The anatomy of the coracohumeral ligament and its relation to the subscapularis muscle.

PubMed

Arai, Ryuzo; Nimura, Akimoto; Yamaguchi, Kumiko; Yoshimura, Hideya; Sugaya, Hiroyuki; Saji, Takahiko; Matsuda, Shuichi; Akita, Keiichi

2014-10-01

Only a few reports describe the extension of the coracohumeral ligament to the subscapularis muscle. The purposes of this study were to histo-anatomically examine the structure between the ligament and subscapularis and to discuss the function of the ligament. Nineteen intact embalmed shoulders were used. In 9 shoulders, the expansion of the ligament was anatomically observed, and in 6 of these 9, the muscular tissue of the supraspinatus and subscapularis was removed to carefully examine the attachments to the tendons of these muscles. Five shoulders were frozen and sagittally sectioned into 3-mm-thick slices. After observation, histologic analysis was performed on 3 of these shoulders. In the remaining 5 shoulders, the coracoid process was harvested to investigate the ligament origin. The coracohumeral ligament originated from the horizontal limb and base of the coracoid process and enveloped the cranial part of the subscapularis muscle. The superficial layer of the ligament covered a broad area of the anterior surface of the muscle. Laterally, it protruded between the long head of the biceps tendon and subscapularis and attached to the tendinous floor, which extended from the subscapularis insertion. Histologically, the ligament consisted of irregular and sparse fibers abundant in type III collagen. The coracohumeral ligament envelops the whole subscapularis muscle and insertion and seems to function as a kind of holder for the subscapularis and supraspinatus muscles. The ligament is composed of irregular and sparse fibers and contains relatively rich type III collagen, which would suggest flexibility. Copyright © 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Study of the trapezius muscle region pressure pain threshold and latency time in young people with and without depressed scapula.

PubMed

Lee, Kuan-Ting; Chuang, Chiung-Cheng; Lai, Chien-Hung; Ye, Jing-Jhao; Wu, Chien-Lung

2015-02-01

The scapula is stabilized in or moved to a certain position to coordinate shoulder function and achieve shoulder and arm movement during the athletic and daily activities. An alteration in the scapular position both at rest and during arm movements is commonly associated with shoulder injury or dysfunction. The purpose of this study was to assess the influence of the depressed scapular position using pressure pain threshold (PPT) and delayed muscle activation of the upper and middle trapezius muscles. The study included 20 subjects who were divided into normal shoulder (n = 12) and depressed shoulder (n = 8) group. PPT was measured in a relaxed position. Muscle activity was recorded using surface electromyography and by calculating each shrug's muscle latency time (MLT). The results revealed that the healthy young subjects with depressed scapular position had significantly lower PPT levels than those with normal scapular position both in the upper and middle trapezius muscle (P < 0.05). MLT of the upper trapezius was significantly delayed in both sides during the shoulder shrugs (P < 0.05). Copyright © 2014 Elsevier Ltd. All rights reserved.

Shoulder abduction and external rotation restoration with nerve transfer.

PubMed

Kostas-Agnantis, Ioannis; Korompilias, Anastasios; Vekris, Marios; Lykissas, Marios; Gkiatas, Ioannis; Mitsionis, Gregory; Beris, Alexander

2013-03-01

In upper brachial plexus palsy patients, loss of shoulder function and elbow flexion is obvious as the result of paralysed muscles innervated by the suprascapular, axillary and musculocutaneus nerve. Shoulder stabilisation, restoration of abduction and external rotation are important as more distal functions will be affected by the shoulder situation. Between 2005 and 2011, eleven patients with upper type brachial plexus palsy were operated on with triceps nerve branch transfer to anterior axillary nerve branch and spinal accessory nerve transfer to the suprascapular nerve for shoulder abduction and external rotation restoration. Nine patients met the inclusion criteria for the study. All patients were men with ages ranged from 21 to 35 years (average, 27.4 years). The interval between injury and surgery ranged from 4 to 11 months (average, 7.2 months). Atrophy of the supraspinatus, infraspinatus and deltoid muscle and subluxation at the glenohumeral joint was obvious in all patients preoperatively. During the pre-op examination all patients had at least muscle grading 4 on the triceps muscle. The mean post-operative value of shoulder abduction was 112.2° (range: 60-170°) while preoperatively none of the patients was able for abduction (p<0.001). The mean post-operative value of shoulder external rotation was 66° (range: 35-110°) while preoperatively none of them was able for external rotation (p<0.001). Postoperative values of shoulder abduction were significantly better that those of external rotation (p=0.0004). The postoperative average muscle grading for shoulder abduction according the MRC scale was 3.6±0.5 and for the shoulder external rotation was 3.2±0.4. Combined nerve transfer by using the spinal accessory nerve for suprascapular nerve neurotisation and one of the triceps nerve branches for axillary nerve and teres minor branch neurotisation is an excellent choice for shoulder abduction and external rotation restoration. Copyright © 2013 Elsevier Ltd. All rights reserved.

Long-term prospective assessment of shoulder function after breast reconstruction involving a latissimus dorsi muscle flap transfer and postoperative radiotherapy.

PubMed

Sowa, Yoshihiro; Morihara, Toru; Kushida, Rie; Sakaguchi, Koichi; Taguchi, Tetsuya; Numajiri, Toshiaki

2017-05-01

Several investigators have evaluated the impaired function of the shoulder after removal of the latissimus dorsi muscle for breast reconstruction. However, a few investigators have studied whether including radiotherapy has a negative effect on functional recovery of the shoulder by a long-term follow-up after surgery. In this study, we compared objective measurements of shoulder function preoperatively and postoperatively for 3 years after latissimus dorsi muscle (LDM) flap transfer and postoperative radiotherapy (PRT). Eighteen patients who underwent unilateral transfer of a pedicled LDM flap and PRT within 2 months of breast-conserving surgery were enrolled in this study. Range of motion (ROM) and muscle strength in exhaustive shoulder movements were measured before surgery, and at 3 and 6 months, and 1 and 3 years. The results of ROM measurements at 3months postsurgery showed significant decreases in both flexion and abduction by 7.1 and 9.2 % and at 3 years postsurgery by 4.7 and 5.7 %. The muscle strength measurements at 3 months postsurgery showed statistically significant decreases both in adduction and in the 2nd medial rotation by 30.7 and 25.9 % and at 3 years postsurgery by 36.4 and 20.4 %. A significant improvement in these impairments was not observed for 3 years after surgery compared with that at 3 months after surgery. A combination of the LDM flap procedure and PRT could be associated with a higher incidence of tissue adhesions in both flexion and abduction and muscle deficit both in adduction and in the 2nd medial rotation.

Architectural analysis and predicted functional capability of the human latissimus dorsi muscle.

PubMed

Gerling, Michael E; Brown, Stephen H M

2013-08-01

The latissimus dorsi is primarily considered a muscle with actions at the shoulder, despite its widespread attachments at the spine. There is some dispute regarding the potential contribution of this muscle to lumbar spine function. The architectural design of a muscle is one of the most accurate predictors of muscle function; however, detailed architectural data on the latissimus dorsi muscle are limited. Therefore, the aim of this study was to quantify the architectural properties of the latissimus dorsi muscle and model mechanical function in light of these new data. One latissimus dorsi muscle was removed from each of 12 human cadavers, separated into regions, and micro-dissected for quantification of fascicle length, sarcomere length, and physiological cross-sectional area. From these data, sarcomere length operating ranges were modelled to determine the force-length characteristics of latissimus dorsi across the spine and shoulder ranges of motion. The physiological cross-sectional area of latissimus dorsi was 5.6±0.5 cm2 and normalized fascicle length was 26.4±1.0 cm, indicating that this muscle is designed to produce a moderate amount of force over a large range of lengths. Measured sarcomere length in the post-mortem neutral spine posture was nearly optimal at 2.69±0.06 μm. Across spine range of motion, biomechanical modelling predicted latissimus dorsi acts across both the ascending and descending limbs of the force-length curve during lateral bend, and primarily at or near the plateau region (where maximum force generation is possible) during flexion/extension and axial twist. Across shoulder range of motion, latissimus dorsi acts primarily on the plateau region and descending limbs of the force length curve during both flexion/extension and abduction/adduction. These data provide novel insights into the ability of the latissimus dorsi muscle to generate force and change length throughout the spine and shoulder ranges of motion. In addition, these findings provide an improved understanding of the spine and shoulder positions at which the force-generating capacity of this muscle can become jeopardized, and consequently how this may affect its spine-stabilizing ability. © 2013 Anatomical Society.

Architectural analysis and predicted functional capability of the human latissimus dorsi muscle

PubMed Central

Gerling, Michael E; Brown, Stephen H M

2013-01-01

The latissimus dorsi is primarily considered a muscle with actions at the shoulder, despite its widespread attachments at the spine. There is some dispute regarding the potential contribution of this muscle to lumbar spine function. The architectural design of a muscle is one of the most accurate predictors of muscle function; however, detailed architectural data on the latissimus dorsi muscle are limited. Therefore, the aim of this study was to quantify the architectural properties of the latissimus dorsi muscle and model mechanical function in light of these new data. One latissimus dorsi muscle was removed from each of 12 human cadavers, separated into regions, and micro-dissected for quantification of fascicle length, sarcomere length, and physiological cross-sectional area. From these data, sarcomere length operating ranges were modelled to determine the force–length characteristics of latissimus dorsi across the spine and shoulder ranges of motion. The physiological cross-sectional area of latissimus dorsi was 5.6 ± 0.5 cm2 and normalized fascicle length was 26.4 ± 1.0 cm, indicating that this muscle is designed to produce a moderate amount of force over a large range of lengths. Measured sarcomere length in the post-mortem neutral spine posture was nearly optimal at 2.69 ± 0.06 μm. Across spine range of motion, biomechanical modelling predicted latissimus dorsi acts across both the ascending and descending limbs of the force–length curve during lateral bend, and primarily at or near the plateau region (where maximum force generation is possible) during flexion/extension and axial twist. Across shoulder range of motion, latissimus dorsi acts primarily on the plateau region and descending limbs of the force length curve during both flexion/extension and abduction/adduction. These data provide novel insights into the ability of the latissimus dorsi muscle to generate force and change length throughout the spine and shoulder ranges of motion. In addition, these findings provide an improved understanding of the spine and shoulder positions at which the force-generating capacity of this muscle can become jeopardized, and consequently how this may affect its spine-stabilizing ability. PMID:23758053

Long-term outcome of accessory nerve to suprascapular nerve transfer in obstetric brachial plexus lesion: functional, morphological, and electrophysiological results.

PubMed

Gmeiner, Matthias; Topakian, Raffi; Göschl, Manuel; Wurm, Sarah; Holzinger, Anita; van Ouwerkerk, Willem J R; Holl, Kurt

2015-09-01

An accessory to suprascapular nerve (XIN-SSN) transfer is considered in patients with obstetric brachial plexus lesion who fail to recover active shoulder external rotation. The aim of this study was to evaluate the quality of extraplexal suprascapular nerve neurotization and to perform a detailed analysis of the infraspinatus muscle (IM) and shoulder external rotation. A XIN-SSN transfer was performed in 14 patients between 2000 and 2007. Patients had been operated at the age of 3.7 ± 2.8 years. Follow-up examinations were conducted up to 8.5 ± 2.5 years. Magnetic resonance imaging was performed to investigate muscle trophism. Fatty muscle degeneration of the IM was classified according to the Goutallier classification. We conducted nerve conduction velocity studies of the suprascapular nerve and needle electromyography of the IM to assess pathologic spontaneous activity and interference patterns. Active glenohumeral shoulder external rotation and global shoulder function were evaluated using the Mallet score. Postoperatively, growth of the IM increased equally on the affected and unaffected sides, although significant differences of muscle thickness persisted over time. There was only grade 1 or 2 fatty degeneration pre- and postoperatively. Electromyography of the IM revealed a full interference pattern in all except one patient, and there was no pathological spontaneous activity. Glenohumeral external rotation as well as global shoulder function increased significantly. Our results indicate that the anastomosis after XIN-SSN transfer is functional and that successful reinnervation of the infraspinatus muscle may enable true glenohumeral active external rotation.

Changes in shoulder muscle size and activity following treatment for breast cancer.

PubMed

Shamley, Delva R; Srinanaganathan, Ragavan; Weatherall, Rosamund; Oskrochi, Reza; Watson, Marion; Ostlere, Simon; Sugden, Elaine

2007-11-01

Morbidity of the shoulder after breast cancer is a well-known phenomenon. MRI studies have shown muscle morbidity in cervical cancer and prostate cancer. In breast cancer clinical observations and patient reports include muscle morbidity in a number of muscles acting at the shoulder. Several of these muscles lie in the field of surgery and radiotherapy. Timed interaction between muscles that stabilise the shoulder and those acting as prime movers is essential to achieve a smooth scapulohumeral rthythm during functional elevation of the arm. CROSS-SECTIONAL STUDY: Seventy-four women treated for unilateral carcinoma of the breast were included in the study. All patients filled out the Shoulder Pain and Disability Index (SPADI). EMG activity of four muscles was recorded during scaption on the affected and unaffected side. Muscle cross sectional area and signal intensity was determined from MRI scans. The association between EMG and covariates was determined using multiple linear regression techniques. Three of the 4 muscles on the affected side demonstrated significantly less EMG activity, particularly when lowering the arm. Upper trapezius demonstrated the greatest loss in activity. Decreased activity in both upper trapezius and rhomboid were significantly associated with an increase in SPADI score and increased time since surgery. Pectoralis major and minor were significantly smaller on the affected side. Muscles affected in the long term are the muscles associated with pain and disability yet are not in the direct field of surgery or radiotherapy. Primary muscle shortening and secondary loss of muscle activity may be producing a movement disorder similar to the 'Dropped Shoulder Syndrome'. Exercise programmes should aim not only for range of movement but also for posture correction and education of potential long-term effects.

The anterior deltoid's importance in reverse shoulder arthroplasty: a cadaveric biomechanical study.

PubMed

Schwartz, Daniel G; Kang, Sang Hoon; Lynch, T Sean; Edwards, Sara; Nuber, Gordon; Zhang, Li-Qun; Saltzman, Matthew

2013-03-01

Frequently, patients who are candidates for reverse shoulder arthroplasty have had prior surgery that may compromise the anterior deltoid muscle. There have been conflicting reports on the necessity of the anterior deltoid thus it is unclear whether a dysfunctional anterior deltoid muscle is a contraindication to reverse shoulder arthroplasty. The purpose of this study was to determine the 3-dimensional (3D) moment arms for all 6 deltoid segments, and determine the biomechanical significance of the anterior deltoid before and after reverse shoulder arthroplasty. Eight cadaveric shoulders were evaluated with a 6-axis force/torque sensor to assess the direction of rotation and 3D moment arms for all 6 segments of the deltoid both before and after placement of a reverse shoulder prosthesis. The 2 segments of anterior deltoid were unloaded sequentially to determine their functional role. The 3D moment arms of the deltoid were significantly altered by placement of the reverse shoulder prosthesis. The anterior and middle deltoid abduction moment arms significantly increased after placement of the reverse prosthesis (P < .05). Furthermore, the loss of the anterior deltoid resulted in a significant decrease in both abduction and flexion moments (P < .05). The anterior deltoid is important biomechanically for balanced function after a reverse total shoulder arthroplasty. Losing 1 segment of the anterior deltoid may still allow abduction; however, losing both segments of the anterior deltoid may disrupt balanced abduction. Surgeons should be cautious about performing reverse shoulder arthroplasty in patients who do not have a functioning anterior deltoid muscle. Copyright © 2013 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

How do deltoid muscle moment arms change after reverse total shoulder arthroplasty?

PubMed

Walker, David R; Struk, Aimee M; Matsuki, Keisuke; Wright, Thomas W; Banks, Scott A

2016-04-01

Although many advantages of reverse total shoulder arthroplasty (RTSA) have been demonstrated, a variety of complications indicate there is much to learn about how RTSA modifies normal shoulder function. This study used a subject-specific computational model driven by in vivo kinematic data to assess how RTSA affects deltoid muscle moment arms after surgery. A subject-specific 12 degree-of-freedom musculoskeletal model was used to analyze the shoulders of 26 individuals (14 RTSA and 12 normal). The model was modified from the work of Holzbaur to directly input 6 degree-of-freedom humeral and scapular kinematics obtained using fluoroscopy. The moment arms of the anterior, lateral, and posterior aspects of the deltoid were significantly different when RTSA and normal cohorts were compared at different abduction angles. Anterior and lateral deltoid moment arms were significantly larger in the RTSA group at the initial elevation of the arm. The posterior deltoid was significantly larger at maximum elevation. There was large intersubject variability within the RTSA group. Placement of implant components during RTSA can directly affect the geometric relationship between the humerus and scapula and the muscle moment arms in the RTSA shoulder. RTSA shoulders maintain the same anterior and posterior deltoid muscle moment-arm patterns as healthy shoulders but show much greater intersubject variation and larger moment-arm magnitudes. These observations provide a basis for determining optimal implant configuration and surgical placement to maximize RTSA function in a patient-specific manner. Published by Elsevier Inc.

Muscle function in glenohumeral joint stability during lifting task.

PubMed

Blache, Yoann; Begon, Mickaël; Michaud, Benjamin; Desmoulins, Landry; Allard, Paul; Dal Maso, Fabien

2017-01-01

Ensuring glenohumeral stability during repetitive lifting tasks is a key factor to reduce the risk of shoulder injuries. Nevertheless, the literature reveals some lack concerning the assessment of the muscles that ensure glenohumeral stability during specific lifting tasks. Therefore, the purpose of this study was to assess the stabilization function of shoulder muscles during a lifting task. Kinematics and muscle electromyograms (n = 9) were recorded from 13 healthy adults during a bi-manual lifting task performed from the hip to the shoulder level. A generic upper-limb OpenSim model was implemented to simulate glenohumeral stability and instability by performing static optimizations with and without glenohumeral stability constraints. This procedure enabled to compute the level of shoulder muscle activity and forces in the two conditions. Without the stability constraint, the simulated movement was unstable during 74%±16% of the time. The force of the supraspinatus was significantly increased of 107% (p<0.002) when the glenohumeral stability constraint was implemented. The increased supraspinatus force led to greater compressive force (p<0.001) and smaller shear force (p<0.001), which contributed to improved glenohumeral stability. It was concluded that the supraspinatus may be the main contributor to glenohumeral stability during lifting task.

Muscle function in glenohumeral joint stability during lifting task

PubMed Central

Begon, Mickaël; Michaud, Benjamin; Desmoulins, Landry; Allard, Paul

2017-01-01

Ensuring glenohumeral stability during repetitive lifting tasks is a key factor to reduce the risk of shoulder injuries. Nevertheless, the literature reveals some lack concerning the assessment of the muscles that ensure glenohumeral stability during specific lifting tasks. Therefore, the purpose of this study was to assess the stabilization function of shoulder muscles during a lifting task. Kinematics and muscle electromyograms (n = 9) were recorded from 13 healthy adults during a bi-manual lifting task performed from the hip to the shoulder level. A generic upper-limb OpenSim model was implemented to simulate glenohumeral stability and instability by performing static optimizations with and without glenohumeral stability constraints. This procedure enabled to compute the level of shoulder muscle activity and forces in the two conditions. Without the stability constraint, the simulated movement was unstable during 74%±16% of the time. The force of the supraspinatus was significantly increased of 107% (p<0.002) when the glenohumeral stability constraint was implemented. The increased supraspinatus force led to greater compressive force (p<0.001) and smaller shear force (p<0.001), which contributed to improved glenohumeral stability. It was concluded that the supraspinatus may be the main contributor to glenohumeral stability during lifting task. PMID:29244838

Is subscapularis recruited in a similar manner during shoulder internal rotation exercises and belly press and lift off tests?

PubMed

Ginn, Karen A; Reed, Darren; Jones, Chelsea; Downes, Anthony; Cathers, Ian; Halaki, Mark

2017-06-01

Although the belly press and lift off tests are recommended to assess subscapularis function, shoulder internal rotation (IR) exercises performed in other shoulder positions are more commonly used to restore subscapularis function. It is not known if shoulder IR exercises specifically activate subscapularis to the same degree as the lift off and belly press tests, and thus have the potential to effect subscapularis strength gains. Therefore, the aim was to compare subscapularis activation levels with those of other shoulder internal rotator muscles during the belly press and lift off tests and shoulder IR exercise positions. Original research. Twenty asymptomatic volunteers performed maximal isometric contractions during the belly press and lift off tests and shoulder IR performed at 90° and 0° abduction in an upright position and supported at 90° abduction in supine. Muscle activation levels were recorded using a combination of indwelling and surface electrodes. Data were normalized to maximum voluntary contractions and averaged. Moderate average subscapularis activation levels were recorded during all shoulder IR tasks examined with no significant difference between tasks (p=0.18). The belly press test was the only IR task in which subscapularis activation levels were significantly higher than all other shoulder internal rotator muscles (p<0.05). Shoulder IR exercises activate subscapularis to similar moderate levels as the belly press and lift off tests and therefore, have similar potential to strengthen subscapularis. However, the belly press test, with significantly higher subscapularis activation than other shoulder internal rotators, more specifically targets subscapularis. Copyright © 2016. Published by Elsevier Ltd.

Scapulohumeral rhythm in shoulders with reverse shoulder arthroplasty.

