the have affected the movement pattern of the scapular sagittal plane with a 2-kg weight to simulate a real work upward rotation during loaded isometric shoulder flexion. position, in contrast to the unloaded arm elevation in the Previous studies have also shown that shoulder positions scapular plane in the study of Ludewig and Cook (2000). affect shoulder muscle strength (Smith et al., 2002). Thus, Other groups have shown that differences in the pattern of these previous findings of position-induced changes in arm elevation resulted in changes in scapular movement kinematics, muscle activation patterns, and length-tension patterns. McQuade and Smidt (1998) reported that the relationship appear to be consistent with our findings. scapulohumeral rhythm was significantly altered according Third, it is possible that the changes in biomechanics of FHP to the external weight on the arm during dynamic humeral influenced muscle activation. When the flexion moment of elevation in the scapular plane. Up to about 40% of the cervical spine is increased in FHP, the level of neck maximum arm elevation, the lighter the load, the higher extensor muscle activation is increased to counterbalance the scapulohumeral rhythm. Doody et al. (1970) also the increased flexion moment. This is consistent with our reported that the scapulohumeral rhythm decreased in the observation that upper trapezius muscle activity was initial phase of motion with additional load during abduc- increased in FHP. tion in the scapular plane. A previous study (Ludewig and Cook, 1996) indicated In the present study, significant increases were observed that scapular upward rotation and posterior tilting were in upper trapezius and lower trapezius muscle activity in FHP significantly decreased in flexed head positions and there vs. NHP. Kinematic changes in scapular motion have been were no significant differences in the EMG activities of the linked to muscle force imbalances between the upper and upper and lower trapezius, levator scapula, or serratus lower or between medial and lateral forces (Sahrmann,
372 J.-H. Weon et al. NHP FHP NHP FHP 50 ** 50 * * * 40 * * * 40 * %MVIC 30 %MVIC 30 20 20 10 10 0 0 30 degree 60 degree NHP FHP NHP FHP 80 100 * * 80 * * 60 * * %MVIC %MVIC 60 40 40 20 20 0 0 90 degree 120 degree SA UT LT Figure 3 Comparison of the EMG activity between muscles in 30, 60, 90, and 120 loaded isometric shoulder flexion. Abbreviation: NHP, neural head posture; FHP, forward head posture; SA, serratus anterior; UT, upper trapezius; LT, lower trapezius. *Padj < 0.017. 2002). Kinematic changes have been reported to occur in Activation of scapular upward rotators during arm patients with shoulder impingement syndrome. Ludewig and elevation is important for movement of glenohumeral joint Cook (2000) reported that construction workers with as decreased scapular upward rotation has been suggested shoulder impingement syndrome showed increased upper to be a mechanical risk factor contributing to the devel- and lower trapezius muscle activity and decreased serratus opment of subacromial impingement syndrome by reducing anterior muscle activity during humeral elevation in the the subacromial space and increased subacromial pressure scapular plane in comparison with subjects without shoulder (Flatow et al., 1994; Kibler and McMullen, 2003; Michener impingement. Overactivity of the upper and lower trapezius et al., 2003; Sahrmann, 2002). During glenohumeral and changes in scapular kinematics may contribute to neck elevation, the serratus anterior is required to work with the and shoulder pain. Increased muscle activation to maintain trapezius to rotate the scapula upward to allow free a certain posture can result in localized muscle fatigue and movement of the humeral head under the coracoacromial may worsen signs and symptoms of repetitive injury in the arch (McQuade et al., 1998). Ludewig and Cook (2000) cervical and shoulder regions (McLean, 2005). Continued reported decreased activity level of the serratus anterior muscle contraction has been shown to be reported to chronic and reduced upward rotation of the scapula in patients with cervical and shoulder pain syndrome (Larsson et al., 1988; subacromial impingement syndrome. In addition, Sluiter et al., 2001), and the progressive deterioration in decreased scapular upward rotation is thought to be asso- posture of computer workers has also been shown to be ciated with glenohumeral instability by altering gleno- associated with increased muscle activity in the trapezius humeral joint alignment. Decreased muscle activity of the during data entry task performance (Kleine et al., 1999). serratus anterior may reduce control or stabilization of Previous studies have demonstrated that there is a trend scapular motion statically or dynamically. We found that toward higher muscle activation while performing similar serratus anterior muscle activity was significantly tasks in individuals with musculoskeletal disorders, espe- decreased during loaded isometric shoulder flexion with cially trapezius myalgia, in comparison with healthy subjects FHP in comparison with NHP, and this change in activity of (Veiersted et al., 1990, 1993; Waersted et al., 1991). In the the serratus anterior muscle may lead to alterations in present study, maintenance of FHP induced stress in the scapular and glenohumeral kinematics. The serratus ante- intervertebral foramen and posterior structures at several rior muscle is an important scapular stabilizing muscle cervical levels and possible injury to joint structures that during arm movement. The serratus anterior is a scapular may result in nociceptor stimulation, and consequently abductor and antagonist of the upper and lower trapezius, reflexive contraction of cervicobrachial muscles to protect which are adductors of the scapula. Decreased activity of tissues from further injury. Such increased muscle activity the serratus anterior muscle may cause scapular adduction may then facilitate further tissue damage (Ha¨gg and Astro¨m, during arm elevation in FHP. The serratus anterior may 1997; Ha¨gg and Suurku¨la, 1991; Hermens and Hutten, 2002). provide proximal stabilization of the scapula on the thorax
Influence of forward head posture 373 during arm movement. Decreased activity of the serratus a biomechanically favorable posture to reduce excessive anterior muscle may cause winging of the scapula during activity of the upper and lower trapezius and to increase arm elevation in FHP. Ludewig and Cook (2000) reported the activity of the serratus anterior. that the serratus anterior showed decreased activity in construction workers with impingement across all References loads (2.3 kg, 4.6 kg loads) and all phases (31e60, 61e90, 91e120) during humeral elevation in the scapular plane in Bergqvist, U., Wolgast, E., Nilsson, B., Voss, M., 1995. Musculo- comparison with subjects without shoulder impingement. skeletal disorders among visual display terminal workers: indi- Prolonged FHP may cause shoulder impingement syndrome vidual, ergonomic, and work organizational factors. 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Journal of Bodywork & Movement Therapies (2010) 14, 375e381 available at www.sciencedirect.com journal homepage: www.elsevier.com/jbmt BIOMECHANICS The effect of patellar taping on joint reaction forces during squatting in subjects with Patellofemoral Pain Syndrome (PFPS) Javid Mostamand a,*, Dan L. Bader b, Zoe¨ Hudson c a Department of Physiotherapy, Faculty of Rehabilitation Sciences, Isfahan University of Medical Sciences, Isfahan, 8174673461, Islamic Republic of Iran b Department of Engineering, Queen Mary University of London, Mile End Road, London, E1 4NS, UK c Centre for Sports and Exercise Medicine, Barts and the London Queen Mary’s School of Medicine and Dentistry, Mann Ward, Mile End Hospital, Bancroft Road, London, E1 4DG, UK Received 24 March 2009; received in revised form 25 June 2009; accepted 1 July 2009 KEYWORDS Summary Introduction: The mechanisms of pain reduction have not completely been estab- Patellar dysfunction; lished following patellar taping in subjects with patellofemoral pain syndrome (PFPS); although PFJ biomechanics it might be related to alteration in the kinetics of the patellofemoral joint. Methods: Patellofemoral Joint Reaction Force (PFJRF) of eighteen subjects with PFPS and eighteen healthy subjects as controls were assessed by a motion-analysis system and one force plate. This procedure was performed on the affected knee of subjects with PFPS, before, during and finally after patellar taping during unilateral squatting. A similar procedure was also performed on the unaffected knees of both groups. Results: The mean values of PFJRF prior to taping (2025 N, SD 347 N) were decreased signifi- cantly following a period of taping (1720 N, SD 303 N) (P < 0.05). There were no significant differences between the mean values of PFJRF among controls (1922 N, SD 398 N) and subjects with PFPS prior to taping (P > 0.05) which might be due to small sample size in both groups and large variability observed in the study. Interpretation: Decreased values of PFJRF may explain the mechanism of pain reduction following patellar taping in subjects with PFPS. ª 2009 Elsevier Ltd. All rights reserved. * Corresponding author. Tel.: þ98 (0) 311 792 2024; fax: þ98 (0) Introduction 311 6687270. Although the aetiology of patellofemoral pain syndrome E-mail addresses: [email protected] (J. Mostamand), (PFPS) is not clearly understood, it has been suggested that [email protected] (D.L. Bader), [email protected] the pain and discomfort is likely to be the result of (Z. Hudson). 1360-8592/$ - see front matter ª 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.jbmt.2009.07.003
376 J. Mostamand et al. abnormal biomechanical factors that alter the distribution Different values of moment in various planes in both of shearing and compressive forces on the patellofemoral healthy and PFPS subjects require more investigations to joint (PFJ) during normal activities (Sikorski et al., 1979). explain any kinetic changes following patellar taping in Patellofemoral pain is usually aggravated during activities subjects with PFPS. As far as the authors know there have associated with the flexed knee; such as stair stepping, been no studies considering the effect of patellar taping on (Crossley et al., 2002) or with prolonged sitting (McConnell, both sagittal plane knee moments and PFJRF of subjects 1986). It is believed that these activities result in higher with PFPS during squatting. Therefore, this study was patellofemoral joint reaction force (PFJRF) and hence aimed to measure these moments and consequently PFJRF, higher patellofemoral joint stress (PFJS) (Reilly and after application of the patellar tape in subjects with PFPS. Martens, 1972; Wallace et al., 2002). It seems that This study was developed to establish methods that could increased level of PFJRF and consequently higher PFJS is indirectly explain the pain reduction mechanism of patellar related to the improper tracking of the patella through the taping. trochlear groove during these activities (Hvid et al., 1981). It is therefore proposed that these forces and stresses may Methods be increased in subjects with PFPS during these knee bent activities, which may cause the perception of pain. Subjects Patellar taping is known as an effective treatment To determine the sample size for testing the hypotheses on method for improving the symptoms of PFPS (Crossley subjects, it was important to establish the variability of the et al., 2002; Ng and Cheng, 2002). It is believed that this PFJRF. As this variable has not previously been reported, method affects the tracking of the patella and centralizing the sample size for this study was based on the quantitative it within the trochlear groove (Powers et al., 1998; data that were collected for PFJRF from subjects. Post hoc McConnell, 2002). The mechanism by which taping affects sample size analysis was therefore conducted after data the PFJ is not completely clear; so, it has been proposed collection on subjects recruited to this study. Based on the that the application of the tape alters the knee extensor sample size analysis with a power of 80% and a two-sided moment and PFJRF of the various articulations associated significance level of 0.05, twelve samples were required to with the knee joint during knee bent activities (Larsen statistically compare the mean PFJRF differences of 302 N et al., 1995; Somes et al., 1997). The effect of patellar (SD 274 N) on the painful knee of subjects with PFPS before taping on the knee moments of healthy subjects has patellar taping (2052 N, SD 336 N) and after application of previously been investigated during stair-stepping task the tape (1750 N, SD 252 N). These values were derived (Selfe et al., 2008). Authors found that patellar taping from thirteen subjects with PFPS. Considering probable reduced the range of coronal and transverse plane knee drop-outs, eighteen subjects with PFPS were recruited in moments. Decreased level of knee extensor moment and the study from the physiotherapy department of Mile End consequently PFJRF and PFJS may therefore explain Hospital of London (Tower Hamlet Primary Care Trust). decreased level of pain following application of tape in These subjects were diagnosed by experienced physio- subjects with PFPS. therapists, using the clinical examinations; although the final decision about entrance of participants into the study In addition, two previous studies assessed the effect of was made by the researcher on the basis of meeting all patellar taping on sagittal plane knee moments during a leg inclusion criteria (Table 1). Eighteen healthy subjects with vertical jump, lateral step-up and stair-stepping task in no history of the knee pain were also selected from the subjects with PFPS (Ernest et al., 1999; Salsich et al., 2002). The results showed that the taping increased the range of sagittal plane knee moments in these subjects. Table 1 Inclusion and exclusion criteria for both groups of study. Exclusion criteria Inclusion criteria PFPS group 1. Anterior or retropatellar pain, insidious in nature, 1. Any traumatic, inflammatory or infectious which was aggravated by at least two of the following pathology in the lower extremity common functional activities of daily life: 2. Dislocation or subluxation in the PFJ - prolonged sitting 3. History of surgery in the knee joint - stair climbing 4. Any signs of secondary osteoarthritis - squatting - running in the knee joint - kneeling - hopping/jumping 2. Pain during an objective single leg squatting of 10-seconds 3. Aged less than 40 years (both genders) 4. Completed consent form Control group 1. Age, gender, weight and height matched to PFPS group As above 2. Completed consent form