PubMed

Walker, David; Matsuki, Keisuke; Struk, Aimee M; Wright, Thomas W; Banks, Scott A

2015-07-01

Little is known about kinematic function of reverse total shoulder arthroplasty (RTSA). Scapulohumeral rhythm (SHR) is a common metric for assessing muscle function and shoulder joint motion. The purpose of this study was to compare SHR in shoulders with RTSA to normal shoulders. Twenty-eight subjects, more than 12 months after unilateral RTSA, were recruited for an Institutional Review Board-approved study. Subjects performed arm abduction in the coronal plane with and without a 1.4-kg hand-held weight. Three-dimensional model-image registration techniques were used to measure orientation and position for the humerus and scapula from fluoroscopic images. Analysis of variance and Tukey tests were used to assess groupwise and pairwise differences. SHR in RTSA shoulders (1.3:1) was significantly lower than in normal shoulders (3:1). Below 30° abduction, RTSA and normal shoulders show a wide range of SHR (1.3:1 to 17:1). Above 30° abduction, SHR in RTSA shoulders was 1.3:1 for unweighted abduction and 1.3:1 for weighted abduction. Maximum RTSA shoulder abduction in weighted trials was lower than in unweighted trials. SHR variability in RTSA shoulders decreased with increasing arm elevation. RTSA shoulders show kinematics that are significantly different from normal shoulders. SHR in RTSA shoulders was significantly lower than in normal shoulders, indicating that RTSA shoulders use more scapulothoracic motion and less glenohumeral motion to elevate the arm. With these observations, it may be possible to improve rehabilitation protocols, with particular attention to the periscapular muscles, and implant design or placement to optimize functional outcomes in shoulders with RTSA. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Muscle strength in breast cancer patients receiving different treatment regimes

PubMed Central

Klassen, Oliver; Schmidt, Martina E.; Ulrich, Cornelia M.; Schneeweiss, Andreas; Potthoff, Karin; Steindorf, Karen

2016-01-01

Abstract Background Muscle dysfunction and sarcopenia have been associated with poor performance status, an increased mortality risk, and greater side effects in oncologic patients. However, little is known about how performance is affected by cancer therapy. We investigated muscle strength in breast cancer patients in different adjuvant treatment settings and also compared it with data from healthy individuals. Methods Breast cancer patients (N = 255) from two randomized controlled exercise trials, staged 0–III and aged 54.4 ± 9.4 years, were categorized into four groups according to their treatment status. In a cross‐sectional design, muscle function was assessed bilaterally by isokinetic dynamometry (0°, 60°, 180°/s) as maximal voluntary isometric contraction (MVIC) and maximal isokinetic peak torque (MIPT) in shoulder rotators and knee flexors and extensors. Additionally, muscular fatigue index (FI%) and shoulder flexibility were evaluated. Healthy women (N = 26), aged 53.3 ± 9.8 years, were tested using the same method. Analysis of covariance was used to estimate the impact of different cancer treatments on skeletal muscle function with adjustment for various clinical and socio‐demographic factors. Results Consistently, lower muscle strength was measured in shoulder and knee strength in patients after chemotherapy. On average, patients had up to 25% lower strength in lower extremities and 12–16% in upper extremities in MVIC and MIPT during cancer treatment compared with healthy women. No substantial difference between patient groups in shoulder strength, but significantly lower shoulder flexibility in patients with radical mastectomy was measured. Chemotherapy‐treated patients had consistently higher FI%. No serious adverse events were reported. Conclusions Breast cancer patients showed markedly impaired muscle strength and joint dysfunctions before and after anticancer treatment. The significant differences between patients and healthy individuals underline the need of exercise therapy as early as possible in order to prevent or counteract the loss of muscle function after curative surgery as well as the consequences of neo‐/adjuvant chemotherapy. PMID:27896952

Multivariate Analyses of Rotator Cuff Pathologies in Shoulder Disability

PubMed Central

Henseler, Jan F.; Raz, Yotam; Nagels, Jochem; van Zwet, Erik W.; Raz, Vered; Nelissen, Rob G. H. H.

2015-01-01

Background Disability of the shoulder joint is often caused by a tear in the rotator cuff (RC) muscles. Four RC muscles coordinate shoulder movement and stability, among them the supraspinatus and infraspinatus muscle which are predominantly torn. The contribution of each RC muscle to tear pathology is not fully understood. We hypothesized that muscle atrophy and fatty infiltration, features of RC muscle degeneration, are predictive of superior humeral head translation and shoulder functional disability. Methods Shoulder features, including RC muscle surface area and fatty infiltration, superior humeral translation and RC tear size were obtained from a consecutive series of Magnetic Resonance Imaging with arthrography (MRA). We investigated patients with superior (supraspinatus, n = 39) and posterosuperior (supraspinatus and infraspinatus, n = 30) RC tears, and patients with an intact RC (n = 52) as controls. The individual or combinatorial contribution of RC measures to superior humeral translation, as a sign of RC dysfunction, was investigated with univariate or multivariate models, respectively. Results Using the univariate model the infraspinatus surface area and fatty infiltration in both the supraspinatus and infraspinatus had a significant contribution to RC dysfunction. With the multivariate model, however, the infraspinatus surface area only affected superior humeral translation (p<0.001) and discriminated between superior and posterosuperior tears. In contrast neither tear size nor fatty infiltration of the supraspinatus or infraspinatus contributed to superior humeral translation. Conclusion Our study reveals that infraspinatus atrophy has the strongest contribution to RC tear pathologies. This suggests a pivotal role for the infraspinatus in preventing shoulder disability. PMID:25710703

Effect of analgesic nerve block electrical stimulation in a patient with adhesive capsulitis.

PubMed

Gulick, Dawn T; Borger, Amy; McNamee, Lauren

2007-01-01

Although the pathophysiology of adhesive capsulitis is poorly understood, the primary goal of therapeutic intervention is to restore pain-free, functional range of motion (ROM) of the shoulder. Pain and muscle guarding, particularly of the subscapularis muscle, are common impairments that occur with adhesive capsulitis. The purpose of this case report is to describe a novel approach to help the pain-muscle guarding-pain cycle associated with pain and limited shoulder motion in a patient with a medical diagnosis of adhesive capsulitis. The patient was a 64-year-old female with adhesive capsulitis. Outcome variables were the Shoulder Pain and Disability Index (SPADI), internal rotation (IR) and external rotation (ER) ROM, and rotational lack. Twelve treatments of moist heat, analgesic nerve block electrical stimulation, contract/relax exercises for shoulder IR/ER, and Pendulum/Codman exercises were administered. After both 2 and 4 weeks of treatment, the patient demonstrated marked improvements in all areas. Overall, there was a 78-106% increase in ROM (IR and ER) and a 50-83% improvement in functional mobility (rotational lack & SPADI). It appears that analgesic electrical stimulation may have helped decrease the pain-muscle guarding cycle associated with adhesive capsulitis to enhance functional outcomes in a timely manner.

Nerve Transfers to Restore Shoulder Function.

PubMed

Leechavengvongs, Somsak; Malungpaishorpe, Kanchai; Uerpairojkit, Chairoj; Ng, Chye Yew; Witoonchart, Kiat

2016-05-01

The restoration of shoulder function after brachial plexus injury represents a significant challenge facing the peripheral nerve surgeons. This is owing to a combination of the complex biomechanics of the shoulder girdle, the multitude of muscles and nerves that could be potentially injured, and a limited number of donor options. In general, nerve transfer is favored over tendon transfer, because the biomechanics of the musculotendinous units are not altered. This article summarizes the surgical techniques and clinical results of nerve transfers for restoration of shoulder function. Copyright © 2016 Elsevier Inc. All rights reserved.

Shoulder functional ratio in elite junior tennis players.

PubMed

Saccol, Michele Forgiarini; Gracitelli, Guilherme Conforto; da Silva, Rogério Teixeira; Laurino, Cristiano Frota de Souza; Fleury, Anna Maria; Andrade, Marília dos Santos; da Silva, Antonio Carlos

2010-02-01

To evaluate shoulder rotation strength and compare the functional ratio between shoulders of elite junior tennis players. This cross-sectional study evaluated muscular rotation performance of 40 junior tennis players (26 male and 14 female) with an isokinetic dynamometer. Strength variables of external (ER) and internal rotators (IR) in concentric and eccentric modes were considered. For the peak torque functional ratio, the eccentric strength of the ER and the concentric strength of the IR were calculated. All variables related to IR were significantly higher on the dominant compared to the non-dominant side in males and females (p<0.05), but only boys exhibited this dominance effect in ER (p<0.05 and p<0.001). Regarding functional ratios, they were significantly lower for the dominant shoulder (p<0.001) and below 1.00 for both groups, indicating that the eccentric strength of the ER was not greater than the concentric strength of the IR. Elite junior tennis players without shoulder injury have shoulder rotation muscle strength imbalances that alter the normal functional ratio between rotator cuff muscles. Although these differences do not seem to affect the athletic performance, detection and prevention with exercise programs at an early age are recommended. Crown Copyright 2009. Published by Elsevier Ltd. All rights reserved.

Effects of spaceflight on the muscles of the murine shoulder.

PubMed

Shen, Hua; Lim, Chanteak; Schwartz, Andrea G; Andreev-Andrievskiy, Alexander; Deymier, Alix C; Thomopoulos, Stavros

2017-12-01

Mechanical loading is necessary for the development and maintenance of the musculoskeletal system. Removal of loading via microgravity, paralysis, or bed rest leads to rapid loss of muscle mass and function; however, the molecular mechanisms that lead to these changes are largely unknown, particularly for the spaceflight (SF) microgravity environment. Furthermore, few studies have explored these effects on the shoulder, a dynamically stabilized joint with a large range of motion; therefore, we examined the effects of microgravity on mouse shoulder muscles for the 15-d Space Transportation System (STS)-131, 13-d STS-135, and 30-d Bion-M1 missions. Mice from STS missions were euthanized within 4 h after landing, whereas mice from the Bion-M1 mission were euthanized within 14 h after landing. The motion-generating deltoid muscle was more sensitive to microgravity than the joint-stabilizing rotator cuff muscles. Mice from the STS-131 mission exhibited reduced myogenic ( Myf5 and -6 ) and adipogenic ( Pparg , Cebpa , and Lep ) gene expression, whereas either no change or an increased expression of these genes was observed in mice from the Bion-M1 mission. In summary, muscle responses to microgravity were muscle-type specific, short-duration SF caused dramatic molecular changes to shoulder muscles and responses to reloading upon landing were rapid.-Shen, H., Lim, C., Schwartz, A. G., Andreev-Andrievskiy, A., Deymier, A. C., Thomopoulos, S. Effects of spaceflight on the muscles of the murine shoulder. © FASEB.

Neural crest does not contribute to the neck and shoulder in the axolotl (Ambystoma mexicanum).

PubMed

Epperlein, Hans-Henning; Khattak, Shahryar; Knapp, Dunja; Tanaka, Elly M; Malashichev, Yegor B

2012-01-01

A major step during the evolution of tetrapods was their transition from water to land. This process involved the reduction or complete loss of the dermal bones that made up connections to the skull and a concomitant enlargement of the endochondral shoulder girdle. In the mouse the latter is derived from three separate embryonic sources: lateral plate mesoderm, somites, and neural crest. The neural crest was suggested to sustain the muscle attachments. How this complex composition of the endochondral shoulder girdle arose during evolution and whether it is shared by all tetrapods is unknown. Salamanders that lack dermal bone within their shoulder girdle were of special interest for a possible contribution of the neural crest to the endochondral elements and muscle attachment sites, and we therefore studied them in this context. We grafted neural crest from GFP+ fluorescent transgenic axolotl (Ambystoma mexicanum) donor embryos into white (d/d) axolotl hosts and followed the presence of neural crest cells within the cartilage of the shoulder girdle and the connective tissue of muscle attachment sites of the neck-shoulder region. Strikingly, neural crest cells did not contribute to any part of the endochondral shoulder girdle or to the connective tissue at muscle attachment sites in axolotl. Our results in axolotl suggest that neural crest does not serve a general function in vertebrate shoulder muscle attachment sites as predicted by the "muscle scaffold theory," and that it is not necessary to maintain connectivity of the endochondral shoulder girdle to the skull. Our data support the possibility that the contribution of the neural crest to the endochondral shoulder girdle, which is observed in the mouse, arose de novo in mammals as a developmental basis for their skeletal synapomorphies. This further supports the hypothesis of an increased neural crest diversification during vertebrate evolution.

Neural Crest Does Not Contribute to the Neck and Shoulder in the Axolotl (Ambystoma mexicanum)

PubMed Central

Epperlein, Hans-Henning; Khattak, Shahryar; Knapp, Dunja; Tanaka, Elly M.; Malashichev, Yegor B.

2012-01-01

Background A major step during the evolution of tetrapods was their transition from water to land. This process involved the reduction or complete loss of the dermal bones that made up connections to the skull and a concomitant enlargement of the endochondral shoulder girdle. In the mouse the latter is derived from three separate embryonic sources: lateral plate mesoderm, somites, and neural crest. The neural crest was suggested to sustain the muscle attachments. How this complex composition of the endochondral shoulder girdle arose during evolution and whether it is shared by all tetrapods is unknown. Salamanders that lack dermal bone within their shoulder girdle were of special interest for a possible contribution of the neural crest to the endochondral elements and muscle attachment sites, and we therefore studied them in this context. Results We grafted neural crest from GFP+ fluorescent transgenic axolotl (Ambystoma mexicanum) donor embryos into white (d/d) axolotl hosts and followed the presence of neural crest cells within the cartilage of the shoulder girdle and the connective tissue of muscle attachment sites of the neck-shoulder region. Strikingly, neural crest cells did not contribute to any part of the endochondral shoulder girdle or to the connective tissue at muscle attachment sites in axolotl. Conclusions Our results in axolotl suggest that neural crest does not serve a general function in vertebrate shoulder muscle attachment sites as predicted by the “muscle scaffold theory,” and that it is not necessary to maintain connectivity of the endochondral shoulder girdle to the skull. Our data support the possibility that the contribution of the neural crest to the endochondral shoulder girdle, which is observed in the mouse, arose de novo in mammals as a developmental basis for their skeletal synapomorphies. This further supports the hypothesis of an increased neural crest diversification during vertebrate evolution. PMID:23300623

Effects of 6-week sling-based training of the external-rotator muscles on the shoulder profile in elite female high school handball players.

PubMed

Genevois, Cyril; Berthier, Philippe; Guidou, Vincent; Muller, Franck; Thiebault, Boris; Rogowski, Isabelle

2014-11-01

In women's handball, the large numbers of throws and passes make the shoulder region vulnerable to overuse injuries. Repetitive throwing motions generate imbalance between shoulder internal- and external-rotator muscles. It has not yet been established whether sling-based training can improve shoulder external-rotator muscle strength. This study investigated the effectiveness of a 6-wk strengthening program in improving shoulder functional profile in elite female high school handball players. Crossover study. National elite handball training center. 25 elite female high school handball players. The program, completed twice per week for 6 wk, included sling-based strengthening exercises using a suspension trainer for external rotation with scapular retraction and scapular retraction alone. Maximal shoulder external- and internal-rotation strength, shoulder external- and internal-rotation range of motion (ROM), and maximal throwing velocity were assessed preintervention and postintervention for dominant and nondominant sides. After sling training, external- and internal-rotation strength increased significantly for both sides (P ≤ .001, and P = .004, respectively), with the result that there was no significant change in external- and internal-rotation strength ratios for either the dominant or the nondominant shoulder. No significant differences were observed for external-rotation ROM, while internal-rotation ROM decreased moderately, in particular in the dominant shoulder (P = .005). Maximal throwing velocity remained constant for the dominant arm, whereas a significant increase was found for the nondominant arm (P = .017). This 6-wk strengthening program was effective in improving shoulder external-rotator muscle strength but resulted in a decrease in the ROM in shoulder internal rotation, while throwing velocity remained stable. Adding a stretching program to this type of sling-based training program might help avoid potential detrimental effects on shoulder ROM.

Changes in shoulder muscle activity pattern on surface electromyography after breast cancer surgery.

PubMed

Yang, Eun Joo; Kwon, YoungOk

2018-02-01

Alterations in muscle activation and restricted shoulder mobility, which are common in breast cancer patients, have been found to affect upper limb function. The purpose of this study was to determine muscle activity patterns, and to compare the prevalence of abnormal patterns among the type of breast surgery. In total, 274 breast cancer patients were recruited after surgery. Type of breast surgery was divided into mastectomy without reconstruction (Mastectomy), reconstruction with tissue expander/implant (TEI), latissimus dorsi (LD) flap, or transverse rectus abdominis flap (TRAM). Activities of shoulder muscles were measured using surface electromyography. Experimental analysis was conducted using a Gaussian filter smoothing method with regression. Patients demonstrated different patterns of muscle activation, such as normal, lower muscle electrical activity, and tightness. After adjusting for BMI and breast surgery, the odds of lower muscle electrical activity and tightness in the TRAM are 40.2% and 38.4% less than in the Mastectomy only group. The prevalence of abnormal patterns was significantly greater in the ALND than SLNB in all except TRAM. Alterations in muscle activity patterns differed by breast surgery and reconstruction type. For breast cancer patients with ALND, TRAM may be the best choice for maintaining upper limb function. © 2017 Wiley Periodicals, Inc.

Anatomy of Shoulder Girdle Muscle Modifications and Walking Adaptation in the Scaly Chinese Pangolin (Manis Pentadactyla Pentadactyla: Pholidota) Compared with the Partially Osteoderm-Clad Armadillos (Dasypodidae).

PubMed

Kawashima, Tomokazu; Thorington, Richard W; Bohaska, Paula W; Chen, Yen-Jean; Sato, Fumi

2015-07-01

Because pangolins are unique mammals with a body and limbs almost entirely sheathed in hard keratinous overlapping scales and with digging and climbing abilities, the shoulder girdle muscles may differ significantly from those of other mammals including the partially osteoderm-clad armadillos. Therefore, we conducted a functional anatomical study of the shoulder girdle muscles in Chinese pangolins (Manis pentadactyla pentadactyla, Pholidota) and some armadillo species (Dasypodidae). Our CT scans revealed that the pangolin's overlapping scales are hard structures completely encasing the limbs. The armadillo's limbs, however, are covered with small relatively soft non-overlapping scales embedded in the skin, and articulate completely free of the hard osteodermal carapace. The attachments of some shoulder girdle muscles in the pangolin have moved from the surrounding edges of the scapula to the spine, and they, therefore, fully cover the scapula. In addition, some pangolin shoulder girdle muscles cross the shoulder joint to insert on the distal humerus, but this does not occur in armadillos. We cannot rule out the possibility that these muscle modifications represent adaptations for digging and/or climbing in pangolins. Our results and previous literature do not establish specific links between them and locomotive modes. However, we propose that the Chinese pangolin may use its derived muscular features when walking to move its armor-restricted forelimbs more effectively by swinging its head from side to side. © 2015 Wiley Periodicals, Inc.

Contributions of muscle imbalance and impaired growth to postural and osseous shoulder deformity following brachial plexus birth palsy: a computational simulation analysis.

PubMed

Cheng, Wei; Cornwall, Roger; Crouch, Dustin L; Li, Zhongyu; Saul, Katherine R

2015-06-01

Two potential mechanisms leading to postural and osseous shoulder deformity after brachial plexus birth palsy are muscle imbalance between functioning internal rotators and paralyzed external rotators and impaired longitudinal growth of paralyzed muscles. Our goal was to evaluate the combined and isolated effects of these 2 mechanisms on transverse plane shoulder forces using a computational model of C5-6 brachial plexus injury. We modeled a C5-6 injury using a computational musculoskeletal upper limb model. Muscles expected to be denervated by C5-6 injury were classified as affected, with the remaining shoulder muscles classified as unaffected. To model muscle imbalance, affected muscles were given no resting tone whereas unaffected muscles were given resting tone at 30% of maximal activation. To model impaired growth, affected muscles were reduced in length by 30% compared with normal whereas unaffected muscles remained normal in length. Four scenarios were simulated: normal, muscle imbalance only, impaired growth only, and both muscle imbalance and impaired growth. Passive shoulder rotation range of motion and glenohumeral joint reaction forces were evaluated to assess postural and osseous deformity. All impaired scenarios exhibited restricted range of motion and increased and posteriorly directed compressive glenohumeral joint forces. Individually, impaired muscle growth caused worse restriction in range of motion and higher and more posteriorly directed glenohumeral forces than did muscle imbalance. Combined muscle imbalance and impaired growth caused the most restricted joint range of motion and the highest joint reaction force of all scenarios. Both muscle imbalance and impaired longitudinal growth contributed to range of motion and force changes consistent with clinically observed deformity, although the most substantial effects resulted from impaired muscle growth. Simulations suggest that treatment strategies emphasizing treatment of impaired longitudinal growth are warranted for reducing deformity after brachial plexus birth palsy. Copyright © 2015 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

High prevalence of shoulder girdle muscles with myofascial trigger points in patients with shoulder pain

PubMed Central

2011-01-01

Background Shoulder pain is reported to be highly prevalent and tends to be recurrent or persistent despite medical treatment. The pathophysiological mechanisms of shoulder pain are poorly understood. Furthermore, there is little evidence supporting the effectiveness of current treatment protocols. Although myofascial trigger points (MTrPs) are rarely mentioned in relation to shoulder pain, they may present an alternative underlying mechanism, which would provide new treatment targets through MTrP inactivation. While previous research has demonstrated that trained physiotherapists can reliably identify MTrPs in patients with shoulder pain, the percentage of patients who actually have MTrPs remains unclear. The aim of this observational study was to assess the prevalence of muscles with MTrPs and the association between MTrPs and the severity of pain and functioning in patients with chronic non-traumatic unilateral shoulder pain. Methods An observational study was conducted. Subjects were recruited from patients participating in a controlled trial studying the effectiveness of physical therapy on patients with unilateral non-traumatic shoulder pain. Sociodemographic and patient-reported symptom scores, including the Disabilities of the Arm, Shoulder, and Hand (DASH) Questionnaire, and Visual Analogue Scales for Pain were compared with other studies. To test for differences in age, gender distribution, and education level between the current study population and the populations from Dutch shoulder studies, the one sample T-test was used. One observer examined all subjects (n = 72) for the presence of MTrPs. Frequency distributions, means, medians, standard deviations, and 95% confidence intervals were calculated for descriptive purposes. The Spearman's rank-order correlation (ρ) was used to test for association between variables. Results MTrPs were identified in all subjects. The median number of muscles with MTrPs per subject was 6 (active MTrPs) and 4 (latent MTrPs). Active MTrPs were most prevalent in the infraspinatus (77%) and the upper trapezius muscles (58%), whereas latent MTrPs were most prevalent in the teres major (49%) and anterior deltoid muscles (38%). The number of muscles with active MTrPs was only moderately correlated with the DASH score. Conclusion The prevalence of muscles containing active and latent MTrPs in a sample of patients with chronic non-traumatic shoulder pain was high. PMID:21711512

Effect of a worktable position on head and shoulder posture and shoulder muscles in manual material handling.

PubMed

Kim, Min-Hee; Yoo, Won-Gyu

2015-06-05

According to a recent research, manual working with high levels of static contraction, repetitive loads, or extreme working postures involving the neck and shoulder muscles causes an increased risk of neck and shoulder musculoskeletal disorders. We investigated the effects of the forwardly worktable position on head and shoulder angles and shoulder muscle activity in manual material handling tasks. The forward head and shoulder angles and the activity of upper trapezius, levator scapulae, and middle deltoid muscle activities of 15 workers were measured during performing of manual material handling in two tasks that required different forward head and shoulder angles. The second manual material task required a significantly increased forward head and shoulder angle. The upper trapezius and levator scapulae muscle activity in second manual material task was increased significantly compared with first manual material task. The middle deltoid muscle activity in second manual material task was not significantly different compared with first manual material task. Based on this result, the forward head and shoulder angles while performing manual work need to be considered in selection of the forward distance of a worktable form the body. The high level contractions of the neck and shoulder muscles correlated with neck and shoulder pain. Therefore, the forward distance of a worktable can be an important factor in preventing neck and shoulder pain in manual material handling workers.

Scapular Bracing and Alteration of Posture and Muscle Activity in Overhead Athletes With Poor Posture

PubMed Central

Cole, Ashley K; McGrath, Melanie L; Harrington, Shana E; Padua, Darin A; Rucinski, Terri J; Prentice, William E

2013-01-01

Context Overhead athletes commonly have poor posture. Commercial braces are used to improve posture and function, but few researchers have examined the effects of shoulder or scapular bracing on posture and scapular muscle activity. Objective To examine whether a scapular stabilization brace acutely alters posture and scapular muscle activity in healthy overhead athletes with forward-head, rounded-shoulder posture (FHRSP). Design Randomized controlled clinical trial. Setting Applied biomechanics laboratory. Patients or Other Participants Thirty-eight healthy overhead athletes with FHRSP. Intervention(s) Participants were assigned randomly to 2 groups: compression shirt with no strap tension (S) and compression shirt with the straps fully tensioned (S + T). Posture was measured using lateral-view photography with retroreflective markers. Electromyography (EMG) of the upper trapezius (UT), middle trapezius (MT), lower trapezius (LT), and serratus anterior (SA) in the dominant upper extremity was measured during 4 exercises (scapular punches, W's, Y's, T's) and 2 glenohumeral motions (forward flexion, shoulder extension). Posture and exercise EMG measurements were taken with and without the brace applied. Main Outcome Measure(s) Head and shoulder angles were measured from lateral-view digital photographs. Normalized surface EMG was used to assess mean muscle activation of the UT, MT, LT, and SA. Results Application of the brace decreased forward shoulder angle in the S + T condition. Brace application also caused a small increase in LT EMG during forward flexion and Y's and a small decrease in UT and MT EMG during shoulder extension. Brace application in the S + T group decreased UT EMG during W's, whereas UT EMG increased during W's in the S group. Conclusions Application of the scapular brace improved shoulder posture and scapular muscle activity, but EMG changes were highly variable. Use of a scapular brace might improve shoulder posture and muscle activity in overhead athletes with poor posture. PMID:23672321

Semiparametric Identification of Human Arm Dynamics for Flexible Control of a Functional Electrical Stimulation Neuroprosthesis

PubMed Central

Schearer, Eric M.; Liao, Yu-Wei; Perreault, Eric J.; Tresch, Matthew C.; Memberg, William D.; Kirsch, Robert F.; Lynch, Kevin M.

2016-01-01

We present a method to identify the dynamics of a human arm controlled by an implanted functional electrical stimulation neuroprosthesis. The method uses Gaussian process regression to predict shoulder and elbow torques given the shoulder and elbow joint positions and velocities and the electrical stimulation inputs to muscles. We compare the accuracy of torque predictions of nonparametric, semiparametric, and parametric model types. The most accurate of the three model types is a semiparametric Gaussian process model that combines the flexibility of a black box function approximator with the generalization power of a parameterized model. The semiparametric model predicted torques during stimulation of multiple muscles with errors less than 20% of the total muscle torque and passive torque needed to drive the arm. The identified model allows us to define an arbitrary reaching trajectory and approximately determine the muscle stimulations required to drive the arm along that trajectory. PMID:26955041

Shoulder External Rotation Fatigue and Scapular Muscle Activation and Kinematics in Overhead Athletes

PubMed Central

Joshi, Mithun; Thigpen, Charles A.; Bunn, Kevin; Karas, Spero G.; Padua, Darin A.

2011-01-01

Context: Glenohumeral external rotation (GH ER) muscle fatigue might contribute to shoulder injuries in overhead athletes. Few researchers have examined the effect of such fatigue on scapular kinematics and muscle activation during a functional movement pattern. Objective: To examine the effects of GH ER muscle fatigue on upper trapezius, lower trapezius, serratus anterior, and infraspinatus muscle activation and to examine scapular kinematics during a diagonal movement task in overhead athletes. Setting: Human performance research laboratory. Design: Descriptive laboratory study. Patients or Other Participants: Our study included 25 overhead athletes (15 men, 10 women; age = 20 ± 2 years, height = 180 ± 11 cm, mass = 80 ± 11 kg) without a history of shoulder pain on the dominant side. Interventions: We tested the healthy, dominant shoulder through a diagonal movement task before and after a fatiguing exercise involving low-resistance, high-repetition, prone GH ER from 0° to 75° with the shoulder in 90° of abduction. Main Outcome Measure(s): Surface electromyography was used to measure muscle activity for the upper trapezius, lower trapezius, serratus anterior, and infraspinatus. An electromyographic motion analysis system was used to assess 3-dimensional scapular kinematics. Repeated-measures analyses of variance (phase × condition) were used to test for differences. Results: We found a decrease in ascending-phase and descending-phase lower trapezius activity (F1,25 = 5.098, P = .03) and an increase in descending-phase infraspinatus activity (F1,25 = 5.534, P = .03) after the fatigue protocol. We also found an increase in scapular upward rotation (F1,24 = 3.7, P = .04) postfatigue. Conclusions: The GH ER muscle fatigue protocol used in this study caused decreased lower trapezius and increased infraspinatus activation concurrent with increased scapular upward rotation range of motion during the functional task. This highlights the interdependence of scapular and glenohumeral force couples. Fatigue-induced alterations in the lower trapezius might predispose the infraspinatus to injury through chronically increased activation. PMID:21944066

Development of the shoulder girdle musculature.

PubMed

Pu, Qin; Huang, Ruijin; Brand-Saberi, Beate

2016-03-01

The muscles of the shoulder region are important for movements of the upper limbs and for stabilizing the girdle elements by connecting them to the trunk. They have a triple embryonic origin. First, the branchiomeric shoulder girdle muscles (sternocleidomastoideus and trapezius muscles) develop from the occipital lateral plate mesoderm using Tbx1 over the course of this development. The second population of cells constitutes the superficial shoulder girdle muscles (pectoral and latissimus dorsi muscles), which are derived from the wing premuscle mass. This muscle group undergoes a two-step development, referred to as the "in-out" mechanism. Myogenic precursor cells first migrate anterogradely into the wing bud. Subsequently, they migrate in a retrograde manner from the wing premuscle mass to the trunk. SDF-1/CXCR4 signaling is involved in this outward migration. A third group of shoulder muscles are the rhomboidei and serratus anterior muscles, which are referred to as deep shoulder girdle muscles; they are thought to be derived from the myotomes. It is, however, not clear how myotome cells make contact to the scapula to form these two muscles. In this review, we discuss the development of the shoulder girdle muscle in relation to the different muscle groups. © 2015 Wiley Periodicals, Inc.

Three-dimensional analysis of the shoulder motion in patients with massive irreparable cuff tears after latissimus dorsi tendon transfer (LDT).

PubMed

Ippolito, Giorgio; Serrao, Mariano; Napoli, Francesco; Conte, Carmela; Miscusi, Massimo; Coppola, Gianluca; Pierelli, Francesco; Costanzo, Giuseppe; De Cupis, Vincenzo

2016-10-01

Latissimus dorsi tendon transfer (LDT) is a recent method for surgical treatment of massive, irreparable posterosuperior cuff tears (MIPCT). So far, there are no studies on the quantitative motion analysis of the shoulder and latissimus dorsi (LD) muscle activation after LDT. The changes in shoulder movements after LDT can be objectively assessed by the 3-D motion analysis. These changes may not be due to an increased activity of the LD muscle as external rotator. The shoulder kinematics of nine patients with MIPCT were recorded through a 3-D motion analysis system, before LTD (T0), and after 3 (T1) and 6 (T2) months post-LDT. Maximal shoulder flexion-extension, abduction-adduction, and horizontal abduction-adduction, and the internal and external circumduction of the shoulder joint were measured during upright standing posture. Surface EMG activity of the LD muscle was recorded during both internal rotation (IR) and external rotation (ER) tasks in three different postures. A significant increase of shoulder movements was observed at T2 compared with T0 for almost all motor tasks. A significant effect of LDT was also found on LD-IR/ER ratio in posture 1 at T2 compared with T0 and T1. No significant effects were found for the LD-IR/ER ratio in the other postures. Our study indicates that LDT is effective in shoulder motion recovery. Such improvement is not associated with a change in function of the LD muscle, which may be induced by a depression of the humeral head into the glenoid cavity instead.

Reverse shoulder arthroplasty for deltoid-deficient shoulder following latissimus dorsi flap transfer. Case report.

PubMed

Dosari, Mohamed Al Ateeq Al; Hameed, Shamsi; Mukhtar, Khalid; Elmhiregh, Aissam

2017-01-01

The usual indication for reverse shoulder arthroplasty is glenohumeral arthritis with inadequate rotator cuff and intact deltoid muscle. We report here a case of reverse shoulder arthroplasty using a lattisimus dorsi flap in a patient with deltoid-deficient shoulder following a gunshot injury. The patient was an otherwise healthy 51-year-old male with a history of gunshot injury of the left shoulder 2006. Upon presentation in 2011, the patient had a loss of most of his shoulder bony and muscular structures. Due to deltoid muscle deficiency, the patient underwent Lattisimus Dorsi muscle flap followed by reverse shoulder arthroplasty in order to establish an upper limb function. Upon discharge, 11days after the surgery, the patient was able to achieve 150° flexion and 90° abduction while in the supine position and 45° in each direction, while sitting. He was able to perform internal rotation (behind back) up to the level of the L1 vertebra, assisted active abduction of 90°, and external rotation of 20°. Power tests showed power of grade 4/5 for both shoulder flexion and extension and grade 2+/5 for both abduction and adduction. At the last follow up one year after the operation, The patient still had passive pain-free full range of motion, but no progress in active range of motion beyond that upon discharge. Reverse shoulder arthroplasty after Latissmus dori flap in patient with deltoid deficient shoulders can be a successful and reproducible approach to treat such conditions. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Arthrographic and clinical findings in patients with hemiplegic shoulder pain.

PubMed

Lo, Sui-Foon; Chen, Shu-Ya; Lin, Hsiu-Chen; Jim, Yick-Fung; Meng, Nai-Hsin; Kao, Mu-Jung

2003-12-01

To identify the etiology of hemiplegic shoulder pain by arthrographic and clinical examinations and to determine the correlation between arthrographic measurements and clinical findings in patients with hemiplegic shoulder pain. Case series. Medical center of a 1582-bed teaching institution in Taiwan. Thirty-two consecutive patients with hemiplegic shoulder pain within a 1-year period after first stroke were recruited. Not applicable. Clinical examinations included Brunnstrom stage, muscle spasticity distribution, presence or absence of subluxation and shoulder-hand syndrome, and passive range of motion (PROM) of the shoulder joint. Arthrographic measurements included shoulder joint volume and capsular morphology. Most patients had onset of hemiplegic shoulder pain less than 2 months after stroke. Adhesive capsulitis was the main cause of shoulder pain, with 50% of patients having adhesive capsulitis, 44% having shoulder subluxation, 22% having rotator cuff tears, and 16% having shoulder-hand syndrome. Patients with adhesive capsulitis showed significant restriction of passive shoulder external rotation and abduction and a higher incidence of shoulder-hand syndrome (P=.017). Those with irregular capsular margins had significantly longer shoulder pain duration and more restricted passive shoulder flexion (P=.017) and abduction (P=.020). Patients with shoulder subluxation had significantly larger PROM (flexion, P=.007; external rotation, P<.001; abduction, P=.001; internal rotation, P=.027), lower muscle tone (P=.001), and lower Brunnstrom stages of the proximal upper extremity (P=.025) and of the distal upper extremity (P=.001). Muscle spasticity of the upper extremity was slightly negatively correlated with shoulder PROM. Shoulder joint volume was moderately positively correlated with shoulder PROM. After investigating the hemiplegic shoulder joint through clinical and arthrographic examinations, we found that the causes of hemiplegic shoulder pain are complicated. Adhesive capsulitis was the leading cause of shoulder pain, followed by shoulder subluxation. Greater PROM of the shoulder joint, associated with larger joint volume, decreased the occurrence of adhesive capsulitis. Proper physical therapy and cautious handling of stroke patients to preserve shoulder mobility and function during early rehabilitation are important for a good outcome.

Scapular kinematic and shoulder muscle activity alterations after serratus anterior muscle fatigue.

PubMed

Umehara, Jun; Kusano, Ken; Nakamura, Masatoshi; Morishita, Katsuyuki; Nishishita, Satoru; Tanaka, Hiroki; Shimizu, Itsuroh; Ichihashi, Noriaki

2018-02-23

Although the serratus anterior muscle has an important role in scapular movement, no study to date has investigated the effect of serratus anterior fatigue on scapular kinematics and shoulder muscle activity. The purpose of this study was to clarify the effect of serratus anterior fatigue on scapular movement and shoulder muscle activity. The study participants were 16 healthy men. Electrical muscle stimulation was used to fatigue the serratus anterior muscle. Shoulder muscle strength and endurance, scapular movement, and muscle activity were measured before and after the fatigue task. The muscle activity of the serratus anterior, upper and lower trapezius, anterior and middle deltoid, and infraspinatus muscles was recorded, and the median power frequency of these muscles was calculated to examine the degree of muscle fatigue. The muscle endurance and median power frequency of the serratus anterior muscle decreased after the fatigue tasks, whereas the muscle activities of the serratus anterior, upper trapezius, and infraspinatus muscles increased. External rotation of the scapula at the shoulder elevated position increased after the fatigue task. Selective serratus anterior fatigue due to electric muscle stimulation decreased the serratus anterior endurance at the flexed shoulder position. Furthermore, the muscle activities of the serratus anterior, upper trapezius, and infraspinatus increased and the scapular external rotation was greater after serratus anterior fatigue. These results suggest that the rotator cuff and scapular muscle compensated to avoid the increase in internal rotation of the scapula caused by the dysfunction of the serratus anterior muscle. Copyright © 2018 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Recovery of Muscle Strength After Intact Arthroscopic Rotator Cuff Repair According to Preoperative Rotator Cuff Tear Size.

PubMed

Shin, Sang-Jin; Chung, Jaeyoon; Lee, Juyeob; Ko, Young-Won

2016-04-01

The recovery of muscle strength after arthroscopic rotator cuff repair based on the preoperative tear size has not yet been well described. The purpose of this study was to evaluate the recovery period of muscle strength by a serial assessment of isometric strength after arthroscopic rotator cuff repair based on the preoperative tear size. The hypothesis was that muscle strength in patients with small and medium tears would recover faster than that in those with large-to-massive tears. Cohort study; Level of evidence, 3. A total of 164 patients who underwent arthroscopic rotator cuff repair were included. Isometric strength in forward flexion (FF), internal rotation (IR), and external rotation (ER) was evaluated preoperatively and at 6, 12, 18, and 24 months after surgery. Preoperative magnetic resonance imaging scans were assessed to evaluate the quality of the rotator cuff muscle, including fatty infiltration, occupation ratio, and tangent sign. Patient satisfaction as well as visual analog scale (VAS) for pain, American Shoulder and Elbow Surgeons (ASES), and Constant scores were assessed at every follow-up. Muscle strength demonstrated the slowest recovery in pain relief and the restoration of shoulder function. To reach the strength of the uninjured contralateral shoulder in all 3 planes of motion, recovery took 6 months in patients with small tears and 18 months in patients with medium tears. Patients with large-to-massive tears showed continuous improvement in strength up to 18 months; however, they did not reach the strength of the contralateral shoulder at final follow-up. At final follow-up, mean strength in FF, IR, and ER was 113.0%, 118.0%, and 112.6% of the contralateral shoulder in patients with small tears, respectively; 105.0%, 112.1%, and 102.6% in patients with medium tears, respectively; and 87.6%, 89.5%, and 85.2% in patients with large-to-massive tears, respectively. Muscle strength in any direction did not significantly correlate with postoperative patient satisfaction (P = .374, .515, and .692 for FF, IR, and ER, respectively), whereas it highly correlated with preoperative quality of the muscle. The recovery of muscle strength after arthroscopic repair was poorly correlated with patient satisfaction. This study recommends that regardless of pain relief and improved shoulder function, patients with larger than medium tears should be encouraged to continue with rehabilitation for the maximal restoration of muscle strength beyond 1 year postoperatively. © 2016 The Author(s).

Axillary nerve injury.

PubMed

Perlmutter, G S

1999-11-01

Axillary nerve injury remains the most common peripheral nerve injury to affect the shoulder. It most often is seen after glenohumeral joint dislocation, proximal humerus fracture, or a direct blow to the deltoid muscle. Compression neuropathy has been reported to occur in the quadrilateral space syndrome, although the true pathophysiology of this disorder remains unclear. The axillary nerve is vulnerable during any operative procedure involving the inferior aspect of the shoulder and iatrogenic injury remains a serious complication of shoulder surgery. During the acute phase of injury, the shoulder should be rested, and when clinically indicated, a patient should undergo an extensive rehabilitation program emphasizing range of motion and strengthening of the shoulder girdle muscles. If no axillary nerve recovery is observed by 3 to 6 months after injury, surgical exploration may be indicated, especially if the mechanism of injury is consistent with nerve rupture. Patients who sustain injury to the axillary nerve have a variable prognosis for nerve recovery although return of function of the involved shoulder typically is good to excellent, depending on associated ligamentous or bony injury.

Parecoxib increases muscle pain threshold and relieves shoulder pain after gynecologic laparoscopy: a randomized controlled trial.

PubMed

Zhang, Hufei; Liu, Xinhe; Jiang, Hongye; Liu, Zimeng; Zhang, Xu-Yu; Xie, Hong-Zhe

2016-01-01

Postlaparoscopic shoulder pain (PLSP) remains a common problem after laparoscopies. The aim of this study was to investigate the correlation between pressure pain threshold (PPT) of different muscles and PLSP after gynecologic laparoscopy, and to explore the effect of parecoxib, a cyclooxygenase-2 inhibitor, on the changes of PPT. The patients were randomly allocated into two groups; group P and group C. In group P, parecoxib 40 mg was intravenously infused at 30 minutes before surgery and 8 and 20 hours after surgery. In group C, normal saline was infused at the corresponding time point. PPT assessment was performed 1 day before surgery and at postoperative 24 hours by using a pressure algometer at bilateral shoulder muscles (levator scapulae and supraspinatus) and forearm (flexor carpi ulnaris). Meanwhile, bilateral shoulder pain was evaluated through visual analog scale score at 24 hours after surgery. Preoperative PPT level of the shoulder, but not of the forearm, was significantly and negatively correlated with the intensity of ipsilateral PLSP. In group C, PPT levels of shoulder muscles, but not of forearm muscles, decreased after laparoscopy at postoperative 24 hours. The use of parecoxib significantly improved the decline of PPT levels of bilateral shoulder muscles (all P <0.01). Meanwhile, parecoxib reduced the incidence of PLSP (group P: 45% vs group C: 83.3%; odds ratio: 0.164; 95% confidence interval: 0.07-0.382; P <0.001) and the intensity of bilateral shoulder pain (both P <0.01). Preoperative PPT levels of shoulder muscles are closely associated with the severity of shoulder pain after gynecologic laparoscopy. PPT levels of shoulder muscles, but not of forearm muscles, significantly decreased after surgery. Parecoxib improved the decrease of PPT and relieved PLSP.

Effects of two stretching methods on shoulder range of motion and muscle stiffness in baseball players with posterior shoulder tightness: a randomized controlled trial.