The effect of patellar taping on joint reaction forces 377 students and staff of Queen Mary University of London as the floor during single leg squatting, while verbal feedback a control group. The age, sex, height and weight of control was used to encourage subjects to hold their trunks in group was matched to those subjects in the PFPS group. For a vertical position. each PFPS subject a relevant control with maximum age difference of 2 years were selected. The difference of The first leg to be tested for each subject in both groups weight and height between each PFPS subject and his/her of study was selected in a randomized order, even and odd, healthy control was supposed to be less than 2 kilograms selected from a container. To implement randomization, and 3 centimeters, respectively. forty numbered tags (twenty evens and twenty odds) were put inside a container and each subject drew a tag from the The study was approved by the East London and City container. Note that labeling was blind to the subjects Research Ethics Committee before recruiting both groups’ drawing the tags. subjects. A written informed consent was taken from each subject. Test procedures Instrumentation Biomechanical assessment of subjects with PFPS in the untaped condition A two camera (DCR-VX2000E, Sony, Japan) motion-analysis Subjects with PFPS were asked to perform a shallow single system (SIMI Motion e 2D & 3D Motion Analysis, version 7.0, leg squat of approximately 45 of knee flexion on the Reality Motion Systems, GmbH, Germany), was used to affected leg (to ensure that the knee flexion angle is 30) record three dimensional coordinates of superficial reflec- and hold it for approximately 10 s to record any resulting tive markers of thigh, shank and foot (Figure 1), at a rate of pain on the standard 100 mm visual analogue scale (VAS). 60 Hz. Unilateral ground reaction force data were also Then they were instructed to stand on one leg on the force collected from one force plate (Figure 1) (Kistler, 2812A1-3, plate and to keep the contralateral leg off the floor. Each version 3.20, Switzerland) at a rate of 600 Hz. subject was then asked to execute a single leg squat from a neutral position (0 degree of knee flexion) to a depth of Preparation of subjects approximately 45 of knee flexion (to ensure that the knee flexion angle is 30), while maintaining heel in contact with Anthropometric data of subjects in both PFPS and healthy the floor (Figure 1). The duration of squatting functions control groups were measured (Winter, 1990) after they were constrained to about 3 seconds measured by a stop met all inclusion criteria. To collect the kinematic data of watch; the measurement was from the initiation of knee subjects using double-sided tape, superficial reflective flexion to return to full knee extension. Thus a maximum markers (2.5-cm spheres) were placed on specific bony period of 12 seconds was assigned to three repetitions, landmarks, namely, the second metatarsal head, lateral including the first 3 seconds of test period for concordance malleolus, lateral shank, lateral femoral epicondyle and of subjects with the activity. Verbal feedback regarding lateral thigh of both legs (Wallace et al., 2002). After both depth and duration of the function were provided preparing the subjects, they were instructed to perform after several practice squats. When the subjects had several practices for single leg squats, although the familiarized themselves with the timing and depth of this subjects with PFPS were warned to practice to a minimum single leg squat, testing would commence. Data were level with the affected knees to avoid exacerbating the simultaneously recorded with the camera system and force pain before the main study. plate. Data collection was stopped when the subjects completed the three single leg squats. On completion of To control any trunk forward flexion or deviation, all this procedure, an identical test procedure was repeated subjects were asked to keep their foot in full contact with on the contralateral leg. Figure 1 Setup used to measure kinematics and kinetics Figure 2 Medial glide taping technique. during single leg squatting.
378 J. Mostamand et al. Biomechanical assessment of subjects with PFPS in the (Winter, 1990). Sagittal- plane knee joint angles and net taped condition knee moments (Mk) were calculated from the inertial After recording data, the patellar tape was immediately properties, segmental kinematics, and force platform data attached over the affected patellar region in subjects with using inverse dynamics equations (Winter, 1990). PFPS in the order of medial glide (Figure 2), according to patellar orientation tests (McConnell, 1986). The choice of The PFJRF was calculated using a biomechanical model taping methods was partly based on assessment of the of the PFJ (Salem and Powers, 2001). Based on the model, patella position and partly on the attainment of pain quadriceps muscle force (Fq) was calculated as the net knee reduction. After application of tape over the patella, each moment (Mk) divided by the moment arm for the quadri- subject was asked to perform a single leg squat and hold it ceps (Lq). for about 10 s for evaluating the pain level on a separate VAS sheet. The taping method was acceptable if the level of FqZMk=Lq pain was decreased by approximately 50% compared to the untaped condition (Crossley et al., 2002). Then the same The moment arm was estimated using the following non- test procedures for collecting both kinematic and kinetic linear equation, based on the curve fitting to the data of data were conducted in taped condition in the same van Eijden et al. (1987): session. LqZ8:0eÀ5X3 À 0:013X2 þ 0:28X þ 0:046 Biomechanical assessment of subjects with PFPS after removal of the tape where, X is the tibiofemoral joint angle. PFJRF was calcu- After finishing the measurements in the taped condition, the subjects in PFPS group were instructed verbally and lated as the product of the quadriceps force (Fq) and also with illustrated diagrams to be able to indepen- a constant (k) as follow: dently apply the taping corrections on a daily basis during the follow-up period (Crossley et al., 2002) (see PFJRFZFq$k Appendix). The constant k was estimated for knee joint angle (X ) using At each evaluation session, subjects were asked to apply the following non-linear equation, based on the curve the patellar tape to check if they can perform it correctly. fitting to the data of van Eijden et al. (1986): The subjects were evaluated during 7 days of follow-up kZÀ7:À0e3:À87eXÀ35þX 21þ:6e1:À54eXÀ23ÀX þ 0:462 1 period, using the VAS, until they became symptom-free; 0:016X þ a period that based on previous studies predicted to last a maximum of 6 weeks (McConnell, 1986; Crossley et al., For each test, kinetic data (Mk, PFJRF) were averaged 2002; Clark et al., 2000; (Eburne and Bannister, 1996); through the 3 repetitions of single leg squatting. Data were Harrison et al., 1999; Kowall et al., 1996). Once the analyzed in the eccentric phase of this activity at 30 of subjects became symptom-free, they were instructed to remove the tape before coming to the human performance knee flexion. laboratory. At that time, each subject was asked to repeat the testing procedure, in an identical method described in Data analysis two previous tests, for the third time on the affected knee. A parametric test (Two-way analysis of variance Z ANOVA) Biomechanical assessment of healthy control subjects was then chosen to compare data between subjects with Subjects in the control group underwent a similar testing PFPS and healthy control in different tape conditions. procedure as subjects in the PFPS group. One testing Though bilateral kinetic data of healthy control subjects session was allocated to these subjects to measure the were collected, paired sample t-tests revealed that the kinematic and kinetic data of both legs without applying differences between the mean values of Mk and PFJRF of any additional intervention during single leg squatting. right and left knees were not statistically significant (P > 0.05). Data sets were therefore combined to compare Data reduction the results between the affected and unaffected knee of subjects with PFPS. For all tests, a 0.05 level was used to Marker-coordinate and force data were processed by the determine statistical significance. SPSS statistical software, SIMI motion-analysis system. Using this system, the version 13.0 was used to perform all statistical analysis. segmental kinematics for the foot, shank and thigh were computed. The inertial properties for the foot, shank and Results thigh were determined from the subject’s total body weight, segment geometry and anthropometric data Table 2 demonstrates the demographic and anthropometric data obtained from both groups of PFPS and control subjects. As Mk and PFJRF were inter-related by constant values and therefore followed the same patterns during Table 2 Anthropometric and demographic data of the PFPS and control groups (mean (SD)). Number Gender Age (years) Weight (kg) Height (cm) PFPS group 18 11 men, 7 women 27.9 (6.3) 71.5 (9.5) 171.3 (5.9) Control group 18 11 men, 7 women 26.4 (4.9) 71.6 (11.1) 171.9 (7.5)
The effect of patellar taping on joint reaction forces 379 Table 3 The mean values (SD) of knee extensor moment (Mk) and patellofemoral joint reaction forces (PFJRF) in subjects with PFPS and healthy control in five different conditions of taping. Significant differences of PFJRF values have been shown between three paired comparisons. Condition of patellar taping Mk (Nm/kg) PFJRF (N) Significant difference between PFJRF values (N) UnNTa 1.51 (0.17) 1895 (286) BTb 1.61 (0.19) 2025 (347) UnNTa- BTb Z 130 WTc 1.43 (0.18) 1796 (297) BTb e WTc Z 229 ATd 1.37 (0.19) 1720 (303) BTb e ATd Z 305 NTHSe 1.53 (0.22) 1922 (398) a UnNT, no-tape unaffected knees. b BT, affected knees before applying the tape. c WT, affected knees with tape. d AT, affected knees after application of the tape. e NTHS, no-tape knee of healthy control subjects. eccentric phase of single leg squatting in 30 degrees of of approximately 50% during each test session, revealed knee flexion, the results of PFJRF measurements were that the magnitudes of these differences were similar. reported as final products of the Mk. The Mk values are summarized in Table 3. Discussion The mean value of PFJRF of the affected knee in Several null hypotheses related to the kinetic data were subjects with PFPS before applying the tape (2025 N, SD tested in the current study. The first hypothesis was that Mk 347 N) was greater than the mean PFJRF for the corre- and PFJRF will not change immediately after application of sponding values of the unaffected knees (1895 N, SD 286 N) patellar tape in PFPS subjects, during single leg squatting. (P < 0.05). The mean value of PFJRF in the before-taped Additionally, that Mk and PFJRF would not change with daily condition was also greater than the taped condition application of patellar tape for at least 6 weeks. The results (1796 N, SD 297 N) and after applying the tape (1720 N, SD indicate that after immediate application of the patellar 303 N) in the affected knees. However, there was no tape and also during less than 6 weeks of follow-up, the significant difference between the mean values of PFJRF in knee extensor moment and PFJRF decreased in the the before-taped condition and no-tape condition, in both affected knee of PFPS subjects. The secondary null knees of healthy control subjects (1922 N, SD 398 N) hypothesis on similarity of kinetic values in both knees was (P > 0.05) (Table 3). also rejected by the results; indicated that values were statistically greater in the affected knees of PFPS subjects Two-way ANOVA revealed that there were significant before application of the tape than unaffected knees. differences between the mean values of PFJRF in five different conditions of taping in subjects with PFPS and In the present study the reduction of pain following healthy controls (F4, 85 Z 2.65, P < 0.05). The multiple application of patellar tape in subjects with PFPS was comparison tests using the least significant difference associated with a decrease in Mk (from 1.61, SD 0.19 Nm/kg (LSD) demonstrated that these values between the condi- to 1.37, SD 0.19 Nm/kg) and consequently reduction in tions of before taping and taped, before and after taping PFJRF. Conversely, two previous studies reported an and also before taping and no-tape of unaffected knees increase in these variables following immediate application were significantly different (P < 0.05), while there were no of patellar tape during different functional activities. Ern- significant differences comparing these values for taped est et al. (1999) showed that the taped condition resulted and after taping condition and also for before taping and in a greater Mk (1.73, SD 0.36 Nm/kg and 1.40, SD 0.27 Nm/ no-tape condition of healthy control subjects (P > 0.05). kg) than the no-tape (1.40, SD 0.46 Nm/kg and 1.21, SD The magnitude of PFJRF differences between before 0.33 Nm/kg) and placebo tape conditions (1.38, SD taping and taped condition and also between taped and 0.32 Nm/kg and 1.28, SD 0.28 Nm/kg) during a single leg after taping, in affected knees was 11.3% and 4.2%, vertical jump and lateral step-up. In another study, Salsich respectively. et al. (2002) also reported the similar increase in Mk, following application of patellar tape during trials of stair The mean levels of pain with tape (31 mm, SD 9 mm) and ascent and descent. In the no-tape condition, during stair after application of the tape in the last test session (16 mm, ascent and descent the Mk was 0.12 (SD 0.17) Nm/kg and SD 9 mm) were lower than the level of pain before appli- 0.37 (SD 0.13) Nm/kg, respectively. This variable after cation of the tape (60 mm, SD 10 mm) in subjects with applying the tape during stair ascent and descent was 0.30 PFPS. The differences between these mean values were (SD 0.17) Nm/kg and 0.55 (SD 0.14) Nm/kg, respectively. significant (F2, 51 Z 101, P < 0.001). There is a possible explanation for the decreased kinetic An immediate pain reduction of approximately 50% values with patellar taping in the current study. This is occurred among the subjects with PFPS, after using related to the quadriceps moment arm which may change a patellar tape in the first session of test. The similar during patellar taping. As the PFJRF are the final product of percentage of pain reduction also occurred in the last test session, compared with the taped condition. Pain reduction
380 J. Mostamand et al. Mk, any potential change in the quadriceps moment arm Conclusion may result in changes in the Mk and therefore the PFJRF. Smidt (1973) found that the maximum length of quadriceps Taping technique aims to align the PFJ and consequently to moment arm is at 30e45 of knee flexion and this length reduce the pain level in subjects with PFJS. This study reaches a minimum when the knee is in the full flexion showed that PFJRF values in the affected knee of subjects where the patella is located distally in the intercondylar with PFPS were greater than those related to the unaf- groove. The quadriceps moment arm and Mk may be altered fected knee, although these values were not different from by any potential movement or position of the patella. A healthy control subjects. This may be related to the small radiographic study showed that application of an infrapa- sample size recruited in both groups to compare their tellar strap could displace the patella proximally and kinetic values. It is possible that a true difference in PFJRF anteriorly compared to the case without the strap in the existed between the affected knee of subjects with PFPS extended knee (Levine, 1978). The proximal displacement before using the tape and the knees of healthy control of the patella may prevent the patella sinking distally into subjects but was not detected, given the large variability the intercondylar groove and thus maintain a longer quad- associated with the eighteen subjects. It was also revealed riceps moment arm. In an optimal condition, the patella is that patellofemoral taping reduced the PFJRF values and situated parallel to the femur in both frontal and the corresponding pain level during single leg squatting. sagittal planes, so that it is equidistant between the two Reduction of pain in subjects with PFPS may be therefore condyles in a slightly flexed knee (McConnell, 1986). In the attributed to the effect of tape in decreasing the value of current study however, the patellar tape was used across PFJRF, although this claim would have been verified using the middle of patella to correct the lateral glide or tilt of only a randomized controlled trial. The reduction of kinetic the patella, holding it in the centre of intercondylar values may be as a result of alteration in the quadriceps groove. This corrective taping might have therefore moment arm following patellar taping. improved patellar position and limited any proximal displacement of the patella, facilitating its distal Acknowledgements displacement into this groove during knee flexion. This condition would decrease the quadriceps moment arm and This article was provided as a part of the study leading to produce a smaller Mk and thus decreased PFJRF. the degree of PhD, which was financially supported by Isfahan University of Medical Sciences and Ministry of Although the knee extensor moment in sagittal plane in Health and Medical Education of Islamic Republic of Iran. subjects with PFPS was measured in the present and previous studies, the reason of differences in the results Conflict of interest statement may be sought in different functional activities recruited in these studies. This difference may be explained in two The authors confirm that there are no conflicts of interests ways. Firstly, the muscle recruitment strategies for various regarding this paper. activities may be changed, leading to altered muscle activities. For example, the isokinetic leg press exercise has Appendix been shown to place a greater demand on the knee Patellar taping techniques extensors than other kinds of closed kinetic chain exer- cises, including stair-stepping task (Wilk et al., 1996). Medial glide technique: To control lateral glide, one end of Therefore in the present study it is possible that squatting the tape is secured to the lateral patellar (kneecap) border placed less demand on the knee extensor moment than and the therapist (patient) glides the patella medially with stair stepping or vertical jump exercises recruited by his thumb while maintaining tension in the tape. Then, he the Ernest et al. (1999) and Salsich et al. (2002). Indeed, lifts the medial soft tissue (skin) toward the patella so that the taping might have contributed to the recruitment of the several skin folds appears, and secures the tape medially quadriceps muscle based on the less muscle demand during and across the knee (Crossley et al., 2002). squatting, thus produced enhanced muscle efficiency. Secondly, generating the necessary muscle forces to propel the body and control the centre of body mass may be different during various functional activities. It is evidential that during stair-stepping task, the individual must be able to activate the muscles properly and generate the necessary forces to propel the body upstairs and downstairs and control the constantly changing centre of body mass (Shumway-Cook and Woollacott, 1995). It seems that displacement of centre of body mass is very smaller during squatting than the stair-stepping task, because during squatting, the body is not required to be lifted to overcome a height and control the constantly changing centre of body mass. Considering the lesser muscle force required for squatting than stair-stepping task, patellar tape might have decreased the quadriceps muscle force more, hence decreased knee extensor moment during this activity.
The effect of patellar taping on joint reaction forces 381 Medial tilt technique: In order to correct lateral tilt of McConnell, J., 1986. The management of chondromalacia patellae: the patella, the tape is secured at the upper middle portion a long-term solution. Australian Journal of Physiotherapy 32, of the patella (kneecap) and the therapist (patient) pulls 215e223. the tape medially to lift the lateral border of the patella, correcting the tilt, then he lifts the medial soft tissues (as McConnell, J., 2002. The physical therapist’s approach to patello- indicated before) and secures tape (Crossley et al., 2002). femoral disorders. Clinics in Sports Medicine 21, 363e387. References Ng, G.Y.F., Cheng, J.M.F., 2002. The effects of patellar taping on pain and neuromuscular performance in subjects with patello- Clark, D.I., Downing, N., Mitchell, J., Coulson, L., Syzpryt, E.P., femoral pain syndrome. Clinical Rehabilitation 16, 821e827. Doherty, M., 2000. 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Journal of Bodywork & Movement Therapies (2010) 14, 382e390 available at www.sciencedirect.com journal homepage: www.elsevier.com/jbmt PAIN PHYSIOLOGY The influence of age and physical activity on the pressure sensitivity of soft tissues of the musculoskeletal system Waldemar Andrzejewski, Krzysztof Kassolik, Marcin Brzozowski*, Katarzyna Cymer Department of Physiotherapy, University School of Physical Education, Faculty of Physiotherapy, 51-612 Wroclaw, al. Paderewskiego 35/p-4, Poland Received 30 January 2009; received in revised form 2 July 2009; accepted 6 July 2009 KEYWORDS Summary Background: The pressure sensitivity of soft tissues is defined as the slightest pres- Pressure sensitivity; sure causing pain. Sex, movement system illnesses, pain ailments may influence the pressure Physical activity; sensitivity. However, there have been few studies on factors determining the level of pressure Age sensitivity of skeletal muscles. Objective: The authors have determined to study the influence of age and physical activity on the pressure sensitivity of skeletal muscles. Methods: The examination of pressure sensitivity of trigger points and muscle insertions was carried out using algometry. Results: 76 volunteers (38 students and 38 individuals aged 50e75) participated in the study. The differences in pressure sensitivity between students and people aged 50e75 were not statistically significant. Pressure sensitivity of students differed depending on their level of physical activity. Conclusions: The level of physical activity influenced the pressure sensitivity of skeletal muscles. Age did not significantly influence pressure sensitivity. ª 2009 Elsevier Ltd. All rights reserved. Introduction * Corresponding author. Tel.: þ48 071 3473091; fax: þ48 071 The pressure sensitivity of soft tissues is defined as the 3473016. smallest degree of pressure that causes pain (Fischer, 1988). Among the factors influencing the pressure sensi- E-mail address: [email protected](M.Brzozowski). tivity are gender, musculoskeletal conditions, painful ailments, and mental health disorders. So far there have 1360-8592/$ - see front matter ª 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.jbmt.2009.07.004
The influence of age and physical activity 383 been few studies which demonstrate the influence of these levels. On the other hand, manual palpation is less objec- factors on the level of pressure sensitivity of skeletal tive but, due to its ease, quickness, and availability, it is muscles. Some studies measured pressure sensitivity in used more frequently than employment of an algometer. relation to fibromyalgia, myofascial pain syndrome, or Both methods can be used clinically, with no need to create nonspecific spinal pain (Mikkelsson et al., 1992; Offen- a special measurement site. Assessing sensitivity assists not bacher and Stucki, 2000). only in determining which muscles are extra sensitive, but also in planning a treatment regimen, and monitoring the Clinical relevance effectiveness of therapy. Therapists who use palpation as a diagnostic tool The influence of such factors as gender, musculoskeletal should take into account factors determining pressure system conditions, and mental health disorders, on the pain sensitivity. The results of the research described in threshold level has been noted in few studies examining this paper suggest that physical activity can influence sensitivity (Fischer, 1987a; Mikkelsson et al., 1992). There the level of pressure sensitivity of muscles, potentially are however no reports of the influence of age and the level modifying pain threshold. An additional finding is that of physical activity on the pressure sensitivity of muscles, there appears to be little influence of age on pressure knowledge of which can be helpful in treating patients of sensitivity. different ages, or different levels of physical activity. Therefore the aim of this study was to evaluate the influ- Fischer researched both pressure sensitivity, and ence of age and physical activity on the pressure sensitivity maximum pressure tolerance, of skeletal muscles with an of skeletal muscles using algometry. algometer. He demonstrated higher pain sensitivity (lower pain threshold) of muscles in a group of men in comparison Material with a group of women, as well as different sensitivities of different muscles (Fischer, 1987a). Fischer found that pain Seventy-six volunteers participated in the study. They were caused by a pressure of up to 3 kg/cm2 is characteristic of divided into four groups on the basis of answers in a ques- unhealthy tissue. Additionally, he concluded that a differ- tionnaire. The first criterion of the division into groups was ence in sensitivity of tissues on both sides of the body the age of the participants and the other was the level of greater than 2 kg/cm2 is proof of a disease state within the physical activity stated in the questionnaire. tissue limits (Fischer, 1986). This comparison of the pres- sure sensitivity of tissues, on both sides of the body, seems In group I were 38 individuals aged 50e75 (mean age: 65 to be more reliable for diagnostic purposes than comparing years). All subjects in group I were students of The Sudetes results with population