PubMed

Yamauchi, Taishi; Hasegawa, Satoshi; Nakamura, Masatoshi; Nishishita, Satoru; Yanase, Ko; Fujita, Kosuke; Umehara, Jun; Ji, Xiang; Ibuki, Satoko; Ichihashi, Noriaki

2016-09-01

The cross-body stretch and sleeper stretch are widely used for improving flexibility of the posterior shoulder. These stretching methods were modified by Wilk. However, few quantitative data are available on the new, modified stretching methods. A recent study reported the immediate effects of stretching and soft tissue mobilization on the shoulder range of motion (ROM) and muscle stiffness in subjects with posterior shoulder tightness. However, the long-term effect of stretching for muscle stiffness is unknown. The objective of this study was to examine the effects of 2 stretching methods, the modified cross-body stretch (MCS) and the modified sleeper stretch (MSS), on shoulder ROM and muscle stiffness in baseball players with posterior shoulder tightness. Twenty-four college baseball players with ROM limitations in shoulder internal rotation were randomly assigned to the MCS or MSS group. We measured shoulder internal rotation and horizontal adduction ROM and assessed posterior shoulder muscle stiffness with ultrasonic shear wave elastography before and after a 4-week intervention. Subjects were asked to perform 3 repetitions of the stretching exercises every day, for 30 seconds, with their dominant shoulder. In both groups, shoulder internal rotation and horizontal adduction ROM were significantly increased after the 4-week intervention. Muscle stiffness of the teres minor decreased in the MCS group, and that of the infraspinatus decreased in the MSS group. The MCS and MSS are effective for increasing shoulder internal rotation and horizontal adduction ROM and decreasing muscle stiffness of the infraspinatus or teres minor. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

38 CFR 4.73 - Schedule of ratings-muscle injuries.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 5302Group II. Function: Depression of arm from vertical overhead to hanging at side (1, 2); downward... muscles of shoulder girdle: (1) Pectoralis major II (costosternal); (2) latissimus dorsi and teres major (teres major, although technically an intrinsic muscle, is included with latissimus dorsi); (3...

38 CFR 4.73 - Schedule of ratings-muscle injuries.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 5302Group II. Function: Depression of arm from vertical overhead to hanging at side (1, 2); downward... muscles of shoulder girdle: (1) Pectoralis major II (costosternal); (2) latissimus dorsi and teres major (teres major, although technically an intrinsic muscle, is included with latissimus dorsi); (3...

38 CFR 4.73 - Schedule of ratings-muscle injuries.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 5302Group II. Function: Depression of arm from vertical overhead to hanging at side (1, 2); downward... muscles of shoulder girdle: (1) Pectoralis major II (costosternal); (2) latissimus dorsi and teres major (teres major, although technically an intrinsic muscle, is included with latissimus dorsi); (3...

38 CFR 4.73 - Schedule of ratings-muscle injuries.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 5302Group II. Function: Depression of arm from vertical overhead to hanging at side (1, 2); downward... muscles of shoulder girdle: (1) Pectoralis major II (costosternal); (2) latissimus dorsi and teres major (teres major, although technically an intrinsic muscle, is included with latissimus dorsi); (3...

38 CFR 4.73 - Schedule of ratings-muscle injuries.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 5302Group II. Function: Depression of arm from vertical overhead to hanging at side (1, 2); downward... muscles of shoulder girdle: (1) Pectoralis major II (costosternal); (2) latissimus dorsi and teres major (teres major, although technically an intrinsic muscle, is included with latissimus dorsi); (3...

Acromiohumeral Distance Change Relates to Middle Trapezius Muscle Activation During Shoulder Elevation With Scapular Retraction.

PubMed

Guney-Deniz, Hande; Harput, Gulcan; Toprak, Ugur; Duzgun, Irem

2018-05-29

The scapular retraction exercises are widely used among clinicians to balance the activity of the scapular muscles as well as the rotator cuff muscles in different shoulder abduction positions. The aim of this study was to investigate the relationship between scapular (middle and upper trapezius) and shoulder muscles (middle deltoid and infraspinatus) activation level differences and acromiohumeral distance changes during shoulder abduction with scapular retraction. Cross-sectional study. University research laboratory. Nineteen asymptomatic individuals were included (mean ± SD age, 22.4 ± 1.8 years). The acromiohumeral distance was measured at 0° and 90° shoulder abduction when scapula was in non-retracted and retracted position with ultrasound imaging. The relationship between muscle activation level changes and acromiohumeral distance difference was analyzed with Pearson correlation test. Middle trapezius muscle activity change correlated with acromiohumeral distance difference (r=0.55, p=0.018) from 0º to 90º shoulder abduction when scapula was retracted. For both non-retracted and retracted scapular positions, no correlations were found between middle deltoid, infraspinatus and upper trapezius muscle activity changes with acromiohumeral distance differences during shoulder abduction (p>0.05). Active scapular retraction exercise especially focusing on the middle trapezius muscle activation seems to be an effective treatment option to optimize the acromiohumeral distance during shoulder abduction.

Scapular allograft reconstruction after total scapulectomy: surgical technique and functional results.

PubMed

Capanna, Rodolfo; Totti, Francesca; Van der Geest, Ingrid C M; Müller, Daniel A

2015-08-01

Scapular allograft reconstruction after total scapulectomy preserving the rotator cuff muscles is an oncologically safe procedure and results in good functional outcome with a low complication rate. The data of 6 patients who underwent scapular allograft reconstruction after a total scapulectomy for tumor resection were retrospectively reviewed. At least 1 of the rotator cuff muscles was preserved and the size-matched scapular allograft fixed to the residual host acromion with a plate and screws. The periscapular muscles and the residual joint capsule were sutured to the corresponding insertions of the allograft. The mean follow-up was 5.5 years (range, 24-175 months). In all patients, a wide surgical margin was achieved. The average functional scores were 20 points for the International Society of Limb Salvage score and 60 points for the American Shoulder and Elbow Surgeons score. Mean active shoulder flexion of 60° (range, 30°-90°) and mean active abduction of 62° (range, 30°-90°) were achieved. During the follow-up, 1 patient (16.6%) had a local recurrence and lung metastasis, whereas the remaining 5 patients (83.3%) were disease free. Two breakages of the osteosynthesis and 2 allograft fractures were observed, necessitating a revision surgery in 2 cases (33.3%). In this series, no infection, allograft resorption, or shoulder instability occurred. Allograft substitution of a completely removed scapula is an oncologically safe procedure, with good functional results, avoiding common complications in prosthetic replacements such as infection and dislocation of the shoulder joint. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Short-Term Effects of Thoracic Spine Manipulation on Shoulder Impingement Syndrome: A Randomized Controlled Trial.

PubMed

Haik, Melina N; Alburquerque-Sendín, Francisco; Camargo, Paula R

2017-08-01

To investigate the short-term effects of thoracic spine manipulation (TSM) on pain, function, scapular kinematics, and scapular muscle activity in individuals with shoulder impingement syndrome. Randomized controlled trial with blinded assessor and patient. Laboratory. Patients with shoulder impingement syndrome (N=61). Participants were randomly allocated to TSM group (n=30) or sham-TSM group (n=31) and attended 2 intervention sessions over a 1-week period. Scapular kinematics and muscle activity were measured at day 1 (baseline, before the first intervention), day 2 preintervention (before second intervention), day 2 postintervention (after the second intervention), and day 3 (follow-up). Shoulder pain and function were assessed by the Disability of the Arm, Shoulder and Hand questionnaire and Western Ontario Rotator Cuff Index at baseline, day 2 preintervention, and follow-up. An assessor blinded to group assignment measured all outcomes. Pain decreased by 0.7 points (95% confidence interval, 1.3-0.1 points) at day 2 preintervention and 0.9 points (95% confidence interval, 1.5-0.3 points) at day 2 postintervention in the TSM group. The Disability of the Arm, Shoulder and Hand questionnaire (P=.01) and Western Ontario Rotator Cuff Index (P=.02) scores improved in both groups. Scapular upward rotation increased during arm lowering (P<.01) at day 2 postintervention (5.3°) and follow-up (3.5°) in the TSM group. Upper trapezius activity increased (P<.05) in the sham-TSM group. Middle trapezius, lower trapezius, and serratus anterior decreased activities in both groups during elevation and lowering of the arm. TSM may increase scapular upward rotation during arm lowering. TSM does not seem to influence activity of the scapular muscles. The results concerning shoulder pain, function, scapular tilt, and internal rotation are not conclusive. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Treatment of Subacromial Impingement Syndrome: Platelet-Rich Plasma or Exercise Therapy? A Randomized Controlled Trial.

PubMed

Nejati, Parisa; Ghahremaninia, Armita; Naderi, Farrokh; Gharibzadeh, Safoora; Mazaherinezhad, Ali

2017-05-01

Subacromial impingement syndrome (SAIS) is the most common disorder of the shoulder. The evidence for the effectiveness of treatment options is inconclusive and limited. Therefore, there is a need for more evidence in this regard, particularly for long-term outcomes. Platelet-rich plasma (PRP) would be an effective method in treating subacromial impingement. Randomized controlled trial; Level of evidence, 1. This was a single-blinded randomized clinical trial with 1-, 3-, and 6-month follow-up. Sixty-two patients were randomly placed into 2 groups, receiving either PRP or exercise therapy. The outcome parameters were pain, shoulder range of motion (ROM), muscle force, functionality, and magnetic resonance imaging findings. Both treatment options significantly reduced pain and increased shoulder ROM compared with baseline measurements. Both treatments also significantly improved functionality. However, the treatment choices were not significantly effective in improving muscle force. Trend analysis revealed that in the first and third months, exercise therapy was superior to PRP in pain, shoulder flexion and abduction, and functionality. However, in the sixth month, only shoulder abduction and total Western Ontario Rotator Cuff score were significantly different between the 2 groups. Both PRP injection and exercise therapy were effective in reducing pain and disability in patients with SAIS, with exercise therapy proving more effective.

The Effect of Glenohumeral Internal-Rotation Deficit on Functional Rotator-Strength Ratio in Adolescent Overhead Athletes.

PubMed

Guney, Hande; Harput, Gulcan; Colakoglu, Filiz; Baltaci, Gul

2016-02-01

Glenohumeral (GH) internal-rotation deficit (GIRD) and lower eccentric external-rotator (ER) to concentric internal-rotator (IR) strength (ER:IR) ratio have been documented as risk factors for shoulder injuries, but there is no information on whether GIRD has an adverse effect on ER:IR ratio in adolescent overhead athletes. The aim of this study was to investigate the effects of GIRD on functional ER:IR ratio of the adolescent overhead athletes. Cross-sectional study. University research laboratory. 52 adolescent overhead athletes. To determine GIRD, the range of GH IR and ER motion was measured with a digital inclinometer. An isokinetic dynamometer was used to assess eccentric and concentric IR and ER muscle strength of the dominant and nondominant shoulders. One-way ANCOVA where sport type was set as a covariate was used to analyze the difference between athletes with and without GIRD. After standardized examinations of all shoulders, the athletes were divided into 2 groups, shoulders with (n = 27) and without GIRD (n = 25). There was a significant difference between groups in functional ER:IR ratio (P < .001). Athletes with GIRD had lower ER:IR ratio (0.56) than athletes without GIRD (0.83). As GIRD has an adverse effect on functional ratio of the shoulder-rotator muscles, interventions for adolescent overhead athletes should include improving GH-rotation range of motion.

Effects of height and load weight on shoulder muscle work during overhead lifting task.

PubMed

Blache, Y; Desmoulins, L; Allard, P; Plamondon, A; Begon, M

2015-01-01

Few musculoskeletal models are available to assess shoulder deeper muscle demand during overhead lifting tasks. Our objective was to implement a musculoskeletal model to assess the effect of lifting height and load on shoulder muscle work. A musculoskeletal model scaled from 15 male subjects was used to calculate shoulder muscle work during six lifting tasks. Boxes containing three different loads (6, 12 and 18 kg) were lifted by the subjects from the waist to shoulder or eye level. After optimisation of the maximal isometric force of the model's muscles, the bio-fidelity of the model was improved by 19%. The latter was able to reproduce the subjects' lifting movements. Mechanical work of the rotator cuff muscles, upper trapezius and anterior deltoid was increased with lifting load and height augmentation. In conclusion, the use of a musculoskeletal model validated by electromyography enabled to evaluate the muscle demand of deep muscles during lifting tasks.

Rehabilitative ultrasound measurement of trapezius muscle contractile states in people with mild shoulder pain.

PubMed

O'Sullivan, Cliona; McCarthy Persson, Ulrik; Blake, Catherine; Stokes, Maria

2012-04-01

The utility of rehabilitative ultrasound imaging (RUSI) for assessing trapezius muscle contractile characteristics was investigated by examining whether muscle thickness changes during contraction (CT) differed between people with and without mild shoulder pain. In 18 subjects with mild shoulder pain (aged 28±8 years) and 18 matched controls, trapezius muscle thickness change was measured in prone at rest at 0° and during isometric CTs at 90° and 120° of shoulder abduction. Images were taken at four sites using a real-time ultrasound scanner (7-MHz linear transducer, 40 mm footprint). Percentage change in muscle thickness from rest was calculated. Differences between painful and non-painful shoulders and participant groups were examined by analysis of variance (ANOVA) and t-tests. There were no significant differences between groups or sides in trapezius muscle thickness change during CT. There was no significant difference in trapezius muscle resting thickness (RT) between painful and non-painful shoulders in the same subjects. Contractile ability of the trapezius muscle, assessed using RUSI was not impaired in subjects with mild shoulder pain during the test manoeuvres used. Further research is warranted involving patients with different severity of symptoms, using other test manoeuvres before RUSI can be advocated for assessing scapular muscle dysfunction. Copyright © 2011 Elsevier Ltd. All rights reserved.

[Results of shoulder isokinetic testing in volleyball players].

PubMed

Michael, J; König, D; Hessling, U; Popken, F; Eysel, P

2003-06-01

Isokinetic testing of the shoulder joint shows valuable indication to possible functional disorders and muscle imbalance. Concentric testing of several parameters using the Cybex 6000 practice unit was done by professional volleyball players performing external and internal rotation of the dominant and non-dominant shoulder at speeds of 60 degrees/s an 180 degrees/s. Sex-specific significant differences were shown which are comparable to other kind of sports.

Effect of virtual reality versus conventional physiotherapy on upper extremity function in children with obstetric brachial plexus injury

PubMed Central

El-Shamy, Shamekh; Alsharif, Rabab

2017-01-01

Objectives: The objective was to evaluate the effects of virtual reality versus conventional physiotherapy on upper extremity function in children with obstetric brachial plexus injury. Methods: Forty children with Erb’s palsy were selected for this randomized controlled study. They were assigned randomly to either group A (conventional physiotherapy program) or group B (virtual reality program using Armeo® spring for 45 min three times/week for 12 successive weeks). Mallet system scores for shoulder function and shoulder abduction, and external rotation range of motion (ROM) were obtained; shoulder abductor, and external rotators isometric strength were evaluated pre-and post-treatment using Mallet scoring system, standard universal goniometer, and handheld dynamometer. Results: The results of this study indicate that the children in both groups showed improvement in shoulder functions post-treatment with greater improvements in group B. The abduction muscle strength after treatment was 8.53 and 11.3 Nm for group A and group B, respectively. The external rotation muscle strength after treatment was 5.88 and 7.45 Nm for group A and group B, respectively. Conclusions: The virtual reality program is a significantly more effective than conventional physiotherapy program in improving the upper extremity functions in children with obstetric brachial plexus injury. PMID:29199193

Treatment of myofascial trigger points in patients with chronic shoulder pain: a randomized, controlled trial

PubMed Central

2011-01-01

Background Shoulder pain is a common musculoskeletal problem that is often chronic or recurrent. Myofascial trigger points (MTrPs) cause shoulder pain and are prevalent in patients with shoulder pain. However, few studies have focused on MTrP therapy. The aim of this study was to assess the effectiveness of multimodal treatment of MTrPs in patients with chronic shoulder pain. Methods A single-assessor, blinded, randomized, controlled trial was conducted. The intervention group received comprehensive treatment once weekly consisting of manual compression of the MTrPs, manual stretching of the muscles and intermittent cold application with stretching. Patients were instructed to perform muscle-stretching and relaxation exercises at home and received ergonomic recommendations and advice to assume and maintain good posture. The control group remained on the waiting list for 3 months. The Disabilities of Arm, Shoulder and Hand (DASH) questionnaire score (primary outcome), Visual Analogue Scale for Pain (VAS-P), Global Perceived Effect (GPE) scale and the number of muscles with MTrPs were assessed at 6 and 12 weeks in the intervention group and compared with those of a control group. Results Compared with the control group, the intervention group showed significant improvement (P < 0.05) on the DASH after 12 weeks (mean difference, 7.7; 95% confidence interval (95% CI), 1.2 to 14.2), on the VAS-P1 for current pain (mean difference, 13.8; 95% CI, 2.6 to 25.0), on the VAS-P2 for pain in the past 7 days (mean difference, 10.2; 95% CI, 0.7 to 19.7) and VAS-P3 most severe pain in the past 7 days (mean difference, 13.8; 95% CI, 0.8 to 28.4). After 12 weeks, 55% of the patients in the intervention group reported improvement (from slightly improved to completely recovered) versus 14% in the control group. The mean number of muscles with active MTrPs decreased in the intervention group compared with the control group (mean difference, 2.7; 95% CI, 1.2 to 4.2). Conclusions The results of this study show that 12-week comprehensive treatment of MTrPs in shoulder muscles reduces the number of muscles with active MTrPs and is effective in reducing symptoms and improving shoulder function in patients with chronic shoulder pain. Trial registration number ISRCTN: ISRCTN75722066 PMID:21261971

A musculoskeletal model of the upper extremity for use in the development of neuroprosthetic systems

PubMed Central

Blana, Dimitra; Hincapie, Juan G.; Chadwick, Edward K.; Kirsch, Robert F.

2008-01-01

Upper extremity neuroprostheses use functional electrical stimulation (FES) to restore arm motor function to individuals with cervical level spinal cord injury. For the design and testing of these systems, a biomechanical model of the shoulder and elbow has been developed, to be used as a substitute for the human arm. It can be used to design and evaluate specific implementations of FES systems, as well as FES controllers. The model can be customized to simulate a variety of pathological conditions. For example, by adjusting the maximum force the muscles can produce, the model can be used to simulate an individual with tetraplegia and to explore the effects of FES of different muscle sets. The model comprises six bones, five joints, nine degrees of freedom, and 29 shoulder and arm muscles. It was developed using commercial, graphics-based modeling and simulation packages that are easily accessible to other researchers and can be readily interfaced to other analysis packages. It can be used for both forward-dynamic (inputs: muscle activation and external load; outputs:motions) and inverse-dynamic (inputs: motions and external load; outputs: muscle activation) simulations. Our model was verified by comparing the model-calculated muscle activations to electromyographic signals recorded from shoulder and arm muscles of five subjects. As an example of its application to neuroprosthesis design, the model was used to demonstrate the importance of rotator cuff muscle stimulation when aiming to restore humeral elevation. It is concluded that this model is a useful tool in the development and implementation of upper extremity neuroprosthetic systems. PMID:18420213

A musculoskeletal model of the upper extremity for use in the development of neuroprosthetic systems.

PubMed

Blana, Dimitra; Hincapie, Juan G; Chadwick, Edward K; Kirsch, Robert F

2008-01-01

Upper extremity neuroprostheses use functional electrical stimulation (FES) to restore arm motor function to individuals with cervical level spinal cord injury. For the design and testing of these systems, a biomechanical model of the shoulder and elbow has been developed, to be used as a substitute for the human arm. It can be used to design and evaluate specific implementations of FES systems, as well as FES controllers. The model can be customized to simulate a variety of pathological conditions. For example, by adjusting the maximum force the muscles can produce, the model can be used to simulate an individual with tetraplegia and to explore the effects of FES of different muscle sets. The model comprises six bones, five joints, nine degrees of freedom, and 29 shoulder and arm muscles. It was developed using commercial, graphics-based modeling and simulation packages that are easily accessible to other researchers and can be readily interfaced to other analysis packages. It can be used for both forward-dynamic (inputs: muscle activation and external load; outputs: motions) and inverse-dynamic (inputs: motions and external load; outputs: muscle activation) simulations. Our model was verified by comparing the model calculated muscle activations to electromyographic signals recorded from shoulder and arm muscles of five subjects. As an example of its application to neuroprosthesis design, the model was used to demonstrate the importance of rotator cuff muscle stimulation when aiming to restore humeral elevation. It is concluded that this model is a useful tool in the development and implementation of upper extremity neuroprosthetic systems.

Importance of latissimus dorsi muscle preservation for shoulder function after scapulectomy.

PubMed

Mimata, Yoshikuni; Nishida, Jun; Nagai, Taro; Tada, Hiroshi; Sato, Kotaro; Doita, Minoru

2018-03-01

Scapulectomy is an inevitable treatment for sarcomas of the scapula. This procedure is unavoidable because it reduces the local recurrence rate but can impair shoulder movements and affect the activities of daily living. This study investigated the factors influencing functional outcomes after scapulectomy. The clinical results of 8 patients (5 males, 3 females) who were diagnosed with primary or metastatic sarcomas of the scapula were retrospectively reviewed. The mean age was 49 years (range, 11-86 years). We examined the correlation between the type of excision of the scapula (total, subtotal, or partial) and postoperative functional outcomes according to the Musculoskeletal Tumor Society (MSTS) score. In partial excision, the glenohumeral joint was preserved; in subtotal excision, the glenoid was completely resected and some bony components were preserved; and in total excision, the entire bony component of the scapula was resected. The average follow-up period was 55 months (range, 9-142 months). The partial, subtotal, and total excision groups had mean functional scores of 96.7%, 76.7%, and 62.2%, respectively. Although the mean functional scores were lower in patients who underwent total and subtotal excisions, 3 patients in whom the latissimus dorsi muscle was preserved had better function (mean MSTS score, 76.7%) than the 2 patients in whom it was not preserved (mean MSTS score, 55.0%). These results suggest that the latissimus dorsi muscle, along with the deltoid and pectoralis major muscles, is one of the stabilizers of the proximal humerus after scapulectomy. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

The effect of trunk rotation during shoulder exercises on the activity of the scapular muscle and scapular kinematics.