standards, which are individually University of Third Age, in Wałbrzych, Poland. In the ques- variable. In the case of double-sided pathological sensi- tionnaire, 34 members of the group (90%) declared they tivity, Fischer suggested comparing the results with those engaged in moderate physical activity, 2 (5%) in light physical taken from neighboring tissues, or the upper limits of norms activity, and the remaining 2 (5%) in vigorous physical established for healthy tissues. activity. The people in this group were relatively healthy and fit for their age, as they were students of the University of Mikkelsson carried out a study on pressure sensitivity in the Third Age, which demands quite a lot of activity within women with fibromyalgia. The measurements were per- the course of the study. All students attended sport classes formed on the tibial and deltoid muscles. The pain at least once a week, e.g. group gymnastics in a gym, strol- threshold in women with fibromyalgia was lower than in ling, Nordic walking or swimming at an indoor swimming healthy matched controls (Mikkelsson et al., 1992). pool. In Poland, such an intensity of physical activity is above average for the age group of 50e75. Measurements are commonly performed on muscles, including myofascial trigger points, and on fascias, tendons, In group II were 38 individuals aged 20e26 (mean age: 22 ligaments, and bone tissues. There are two ways to years). All subjects in group II were students of The examine pressure sensitivity: manual palpation (Andrze- University School of Physical Education in Wroclaw, Poland. jewski et al., 2007b, 2006; Kassolik et al., 2005) and The members of this group were healthy and fit as they examination with an algometer, which was designed were students of the University School of Physical Educa- specifically for this purpose1 (Andrzejewski et al., 2007a, tion and both before being admitted to the university and 2005; Fischer, 1987a,b, 1984, 1986; Offenbacher and during the course of study they had undergone several Stucki, 2000; Reeves et al., 1986; Ronat et al., 2003). medical examinations, which were essential to pass an exam on motor fitness in order to continue their studies. In The evaluation of pressure sensitivity is a relatively easy the questionnaire, 16 members of this group (42% of group and quick diagnostic method. It can be used by various II) declared they engaged in vigorous physical activity, 16 healthcare providers, including physicians, occupational individuals (42% of group II) moderate physical activity, and therapists, physical therapists, bodyworkers, etc. Exam- the remaining 6 (16% of group II) light physical activity. ining sensitivity with an algometer makes the assessment of a patient’s condition more objective, as it limits the Out of group II, two further study groups were created: patients’ subjectivism and their indecision regarding pain group III, which consisted of 16 students from group II declaring vigorous physical activity, and group IV, consisting 1 ZAKqAD USqUG ELEKTRONICZNYCH, Niedziałkowskiego Street of 16 students from group II who declared moderate phys- 22, 51-507 Wrocław, Poland. ical activity. Groups I (University of the Third Age students) and II (University School of Physical Education students) were
384 W. Andrzejewski et al. created to see if age influenced pressure sensitivity. Groups III (University School of Physical Education students with vigorous physical activity) and IV (University School of Physical Education students with moderate physical activity) were created to check if a different level of physical activity influenced the pressure sensitivity of soft tissues. Because of the small differences between the levels of physical activity in the group of University of the Third Age students, group I was not taken into account when evaluating the influence of physical activity on pressure sensitivity. Methods The study consisted of two parts: a questionnaire (Figure 1) Figure 2 Algometer. and an examination of the pressure sensitivity of muscles. First the study participants completed the questionnaire, The value of the measurement was then recorded and the than they underwent an examination of pressure sensitivity device reset, by pressing the button on the upper surface of with an algometer. the main part of the instrument. The algometer used in this study was developed through The therapist successively pressed attachment sites and a joint venture between Wroclaw University of Technology trigger points of fifteen chosen muscles which, from the and the Department of Physical Therapy and Massage at the authors’ experience, frequently present overstrain changes University School of Physical Education in Wroclaw under the and, therefore, are most often subject to therapeutic supervision of Waldemar Andrzejewski Ph.D. The algometer activities. Table 1 includes all the points of the attach- features a 1 cm2 application head, a shut-off button for ments of the tested muscles. Localization of latent trigger subjects, and a reset button (Figure 2). Measurements are points was performed according to Travell and Simons displayed in units of pressure (kg/cm2) with a sensitivity of 1 g. (Travell and Simons, 1992; Simons et al., 1999). Prior to the measurement, all the participants were Muscles on both body sides were evaluated. During the informed about procedures and were given instructions on measurement the subjects were lying relaxed, on one side, how to behave during the measurement. Before the actual with the legs supported, while the other side was being measurements three trials were performed so that subjects examined. Right limbs of patients were placed on massage could easily distinguish the sensations of pressure and pain cushions. Subjects held the shut-off button of the algometer. and were able to stop the measurement at the proper moment. Each subject heard the same instruction: ‘During Each point was measured bilaterally. The maximum the measurement, certain points on your body will be applied pressure was 10 kg/cm2 to minimize the risk of pressed. The moment you feel the first pain sensation in the damaging the tissue at higher pressures. The subjects had measured area, and not only the sensation of pressure refrained from any kind of physiotherapeutic treatment, or without any pain, please simultaneously say ‘stop’ and the use of painkillers, for a period of at least three months press the button you are holding in your hand.’ before the study. All the subjects were examined by the same therapist, and the measurement was taken using the First the therapist palpated the point in the tissue to be same instrument. All the individuals had agreed to parti- examined and then put the head of the algometer at a right cipate in the study. The study was approved by the local angle and pressed it gradually into the tissue at a rate of University Ethics Committee. 100 g/s. Only the therapist could see the display unit of the algometer. The researchers adopted the hypothesis that age and physical activity influenced pressure sensitivity of skeletal Subjects stopped the measurement by pressing the muscles. In order for the hypothesis to be accepted, at button at the exact moment when they feel a sharp pain in least 60% (clear majority) of muscles tested needed to the area where the head of the algometer had been placed. First and last name : ................................................................................. Age (years) : ................................................................................. Physical activity : 1. light (up to 2 times per week) 2. moderate (at least 3 times per week for 30 minutes) 3. vigorous (at least 5 times per week for 30 minutes or professional sport) Taking painkillers within the recent three months 1. yes 2. no Painful ailments – if present, where exactly Figure 1 The research questionnaire.
The influence of age and physical activity 385 Table 1 The points of pressure sensitivity measurement points of the muscles on the left body side. Statistically on chosen muscles. significant differences (p < 0.05) were found in only two muscles, namely the flexor carpi radialis and the adductor Name of muscle Place of insertion magnus (13.3% of all the researched muscles). Superior fibular Lateral surface of Table 4 presents the mean values of the pressure retinaculum calcaneum sensitivity and the level of statistical significance of the Base of first metatarsal differences between groups I and II at muscle insertions on Peroneus longus Linea aspera of femur the right side of the body. Statistically significant differ- Biceps femoris Gluteal tuberosity ences in pressure sensitivity were found in only four Gluteus maximus Superior surface of greater muscles, namely peroneus longus muscle, biceps femoris Gluteus medius trochanter muscle, gluteus maximus muscle, and adductor magnus Lateral surface of anterior muscle (26.7% of all the researched muscles). Tensor fasciae latae superior iliac spine Labium externum of crest Table 5 presents the mean values of pressure sensitivity Latissimus dorsi of iliac bone and the statistical significance between groups I and II at Posterior superior iliac spine trigger points of the muscles on the right body side. Erector spinae Greater tubercle of humeral Statistically significant differences (p < 0.05) were found in Infraspinatus bone the following muscles: the peroneus longus, infraspinatus, Superior angle of scapula flexor carpi radialis, and adductor magnus (26.7% of all the Levator scapulae Crest of greater tubercle researched muscles). Pectoralis major of humerus Coracoid process Tables 6e9 present the comparison of pressure sensi- Pectoralis minor Pisiform tivity between groups III and IV. Of a total 60 point to point Flexor carpi ulnaris Base of second metacarpal comparisons, 55 (91.7%) reached statistical significance. Flexor carpi radialis Medial femoral epicondyle Adductor magnus Table 6 presents the mean values of the pressure sensitivity of the muscles and the statistical differences demonstrate a significant difference between values of between groups III (University School of Physical Education pressure sensitivity in the compared groups. students with vigorous physical activity) and IV (University School of Physical Education students with moderate Results physical activity), at muscle insertions of the left side of the body. In the majority of the muscles (80% of all the The mean of the pressure sensitivities for a given body side researched muscles), the difference was statistically for each muscle in all groups was calculated. The results significant (p < 0.05). An increased pain threshold was were analyzed using Student’s t test for independent observed in all the muscles of those in group III. samples with a probability of 0.05. For groups I and II a t test for large samples was used and for groups III and IV a t Table 7 presents the mean values of the pressure test for small samples. The aim was to check if there were sensitivity of the muscles and the statistical differences statistically significant differences in sensitivity between between groups III and IV at trigger points of the left side of groups I (University of the Third Age students) and II the body. In all the muscles the difference was statistically (University School of Physical Education students) and significant (p < 0.05). An increased pain threshold was groups III (University School of Physical Education students, characteristic of those in group III. vigorous physical activity) and IV (University School of Physical Education students, moderate physical activity). Table 8 presents the mean values of the pressure The results are presented in Tables 2e9. sensitivity of the muscles and the statistical difference between the groups III and IV at muscle insertions of the Tables 2e5 present the comparison of pressure sensitivity right side of the body. In fourteen muscles (93.3% of all the between groups I and II. Of a total 60 point to point researched muscles) the difference was statistically comparisons, 44 (73.3%) did not reach statistical significance. significant (p < 0.05). The difference observed in the erector spinae was not statistically significant. An increased Table 2 presents the mean values of the pressure sensi- pain threshold was characteristic of those of group III. tivity and the statistical significance of the differences between groups I and II at muscle insertions on the left side of Table 9 presents the mean values of the pressure the body. In the majority of muscles (60% of all the researched sensitivity of the muscles and the statistical differences muscles) there were no statistically significant differences between groups III and IV at trigger points of the right side between the two groups. In six of the muscles (peroneus of the body. In fourteen muscles (93.3% of all the longus muscle, biceps femoris muscle, gluteus maximus researched muscles) the difference was statistically muscle, flexor carpi ulnaris muscle, flexor carpi radialis significant (p < 0.05). The difference observed in the tensor muscle, adductor magnus muscle) there was a statistically fasciae latae muscle was not statistically significant. Similar significant increased pressure sensitivity in group I. to the above measurements, an increased pain threshold was characteristic of the muscles of those in group III. Table 3 presents the mean values of the pressure sensitivity of the muscles and the level of statistical Discussion significance of differences between groups I and II at trigger So far, there have been no reports in the literature of the influence of age and physical activity on the pressure sensitivity of muscles.
386 W. Andrzejewski et al. Table 2 Mean values of the pressure sensitivity (kg/cm2) at muscle insertions on the left side of the body for groups I (University of the Third Age students) and II (University School of Physical Education students). No Researched Group I Group II Statistically site e insertion kg/cm2 kg/cm2 significant left side 1 Superior fibular retinaculum 5.015 5.212 NS 6.479 * 2 Peroneus longus muscle 5.012 5.967 * 6.611 * 3 Biceps femoris muscle 4.706 5.986 NS 4.271 NS 4 Gluteus maximus muscle 5.182 4.557 NS 4.897 NS 5 Gluteus medius muscle 5.296 4.100 NS 4.138 NS 6 Tensor fasciae latae muscle 4.583 4.364 NS 3.600 NS 7 Latissimus dorsi muscle 4.691 5.177 * 5.760 * 8 Erector spinae muscle 5.129 4.599 * 9 Infraspinatus muscle 3.660 10 Levator scapulae muscle 3.970 11 Pectoralis major muscle 4.007 12 Pectoralis minor muscle 3.086 13 Flexor carpi ulnaris muscle 4.430 14 Flexor carpi radialis muscle 4.447 15 Adductor magnus muscle 3.347 NS e no statistically significant differences. * e statistically significant difference (p < 0.05). This study demonstrates that the differences in pre- and dynamic overloading which could be a result of over- ssure sensitivity between students and people aged 50e75 training. The relatively low pressure sensitivity in the group of were not statistically significant in 73.3% of all the the people aged 50e75 may be the result of their quite high, for researched muscles. In the majority of cases, age does not this group age, levels of fitness and physical activity. significantly influence pressure sensitivity, which is surprising considering the distinct difference in fitness and Generally, in Poland only a few percent of people over physical efficiency between the young and participants the age of 50 regularly attend organized recreation and aged 50e75. sports activities. It is commonly known that physical activity influences all human body systems in a positive The observed increased values of pressure sensitivity in way. Also the musculoskeletal system and, more precisely, some muscles of the younger people may be the result of static skeletal muscles are influenced very positively. It has been Table 3 Mean values of the pressure sensitivity (kg/cm2) at the trigger points of the muscles on the left body side for groups I (University of the Third Age students) and II (University School of Physical Education students). No Researched site e trigger Group I Group II Statistically point left side kg/cm2 kg/cm2 significant 1 Superior fibular retinaculum 4.225 4.867 NS 5.244 NS 2 Peroneus longus muscle 4.740 6.204 NS 5.211 NS 3 Biceps femoris muscle 5.421 5.280 NS 3.946 NS 4 Gluteus maximus muscle 5.119 4.696 NS 4.990 NS 5 Gluteus medius muscle 5.668 5.119 NS 2.499 NS 6 Tensor fasciae latae muscle 4.566 2.574 NS 3.339 NS 7 Latissimus dorsi muscle 4.129 4.245 NS 4.321 * 8 Erector spinae muscle 5.115 4.407 * 9 Infraspinatus muscle 4.406 10 Levator scapulae muscle 2.102 11 Pectoralis major muscle 2.578 12 Pectoralis minor muscle 2.934 13 Flexor carpi ulnaris muscle 4.185 14 Flexor carpi radialis muscle 3.516 15 Adductor magnus muscle 2.624 NS e no statistically significant differences. * e statistically significant difference (p < 0.05).
The influence of age and physical activity 387 Table 4 Mean values of the pressure sensitivity (kg/cm2) at muscle insertions on the right side of the body for groups I (University of the Third Age students) and II (University School of Physical Education students). No Researched site e insertion Group I Group II Statistically right side kg/cm2 kg/cm2 significant 1 Superior fibular retinaculum 5.073 5.275 NS 6.136 * 2 Peroneus longus muscle 4.946 6.392 * 6.626 * 3 Biceps femoris muscle 4.458 6.198 NS 4.986 NS 4 Gluteus maximus muscle 5.042 4.372 NS 4.642 NS 5 Gluteus medius muscle 5.369 4.690 NS 3.795 NS 6 Tensor fasciae latae muscle 4.942 4.455 NS 3.848 NS 7 Latissimus dorsi muscle 5.002 5.274 NS 5.239 NS 8 Erector spinae muscle 5.364 5.359 * 9 Infraspinatus muscle 3.967 10 Levator scapulae muscle 4.028 11 Pectoralis major muscle 3.779 12 Pectoralis minor muscle 3.248 13 Flexor carpi ulnaris muscle 4.660 14 Flexor carpi radialis muscle 4.809 15 Adductor magnus muscle 3.127 NS e no statistically significant differences. * e statistically significant difference (p < 0.05). shown that, under the influence of physical activity, the ulnar flexor muscle of the wrist, and radial flexor muscle of number of capillary vessels in skeletal muscles is increased the wrist. and thus tissue metabolism and tissue efficiency is improved (Jasko´lski et al., 2002). Due to recurrent ankle or wrist sprains, microinjuries in the above mentioned muscles may be triggered and, However, from the authors’ own observations, there are consequently, sensitivity of the muscles in middle-aged and some muscles which, during a lifetime, are subject to elderly people may be increased. This possibility is reflec- greater wear than other muscles. Among basic factors ted in the research, as the differences in the pressure influencing ‘‘greater wear’’ are recurrent minor injuries sensitivity between young participants and University of and lesions occurring while performing everyday activities. the Third Age students, were evident only in the case of the This situation is mostly characteristic of muscles stabilizing above-mentioned muscles. ankle joints: long peroneal muscle and short peroneal muscle, and muscles stabilizing the brachiocarpal joint: the Greater muscle sensitivity may also be increased by degenerative changes in venous and arterial vessels e.g. Table 5 Mean values of the pressure sensitivity (kg/cm2) at trigger points of the muscles of the right body side for groups I (University of the Third Age students) and II (University School of Physical Education students). No Researched site e trigger Group I Group II Statistically point right side kg/cm2 kg/cm2 significant 1 Superior fibular retinaculum 4.244 4.564 NS 5.983 * 2 Peroneus longus muscle 4.282 6.204 NS 5.585 NS 3 Biceps femoris muscle 5.264 5.698 NS 4.415 NS 4 Gluteus maximus muscle 5.250 4.442 NS 4.844 NS 5 Gluteus medius muscle 5.692 5.300 * 2.690 NS 6 Tensor fasciae latae muscle 4.959 2.801 NS 3.065 NS 7 Latissimus dorsi muscle 4.322 4.717 NS 4.970 * 8 Erector spinae muscle 5.050 3.921 * 9 Infraspinatus muscle 4.439 10 Levator scapulae muscle 2.336 11 Pectoralis major muscle 2.535 12 Pectoralis minor muscle 2.923 13 Flexor carpi ulnaris muscle 4.078 14 Flexor carpi radialis muscle 3.803 15 Adductor magnus muscle 2.368 NS e no statistically significant differences. * e statistically significant difference (p < 0.05).
388 W. Andrzejewski et al. Table 6 Mean values of the pressure sensitivity (kg/cm2) at muscle insertions on the left side of the body for groups III (University School of Physical Education students, vigorous physical activity) and IV (University School of Physical Education students, moderate physical activity). No Researched site e insertion Group III Group IV Statistically kg/cm2 significant left side kg/cm2 1 Superior fibular retinaculum 6.109 4.441 * 5.605 * 2 Peroneus longus muscle 7.765 5.008 * 5.560 * 3 Biceps femoris muscle 7.172 5.242 * 3.452 * 4 Gluteus maximus muscle 8.129 4.413 NS 4.337 * 5 Gluteus medius muscle 7.249 3.468 * 3.630 NS 6 Tensor fasciae latae muscle 5.310 3.676 * 2.980 * 7 Latissimus dorsi muscle 5.069 4.469 * 5.338 NS 8 Erector spinae muscle 5.557 4.219 * 9 Infraspinatus muscle 4.793 10 Levator scapulae muscle 4.992 11 Pectoralis major muscle 5.263 12 Pectoralis minor muscle 4.614 13 Flexor carpi ulnaris muscle 6.339 14 Flexor carpi 6.723 radialis muscle 15 Adductor magnus muscle 5.428 NS e no statistically significant differences. * e statistically significant difference (p < 0.05). the deep femoral artery and deep veins of the thigh. The comparison with the same muscle of younger participants in vessels are located in the adductor canal (Hunter’s canal) the study. and, therefore, their degenerative changes lead to an increase in a rest tonus of muscles of the adductor canal Moreover, there is also an increased sensitivity of the and, therefore, also of the adductor magnus muscle. This is gluteus maximus muscle which, through the sacrotuberous also reflected in the research as the adductor magnus ligament, remains in structural contact with the adductor muscle of University of the Third Age students, despite its magnus muscle, attaching to the ischial tuberosity. Any physical activity, presents greater pressure sensitivity in increase in the rest tonus of the adductor magnus muscle is balanced by an increase in the resting tonus of the Table 7 Mean values of the pressure sensitivity (kg/cm2) at the trigger points of the left side of the body for groups III (University School of Physical Education students, vigorous physical activity) and IV (University School of Physical Education students, moderate physical activity). No Researched site e trigger Group III Group IV Statistically point left side kg/cm2 kg/cm2 significant 1 Superior fibular retinaculum 5.668 4.381 * 4.216 * 2 Peroneus longus muscle 6.415 5.255 * 4.188 * 3 Biceps femoris muscle 7.531 4.332 * 3.325 * 4 Gluteus maximus muscle 6.549 3.644 * 4.103 * 5 Gluteus medius muscle 6.407 4.357 * 2.043 * 6 Tensor fasciae latae muscle 4.521 1.997 * 2.878 * 7 Latissimus dorsi muscle 5.839 3.533 * 3.752 * 8 Erector spinae muscle 6.011 3.911 * 9 Infraspinatus muscle 6.162 10 Levator scapulae muscle 2.944 11 Pectoralis major muscle 3.228 12 Pectoralis minor muscle 3.969 13 Flexor carpi ulnaris muscle 5.342 14 Flexor carpi radialis muscle 5.361 15 Adductor magnus muscle 5.075 NS e no statistically significant differences. * e statistically significant difference (p < 0.05.