PubMed

Yamauchi, Taishi; Hasegawa, Satoshi; Matsumura, Aoi; Nakamura, Masatoshi; Ibuki, Satoko; Ichihashi, Noriaki

2015-06-01

In patients with shoulder disease, kinetic chain exercises including hip or trunk movement are recommended. However, the actual muscle activation and scapular kinematics of these exercises are not known. The purpose of this study was to examine the effect of trunk rotation on shoulder exercises that are devised to improve scapular function. Thirteen healthy young men participated in this study. Scaption, external rotation in the first and second positions, and prone scapular retraction at 45°, 90°, and 145° of shoulder abduction were performed with and without trunk rotation. Electromyography was used to assess the scapular muscle activity of the upper trapezius (UT), middle trapezius (MT), lower trapezius (LT), and serratus anterior (SA), and electromagnetic motion capture was used to assess scapular motion. The muscle activity ratio, which is the activity of the UT to the MT, LT, and SA, was calculated. These data were compared between 2 conditions (with and without trunk rotation) for each exercise. Adding trunk rotation to scaption, the first external rotation, and the second external rotation significantly increased scapular external rotation and posterior tilt, and all 3 exercises increased LT activation. In addition, trunk rotation with scapular retraction at 90° and 145° of shoulder abduction significantly decreased the UT/LT ratio. Our findings suggest that shoulder exercises with trunk rotation in this study may be effective in patients who have difficulty in enhancing LT activity and suppressing excessive activation of the UT or in cases in which a decreased scapular external rotation or posterior tilt is observed. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Comparison of muscles activity of abled bodied and amputee subjects for around shoulder movement.

PubMed

Kaur, Amanpreet; Agarwal, Ravinder; Kumar, Amod

2016-05-12

Worldwide, about 56% of the amputees are upper limb amputees. This research deals a method with two-channel surface electromyogram (SEMG) signal recorded from around shoulder to estimate the changes in muscle activity in non-amputee and the residual limb of trans humeral amputees with different movements of arm. Identification of different muscles activity of near shoulder amputee and non-amputee persons. SEMG signal were acquired during three distinct exercises from three-selected muscles location around shoulder. The participants were asked to move their dominant arm from an assigned position to record their muscles activity recorded with change in position. Results shows the muscles activity in scalene is more than the other muscles like pectoralis and infraspinatus with the same shoulder motion. In addition, STFT (Short-Time Fourier Transform) spectrogram with window length of 256 samples at maximum of 512 frequency bins using hamming window has used to identify the signal for the maximum muscles activity with best resolution in spectrum plot. The results suggest that one can use this analysis for making a suitable device for around shoulder prosthetic users based on muscles activation of amputee persons.

[The Effect of Activation of the Shoulder Girdle Muscles on Functional Outcomes of Rehabilitation in Patients with Surgically Treated Distal Radius Fractures].

PubMed

Jančíková, V; Opavský, J; Dráč, P; Krobot, A; Čižmář, I

2017-01-01

PURPOSE OF THE STUDY The aim of the study was to assess the functional outcomes of rehabilitation in patients with surgically treated distal radius fractures in the early postoperative period. We compared the functional outcomes of patients undergoing standard rehabilitation with the group of patients whose postoperative rehabilitation was extended with shoulder girdle exercises of the affected upper limb while the wrist was immobilized. Several indices and variables were used for the assessment of the functional therapeutic outcomes of the affected wrist. MATERIAL AND METHODS Forty patients (32 females and 8 males, the mean age 60.5 years) with distal radius fractures treated by internal fixation using volar surgical approach were involved in the study between 2013-2016. The tested subjects were randomized and split into two groups according to the selected method of rehabilitation. The tested subjects with standard rehabilitation extended with shoulder girdle muscles activation were labelled as group I. It included patients (n = 20) of the mean age 59.8 (age range 42-73 years) with immobilized wrist (i.e. for 3-4 weeks) performing shoulder girdle muscles exercises at the same time. Furthermore, standard kinesiotherapy continued after their fixation was removed. The other tested group, labelled as group II (n = 20), the mean age 61.3 (variation 40-74 years of age) involved patients with distal radius fractures. Only standard rehabilitation was performed in this group as late as their forearm fixation was removed. The following indices and parameters were assessed in the early postoperative period (i.e. by 8 weeks after the fixation removal): wrist and fingers range of motion (ROM), hand grip strength (dynamometry), local swelling, pain, scores of a nine hole peg test (NHPT), and a DASH score. RESULTS After the fixation had been removed, the group I reported statistically significantly higher values of movement compared to the values of the contralateral limb in the following directions: dorsal flexion, palmar flexion, MP joints flexion, flexion of PIP joints (proximal interphalangeal), and flexion of DIP joints (distal interphalangeal). After eight weeks, the group I manifested significantly higher values in dorsal flexion, palmar flexion and ulnar deviation in the wrist. There were no significant differences in other movement directions. The hand grip strength mean value examined with a dynamometer was significantly higher in the group I in the sixth and eighth week of testing (group I - 58.9% strength of a healthy limb after six weeks, or 66.5% after eight weeks). The results in the group II were 49.9% strength of a healthy limb after six weeks, or 56.6% after eight weeks. The group I showed statistically significantly lower values of wrist swelling and higher finger dexterity in the NHPT in all measured weeks. Lower pain intensity in the group I during the measurements was observed. At the same time, this group showed significantly better results in the DASH score. DISCUSSION The results of this study are useful for clinical practice. They confirm a functional relation between the activity of hand muscles and the shoulder muscle activity. The differences in the functional ability of the hand and the functional state of the injured wrist were detected as early as in the early postoperative period. It could be stated that the tested subjects in the group I showed a greater and faster improvement in the physical function of the injured hand. This was also accompanied by a positive psychological effect. We had not found a study of a similar type in the available literature that we could have compared our submitted results to. CONCLUSIONS Shoulder girdle muscles exercises after a distal radius fracture, while wrist is immobilized, can evidently enhance functional capability and accelerate the hand-function restitution. Early functional outcomes of the injured wrist after the rehabilitation with shoulder girdle muscles exercises support the efficiency of this broadened rehabilitation protocol. Key words: distal radius frac,ture, hand, shoulder, functional treatment, rehabilitation.

Humeral component retroversion in reverse total shoulder arthroplasty: a biomechanical study.

PubMed

Gulotta, Lawrence V; Choi, Dan; Marinello, Patrick; Knutson, Zakary; Lipman, Joseph; Wright, Timothy; Cordasco, Frank A; Craig, Edward V; Warren, Russell F

2012-09-01

Reverse total shoulder arthroplasty offers pain relief and functional improvement for patients with rotator cuff-deficient shoulders. The purpose of this study was to determine the optimal amount of humeral retroversion for this prosthesis. Six cadaveric shoulders underwent computed tomography (CT) imaging and were then dissected of soft tissues, except for their tendinous attachments. A reverse total shoulder arthroplasty was implanted in 0°, 20°, 30°, and 40° of retroversion, and the shoulders were mounted on a simulator to determine the muscle forces required to achieve 30° and 60° of scaption. CT images were converted into 3-dimensional models, and the amount of internal and external rotation was determined with computer modeling at various scaption angles. No differences were found in the forces required for 30° or 60° of scaption for any muscle, at any retroversion. With increasing retroversion, more impingement-free external rotation was obtained, with a concomitant decrease in the amount of internal rotation. Above 60°, the humerus was allowed to rotate around the glenosphere unencumbered. Increasing retroversion did not affect the muscle force requirements for scaption across the shoulder. Placing the humeral component in 0° to 20° of retroversion allows maximum internal rotation with the arm at the side, a movement that is required for daily activities. This limits external rotation with the arm at the side, but has no effect on external rotation with the arm elevated. Copyright © 2012 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

Reflex muscle contraction in anterior shoulder instability.

PubMed

Wallace, D A; Beard, D J; Gill, R H; Eng, B; Carr, A J

1997-01-01

Reduced proprioception may contribute to recurrent anterior shoulder instability. Twelve patients with unilateral shoulder instability were investigated for evidence of deficient proprioception with an activated pneumatic cylinder and surface electromyography electrodes; the contralateral normal shoulder was used as a control. The latency between onset of movement and the detection of muscle contraction was used as an index of proprioception. No significant difference in muscle contraction latency was detected between the stable and unstable shoulders, suggesting that there was no significant defect in muscular reflex activity. This study does not support the use proprioception-enhancing physiotherapy in the treatment of posttraumatic anterior shoulder instability.

Improving anterior deltoid activity in a musculoskeletal shoulder model - an analysis of the torque-feasible space at the sternoclavicular joint.

PubMed

Ingram, David; Engelhardt, Christoph; Farron, Alain; Terrier, Alexandre; Müllhaupt, Philippe

2016-01-01

Modelling the shoulder's musculature is challenging given its mechanical and geometric complexity. The use of the ideal fibre model to represent a muscle's line of action cannot always faithfully represent the mechanical effect of each muscle, leading to considerable differences between model-estimated and in vivo measured muscle activity. While the musculo-tendon force coordination problem has been extensively analysed in terms of the cost function, only few works have investigated the existence and sensitivity of solutions to fibre topology. The goal of this paper is to present an analysis of the solution set using the concepts of torque-feasible space (TFS) and wrench-feasible space (WFS) from cable-driven robotics. A shoulder model is presented and a simple musculo-tendon force coordination problem is defined. The ideal fibre model for representing muscles is reviewed and the TFS and WFS are defined, leading to the necessary and sufficient conditions for the existence of a solution. The shoulder model's TFS is analysed to explain the lack of anterior deltoid (DLTa) activity. Based on the analysis, a modification of the model's muscle fibre geometry is proposed. The performance with and without the modification is assessed by solving the musculo-tendon force coordination problem for quasi-static abduction in the scapular plane. After the proposed modification, the DLTa reaches 20% of activation.

Isokinetic strength differences between patients with primary reverse and total shoulder prostheses: muscle strength quantified with a dynamometer.

PubMed

Alta, Tjarco D W; Veeger, DirkJan H E J; de Toledo, Joelly M; Janssen, Thomas W J; Willems, W Jaap

2014-11-01

Range of motion after total shoulder arthroplasty is better than after reverse shoulder arthroplasty, however with similar clinical outcome. It is unclear if this difference can only be found in the different range of motion or also in the force generating capacity. (1) are isokinetically produced joint torques of reverse shoulder arthroplasty comparable to those of total shoulder arthroplasty? (2) Does this force-generating capacity correlate with functional outcome? Eighteen reverse shoulder arthroplasty patients (71years (SD 9years)) (21 shoulders, follow-up of 21months (SD 10months)) were recruited, 12 total shoulder arthroplasty patients (69years (SD 9years)) (14 shoulders, follow-up of 35months (SD 11months)). Pre- and post-operative Constant-Murley scores were obtained; two isokinetic protocols (ab-/adduction and ex-/internal rotations) at 60°/s were performed. Twelve of 18 reverse shoulder arthroplasty patients generated enough speed to perform the test (13 shoulders). Mean ab-/adduction torques are 16.3Nm (SD 5.6Nm) and 20.4Nm (SD 11.8Nm). All total shoulder arthroplasty patients generated enough speed (14 shoulders). Mean ab-/adduction torques are 32.1Nm (SD 13.3Nm) and 43.1Nm (SD 21.5Nm). Only 8 reverse shoulder arthroplasty patients (9 shoulders) could perform ex-/internal rotation tasks and all total shoulder arthroplasty patients. Mean ex-/internal rotation torques are 9.3Nm (SD 4.7Nm) and 9.2Nm (SD 2.1Nm) for reverse shoulder arthroplasty, and 17.9Nm (SD 7.7Nm) and 23.5Nm (SD 10.6Nm) for total shoulder arthroplasty. Significant correlations between sub-scores: activity, mobility and strength and external rotation torques for reverse shoulder arthroplasty. Moderate to strong correlation for sub-scores: strength in relation to abduction, adduction and internal rotation torques for total shoulder arthroplasty. Shoulders with a total shoulder arthroplasty are stronger. This can be explained by the absence of rotator cuff muscles and (probably) medialized center of rotation in reverse shoulder arthroplasty. The strong correlation between external rotation torques and post-operative Constant-Murley sub-scores demonstrates that external rotation is essential for good clinical functioning in reverse shoulder arthroplasty. Copyright © 2014 Elsevier Ltd. All rights reserved.

Treatment of Subacromial Impingement Syndrome: Platelet-Rich Plasma or Exercise Therapy? A Randomized Controlled Trial

PubMed Central

Nejati, Parisa; Ghahremaninia, Armita; Naderi, Farrokh; Gharibzadeh, Safoora; Mazaherinezhad, Ali

2017-01-01

Background: Subacromial impingement syndrome (SAIS) is the most common disorder of the shoulder. The evidence for the effectiveness of treatment options is inconclusive and limited. Therefore, there is a need for more evidence in this regard, particularly for long-term outcomes. Hypothesis: Platelet-rich plasma (PRP) would be an effective method in treating subacromial impingement. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: This was a single-blinded randomized clinical trial with 1-, 3-, and 6-month follow-up. Sixty-two patients were randomly placed into 2 groups, receiving either PRP or exercise therapy. The outcome parameters were pain, shoulder range of motion (ROM), muscle force, functionality, and magnetic resonance imaging findings. Results: Both treatment options significantly reduced pain and increased shoulder ROM compared with baseline measurements. Both treatments also significantly improved functionality. However, the treatment choices were not significantly effective in improving muscle force. Trend analysis revealed that in the first and third months, exercise therapy was superior to PRP in pain, shoulder flexion and abduction, and functionality. However, in the sixth month, only shoulder abduction and total Western Ontario Rotator Cuff score were significantly different between the 2 groups. Conclusion: Both PRP injection and exercise therapy were effective in reducing pain and disability in patients with SAIS, with exercise therapy proving more effective. PMID:28567426

Effects of humeral head compression taping on the isokinetic strength of the shoulder external rotator muscle in patients with rotator cuff tendinitis.

PubMed

Kim, Moon-Hwan; Oh, Jae-Seop

2015-01-01

[Purpose] The purpose of this study was to examine the effects of humeral head compression taping (HHCT) on the strength of the shoulder external rotator muscle in patients with rotator cuff tendinitis. [Subjects and Methods] Twenty patients with rotator cuff tendinitis were recruited. The shoulder external rotator strength was measured using a Biodex isokinetic dynamometer system. A paired t-test was performed to evaluate within-group differences in the strength of the shoulder external rotator muscle. [Results] Significantly higher shoulder external rotator peak torque and peak torque per body weight were found in the HHCT condition than in the no-taping condition. [Conclusion] HHCT may effectively increase the shoulder external rotator muscle strength in patients with rotator cuff tendinitis.

Features of Golf-Related Shoulder Pain in Korean Amateur Golfers

PubMed Central

2017-01-01

Objective To investigate the causes and characteristics of golf-related shoulder injuries in Korean amateur golfers. Methods Golf-related surveys were administered to, and ultrasonography were conducted on, 77 Korean amateur golfers with golf-related shoulder pain. The correlation between the golf-related surveys and ultrasonographic findings were investigated. Results The non-dominant shoulder is more likely to have golf-related pain and abnormal findings on ultrasonography than is the dominant shoulder. Supraspinatus muscle tear was the most frequent type of injury on ultrasonography, followed by subscapularis muscle tear. Investigation of the participants' golf-related habits revealed that only the amount of time spent practicing golf was correlated with supraspinatus muscle tear. No correlation was observed between the most painful swing phases and abnormal ultrasonographic findings. Participants who had not previously visited clinics were more likely to present with abnormal ultrasonographic findings, and many of the participants complained of additional upper limb pain. Conclusion Golf-related shoulder injuries and pain are most likely to be observed in the non-dominant shoulder. The supraspinatus muscle was the most susceptible muscle to damage. A correlation was observed between time spent practicing golf and supraspinatus muscle tear. PMID:28758076

Long periods with uninterrupted muscle activity related to neck and shoulder pain.

PubMed

Hanvold, Therese N; Wærsted, Morten; Veiersted, Kaj Bo

2012-01-01

The aim was to analyze the relationship between periods with uninterrupted neck muscle activity for ≥ 4 min and neck and shoulder pain. The trapezius muscle activity was recorded bilaterally on 40 young workers and students during a full shift. Neck and shoulder pain, mechanical work load and decision control were reported at the same time as the muscle activity recording and 6 months later. A dose-response relationship was found between uninterrupted muscle activity and neck and shoulder pain, with a ten-fold higher risk for the group with more than half, compared to less than a third, of the shift with uninterrupted muscle activity. Self-reported mechanical work load showed a small but protective effect related to pain. Gender and decision control did not emerge as important risk factors in this model. In conclusion, this study indicates that work or other exposures that contains long periods with uninterrupted neck muscle activity of 4 min duration or longer should be minimized to reduce risk of neck and shoulder pain.

Effect of reverse shoulder design philosophy on muscle moment arms.

PubMed

Hamilton, Matthew A; Diep, Phong; Roche, Chris; Flurin, Pierre Henri; Wright, Thomas W; Zuckerman, Joseph D; Routman, Howard

2015-04-01

This study analyzes the muscle moment arms of three different reverse shoulder design philosophies using a previously published method. Digital bone models of the shoulder were imported into a 3D modeling software and markers placed for the origin and insertion of relevant muscles. The anatomic model was used as a baseline for moment arm calculations. Subsequently, three different reverse shoulder designs were virtually implanted and moment arms were analyzed in abduction and external rotation. The results indicate that the lateral offset between the joint center and the axis of the humerus specific to one reverse shoulder design increased the external rotation moment arms of the posterior deltoid relative to the other reverse shoulder designs. The other muscles analyzed demonstrated differences in the moment arms, but none of the differences reached statistical significance. This study demonstrated how the combination of variables making up different reverse shoulder designs can affect the moment arms of the muscles in different and statistically significant ways. The role of humeral offset in reverse shoulder design has not been previously reported and could have an impact on external rotation and stability achieved post-operatively. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Shoulder Rotator Muscle Dynamometry Characteristics: Side Asymmetry and Correlations with Ball-Throwing Speed in Adolescent Handball Players

PubMed Central

Pontaga, Inese; Zidens, Janis

2014-01-01

The aim of the investigation was to: 1) compare shoulder external/internal rotator muscles’ peak torques and average power values and their ratios in the dominant and non-dominant arm; 2) determine correlations between shoulder rotator muscles’ peak torques, average power and ball-throwing speed in handball players. Fourteen 14 to 15-year-old male athletes with injury-free shoulders participated in the study (body height: 176 ± 7 cm, body mass 63 ± 9 kg). The tests were carried out by an isokinetic dynamometer system in the shoulder internal and external rotation movements at angular velocities of 60°/s, 90°/s and 240°/s during concentric contractions. The eccentric external– concentric internal rotator muscle contractions were performed at the velocity of 90°/s. The player threw a ball at maximal speed keeping both feet on the floor. The speed was recorded with reflected light rays. Training in handball does not cause significant side asymmetry in shoulder external/internal rotator muscle peak torques or the average power ratio. Positive correlations between isokinetic characteristics of the shoulder internal and external rotator muscles and ball-throwing speed were determined. The power produced by internal rotator muscles during concentric contractions after eccentric contractions of external rotator muscles was significantly greater in the dominant than in the non-dominant arm. Thus, it may be concluded that the shoulder eccentric external/concentric internal rotator muscle power ratio is significantly greater than this ratio in the concentric contractions of these muscles. PMID:25414738

INTEGRITY OF THE SUBSCAPULARIS TENDON AFTER OPEN SURGERY FOR THE TREATMENT OF ANTERIOR SHOULDER INSTABILITY: A CLINICAL AND RADIOLOGICAL EVALUATION.

PubMed

Lech, Osvandré; Piluski, Paulo; Tambani, Renato; Castro, Nero; Pimentel, Gilnei

2009-01-01

To evaluate the integrity of the subscapularis tendon by strength, function and magnetic resonance imaging after deltopectoralis access for anterior shoulder instability. 20 patients with anterior shoulder instability have been evaluated. Minimum follow-up was 12 months, with a mean of 40 months. Only male patients were included, with a mean of age of 29 years (20 - 42 years). The patients have been submitted to physical examinations of mobility, muscular strength, Belly Test and Gerber Test. The isokinetic strength in internal and external rotation, in angular speeds of 60(0)/s and 180(0)/s, for both shoulders was measured using a dynamometer. In 15 patients magnetic resonance imaging (MRI) was carried out on both shoulders for evaluating the thickness, cross-sectional area and atrophy of the subscapularis muscle. A significant difference was found between torque peaks at the speed of 60(0)/s for internal (p=0.036) and external (p=0.008) rotation. However, at 180(0)/s the opposite happens (internal rotation: p=0.133; external rotation: p=0.393). Subscapularis muscle thickness and area are significantly smaller than the normal side, with a deficit of 19% and 23%, respectively. According to Rowe and UCLA scores, we find excellent and good results for the majority of patients, with a mean of 88 and 31.6 points, respectively. Despite of the good functional results, open surgery can limit strength and reduce the thickness and the cross-sectional area of subscapularis muscle. However, the best results were found in the patients who had the dominant side operated.

Muscle activation when performing the chest press and shoulder press on a stable bench vs. a Swiss ball.