The influence of age and physical activity 389 Table 8 Mean values of the pressure sensitivity (kg/cm2) at muscle insertions of the right side of the body for groups III (University School of Physical Education students, vigorous physical activity) and IV (University School of Physical Education students, moderate physical activity). No Researched site e insertion Group III Group IV Statistically kg/cm2 significant right side kg/cm2 1 Superior fibular retinaculum 6.548 4.282 * 5.207 * 2 Peroneus longus muscle 7.212 5.267 * 5.457 * 3 Biceps femoris muscle 7.515 5.082 * 4.179 * 4 Gluteus maximus muscle 8.157 3.404 * 4.189 NS 5 Gluteus medius muscle 7.519 3.996 * 3.104 * 6 Tensor fasciae latae muscle 5.837 3.812 * 3.333 * 7 Latissimus dorsi muscle 5.575 4.367 * 4.729 * 8 Erector spinae muscle 5.299 3.945 * 9 Infraspinatus muscle 5.514 10 Levator scapulae muscle 4.868 11 Pectoralis major muscle 5.645 12 Pectoralis minor muscle 4.760 13 Flexor carpi ulnaris muscle 6.550 14 Flexor carpi radialis muscle 6.146 15 Adductor magnus muscle 5.135 NS e no statistically significant differences. * e statistically significant difference (p < 0.05). sacrotuberous ligament, and of gluteus maximus (Myers, declared a moderate level of physical activity, while 2001). a further 42% of the group declared a high level. It is considered that the lack of statistically significant Physical activity is commonly regarded as a factor differences in pressure sensitivity of most tissues prolonging youth, simultaneously retarding the aging between the age groups may be caused by the relatively process. In the questionnaire, 90% of the group of high level of physical activity reported by the University University of the Third Age students declared of the Third Age students and the University School of a moderate level of physical activity. In the group of Physical Education students. University School of Physical Education students, 42% Table 9 Mean values of the pressure sensitivity (kg/cm2) at trigger points of muscles of the right body side for groups III (University School of Physical Education students, vigorous physical activity) and IV (University School of Physical Education students, moderate physical activity). No Researched site e trigger Group III Group IV Statistically point right side kg/cm2 kg/cm2 significant 1 Superior fibular retinaculum 5.569 3.882 * 4.912 * 2 Peroneus longus muscle 7.319 4.774 * 4.253 * 3 Biceps femoris muscle 8.022 4.458 * 3.771 NS 4 Gluteus maximus muscle 7.185 3.661 * 3.868 * 5 Gluteus medius muscle 7.040 4.245 * 2.257 * 6 Tensor fasciae latae muscle 5.318 2.172 * 2.454 * 7 Latissimus dorsi muscle 5.339 3.755 * 4.218 * 8 Erector spinae muscle 5.896 3.251 * 9 Infraspinatus muscle 6.584 10 Levator scapulae muscle 3.096 11 Pectoralis major muscle 3.570 12 Pectoralis minor muscle 3.883 13 Flexor carpi ulnaris muscle 5.891 14 Flexor carpi radialis muscle 6.257 15 Adductor magnus muscle 4.878 NS e no statistically significant differences. * e statistically significant difference (p < 0.05).
390 W. Andrzejewski et al. In group III (University School of Physical Education References students with vigorous physical activity) there was statis- tically significantly lower pressure sensitivity in most of the Andrzejewski, W., Kassolik, K., Czaplicka, A., Czaplicki, P., studied muscles (91.7%) compared to group IV (University Pia˛tkowski, P., 2007a. Algometryczna ocena efektywno´sci fiz- School of Physical Education students with moderate joterapii w zespołach bo´lowych kre˛gosłupa le˛d´zwiowo-krzy- physical activity). This may have been caused by the z_ owego. Kwartalnik Ortopedyczny 2, 152e161. difference in the level of physical activity between the two groups. No muscle, apart from one, had a sensitivity Andrzejewski, W., Kassolik, K., Steciwko, A., Rakus, J., 2007b. threshold under 3 kg/cm2. Only the levator scapulae Skuteczno´s´c masaz_ u medycznego w bo´lach kre˛gosłupa u oso´b w muscles on the left side of the body, at a trigger point, had wieku starszym. Family Medicine & Primary Care Review 9 (2), a sensitivity level of 2.944 kg/cm2, which only slightly 195e203. diverges from the accepted level of 3 kg/cm2. According to Fischer’s criteria, this level may be described as the norm Andrzejewski, W., Kassolik, K., Kara´s, A., Kara´s, G., Trze˛sicka, E., under which tissues present increased pressure sensitivity. 2006. Ocena efektywno´sci masaz_ u medycznego u oso´b z bo´lami It can therefore be concluded that physical activity influ- dolnego odcinka kre˛gosłupa. Fizjoterapia Polska 6 (4), 150e156. ences the pressure sensitivity of muscles in a very positive way. In group IV there were muscles whose sensitivities Andrzejewski, W., Kassolik, K., Stodo´łka, J., Marcinkowski, q, were below this level. These muscles were the levator Mucha, A., Migasiewicz, J., Błach, W., 2005. Ocena dolegli- scapulae, pectoralis major, and pectoralis minor. The wo´sci bo´lowych narza˛du ruchu wyste˛puja˛cych u studento´w muscles are very frequently characterized by some pain Akademii Wychowania Fizycznego. Medycyna Sportowa 21 (5), relating to trigger points, which may be observed in the 358e365. findings of the study on both body sides. Fischer, A.A., 1987a. Pressure algometry over normal muscles. The presented findings cannot serve as precise norms for Standard values, validity and reproducibility of pressure the populations of young and elderly people, or of pop- threshold. Pain 30, 115e126. ulations of people performing moderate or vigorous phys- ical activity, but they can help in an approximate Fischer, A.A., 1988. Documentation of myofascial trigger points. determination of pressure sensitivity in similar research Archives of Physical Medicine and Rehabilitation 69, 286e291. groups. Despite attempts to determine norms for the sensitivity of given muscles, it is difficult, or even impos- Fischer, A.A., 1984. Diagnosis and management of chronic pain in sible to determine these very precisely, as several factors physical medicine and rehabilitation. In: Ruskin, A.P. (Ed.), may influence them, such as posture, gender, and the Current Therapy in Psychiatry. Saunders, Philadelphia. emotional state of the subject (Merskey and Spear, 1964). However, it seems important to determine more precisely Fischer, A.A., 1986. Pressure threshold meter: its use for quantifi- what factors may influence the pressure sensitivity of cation of tender spots. Archives of Physical Medicine and muscles and up to what level. This would allow using this Rehabilitation 67, 836e838. knowledge in the clinical practice, where the evaluation of pressure sensitivity of muscles plays an important role in Fischer, A.A., 1987b. Tissue compliance meter for objective, determining the general condition of a patient, as quantitative documentation of soft tissue consistency and a measure of the effectiveness of therapy. pathology. Archives of Physical Medicine and Rehabilitation 68, 122e125. This study may act as a stimulus to do more research in a larger group, taking into consideration the influence of Jasko´lski, A., Jasko´lska, A., Adach, Z., 2002. Podstawy fizjologii diverse factors on the pressure sensitivity of muscles. The wysiłku fizycznego. AWF, Wrocław. results of studies on pressure sensitivity in different age or professional groups with an additional division into the Kassolik, K., Andrzejewski, W., Trze˛sicka, E., Ostrowska, B., 2005. gender of the subjects could be of great interest. Ocena skuteczno´sci masaz_ u medycznego w zespole bolesnego barku. Fizjoterapia Polska 5 (2), 201e206. Conclusions Merskey, H., Spear, F.G., 1964. The reliability of the pressure algo- 1. The level of physical activity influences the pressure meter. British Journal of Social and Clinical Psychology 3, 130e136. sensitivity of skeletal muscles. 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Journal of Bodywork & Movement Therapies (2010) 14, 391e396 available at www.sciencedirect.com journal homepage: www.elsevier.com/jbmt PAIN DISTRIBUTION Referred pain areas of active myofascial trigger points in head, neck, and shoulder muscles, in chronic tension type headache Ce´sar Fern´andez-de-las-Pen˜as, PT, PhD a,b,c,*, Hong-You Ge, MD, PhD b, Cristina Alonso-Blanco, PT, MSc d, Javier Gonz´alez-Iglesias, PT e, Lars Arendt-Nielsen, DMSc, PhD b a Department of Physical Therapy, Occupational Therapy, Physical Medicine and Rehabilitation of Universidad Rey Juan Carlos, Alcorco´n, Madrid, Spain b Center for Sensory-Motor Interaction (SMI), Department of Health Science and Technology, Aalborg University, Aalborg, Denmark c Esthesiology Laboratory of Universidad Rey Juan Carlos, Alcorco´n, Madrid, Spain d Department of Health Sciences II, Universidad Rey Juan Carlos, Madrid, Spain e Centro de Fisioterapia Integral, Candas, Asturias, Spain Received 2 April 2009; received in revised form 27 June 2009; accepted 28 June 2009 KEYWORDS Summary Our aim was to analyze the differences in the referred pain patterns and size of Tension type headache; the areas of those myofascial trigger points (TrPs) involved in chronic tension type headache Muscle trigger points; (CTTH) including a number of muscles not investigated in previous studies. Thirteen right Referred pain areas handed women with CTTH (mean age: 38 Æ 6 years) were included. TrPs were bilaterally searched in upper trapezius, sternocleidomastoid, splenius capitis, masseter, levator scap- ulae, superior oblique (extra-ocular), and suboccipital muscles. TrPs were considered active when both local and referred pain evoked by manual palpation reproduced total or partial pattern similar to a headache attack. The size of the referred pain area of TrPs of each muscle was calculated. The mean number of active TrPs within each CTTH patient was 7 (95% CI 6.2e8.0). A greater number (T Z 2.79; p Z 0.016) of active TrPs was found at the right side (4.2 Æ 1.5) when compared to the left side (2.9 Æ 1.0). TrPs in the suboccipital muscles were most prevalent (n Z 12; 92%), followed by the superior oblique muscle (n Z 11/n Z 9 right/left side), the upper trapezius muscle (n Z 11/n Z 6) and the masseter muscle (n Z 9/n Z 7). The ANOVA showed significant differences in the size of the referred pain area between muscles (F Z 4.7, p Z 0.001), but not between sides (F Z 1.1; p Z 0.3): as * Corresponding author: Facultad de Ciencias de la Salud, Universidad Rey Juan Carlos, Avenida de Atenas s/n, 28922 Alcorco´n, Madrid, Spain. Tel.: þ34 91 488 8884; fax: þ34 91 488 8957. E-mail address: [email protected] (C. Ferna´ndez-de-las-Pen˜as). 1360-8592/$ - see front matter ª 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.jbmt.2009.06.008
392 C. Ferna´ndez-de-las-Pen˜as et al. determined by a Bonferroni post hoc analysis the referred pain area elicited by levator scap- ulae TrPs was significantly greater than the area from the sternocleidomastoid (p Z 0.02), masseter (p Z 0.003) and superior oblique (p Z 0.001) muscles. Multiple active TrPs exist in head, neck and shoulder muscles in women with CTTH. The referred pain areas of TrPs located in neck muscles were larger than the referred pain areas of head muscles. Spatial summation of nociceptive inputs from multiple active TrPs may contribute to clinical manifestations of CTTH. ª 2009 Elsevier Ltd. All rights reserved. Introduction muscles in which TrPs can refer pain to the head and hence contribute to CTTH (Figure 1), e.g. masseter, splenius Headache is one of the most prevalent neurological disor- capitis, levator scapulae (Simons et al., 1999), which have ders (Bendtsen and Jensen, 2009). Tension-type headache not been included in recent published studies. Therefore, is the most common form of headache and its chronic form the aim of this study was to analyze the differences in the (chronic tension-type headache: CTTH) is one of the most referred pain patterns and size of the areas of those muscle neglected (Bendtsen and Jensen, 2006) and is difficult to TrPs involved in CTTH including a number of muscles not treat. It has been reported a prevalence rate of 38.3% for investigated in previous studies. episodic tension type headache and 2.2% for CTTH (Schwartz et al., 1998). The prevalence of this headache Material and methods has increased over the years (Lyngberg et al., 2005). CTTH may cause substantial levels of disability, not only to Patients patients and their relative families, but also to the global society due to very high prevalence (Stovner et al., 2007). Thirteen women diagnosed with CTTH, aged from 30 to 50 (mean age: 38 Æ 6 years) years of age participated in this Although there has been an increasing interest in the study. Patients were recruited from an advertisement in pathogenic mechanisms of CTTH, the real patho-anatomical a local newspaper. All subjects were right-handed. Patients mechanisms remain to be fully elucidated (Fumal and were interviewed by an experienced clinician to be certain Schoenen, 2008). It seems clear that hyper-excitability of that they fit the inclusion criteria of the International nociceptive pathway plays an important role in CTTH Headache Society (IHS) criteria for CTTH (IHS, 2004). (Bendtsen and Schoenen, 2006). It has been recently postu- Headache pain features, temporal profile, family history, lated that CTTH pain, at least in part, may be associated with and past and current medications were ascertained from referred pain elicited by trigger points (TrPs) in head, neck the history. To be included, patients had to describe all the and shoulder muscles (Ferna´ndez-de-las-Pen˜as et al., characteristics typical of this headache: bilateral location, 2007a). A myofascial TrPs is defined as a hypersensitive spot pressing and tightening pain, mild or moderate intensity within a taut band of a skeletal muscle that elicits a referred ( 6 on a 11-point numerical pain rate scale from 0 to 10) distant pain (Simons et al., 1999). From a clinical point of and no aggravation of headache during physical activity. No view, TrPs may be active or latent. Active TrPs cause symp- patient reported photophobia, phonophobia, vomiting or toms and both their local and referred pain evoke a familiar evident nausea during headaches. In addition, patients had pain for the patient. In CTTH, active TrPs evoke symptoms to have headaches for at least 15 days/month. Other similar to those patients perceive during their headache primary headaches were excluded. Each patient fulfilled attacks. We have demonstrated that CTTH is associated with the criteria for CTTH, and there was no apparent evidence active TrPs in the suboccipital (Ferna´ndez-de-las-Pen˜as of secondary headaches. Medication-overuse headache as et al., 2006a), upper trapezius (Ferna´ndez-de-las-Pen˜as defined by the IHS was also ruled out. Furthermore, et al., 2007b), superior oblique (Ferna´ndez-de-las-Pen˜as patients completed a headache diary for 4 weeks in order et al., 2005), sternocleidomastoid (Ferna´ndez-de-las-Pen˜as to substantiate the diagnosis (Phillip et al., 2007). et al., 2006b), temporalis (Ferna´ndez-de-las-Pen˜as et al., 2007c), and lateral rectus of the eye (Ferna´ndez-de- All patients had received several prophylactic drugs las-Pen˜as et al., 2009) muscles. Additionally, we also several years ago, but none of them were taking any formulated an updated pain model for CTTH involving both prophylactic drug at the time the study was conducted. peripheral sensitization from active muscle TrPs and central Furthermore, patients who received any non-pharmaco- sensitization in which active TrPs located in those muscles logical treatment (physical therapy, relaxation) within innervated by C1eC3 segments or the trigeminal nerve may 6 months prior to the study were not considered for the be responsible for peripheral nociception producing study. Ethical approval of the study was granted by the a continuous afferent barrage into the nucleus caudalis of Local Ethics Committee (VN 2005-0041). Informed consent the trigeminal nerve sensitizing the central nervous system in was obtained from all subjects, and all procedures were CTTH (Ferna´ndez-de-las-Pen˜as et al., 2007d). conducted according to the Declaration of Helsinki. Previous studies in patients with CTTH have shown larger Headache characteristics referred pain areas elicited from TrPs in the upper trape- zius (Ferna´ndez-de-las-Pen˜as et al., 2007b) and the tem- An 11-point numerical pain rating scale (Jensen et al., poralis (Ferna´ndez-de-las-Pen˜as et al., 2007c) muscles as 1999) (NPRS; range: 0 Z no pain, to 10 Z maximum pain) compared to controls. In addition, there are a number of
Referred pain areas of active TrPs in head, neck, and shoulder muscles, in CTTH 393 Figure 1 Referred pains from upper trapezius, sternocleidomastoid, suboccipital, splenius capitis, splenius cervicis, semispinalis capitis and temporalis muscle TrPs as described by Simons et al. Reprinted with permission from Simons, D., Travell, J., Simons, L., 1999. Travell & Simons’ Myofascial Pain and Dysfunction: The Trigger Point Manual, Vol. 1, second ed. Williams & Wilkins, Baltimore. was used to assess headache intensity. The headache diary (1999): (1) presence of a palpable taut band within a skel- was used to calculate the following variables: (1) headache etal muscle; (2) presence of a hypersensitive tender spot in intensity, calculated from the mean of the NPRS of the days the taut band; (3) local twitch response elicited by snap- with headache; (2) headache frequency, calculated by ping palpation of the taut band; and (4) reproduction of the dividing the number of days with headache by the number typical referred pain pattern of the TrP in response to of analyzed weeks (days/week); and (3) headache dura- compression. For suboccipital and superior oblique muscles tion, calculated by dividing the sum of the total hours of we adopted the previous published guidelines (Ferna´ndez- headache by the number of days with headache (hours/ de-las-Pen˜as et al., 2005, 2006a). Briefly, the diagnosis of day). Patients also drew their headache pattern on an suboccipital TrPs was made when there was tenderness in anatomical map. the suboccipital region, referred pain evoked by main- tained pressure for 10 s, and increased referred pain with Muscle trigger point examination muscle contraction [extension of the headeneck] (Ferna´ndez-de-las-Pen˜as et al., 2006a). For the diagnosis of Patients were asked to avoid any analgesic or muscle superior oblique muscle TrPs, we searched for both local relaxant 48 h prior to the examination, and they were and referred pain elicited by palpation of the superior- examined when their headache intensity was less than 4 on internal corner of the orbit and increased referred pain the NPRS. Myofascial TrPs were bilaterally explored in with both contraction [infra-adduction of the eye] and upper trapezius, splenius capitis, sternocleidomastoid, stretching [supra-abduction of the eye] of the muscle masseter, superior oblique, levator scapulae and sub- (Ferna´ndez-de-las-Pen˜as et al., 2005). TrPs were consid- occipital muscles by an observer assessor who had more ered active if both the local and the referred pain evoked than 8 years of experience in TrP diagnosis. For the upper by manual palpation reproduced total or partial pattern of trapezius, sternocleidomastoid, splenius capitis, masseter the headache (Simons et al., 1999). and levator scapulae muscles, TrP diagnosis was conducted following the diagnostic criteria described by Simons et al. Muscle TrPs were searched in each muscle with a 1-min interval between two consecutive points. After TrP
394 C. Ferna´ndez-de-las-Pen˜as et al. examination on each point, patients were asked to draw between head pain areas and pain clinical parameters the distribution of referred pain (if it was elicited during (intensity, duration or frequency) were found. examination) on an anatomical map. The referred pain area of muscle TrPs was calculated with a digitizer (ACECAD Muscle TrPs in CTTH: number, location D9000, Taiwan). and referred pain areas Statistical analysis The mean number of active TrPs within each CTTH patient was 7 (95% CI 6.2e8.0). A greater number (T Z 2.79; Data was analyzed with SPSSâ version 14.0 (SPSS Inc, Chi- p Z 0.016) of active TrPs was found on the right side cago, IL) Results are expressed as mean and 95% confidence (4.2 Æ 1.5) when compared to the left side (2.9 Æ 1.0). interval in the text. The KolmogoroveSmirnov test showed a normal distribution of quantitative data (p > 0.05). The TrPs in the suboccipital muscles were most prevalent differences in the number of active TrPs between both (n Z 12; 92%), followed by the superior oblique muscle sides were assessed with the non-parametric Wilcoxon (n Z 11 [85%]/n Z 9 [69%] right/left side), the upper Signed-Rank test. The chi square (c2) test was used to trapezius muscle (n Z 11 [85%]/n Z 6 [46%]) and the assess the differences in the size of the distribution of masseter muscle (n Z 9 [69%]/n Z 7 [54%]). The distribu- active TrPs within each muscle on each side. A two-way tion of active muscle TrPs was significantly different ANOVA was used to detect the differences in referred pain between sides for the upper trapezius (c2 Z 4.792; area (cm2) between muscles and sides. The Bonferroni test p Z 0.045), the sternocleidomastoid (c2 Z 4.524; was conducted as post hoc analysis. The Pearson (r) test p Z 0.045) and the levator scapulae muscles (c2 Z 5.406; was used for the correlation analysis between referred pain p Z 0.0354). In such a way, active TrPs were mostly located areas and clinical variables relating to headache (intensity, in the right side in both upper trapezius and sternocleido- frequency, duration, history). The statistical analysis was mastoid muscles, whereas levator scapulae TrPs were conducted at a 95% confidence level. A p value-less than mostly located in the left side. The distribution of active 0.05 was considered statistically significant. TrPs in the analyzed muscles is shown in Table 1, and referred pain areas of particular muscles in Table 2. Results The ANOVA showed significant differences in referred Clinical features of the sample pain areas between muscles (F Z 4.7, p Z 0.001), but not between sides (F Z 1.1; p Z 0.3). Based on a Bonferroni In this CTTH sample, mean duration of the headache history post hoc analysis, the referred pain area elicited from was 11.5 years (95% CI 7.2e15.8 years). The mean head- levator scapulae TrPs was significantly greater than the ache period per day was 7.2 h (95% CI 5.8e8.5 h), the mean referred pain from the sternocleidomastoid (p Z 0.02), the intensity per episode was 4.8 (95% CI 4.4e5.2), and the masseter (p Z 0.003) and the superior oblique (p Z 0.001) number of days per week with headache was 4.5 (95% CI muscles. Referred pain areas of upper trapezius, splenius 4.1e5.0 days/week). The day of the examination mean capitis, suboccipital, and levator scapulae were not headache intensity was 2.3 (95% CI 2.0e2.6). Headache significantly different (p > 0.3). intensity was positively associated with the headache duration of individual attacks (r Z 0.65; p Z 0.02): the Discussion greater the intensity, the longer the duration of the head- ache. The mean head pain area reported by the patients This study showed the existence of multiple active TrPs in during their attacks was 4.1 cm2 (95% CI 2.6e5.6) in the different head, neck and shoulder muscles in patients with frontal region, 5.9 (95% CI 4.7e7.2) in the occipital region CTTH. Both the local and referred pain elicited by active (including the posterior part of the neck region), 3.3 (95% CI TrPs reproduced the headache pattern in all the patients. 2.5e4.1) in the left side of the head, and 2.8 (95% CI 1.9e The presence of bilateral active TrPs in trigemino-cervical 3.8) in the right side of the head (Figure 2). No correlation muscles provides a plausible explanation for the symmet- rical bilateral distribution of pain observed in patients with CTTH. Figure 2 Symptom area of the patients with chronic tension type headache included in the current study.