PubMed

Uribe, Brandon P; Coburn, Jared W; Brown, Lee E; Judelson, Daniel A; Khamoui, Andy V; Nguyen, Diamond

2010-04-01

The aim of this study was to examine the effects of a stable surface (bench) vs. an unstable surface (Swiss ball) on muscle activation when performing the dumbbell chest press and shoulder press. Sixteen healthy men (24.19 +/- 2.17 years) performed 1 repetition maximum (1RM) tests for the chest press and shoulder press on a stable surface. A minimum of 48 hours post 1RM, subjects returned to perform 3 consecutive repetitions each of the chest press and shoulder press at 80% 1RM under 4 different randomized conditions (chest press on bench, chest press on Swiss ball, shoulder press on bench, shoulder press on Swiss ball). Electromyography was used to assess muscle activation of the anterior deltoid, pectoralis major, and rectus abdominus. The results revealed no significant difference in muscle activation between surface types for either exercise. This suggests that using an unstable surface neither improves nor impairs muscle activation under the current conditions. Coaches and other practitioners can expect similar muscle activation when using a Swiss ball vs. a bench.

The effects of shoulder stabilization exercises and pectoralis minor stretching on balance and maximal shoulder muscle strength of healthy young adults with round shoulder posture.

PubMed

Kim, Mi-Kyoung; Lee, Jung Chul; Yoo, Kyung-Tae

2018-03-01

[Purpose] The purpose of this study was to analyze the effects of pectoralis minor stretching and shoulder strengthening with an elastic band on balance and maximal shoulder muscle strength in young adults with rounded shoulder posture. [Subjects and Methods] Nineteen subjects with rounded shoulder posture were randomly divided into 2 groups: a shoulder stabilization exercise group and a stretching exercise group. The groups performed each exercise for 40 minutes, 3 times a week, for 4 weeks. Static balance (eyes open and closed), dynamic balance (the limits of stability in 4 directions) and shoulder muscle strength in 5 directions were measure before and after the exercises. [Results] The stretching exercise demonstrated a significant difference between the pre- and post-exercise in the static balance with eyes closed and extension and horizontal abduction strength while the stabilization exercise demonstrated significant difference in the left and right directions between the pre- and post-exercise of the dynamic balance and flexion strength. The stabilization exercise demonstrated significant differences shown in the flexion between the pre- and post-test. [Conclusion] The shoulder stabilization and stretching exercises improved the static balance, dynamic balance, and muscle strength.

Shoulder muscle strength in paraplegics before and after kayak ergometer training.

PubMed

Bjerkefors, Anna; Jansson, Anna; Thorstensson, Alf

2006-07-01

The purpose was to investigate if shoulder muscle strength in post-rehabilitated persons with spinal cord injury (SCI) was affected by kayak ergometer training and to compare shoulder strength in persons with SCI and able-bodied persons. Ten persons with SCI (7 males and 3 females, injury levels T3-T12) performed 60 min kayak ergometer training three times a week for 10 weeks with progressively increased intensity. Maximal voluntary concentric contractions were performed during six shoulder movements: flexion and extension (range of motion 65 degrees ), abduction and adduction (65 degrees ), and external and internal rotation (60 degrees ), with an angular velocity of 30 degrees s(-1). Position specific strength was assessed at three shoulder angles (at the beginning, middle and end of the range of motion) in the respective movements. Test-retests were performed for all measurements before the training and the mean intraclass correlation coefficient was 0.941 (95% CI 0.928-0.954). There was a main effect of kayak ergometer training with increased shoulder muscle strength after training in persons with SCI. The improvements were independent of shoulder movement, and occurred in the beginning and middle positions. A tendency towards lower shoulder muscle strength was observed in the SCI group compared to a matched reference group of able-bodied persons. Thus, it appears that post-rehabilitated persons with SCI have not managed to fully regain/maintain their shoulder muscle strength on a similar level as that of able-bodied persons, and are able to improve their shoulder muscle strength after a period of kayak ergometer training.

Contributions of Altered Stretch Reflex Coordination to Arm Impairments Following Stroke

PubMed Central

Ravichandran, Vengateswaran J.; Krutky, Matthew A.; Perreault, Eric J.

2010-01-01

Patterns of stereotyped muscle coactivation, clinically referred to as synergies, emerge following stroke and impair arm function. Although researchers have focused on cortical contributions, there is growing evidence that altered stretch reflex pathways may also contribute to impairment. However, most previous reflex studies have focused on passive, single-joint movements without regard to their coordination during volitional actions. The purpose of this study was to examine the effects of stroke on coordinated activity of stretch reflexes elicited in multiple arm muscles following multijoint perturbations. We hypothesized that cortical injury results in increased stretch reflexes of muscles characteristic of the abnormal flexor synergy during active arm conditions. To test this hypothesis, we used a robot to apply position perturbations to impaired arms of 10 stroke survivors and dominant arms of 8 healthy age-matched controls. Corresponding reflexes were assessed during volitional contractions simulating different levels of gravitational support, as well as during voluntary flexion and extension of the elbow and shoulder. Reflexes were quantified by average rectified surface electromyogram, recorded from eight muscles spanning the elbow and shoulder. Reflex coordination was quantified using an independent components analysis. We found stretch reflexes elicited in the stroke group were significantly less sensitive to changes in background muscle activation compared with those in the control group (P < 0.05). We also observed significantly increased reflex coupling between elbow flexor and shoulder abductor–extensor muscles in stroke subjects relative to that in control subjects. This increased coupling was present only during volitional tasks that required elbow flexion (P < 0.001), shoulder extension (P < 0.01), and gravity opposition (P < 0.01), but not during the “no load” condition. During volitional contractions, reflex amplitudes scaled with the level of impairment, as assessed by Fugl-Meyer scores (r2 = 0.63; P < 0.05). We conclude that altered reflex coordination is indicative of motor impairment level and may contribute to impaired arm function following stroke. PMID:20962072

Tendon transfer options about the shoulder in patients with brachial plexus injury.

PubMed

Elhassan, Bassem; Bishop, Allen T; Hartzler, Robert U; Shin, Alexander Y; Spinner, Robert J

2012-08-01

The purpose of this study was to evaluate the early outcome of shoulder tendon transfer in patients with brachial plexus injury and to determine the factors associated with favorable outcomes. Fifty-two patients with traumatic brachial plexus injury and a paralytic shoulder were included in the study. All patients were evaluated at a mean of nineteen months (range, twelve to twenty-eight months) postoperatively. Twelve patients had a C5-6 injury, twenty-two had a C5-7 injury, five had a C5-8 injury, and thirteen had a C5-T1 injury. Transfer of the lower portion of the trapezius muscle was performed either in isolation or as part of multiple tendon transfers to improve shoulder function. Additional muscles transferred included the middle and upper portions of the trapezius, levator scapulae, upper portion of the serratus anterior, teres major, latissimus dorsi, and pectoralis major. All patients had a stable shoulder postoperatively. Shoulder external rotation improved substantially in all patients from no external rotation (hand-on-belly position) to a mean of 20° (p = 0.001). Patients who underwent additional transfers had marginal improvement of shoulder flexion, from a mean of 10° preoperatively to 60° postoperatively, and of shoulder abduction, from a mean of 10° to 50° (p = 0.01 for each). Mean pain on a visual analog scale improved from 6 points preoperatively to 2 points postoperatively. The mean Disabilities of the Arm, Shoulder and Hand (DASH) score improved from 59 to 47 points (p = 0.001). The mean Subjective Shoulder Value improved from 5% to 40% (p = 0.001). Greater age, higher body mass index, and more extensive nerve injury were associated with a poorer DASH score in a multivariate analysis (p = 0.003). Tendon transfers about the shoulder can improve shoulder function in patients with brachial plexus injury resulting in a paralytic shoulder. Significant improvement of shoulder external rotation but only marginal improvements of shoulder abduction and flexion can be achieved. The outcome can be expected to be better in patients with less severe nerve injury.

Modulation of shoulder muscle and joint function using a powered upper-limb exoskeleton.

PubMed

Wu, Wen; Fong, Justin; Crocher, Vincent; Lee, Peter V S; Oetomo, Denny; Tan, Ying; Ackland, David C

2018-04-27

Robotic-assistive exoskeletons can enable frequent repetitive movements without the presence of a full-time therapist; however, human-machine interaction and the capacity of powered exoskeletons to attenuate shoulder muscle and joint loading is poorly understood. This study aimed to quantify shoulder muscle and joint force during assisted activities of daily living using a powered robotic upper limb exoskeleton (ArmeoPower, Hocoma). Six healthy male subjects performed abduction, flexion, horizontal flexion, reaching and nose touching activities. These tasks were repeated under two conditions: (i) the exoskeleton compensating only for its own weight, and (ii) the exoskeleton providing full upper limb gravity compensation (i.e., weightlessness). Muscle EMG, joint kinematics and joint torques were simultaneously recorded, and shoulder muscle and joint forces calculated using personalized musculoskeletal models of each subject's upper limb. The exoskeleton reduced peak joint torques, muscle forces and joint loading by up to 74.8% (0.113 Nm/kg), 88.8% (5.8%BW) and 68.4% (75.6%BW), respectively, with the degree of load attenuation strongly task dependent. The peak compressive, anterior and superior glenohumeral joint force during assisted nose touching was 36.4% (24.6%BW), 72.4% (13.1%BW) and 85.0% (17.2%BW) lower than that during unassisted nose touching, respectively. The present study showed that upper limb weight compensation using an assistive exoskeleton may increase glenohumeral joint stability, since deltoid muscle force, which is the primary contributor to superior glenohumeral joint shear, is attenuated; however, prominent exoskeleton interaction moments are required to position and control the upper limb in space, even under full gravity compensation conditions. The modeling framework and results may be useful in planning targeted upper limb robotic rehabilitation tasks. Copyright © 2018 Elsevier Ltd. All rights reserved.

Comparison Between Neck and Shoulder Stiffness Determined by Shear Wave Ultrasound Elastography and a Muscle Hardness Meter.

PubMed

Akagi, Ryota; Kusama, Saki

2015-08-01

The goals of this study were to compare neck and shoulder stiffness values determined by shear wave ultrasound elastography with those obtained with a muscle hardness meter and to verify the correspondence between objective and subjective stiffness in the neck and shoulder. Twenty-four young men and women participated in the study. Their neck and shoulder stiffness was determined at six sites. Before the start of the measurements, patients rated their present subjective symptoms of neck and shoulder stiffness on a 6-point verbal scale. At all measurement sites, the correlation coefficients between the values of muscle hardness indices determined by the muscle hardness meter and shear wave ultrasound elastography were not significant. Furthermore, individuals' subjective neck and shoulder stiffness did not correspond to their objective symptoms. These results suggest that the use of shear wave ultrasound elastography is essential to more precisely assess neck and shoulder stiffness. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Reduced muscle fiber force production and disrupted myofibril architecture in patients with chronic rotator cuff tears.

PubMed

Mendias, Christopher L; Roche, Stuart M; Harning, Julie A; Davis, Max E; Lynch, Evan B; Sibilsky Enselman, Elizabeth R; Jacobson, Jon A; Claflin, Dennis R; Calve, Sarah; Bedi, Asheesh

2015-01-01

A persistent atrophy of muscle fibers and an accumulation of fat, collectively referred to as fatty degeneration, commonly occur in patients with chronic rotator cuff tears. The etiology of fatty degeneration and function of the residual rotator cuff musculature have not been well characterized in humans. We hypothesized that muscles from patients with chronic rotator cuff tears have reduced muscle fiber force production, disordered myofibrils, and an accumulation of fat vacuoles. The contractility of muscle fibers from biopsy specimens of supraspinatus muscles of 13 patients with chronic full-thickness posterosuperior rotator cuff tears was measured and compared with data from healthy vastus lateralis muscle fibers. Correlations between muscle fiber contractility, American Shoulder and Elbow Surgeons (ASES) scores, and tear size were analyzed. Histology and electron microscopy were also performed. Torn supraspinatus muscles had a 30% reduction in maximum isometric force production and a 29% reduction in normalized force compared with controls. Normalized supraspinatus fiber force positively correlated with ASES score and negatively correlated with tear size. Disordered sarcomeres were noted, along with an accumulation of lipid-laden macrophages in the extracellular matrix surrounding supraspinatus muscle fibers. Patients with chronic supraspinatus tears have significant reductions in muscle fiber force production. Force production also correlates with ASES scores and tear size. The structural and functional muscle dysfunction of the residual muscle fibers is independent of the additional area taken up by fibrotic tissue. This work may help establish future therapies to restore muscle function after the repair of chronically torn rotator cuff muscles. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Effects of Shoulder Flexion Loaded by an Elastic Tubing Band on EMG Activity of the Gluteal Muscles during Squat Exercises

PubMed Central

Kang, Min-Hyeok; Jang, Jun-Hyeok; Kim, Tae-Hoon; Oh, Jae-Seop

2014-01-01

[Purpose] We investigated the effects of shoulder flexion loaded by an elastic tubing band during squat exercises, by assessing electromyographic activities of the gluteus maximus and gluteus medius. [Subjects] In total, 17 healthy males were recruited. [Methods] Participants performed squat exercises with and without shoulder flexion loaded by a tubing band. Gluteal muscle activities during the downward and upward phases of the squat exercises were recorded using a surface electromyography (EMG) system. The mean electromyographic activities of the gluteal muscles during squat exercises with and without loaded shoulder flexion were compared using the paired t-test. [Results] Electromyographic activities of the gluteus maximus and gluteus medius were greater in both the upward and downward phases of the squat with loaded shoulder flexion. [Conclusions] The combination of squat and loaded shoulder flexion can be an effective exercise for increasing gluteal muscle activity. PMID:25435701

Long-latency reflexes of elbow and shoulder muscles suggest reciprocal excitation of flexors, reciprocal excitation of extensors, and reciprocal inhibition between flexors and extensors

PubMed Central

Meriggi, Jenna; Parikh, Nidhi; Saad, Kenneth

2016-01-01

Postural corrections of the upper limb are required in tasks ranging from handling an umbrella in the changing wind to securing a wriggling baby. One complication in this process is the mechanical interaction between the different segments of the arm where torque applied at one joint induces motion at multiple joints. Previous studies have shown the long-latency reflexes of shoulder muscles (50–100 ms after a limb perturbation) account for these mechanical interactions by integrating information about motion of both the shoulder and elbow. It is less clear whether long-latency reflexes of elbow muscles exhibit a similar capability and what is the relation between the responses of shoulder and elbow muscles. The present study utilized joint-based loads tailored to the subjects' arm dynamics to induce well-controlled displacements of their shoulder and elbow. Our results demonstrate that the long-latency reflexes of shoulder and elbow muscles integrate motion from both joints: the shoulder and elbow flexors respond to extension at both joints, whereas the shoulder and elbow extensors respond to flexion at both joints. This general pattern accounts for the inherent flexion-extension coupling of the two joints arising from the arm's intersegmental dynamics and is consistent with spindle-based reciprocal excitation of shoulder and elbow flexors, reciprocal excitation of shoulder and elbow extensors, and across-joint inhibition between the flexors and extensors. PMID:26864766

Exercises focusing on rotator cuff and scapular muscles do not improve shoulder joint position sense in healthy subjects.

PubMed

Lin, Yin-Liang; Karduna, Andrew

2016-10-01

Proprioception is essential for shoulder neuromuscular control and shoulder stability. Exercise of the rotator cuff and scapulothoracic muscles is an important part of shoulder rehabilitation. The purpose of this study was to investigate the effect of rotator cuff and scapulothoracic muscle exercises on shoulder joint position sense. Thirty-six healthy subjects were recruited and randomly assigned into either a control or training group. The subjects in the training group received closed-chain and open-chain exercises focusing on rotator cuff and scapulothoracic muscles for four weeks. Shoulder joint position sense errors in elevation, including the humerothoracic, glenohumeral and scapulothoracic joints, was measured. After four weeks of exercise training, strength increased overall in the training group, which demonstrated the effect of exercise on the muscular system. However, the changes in shoulder joint position sense errors in any individual joint of the subjects in the training group were not different from those of the control subjects. Therefore, exercises specifically targeting individual muscles with low intensity may not be sufficient to improve shoulder joint position sense in healthy subjects. Future work is needed to further investigate which types of exercise are more effective in improving joint position sense, and the mechanisms associated with those changes. Copyright © 2016 Elsevier B.V. All rights reserved.

Exercises focusing on rotator cuff and scapular muscles do not improve shoulder joint position sense in healthy subjects

PubMed Central

Lin, Yin-Liang; Karduna, Andrew

2016-01-01

Proprioception is essential for shoulder neuromuscular control and shoulder stability. Exercise of the rotator cuff and scapulothoracic muscles is an important part of shoulder rehabilitation. The purpose of this study was to investigate the effect of rotator cuff and scapulothoracic muscle exercises on shoulder joint position sense. Thirty-six healthy subjects were recruited and randomly assigned into either a control or training group. The subjects in the training group received closed-chain and open-chain exercises focusing on rotator cuff and scapulothoracic muscles for four weeks. Shoulder joint position sense errors in elevation, including the humerothoracic, glenohumeral and scapulothoracic joints, was measured. After four weeks of exercise training, strength increased overall in the training group, which demonstrated the effect of exercise on the muscular system. However, the changes in shoulder joint position sense errors in any individual joint of the subjects in the training group were not different from those of the control subjects. Therefore, exercises specifically targeting individual muscles with low intensity may not be sufficient to improve shoulder joint position sense in healthy subjects. Future work is needed to further investigate which types of exercise are more effective in improving joint position sense, and the mechanisms associated with those changes. PMID:27475714

The initial effects of a sustained glenohumeral postero-lateral glide during elevation on shoulder muscle activity: A repeated measures study on asymptomatic shoulders.

PubMed

Ribeiro, Daniel Cury; de Castro, Marcelo Peduzzi; Sole, Gisela; Vicenzino, Bill

2016-04-01

Manual therapy enhances pain-free range of motion and reduces pain levels, but its effect on shoulder muscle activity is unclear. This study aimed to assess the effects of a sustained glenohumeral postero-lateral glide during elevation on shoulder muscle activity. Thirty asymptomatic individuals participated in a repeated measures study of the electromyographic activity of the supraspinatus, infraspinatus, posterior deltoid, and middle deltoid. Participants performed four sets of 10 repetitions of shoulder scaption and abduction with and without a glide of the glenohumeral joint. Repeated-measures multivariate analysis of variance (MANOVA) was used to assess the effects of movement direction (scaption and abduction), and condition (with and without glide) (within-subject factors) on activity level of each muscle (dependent variables). Significant MANOVAs were followed-up with repeated-measures one-way analysis of variance. During shoulder scaption with glide, the supraspinatus showed a reduction of 4.1% maximal isometric voluntary contraction (MVIC) (95% CI 2.4, 5.8); and infraspinatus 1.3% MVIC (95% CI 0.5, 2.1). During shoulder abduction with a glide, supraspinatus presented a reduction of 2.5% MVIC (95% CI 1.1, 4.0), infraspinatus 2.1% MVIC (95% CI 1.0, 3.2), middle deltoid 2.2% MVIC (95% CI = 0.4, 4.1), posterior deltoid 2.1% MVIC (95% CI 1.3, 2.8). In asymptomatic individuals, sustained glide reduced shoulder muscle activity compared to control conditions. This might be useful in enhancing shoulder movement in clinical populations. Reductions in muscle activity might result from altered joint mechanics, including simply helping to lift the arm, and/or through changing afferent sensory input about the shoulder. Copyright © 2015 Elsevier Ltd. All rights reserved.

Proton Density Fat-Fraction of Rotator Cuff Muscles Is Associated With Isometric Strength 10 Years After Rotator Cuff Repair: A Quantitative Magnetic Resonance Imaging Study of the Shoulder.

PubMed

Karampinos, Dimitrios C; Holwein, Christian; Buchmann, Stefan; Baum, Thomas; Ruschke, Stefan; Gersing, Alexandra S; Sutter, Reto; Imhoff, Andreas B; Rummeny, Ernst J; Jungmann, Pia M

2017-07-01

Quantitative muscle fat-fraction magnetic resonance (MR) imaging techniques correlate with semiquantitative Goutallier scores with failure after rotator cuff (RC) repair. To investigate the relationship of proton density fat fraction (PDFF) of the RC muscles with semiquantitative MR scores, cartilage T2 relaxation times, and clinical isometric strength measurements in patients 10 years after unilateral RC repair. Cross-sectional study; Level of evidence, 3. Bilateral shoulder MR imaging was performed in 13 patients (11 male, 2 female; age, 72 ± 8 years) 10.9 ± 0.4 years after unilateral autologous periosteal flap augmented RC repair (total shoulders assessed, N = 26). Goutallier classification, muscle atrophy, RC tendon integrity, and cartilage defects were determined based on morphological MR sequences. A paracoronal 2D multi-slice multi-echo sequence was used for quantitative cartilage T2 mapping. A chemical shift-encoding-based water-fat separation technique (based on a 6-echo 3D spoiled gradient echo sequence) was used for quantification of the PDFF of RC muscles. Isometric shoulder abduction strength was measured clinically. Mean and SD, Pearson correlation, and partial Spearman correlation were calculated. There were 6 RC full-thickness retears in ipsilateral shoulders and 6 RC full-thickness tears in contralateral shoulders. Isometric shoulder abduction strength was not significantly different between ipsilateral and contralateral shoulders (50 ± 24 N vs 54 ± 24 N; P = .159). The mean PDFF of RC muscles was 11.7% ± 10.4% (ipsilateral, 14.2% ± 8.5%; contralateral, 9.2% ± 7.8%; P = .002). High supraspinatus PDFF correlated significantly with higher Goutallier scores ( R = 0.75, P < .001) and with lower isometric muscle strength ( R = -0.49, P = .011). This correlation remained significant after adjustment for muscle area measurements and tendon rupture ( R = -0.41, P = .048). More severe cartilage defects at the humerus were significantly associated with higher supraspinatus PDFF ( R = 0.44; P = .023). Cartilage T2 values did not correlate with muscle PDFF ( P > .05). MR imaging-derived RC muscle PDFF is associated with isometric strength independent of muscle atrophy and tendon rupture in shoulders with early and advanced degenerative changes. It therefore provides complementary, clinically relevant information in tracking RC muscle composition on a quantitative level.