Referred pain areas of active TrPs in head, neck, and shoulder muscles, in CTTH 395 Table 1 Number of patients with chronic tension type headache (n) with active trigger points (TrPs) located in each muscle. Upper trapezius muscle Sternocleidomastoid muscle Masseter muscle Left side Right side Left side Right side Left side Right side Active TrPs (n) 6 11 2 6 79 7 64 No TrPs (n) 7 2 11 Splenius capitis muscle Levator scapulae muscle Superior oblique muscle Left side Right side Left side Right side Left side Right side Active TrPs (n) 44 84 9 11 No TrPs (n) 99 59 42 We found up to seven active muscle TrPs within each Previously we assessed referred pain areas from the upper headache patient, supporting the assumption of spatial trapezius (Ferna´ndez-de-las-Pen˜as et al., 2007b) and tem- summation of TrP activity in CTTH, as we have previously poralis (Ferna´ndez-de-las-Pen˜as et al., 2007c) muscles, but suggested (Ferna´ndez-de-las-Pen˜as et al., 2007a,b,d). Our not from the remaining muscles included in the current results underscore the importance of searching for multiple study. The current study increases the number of muscle active TrPs in different muscles in patients with CTTH. This TrPs which referred pain is contributing to headache pain finding increases the relevance of multiple TrPs because pattern in CTTH. Additionally, we also showed that the active TrPs constitute an important source of peripheral referred pain areas of the analyzed muscles covered the nociception since higher concentrations of chemical medi- extension of the entire headache pain pattern of the ators (bradykinin, calcitonin gene-related peptide, patients, although we should consider that the referred substance P, and serotonin) may be present in active pain areas of some muscle TrPs, e.g. suboccipital, splenius muscle TrPs (Shah et al., 2005). This hypothesis would be capitis, and upper trapezius, are located in the same region related to previous assumptions that peripheral nociception of the head (frontal or lateral side of the head or neck). In and sensitization mechanisms would play a crucial role in addition, we should take into account that the referred the evolution from episodic to chronic tension type head- pain pattern of the levator scapulae muscle did not reach ache (Bendtsen and Schoenen, 2006). Therefore, clinicians the head. Nevertheless, since all CTTH patients reported should search and treat active muscle TrPs in the muscu- neck pain symptoms, active TrPs in this muscle are related lature which receives a trigemino-cervical innervation in to the neck pain pattern present in CTTH. Finally, the patients with CTTH and try to treat those which referred referred pain patterns elicited by active TrPs in the current pain TrP reproduced the headache attack. study were very similar to those previously reported by Simons et al. (1999) and by Beat de Jung (2006). Never- We also calculated the referred pain areas elicited by theless, some slight differences may be observed, probably active TrPs and found that referred pain areas of sub- due to the pathology of the patients included, or due to the occipital and levator scapulae muscle TrPs were the com- sensitization state in which the patients were explored. monest ones. It is interesting to note that neck (suboccipital, levator scapulae or splenius capitis), instead An interesting finding was that active TrPs in the upper of head muscles (masseter or superior oblique), showed the trapezius and sternocleidomastoid muscles were mostly greatest referred pain areas. These findings claim for the located in the right side, whereas levator scapulae TrPs relevance of neck muscles in pain perception in CTTH. were mostly located in the left side. These results are Table 2 Referred pain areas of active trigger points on each muscles in patients with chronic tension type headache. Patients with chronic tension type headache Upper trapezius Right side (n Z 11) 3.4 Æ 1.2 (2.5e4.2) Sternocleidomastoid Left side (n Z 6) 2.9 Æ 1.2 (1.7e4.2) Masseter Right side (n Z 6) 2.5 Æ 0.7 (1.8e3.2) Splenius capitis Left side (n Z 2) 1.8 Æ 0.4 (1.4e2.6) Levator scapulae Right side (n Z 9) 2.2 Æ 0.5 (1.8e2.6) Superior oblique Left side (n Z 7) 2.8 Æ 1.0 (1.9e3.8) Suboccipital Right side (n Z 4) 3.8 Æ 0.5 (3.1e4.6) Left side (n Z 4) 3.1 Æ 1.5 (1.0e4.4) Right side (n Z 4) 4.9 Æ 1.1 (3.1e6.6) Left side (n Z 8) 4.1 Æ 2.0 (2.4e5.8) Right side (n Z 11) 2.5 Æ 1.1 (1.7e3.2) Left side (n Z 9) 2.7 Æ 1.6 (1.5e4.0) n Z 12 4.5 Æ 1.3 (3.7e5.4) Referred pain areas (cm2) are expressed as means Æ standard deviation (95% confidence interval).
396 C. Ferna´ndez-de-las-Pen˜as et al. similar to those found in a previous study (Ferna´ndez-de- Ferna´ndez-de-las-Pen˜as, C., Cuadrado, M.L., Gerwin, R.D., las-Pen˜as et al., 2007b) in which TrPs in the upper trapezius Pareja, J.A., 2005. Referred pain from the trochlear region in muscle were also located in the dominant side. A greater tension-type headache: a myofascial trigger point from the prevalence of TrPs in the right side may be related to the superior oblique muscle. Headache 45, 731e737. fact that all patients were right-hand dominant. Bernard (1997) found that highly repetitive work and forceful arm or Ferna´ndez-de-las-Pen˜as, C., Alonso-Blanco, C., Cuadrado, M.L., hand movements cause neck and shoulder pain. Repetitive Gerwin, R.D., Pareja, J.A., 2006a. Trigger points in the sub- use of the muscle in the dominant side may be a factor to occipital muscles and forward head posture in tension type the development of TrPs (Simons, 2004). Nevertheless, this headache. Headache 46, 454e460. hypothesis does not explain why active TrPs in the levator scapulae were more prevalent on the non-dominant side. Ferna´ndez-de-las-Pen˜as, C., Alonso-Blanco, C., Cuadrado, M.L., Future studies should investigate this topic. Gerwin, R.D., Pareja, J.A., 2006b. Myofascial trigger points and their relationship with headache clinical parameters in chronic We should recognize some limitations of the study. tension type headache. Headache 46, 1264e1272. Firstly, we only included women with CTTH; therefore our results cannot be extrapolated to men with CTTH. Future Ferna´ndez-de-las-Pen˜as, C., Ge, H.Y., Arendt-Nielsen, L., studies should include men with CTTH for a more general- Cuadrado, M.L., Pareja, J.A., 2007a. Referred pain from ization of the results of the current study. Secondly, we trapezius muscle trigger point shares similar characteristics included a small sample size, so future studies with with chronic tension type headache. Eur. J. Pain 11, a greater number of patients is recommended. Thirdly, 475e482. since active TrPs are not found often in healthy controls we only included patients, in the current study. The reason was Ferna´ndez-de-las-Pen˜as, C., Ge, H.Y., Arendt-Nielsen, L., that we wanted to investigate referred pain areas in active Cuadrado, M.L., Pareja, J.A., 2007b. The local and referred TrPs in a patient population. pain from myofascial trigger points in the temporalis muscle contributes to pain profile in chronic tension-type headache. Conclusions Clin. J. Pain 23, 786e792. The present study showed the existence of multiple active Ferna´ndez-de-las-Pen˜as, C., Simons, D.G., Cuadrado, M.L., TrPs in different head, neck and shoulder muscles in women Pareja, J.A., 2007c. The role of myofascial trigger points in CTTH. Both the local and referred pain elicited by active musculoskeletal pain syndromes of the head and neck. Curr. TrPs reproduced the headache pattern in patients. 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Journal of Bodywork & Movement Therapies (2010) 14, 397e402 available at www.sciencedirect.com journal homepage: www.elsevier.com/jbmt CASE STUDY Diagnosis and treatment of posterior interosseous nerve syndrome using soft tissue manipulation therapy: A case study John Saratsiotis, BSc, BA, DC a,*, Emmanouil Myriokefalitakis, MD b a Doctor of Chiropractic, Private Practice, Roupel 9, Peristeri, Athens, Attiki 121-34, Greece b Orthopaedic Resident, A’ Orthopaedic Department, General Hospital ‘‘G. Gennimatas’’, Athens, Greece Received 29 September 2009; received in revised form 22 October 2009; accepted 11 November 2009 KEYWORDS Summary Peripheral nerve entrapments of the upper and lower extremity are commonly Peripheral nerve seen in practice. Chronically repetitive movement patterns lead to constriction of the nerve entrapment; due to the development of local fibrosis within the soft tissues surrounding the nerve which Posterior interroseous also affects nerve traction, mobility, and function. A case is presented of a patient with motor nerve; weakness in the wrist and hand in order to illustrate the diagnosis and treatment of posterior Posterior interroseous interosseous nerve (PIN) syndrome. Using Active Release Techniques Soft Tissue Management nerve syndrome; and Peripheral Nerve Release Systemsâ the patient’s symptomatology was resolved. Soft Active release tissue-based management in conjunction with neural gliding may be beneficial in the conser- technique; vative management of PIN syndrome. Further research into the pathophysiology of nerve Peripheral nerve release entrapments will have immediate impact on the management of neuropathies and likely result in emphasizing conservative management and rehabilitation rather than surgical intervention particularly in cases not involving denervation or paralysis. ª 2009 Elsevier Ltd. All rights reserved. Introduction (crush) injury or chronic injury. In both cases, the patho- physiology is similar (local ischaemia due to mechanical Peripheral nerve entrapments of the upper and lower pressure), however the pathogenesis differs according to extremity are commonly seen in practice. An entrapment current research (Pham and Gupta, 2009; McKinnon, 2002). can occur anywhere along the course of a peripheral nerve Acute injuries (crush injuries) are characterized by axonal (even though usually entrapment occurs at specific sites). injury (triggering Schwann cell dedifferentiation) and The etiology of these syndromes is typically traumatic subsequent Wallerian degeneration (Pham and Gupta, 2009). In chronic nerve compression injuries simultaneous * Corresponding author. Tel.: þ30 695 506 9285. E-mail address: [email protected] (J. Saratsiotis). 1360-8592/$ - see front matter ª 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.jbmt.2009.11.002
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