A pragmatic regional interdependence approach to primary frozen shoulder: a retrospective case series.

PubMed

Wong, Christopher Kevin; Strang, Bryanna L; Schram, Galen A; Mercer, Elizabeth A; Kesting, Rebecca S; Deo, Kabi S

2018-05-01

Although the shoulder is known to move together with the scapula and other upper quarter joints, the current frozen shoulder clinical practice guidelines describe only physical therapy study treatments directed to the shoulder. None received a strong recommendation, highlighting the need for alternate interventions. This retrospective case series describes a pragmatic regional interdependence approach to frozen shoulder with impairment and functional outcomes, noting whether final ROM approached normal. Five consecutive patients referred with frozen shoulder diagnoses attended 11-21 sessions over 5-10 weeks with one physical therapist. Treatment addressed inter-related regions (shoulder, shoulder girdle, scapulothoracic/humerothoracic, and spine) following a pragmatic approach using impairment-based interventions (joint/soft tissue mobilization, muscle stretching/strengthening) as well as patient education, modalities and warm up that addressed individual presentations. All patients improved on all outcomes. Mean shoulder ROM at discharge, the impairment outcome, demonstrated large effect size increases: flexion (117 ± 10-179 ± 12, d  = 5.9), abduction (74 ± 8-175 ± 9, d  = 9.3), external rotation (23 ± 7-89 ± 2, d  = 12.0). The Disability of Arm Shoulder Hand functional outcome score upon follow up demonstrated a large effect size improvement ( d  = 1.5) from 40.0 ± 19.4-6.2 ± 3.7. Final ROM approached normal. This case series utilized a regional interdependence approach to frozen shoulder that included manual therapy interventions directed to consistent upper quarter body segments. Shoulder ROM was returned to near normal with functional improvements evident months after discharge. A pragmatic regional interdependence approach addressing multiple joints related to shoulder function may benefit other people with frozen shoulder. 4.

Correlations among visual analogue scale, neck disability index, shoulder joint range of motion, and muscle strength in young women with forward head posture.

PubMed

Shin, Young Jun; Kim, Won Hyo; Kim, Seong Gil

2017-08-01

This study investigated the correlation between the neck disability index (NDI) and visual analogue scale (VAS), which are indicators of neck pain, shoulder joint range of motion (ROM), and muscle strength in women with a slight forward head posture. This study was carried out on 42 female college students attending Uiduk University in Gyeongju, Korea. The neck pain and disability index for each subject was measured using VAS and NDI, respectively. Two physiotherapists measured the shoulder joint ROM and muscle strengths of the subjects using a goniometer and a dynamometer, respectively. External rotation, internal rotation, and abduction of the shoulder joint were measured for each subject. A significant negative correlation between neck pain and shoulder joint ROM in external rotation and the muscle strength of the shoulder joint in abduction was found in the subjects. In addition, a significant positive correlation was observed between ROM in external rotation and muscle strength in abduction. This study showed a significant negative correlation between neck pain and ROM in external rotation as well as between neck pain and the muscle strength in abduction.

Influence of Body Position on Shoulder and Trunk Muscle Activation During Resisted Isometric Shoulder External Rotation.

PubMed

Krause, David A; Dueffert, Lucas G; Postma, Jaclyn L; Vogler, Eric T; Walsh, Amy J; Hollman, John H

External rotation (ER) strengthening of the shoulder is an integral component of rehabilitative and preventative programs for overhead athletes. A variety of shoulder ER strengthening exercises are reported, including those intended to integrate the core musculature. The purpose of this study was to examine ER torque and electromyographic (EMG) activation of shoulder and trunk muscles while performing resisted isometric shoulder ER in 3 positions (standing, side lying, and side plank). Significantly greater force and shoulder muscle activation would be generated while side lying given the inherent stability of the position, and greater trunk muscle activation would be generated in the less stable plank position. Quasi-experimental repeated-measures study. Level 5. A convenience sample of 25 healthy overhead recreational athletes (9 men, 16 women) participated in this study. EMG electrodes were placed on the infraspinatus, posterior deltoid, middle trapezius, multifidi, internal obliques, and external obliques. EMG signals were normalized to a maximal isometric contraction. Participants performed resisted isometric ER in standing, side-lying, and side plank positions. Results were analyzed using a repeated-measures analysis of variance with post hoc Bonferroni corrections (α = 0.05). There was no significant difference in ER torque between positions (α = 0.05). A significant difference in EMG activity of shoulder and trunk musculature between positions was found in 7 of the 8 muscles monitored. Significantly greater EMG activity in the infraspinatus, middle trapezius, and the nondominant external and internal obliques was found in the side plank position as compared with standing and side lying. While there was no difference in ER torque between the 3 exercise positions, EMG activity of the shoulder and trunk muscles was dependent on body position. If a clinician is seeking to integrate trunk muscle activation while performing shoulder ER strengthening, the side plank position is preferred as compared with standing or side lying.

Adaptive functional specialisation of architectural design and fibre type characteristics in agonist shoulder flexor muscles of the llama, Lama glama.

PubMed

Graziotti, Guillermo H; Chamizo, Verónica E; Ríos, Clara; Acevedo, Luz M; Rodríguez-Menéndez, J M; Victorica, C; Rivero, José-Luis L

2012-08-01

Like other camelids, llamas (Lama glama) have the natural ability to pace (moving ipsilateral limbs in near synchronicity). But unlike the Old World camelids (bactrian and dromedary camels), they are well adapted for pacing at slower or moderate speeds in high-altitude habitats, having been described as good climbers and used as pack animals for centuries. In order to gain insight into skeletal muscle design and to ascertain its relationship with the llama's characteristic locomotor behaviour, this study examined the correspondence between architecture and fibre types in two agonist muscles involved in shoulder flexion (M. teres major - TM and M. deltoideus, pars scapularis - DS and pars acromialis - DA). Architectural properties were found to be correlated with fibre-type characteristics both in DS (long fibres, low pinnation angle, fast-glycolytic fibre phenotype with abundant IIB fibres, small fibre size, reduced number of capillaries per fibre and low oxidative capacity) and in DA (short fibres, high pinnation angle, slow-oxidative fibre phenotype with numerous type I fibres, very sparse IIB fibres, and larger fibre size, abundant capillaries and high oxidative capacity). This correlation suggests a clear division of labour within the M. deltoideus of the llama, DS being involved in rapid flexion of the shoulder joint during the swing phase of the gait, and DA in joint stabilisation during the stance phase. However, the architectural design of the TM muscle (longer fibres and lower fibre pinnation angle) was not strictly matched with its fibre-type characteristics (very similar to those of the postural DA muscle). This unusual design suggests a dual function of the TM muscle both in active flexion of the shoulder and in passive support of the limb during the stance phase, pulling the forelimb to the trunk. This functional specialisation seems to be well suited to a quadruped species that needs to increase ipsilateral stability of the limb during the support phase of the pacing gait. Compared with other species, llama skeletal muscles are well suited for greater force generation combined with higher fatigue resistance during exercise. These characteristics are interpreted as being of high adaptive value, given the llama's habitat and its use as a pack animal. © 2012 The Authors. Journal of Anatomy © 2012 Anatomical Society.

Adaptive functional specialisation of architectural design and fibre type characteristics in agonist shoulder flexor muscles of the llama, Lama glama

PubMed Central

Graziotti, Guillermo H; Chamizo, Verónica E; Ríos, Clara; Acevedo, Luz M; Rodríguez-Menéndez, J M; Victorica, C; Rivero, José-Luis L

2012-01-01

Like other camelids, llamas (Lama glama) have the natural ability to pace (moving ipsilateral limbs in near synchronicity). But unlike the Old World camelids (bactrian and dromedary camels), they are well adapted for pacing at slower or moderate speeds in high-altitude habitats, having been described as good climbers and used as pack animals for centuries. In order to gain insight into skeletal muscle design and to ascertain its relationship with the llama’s characteristic locomotor behaviour, this study examined the correspondence between architecture and fibre types in two agonist muscles involved in shoulder flexion (M. teres major – TM and M. deltoideus, pars scapularis – DS and pars acromialis – DA). Architectural properties were found to be correlated with fibre-type characteristics both in DS (long fibres, low pinnation angle, fast-glycolytic fibre phenotype with abundant IIB fibres, small fibre size, reduced number of capillaries per fibre and low oxidative capacity) and in DA (short fibres, high pinnation angle, slow-oxidative fibre phenotype with numerous type I fibres, very sparse IIB fibres, and larger fibre size, abundant capillaries and high oxidative capacity). This correlation suggests a clear division of labour within the M. deltoideus of the llama, DS being involved in rapid flexion of the shoulder joint during the swing phase of the gait, and DA in joint stabilisation during the stance phase. However, the architectural design of the TM muscle (longer fibres and lower fibre pinnation angle) was not strictly matched with its fibre-type characteristics (very similar to those of the postural DA muscle). This unusual design suggests a dual function of the TM muscle both in active flexion of the shoulder and in passive support of the limb during the stance phase, pulling the forelimb to the trunk. This functional specialisation seems to be well suited to a quadruped species that needs to increase ipsilateral stability of the limb during the support phase of the pacing gait. Compared with other species, llama skeletal muscles are well suited for greater force generation combined with higher fatigue resistance during exercise. These characteristics are interpreted as being of high adaptive value, given the llama’s habitat and its use as a pack animal. PMID:22625659

The Effects of Bag Style on Muscle Activity of the Trapezius, Erector Spinae and Latissimus Dorsi During Walking in Female University Students

PubMed Central

Hardie, Rebecca; Haskew, Rachel; Harris, Joel; Hughes, Gerwyn

2015-01-01

Back pain is common in adolescents which has been associated with carrying a bag. However, there is little research examining the effects of bag style in female adolescents. The aim of the study was to investigate the effects of different bag conditions on muscle activity of the trapezius, erector spinae and latissimus dorsi muscles in female university students during walking. Twelve female university students walked on a treadmill for 5 minutes at 1.1 m/s during five conditions; control, 1 strapped rucksack, 2 strapped rucksack, ipsilateral shoulder strap and contralateral shoulder strap, each containing 10% bodyweight. Electromyography for the trapezius, erector spinae and latissimus dorsi was recorded for the last 30 s of each condition. Two-way ANOVA and paired t-tests were used to identify differences between right and left muscles and between bag conditions. Results showed that muscle activity of the left trapezius was significantly higher than the right trapezius during the 1 strap rucksack condition. For the left trapezius, the 2 strapped rucksack and the control condition had significantly lower muscle activity compared to the 1 strapped rucksack and the ipsilateral shoulder strap. For the left erector spinae muscle, there was significantly greater muscle activity when wearing the contralateral shoulder strap compared to the control. For the right erector spinae, significantly lower muscle activity was observed when wearing the 2 strapped rucksack compared to the ipsilateral shoulder strap and contralateral shoulder strap. There were no significant differences in muscle activity of the latissimus dorsi muscles between any of the bag conditions. These findings suggest that a two strapped rucksack should be used when carrying loads to reduce spinal muscle activity which may, in turn, reduce reports of back pain in female adolescents. PMID:25964808

Strength and fatigability of selected muscles in upper limb: assessing muscle imbalance relevant to tennis elbow.

PubMed

Alizadehkhaiyat, O; Fisher, A C; Kemp, G J; Frostick, S P

2007-08-01

The aetiology of tennis elbow has remained uncertain for more than a century. To examine muscle imbalance as a possible pathophysiological factor requires a reliable method of assessment. This paper describes the development of such a method and its performance in healthy subjects. We propose a combination of surface and fine-wire EMG of shoulder and forearm muscles and wrist strength measurements as a reliable tool for assessing muscle imbalance relevant to the pathophysiology of tennis elbow. Six healthy volunteers participated. EMG data were acquired at 50% maximal voluntary isometric contraction from five forearm muscles during grip and three shoulder muscles during external rotation and abduction, and analysed using normalized median frequency slope as a fatigue index. Wrist extension/flexion strength was measured using a purpose-built dynamometer. Significant negative slope of median frequency was found for all muscles, with good reproducibility, and no significant difference in slope between the different muscles of the shoulder and the wrist. (Amplitude slope showed high variability and was therefore unsuitable for this purpose.) Wrist flexion was 27+/-8% stronger than extension (mean+/-SEM, p=0.006). This is a reliable method for measuring muscle fatigue in forearm and shoulder. EMG and wrist strength studies together can be used for assessing and identifying the muscle balance in the wrist-forearm-shoulder chain.

Effectiveness of Functional Electrical Stimulation in Improving Clinical Outcomes in the Upper Arm following Stroke: A Systematic Review and Meta-Analysis

PubMed Central

Vafadar, Amir K.; Côté, Julie N.; Archambault, Philippe S.

2015-01-01

Background. Different therapeutic methods are being used to prevent or decrease long-term impairments of the upper arm in stroke patients. Functional electrical stimulation (FES) is one of these methods, which aims to stimulate the nerves of the weakened muscles so that the resulting muscle contractions resemble those of a functional task. Objectives. The objective of this study was to review the evidence for the effect of FES on (1) shoulder subluxation, (2) pain, and (3) upper arm motor function in stroke patients, when added to conventional therapy. Methods. From the 727 retrieved articles, 10 (9 RCTs, 1 quasi-RCT) were selected for final analysis and were rated based on the PEDro (Physiotherapy Evidence Database) scores and the Sackett's levels of evidence. A meta-analysis was performed for all three considered outcomes. Results. The results of the meta-analyses showed a significant difference in shoulder subluxation in experimental groups compared to control groups, only if FES was applied early after stroke. No effects were found on pain or motor function outcomes. Conclusion. FES can be used to prevent or reduce shoulder subluxation early after stroke. However, it should not be used to reduce pain or improve upper arm motor function after stroke. PMID:25685805

INTEGRITY OF THE SUBSCAPULARIS TENDON AFTER OPEN SURGERY FOR THE TREATMENT OF ANTERIOR SHOULDER INSTABILITY: A CLINICAL AND RADIOLOGICAL EVALUATION

PubMed Central

Lech, Osvandré; Piluski, Paulo; Tambani, Renato; Castro, Nero; Pimentel, Gilnei

2015-01-01

Objective: To evaluate the integrity of the subscapularis tendon by strength, function and magnetic resonance imaging after deltopectoralis access for anterior shoulder instability. Methods: 20 patients with anterior shoulder instability have been evaluated. Minimum follow-up was 12 months, with a mean of 40 months. Only male patients were included, with a mean of age of 29 years (20 − 42 years). The patients have been submitted to physical examinations of mobility, muscular strength, Belly Test and Gerber Test. The isokinetic strength in internal and external rotation, in angular speeds of 600/s and 1800/s, for both shoulders was measured using a dynamometer. In 15 patients magnetic resonance imaging (MRI) was carried out on both shoulders for evaluating the thickness, cross-sectional area and atrophy of the subscapularis muscle. Results: A significant difference was found between torque peaks at the speed of 600/s for internal (p=0.036) and external (p=0.008) rotation. However, at 1800/s the opposite happens (internal rotation: p=0.133; external rotation: p=0.393). Subscapularis muscle thickness and area are significantly smaller than the normal side, with a deficit of 19% and 23%, respectively. According to Rowe and UCLA scores, we find excellent and good results for the majority of patients, with a mean of 88 and 31.6 points, respectively. Conclusion: Despite of the good functional results, open surgery can limit strength and reduce the thickness and the cross-sectional area of subscapularis muscle. However, the best results were found in the patients who had the dominant side operated. PMID:27004190

Scapulothoracic muscle activity and recruitment timing in patients with shoulder impingement symptoms and glenohumeral instability.

PubMed

Struyf, Filip; Cagnie, Barbara; Cools, Ann; Baert, Isabel; Brempt, Jolien Van; Struyf, Pieter; Meeus, Mira

2014-04-01

Various studies have investigated scapulothoracic muscle activity and recruitment patterns in relation to shoulder complaints in different populations, but a consensus review is lacking. To systematically review the state of the art regarding scapulothoracic muscle activity and recruitment timing in subjects with shoulder pain compared to pain free controls. Systematic review. The search for relevant articles was performed in Pubmed and Web of Science, including Web of Knowledge, using key words related to shoulder pain, scapulothoracic muscle activity or recruitment timing. Articles were included till November 2012. Case-control studies concerning the scapulothoracic region and muscle recruitment using electromyography (EMG) were included. Articles regarding rotator cuff muscles or neck-shoulder pathologies or studies handling a treatment outcome, were excluded. The methodological quality of the articles was assessed using appropriate risk of bias criteria for case-control studies. A total of 12 articles were included in the systematic review, containing patients with Shoulder Impingement Syndrome (SIS) or glenohumeral instability. In patients with SIS 3 out of 6 articles showed increased upper trapezius muscle (UT) activity, 3 out of 5 studies showed decreased lower trapezius muscle (LT) activity and 3 out of 5 articles showed decreased serratus anterior muscle (SA) activity. Patients with glenohumeral instability showed contradictory results on scapulothoracic muscle activity patterns. In both SIS and glenohumeral instability patients, no consensus was found on muscle recruitment timing. Patients with SIS and glenohumeral instability display numerous variations in scapulothoracic muscle activity compared to healthy controls. In the SIS-group, the LT and SA muscle activity is decreased. In addition, the UT muscle activity is increased among the SIS patients, whereas no clear change is seen among patients with glenohumeral instability. Although the scapulothoracic muscle activity changed, no consensus could be made regarding muscle recruitment timing. Copyright © 2013 Elsevier Ltd. All rights reserved.

Allograft reconstruction after resection of malignant tumors of the scapula.

PubMed

Mnaymneh, Walid A; Temple, H Thomas; Malinin, Theodore I

2002-12-01

The oncologic and functional outcomes of six patients who had scapular allograft reconstruction after scapulectomy for malignant tumors were reviewed. Five patients had Stage IIB and one patient had Stage IB tumors. Total scapulectomy was done in five patients, and partial scapulectomy (glenoid and neck) was done in one patient. Frozen glycerolized scapular allografts were implanted and fixed with plates and screws. The scapular muscles were reattached to the allograft. Tendon reconstruction to replace the excised muscles was done in two patients. The patients were followed up for an average of 3.8 years (range, 2-6 years). Cosmesis, elbow, and hand function were good in all patients. There were no infections, nonunions, or shoulder dislocations. One patient fractured the body of the allograft after a fall. One patient had local recurrence and had scapulectomy 5 years postoperatively. Two patients died 3 and 5 years postoperatively with lung metastases but with functioning grafts. The mean functional result using the Musculoskeletal Tumor Society functional score was 82 (range, 77-87). In this series, scapular allograft reconstruction restored cosmesis, shoulder stability, and function. Preservation or reconstruction of rotator cuff muscles is recommended.

Age-Related Degenerative Functional, Radiographic, and Histological Changes of the Shoulder in Non-Human Primates

PubMed Central

Plate, Johannes F.; Bates, Christopher M.; Mannava, Sandeep; Smith, Thomas L.; Jorgensen, Matthew J.; Register, Thomas C.; Stehle, John R.; High, Kevin P.; Shively, Carol A.; Kaplan, Jay R.; Saul, Katherine R.; Tuohy, Christopher J.

2013-01-01

Background Non-human primates have similar shoulder anatomy and physiology compared to humans and may represent a previously underutilized model for shoulder research. This study sought to identify naturally occurring bony and muscular degeneration in the shoulder of non-human primates and to assess relationships between structural and functional aspects of the shoulder and measures of physical function of the animals. We hypothesized that age-related degenerative changes in the shoulders of non-human primates would resemble those observed in aging humans. Methods Middle-aged (n=5, ages 9.4 to 11.8 years) and elderly (n=6, ages 19.8 to 26.4 years) female vervet monkeys were studied for changes in mobility and shoulder function, and radiographic and histologic signs of age-related degeneration. Results Four out of six (4/6) elderly animals had degenerative changes of the glenoid compared to 0/5 of the middle-aged animals (p=0.005). Elderly animals had glenoid retroversion, decreased joint space, walked slower and spent less time climbing and hanging than middle-aged vervets (p<0.05). Physical mobility and shoulder function correlated with glenoid version angle (p<0.05). Supraspinatus muscles of elderly animals were less dense (p=0.001), had decreased fiber cross-sectional area (p<0.001), but similar amounts of nuclear material (p=0.085). Degenerative rotator cuff tears were not observed in any of the eleven animals. Discussion and Conclusion The vervet monkey naturally undergoes age-related functional, radiographic and histological changes of the shoulder and may qualify as an animal model for selected translational research of shoulder osteoarthritis. Level of evidence Basic Science Study, in-vivo Animal Model PMID:23352182

Anterior deltoid deficiency in reverse total shoulder replacement: a biomechanical study with cadavers.

PubMed

Gulotta, L V; Choi, D; Marinello, P; Wright, T; Cordasco, F A; Craig, E V; Warren, R F

2012-12-01

Reverse total shoulder replacement (RTSR) depends on adequate deltoid function for a successful outcome. However, the anterior deltoid and/or axillary nerve may be damaged due to prior procedures or injury. The purpose of this study was to determine the compensatory muscle forces required for scapular plane elevation following RTSR when the anterior deltoid is deficient. The soft tissues were removed from six cadaver shoulders, except for tendon attachments. After implantation of the RTSR, the shoulders were mounted on a custom-made shoulder simulator to determine the mean force in each muscle required to achieve 30° and 60° of scapular plane elevation. Two conditions were tested: 1) Control with an absent supraspinatus and infraspinatus; and 2) Control with anterior deltoid deficiency. Anterior deltoid deficiency resulted in a mean increase of 195% in subscapularis force at 30° when compared with the control (p = 0.02). At 60°, the subscapularis force increased a mean of 82% (p < 0.001) and the middle deltoid force increased a mean of 26% (p = 0.04). Scapular plane elevation may still be possible following an RTSR in the setting of anterior deltoid deficiency. When the anterior deltoid is deficient, there is a compensatory increase in the force required by the subscapularis and middle deltoid. Attempts to preserve the subscapularis, if present, might maximise post-operative function.

Sports Injuries to the Latissimus Dorsi and Teres Major.

PubMed

Donohue, Benjamin F; Lubitz, Marc G; Kremchek, Timothy E

2017-08-01

Injuries to the latissimus dorsi and teres major muscles, while rare, are debilitating. They are seen in a variety of sports, although disproportionately in the throwing shoulder of baseball pitchers. There have been 25 case reports and 2 case series published on the nonoperative and operative management of these injuries. Latissimus dorsi and teres major muscle anatomy, function, and common injury patterns are well described in these case reports. Also well detailed are the typical patient presentation, physical examination, and imaging findings. Latissimus dorsi tendon injuries are sometimes treated operatively, whereas latissimus dorsi muscle belly or isolated teres major injuries are treated nonoperatively. Nonoperative treatment includes oral anti-inflammatories and shoulder physical therapy. A number of surgical patient positions, approaches, and fixation constructs have been described, although 2 techniques of positioning and surgical approach are used most commonly. Fixation is most often performed with suture anchors. Return-to-play timing, shoulder strength, and healing on magnetic resonance imaging are variable. No standard of care currently exists for the treatment of latissimus dorsi or teres major injuries. If treating a patient with an injury to either muscle, the clinician should be familiar with accumulated experience as reported in the published literature.

Shoulder arthroplasty for sequelae of poliomyelitis.

PubMed

Werthel, Jean-David; Schoch, Bradley; Sperling, John W; Cofield, Robert; Elhassan, Bassem T

2016-05-01

Polio infection can often lead to orthopedic complications such as arthritis, osteoporosis, muscle weakness, skeletal deformation, and chronic instability of the joints. The purpose of this study was to assess the outcomes and associated complications of arthroplasty in shoulders with sequelae of poliomyelitis. Seven patients (average age, 70 years) were treated between 1976 and 2013 with shoulder arthroplasty for the sequelae of polio. One patient underwent reverse shoulder arthroplasty, 2 had a hemiarthroplasty, and 4 had total shoulder arthroplasty. Average follow-up was 87 months. Outcome measures included pain, range of motion, and postoperative modified Neer ratings. Overall pain scores improved from 5 to 1.6 points (on a 5-point scale) after shoulder arthroplasty. Six shoulders had no or mild pain at latest follow-up, and 6 shoulders rated the result as much better or better. Mean shoulder elevation improved from 72° to 129°, and external rotation improved from 11° to 56°. Average strength in elevation decreased from 3.9 to 3.4 postoperatively, and external rotation strength decreased from 3.9 to 3.3. This, however, did not reach significance. Evidence of muscle imbalance with radiographic instability was found in 4 shoulders that demonstrated superior subluxation, anterior subluxation, or both. This remained asymptomatic. No shoulder required revision or reoperation. Shoulder arthroplasty provides significant pain relief and improved motion in patients with sequelae of poliomyelitis. Muscle weakness may be responsible for postoperative instability, and careful selection of the patient with good upper extremity muscles must be made. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Refinements in pectus carinatum correction: the pectoralis muscle split technique.

PubMed

Schwabegger, Anton H; Jeschke, Johannes; Schuetz, Tanja; Del Frari, Barbara

2008-04-01

The standard approach for correction of pectus carinatum deformity includes elevation of the pectoralis major and rectus abdominis muscle from the sternum and adjacent ribs. A postoperative restriction of shoulder activity for several weeks is necessary to allow stable healing of the elevated muscles. To reduce postoperative immobilization, we present a modified approach to the parasternal ribs using a pectoralis muscle split technique. At each level of rib cartilage resection, the pectoralis muscle is split along the direction of its fibers instead of elevating the entire muscle as performed with the standard technique. From July 2000 to May 2007, we successfully used this technique in 33 patients with pectus carinatum deformity. After the muscle split approach, patients returned to full unrestricted shoulder activity as early as 3 weeks postoperatively, compared to 6 weeks in patients treated with muscle flap elevation. Postoperative pain was reduced and the patients were discharged earlier from the hospital than following the conventional approach. The muscle split technique is a modified surgical approach to the parasternal ribs in patients with pectus carinatum deformity. It helps to maintain pectoralis muscle vascularization and function and can reduce postoperative pain, hospitalization, and rehabilitation period.

Serratus anterior and lower trapezius muscle activities during multi-joint isotonic scapular exercises and isometric contractions.

PubMed

Tsuruike, Masaaki; Ellenbecker, Todd S

2015-02-01

Proper scapular function during humeral elevation, such as upward rotation, external rotation, and posterior tilting of the scapula, is necessary to prevent shoulder injury. However, the appropriate intensity of rehabilitation exercise for the periscapular muscles has yet to be clarified. To identify the serratus anterior, lower trapezius, infraspinatus, and posterior deltoid muscle activities during 2 free-motion exercises using 3 intensities and to compare these muscle activities with isometric contractions during quadruped shoulder flexion and external rotation and abduction of the glenohumeral joint. Cross-sectional study. Health Science Laboratory. A total of 16 uninjured, healthy, active, male college students (age = 19.5 ± 1.2 years, height = 173.1 ± 6.5 cm, weight = 68.8 ± 6.6 kg). Mean electromyographic activity normalized by the maximal voluntary isometric contraction was analyzed across 3 intensities and 5 exercises. Intraclass correlation coefficients were calculated for electromyographic activity of the 4 muscles in each free-motion exercise. Significant interactions in electromyographic activity were observed between intensities and exercises (P < .05). The quadruped shoulder-flexion exercise activated all 4 muscles compared with other exercises. Also, the modified robbery free-motion exercise activated the serratus anterior, lower trapezius, and infraspinatus compared with the lawn-mower free-motion exercise. However, neither exercise showed a difference in posterior deltoid electromyographic activity. Three intensities exposed the nature of the periscapular muscle activities across the different exercises. The free-motion exercise in periscapular muscle rehabilitation may not modify serratus anterior, lower trapezius, and infraspinatus muscle activities unless knee-joint extension is limited.

Active stiffness and strength in people with unilateral anterior shoulder instability: a bilateral comparison.

PubMed

Olds, Margie; McNair, Peter; Nordez, Antoine; Cornu, Christophe

2011-01-01

Active muscle stiffness might protect the unstable shoulder from recurrent dislocation. To compare strength and active stiffness in participants with unilateral anterior shoulder instability and to examine the relationship between active stiffness and functional ability. Cross-sectional study. University research laboratory. Participants included 16 males (age range, 16-40 years; height = 179.4 ± 6.1 cm; mass = 79.1 ± 6.8 kg) with 2 or more episodes of unilateral traumatic anterior shoulder instability. Active stiffness and maximal voluntary strength were measured bilaterally in participants. In addition, quality of life, function, and perceived instability were measured using the Western Ontario Stability Index, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form, and Single Alpha Numeric Evaluation, respectively. We found less horizontal adduction strength (t(15) = -4.092, P = .001) and less stiffness at 30% (t(14) = -3.796, P = .002) and 50% (t(12) = -2.341, P = .04) maximal voluntary strength in the unstable than stable shoulder. Active stiffness was not correlated with quality of life, function, or perceived instability (r range, 0.0-0.25; P > .05). The observed reduction in stiffness in the unstable shoulder warrants inclusion of exercises in the rehabilitation program to protect the joint from perturbations that might lead to dislocation. The lack of association between active stiffness and quality of life, function, or perceived instability might indicate that stiffness plays a less direct role in shoulder stability.

Comparing trapezius muscle activity in the different planes of shoulder elevation.

PubMed

Ishigaki, Tomonobu; Ishida, Tomoya; Samukawa, Mina; Saito, Hiroshi; Hirokawa, Motoki; Ezawa, Yuya; Sugawara, Makoto; Tohyama, Harukazu; Yamanaka, Masanori

2015-05-01

[Purpose] The purpose of this study was to compare the upper, middle, and lower trapezius muscles' activity in the different planes of shoulder elevation. [Subjects] Twenty male subjects volunteered for this study. [Methods] Surface electromyographic (EMG) activity for each of the three regions of the trapezius muscles in the three different planes of elevation were collected while the participants maintained 30, 60, and 90 degrees of elevation in each plane. The EMG data were normalized with maximum voluntary isometric contraction (%MVIC), and compared among the planes at each angle of elevation. [Results] There were significantly different muscle activities among the elevation planes at each angle. [Conclusion] This study found that the three regions of the trapezius muscles changed their activity depending on the planes of shoulder elevation. These changes in the trapezius muscles could induce appropriate scapular motion to face the glenoid cavity in the correct directions in different planes of shoulder elevation.

Muscle recruitment patterns of the subscapularis, serratus anterior and other shoulder girdle muscles during isokinetic internal and external rotations.

PubMed

Gaudet, Sylvain; Tremblay, Jonathan; Begon, Mickael

2018-05-01

The aims of this study were to investigate the differences in peak muscle activity and recruitment patterns during high- and low-velocity, concentric and eccentric, internal and external isokinetic shoulder rotations. Electromyographic activity of the rotator cuff and eight superficial muscles of the shoulder girdle was recorded on 25 healthy adults during isokinetic internal and external shoulder rotation at 60°/s and 240°/s. Peak muscle activity, electromyographic envelopes and peak isokinetic moments were analyzed using three-factor ANOVA and statistical parametric mapping. The subscapularis and serratus anterior showed moderate to high peak activity levels during each conditions, while the middle and posterior deltoids, upper, middle and lower trapezius, infraspinatus and supraspinatus showed higher peak activity levels during external rotations (+36.5% of maximum voluntary activation (MVA)). The pectoralis major and latissimus dorsi were more active during internal rotations (+40% of MVA). Only middle trapezius and pectoralis major electromyographic activity decreased with increasing velocity. Peak muscle activity was similar or lower during eccentric contractions, although the peak isokinetic moment increased by 35% on average. The subscapularis and serratus anterior appear to be important stabilizers of the glenohumeral joint and scapula. Isokinetic eccentric training at high velocities may allow for faster recruitment of the shoulder girdle muscles, which could improve joint stability during shoulder internal and external rotations.

The effect of work-related sustained trapezius muscle activity on the development of neck and shoulder pain among young adults.

PubMed

Hanvold, Therese N; Wærsted, Morten; Mengshoel, Anne Marit; Bjertness, Espen; Stigum, Hein; Twisk, Jos; Veiersted, Kaj Bo

2013-07-01

This study aimed to evaluate if sustained trapezius muscle activity predicts neck and shoulder pain over a 2.5-year period. Forty young adults (15 hairdressers, 14 electricians, 5 students and 6 with various work) were followed during their first years of working life. Self-reported neck and shoulder pain during the last four weeks was assessed seven times over the observational period. Upper-trapezius muscle activity was measured during a full working day by bilateral surface electromyography (EMG) at baseline (winter 2006/7). Sustained trapezius muscle activity was defined as continuous muscle activity with amplitude >0.5% EMGmax lasting >4 minutes. The relative time of sustained muscle activity during the working day was calculated and further classified into low (0-29%), moderate (30-49%) and high (50-100%) level groups. Generalized estimating equations (GEE), adjusted for time, gender, mechanical workload, control-over-work intensity, physical activity, tobacco use, and prior neck and shoulder pain, showed that participants with a high level of sustained muscle activity had a rate of neck and shoulder pain three times higher than the low level group during a 2.5-year period. The association was strongest at the same time and shortly after the EMG measurement, indicating a time-lag of ≤6 months. The results support the hypothesis that sustained trapezius muscle activity is associated with neck and shoulder pain. This association was strongest analyzing cross-sectional and short-term effects.

Shoulder horizontal abduction stretching effectively increases shear elastic modulus of pectoralis minor muscle.

PubMed

Umehara, Jun; Nakamura, Masatoshi; Fujita, Kosuke; Kusano, Ken; Nishishita, Satoru; Araki, Kojiro; Tanaka, Hiroki; Yanase, Ko; Ichihashi, Noriaki

2017-07-01

Stretching maneuvers for the pectoralis minor muscle, which involve shoulder horizontal abduction or scapular retraction, are performed in clinical and sports settings because the tightness of this muscle may contribute to scapular dyskinesis. The effectiveness of stretching maneuvers for the pectoralis minor muscle is unclear in vivo. The purpose of this study was to verify the effectiveness of stretching maneuvers for the pectoralis minor muscle in vivo using ultrasonic shear wave elastography. Eighteen healthy men participated in this study. Elongation of the pectoralis minor muscle was measured for 3 stretching maneuvers (shoulder flexion, shoulder horizontal abduction, and scapular retraction) at 3 shoulder elevation angles (30°, 90°, and 150°). The shear elastic modulus, used as the index of muscle elongation, was computed using ultrasonic shear wave elastography for the 9 aforementioned stretching maneuver-angle combinations. The shear elastic modulus was highest in horizontal abduction at 150°, followed by horizontal abduction at 90°, horizontal abduction at 30°, scapular retraction at 30°, scapular retraction at 90°, scapular retraction at 150°, flexion at 150°, flexion at 90°, and flexion at 30°. The shear elastic moduli of horizontal abduction at 90° and horizontal abduction at 150° were significantly higher than those of other stretching maneuvers. There was no significant difference between horizontal abduction at 90° and horizontal abduction at 150°. This study determined that shoulder horizontal abduction at an elevation of 90° and horizontal abduction at an elevation of 150° were the most effective stretching maneuvers for the pectoralis minor muscle in vivo. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Are pain location and physical examinations useful in locating a tear site of the rotator cuff?

PubMed

Itoi, Eiji; Minagawa, Hiroshi; Yamamoto, Nobuyuki; Seki, Nobutoshi; Abe, Hidekazu

2006-02-01

Pain is the most common symptom of patients with rotator cuff tendinopathy, but little is known about the relationship between the site of pain and the site of cuff pathologic lesions. Also, accuracies of physical examinations used to locate a tear by assessing the muscle strength seem to be affected by the threshold for muscle weakness, but no studies have been reported regarding the efficacies of physical examinations in reference to their threshold. Pain location is useful in locating a tear site. Efficacies of physical examinations to evaluate the function of the cuff muscles depend on the threshold for muscle weakness. Case series; Level of evidence, 4. The authors retrospectively reviewed the clinical charts of 160 shoulders of 149 patients (mean age, 53 years) with either rotator cuff tears (140 shoulders) or cuff tendinitis (20 shoulders). The location of pain was recorded on a standardized form with 6 different areas. The diagnostic accuracies of the following tests were assessed with various thresholds for muscle weakness: supraspinatus test, the external rotation strength test, and the lift-off test. Lateral and anterior portions of the shoulder were the most common sites of pain regardless of existence of tear or tear location. The supraspinatus test was most accurate when it was assessed to have positive results with the muscle strength less than manual muscle testing grade 5, whereas the lift-off test was most accurate with a threshold less than grade 3. The external rotation strength test was most accurate with a threshold of less than grade 4+. The authors conclude that pain location is not useful in locating the site of a tear, whereas the physical examinations aiming to locate the tear site are clinically useful when assessed to have positive results with appropriate threshold for muscle weakness.

Subacromial impingement syndrome: An electromyographic study of shoulder girdle muscle fatigue.

PubMed

Alizadehkhaiyat, Omid; Roebuck, Margaret M; Makki, Ahmed T; Frostick, Simon P

2018-02-01

Muscle fatigue affecting glenohumeral and/or scapular muscles is suggested as one of the contributing factors to the development of subacromial impingement syndrome (SAIS). Nonetheless, the fatigability of shoulder girdle muscles in association with the pathomechanics of SAIS has not been reported. This study aimed to measure and compare fatigue progression within the shoulder girdle musculature of patients and healthy controls. 75 participants including 39 patients (20 females; 19 males) and 36 healthy controls (15 females; 21 males) participated in the study. Study evaluated the progression of muscle fatigue in 15 shoulder girdle muscles by means of surface and fine-wire EMG during submaximal contraction of four distinct movements (abduction, flexion, internal and external rotation). Shoulder strength, subjective pain experience (McGill Pain Questionnaire), and psychological status (Hospital Anxiety and Depression Scale) were also assessed. The results were compared between patient and control groups according to the gender. Despite marked fatigue observed in the majority of muscles particularly during flexion and abduction at 90°, overall results indicated a lower tendency of fatigue progression in the impingement group across the tests (p < 0.05 - p < 0.001). Shoulder Strength, pain experience, and psychological status were significantly different between the two groups (P < .05). Lower tendency to fatigue progression in the impingement group can be attributed to the presence of fear avoidance and pain-related muscle inhibition, which in turn lead to adaptations in motor programme to reduce muscle recruitment and activation. The significantly higher levels of pain experience and anxiety/depression in the impingement group further support this proposition. Copyright © 2017 Elsevier Ltd. All rights reserved.

The effects of workplace stressors on muscle activity in the neck-shoulder and forearm muscles during computer work: a systematic review and meta-analysis.

PubMed

Eijckelhof, B H W; Huysmans, M A; Bruno Garza, J L; Blatter, B M; van Dieën, J H; Dennerlein, J T; van der Beek, A J

2013-12-01

Workplace stressors have been indicated to play a role in the development of neck and upper extremity pain possibly through an increase of sustained (low-level) muscle activity. The aim of this review was to study the effects of workplace stressors on muscle activity in the neck-shoulder and forearm muscles. An additional aim was to find out whether the muscles of the neck-shoulder and the forearm are affected differently by different types of workplace stressors. A systematic literature search was conducted on studies investigating the relation between simulated or realistic workplace stressors and neck-shoulder and forearm muscle activity. For studies meeting the inclusion criteria, a risk of bias assessment was performed and data were extracted for synthesis. Results were pooled when possible and otherwise described. Twenty-eight articles met the inclusion criteria, reporting data of 25 different studies. Except for one field study, all included studies were laboratory studies. Data of 19 articles could be included in the meta-analysis and revealed a statistically significant, medium increase in neck-shoulder and forearm muscle activity as a result of workplace stressors. In subgroup analyses, we found an equal effect of different stressor types (i.e. cognitive/emotional stress, work pace, and precision) on muscle activity in both body regions. In conclusion, simulated workplace stressors result in an increase in neck-shoulder and forearm muscle activity. No indications were found that different types of stressors affect these body regions differently. These conclusions are fully based on laboratory studies, since field studies on this topic are currently lacking.

The immediate effect of muscle release intervention on muscle activity and shoulder kinematics in patients with frozen shoulder: a cross-sectional, exploratory study.

PubMed

Shih, Yi-Fen; Liao, Pei-Wen; Lee, Chun-Shou

2017-11-28

Contractile tissue plays an important role in mobility deficits in frozen shoulder (FS). However, no study has assessed the effect of the muscle release technique on the muscle activation and kinematics in individuals with FS. The purposes of this study were to assess the differences in shoulder muscle activity and kinematics between the FS and asymptomatic groups; and to determine the immediate effects of muscle release intervention in the FS group. Twenty patients with FS and 20 asymptomatic controls were recruited. The outcome measures included muscle activity of the upper and lower trapezius (UT and LT), infraspinatus (ISp), pectoralis major (PM), and teres major (TM), shoulder kinematics (humeral elevation, scapular posterior tilt (PT) and upward rotation (UR), shoulder mobility, and pain. Participants in the FS group received one-session of heat and manual muscle release. Measurements were obtained at baseline, and immediately after intervention. Multivariate analysis of variance was used for data analysis. The level of significance was set at α=0.05. Compared to the controls, the FS group revealed significantly decreased LT (difference =55.89%, P=0.001) and ISp muscle activity (difference =26.32%, P =0.043) during the scaption task, and increased PM activity (difference =6.31%, P =0.014) during the thumb to waist task. The FS group showed decreased humeral elevation, scapular PT, and UR (difference = 35.36°, 10.18°, 6.73° respectively, P <0.05). Muscle release intervention immediately decreased pain (VAS drop 1.7, P <0.001); improved muscle activity during scaption (UT: 12.68% increase, LT: 35.46% increase, P <0.05) and hand to neck (UT: 12.14% increase, LT: 34.04% increase, P <0.05) task; and increased peak humeral elevation and scapular PT during scaption (95.18°±15.83° to 98.24°±15.57°, P=0.034; 11.06°±3.94° to 14.36°±4.65°, P=0.002), and increased scapular PT during the hand to neck (9.47°±3.86° to 12.80°±8.33°, P=0.025) task. No statistical significance was found for other group comparisons or intervention effect. Patients with FS presented with altered shoulder muscle activity and kinematics, and one-session of heat and manual muscle release showed beneficial effects on shoulder muscle performance, kinematics, mobility, and pain. Retrospectively registered on Jan 18, 2016 (ACTRN 12616000031460 ).

Scapular kinematics and muscle activities during pushing tasks.

PubMed

Huang, Chun-Kai; Siu, Ka-Chun; Lien, Hen-Yu; Lee, Yun-Ju; Lin, Yang-Hua

2013-01-01

Pushing tasks are functional activities of daily living. However, shoulder complaints exist among workers exposed to regular pushing conditions. It is crucial to investigate the control of shoulder girdles during pushing tasks. The objective of the study was to demonstrate scapular muscle activities and motions on the dominant side during pushing tasks and the relationship between scapular kinematics and muscle activities in different pushing conditions. Thirty healthy adults were recruited to push a four-wheel cart in six pushing conditions. The electromyographic signals of the upper trapezius (UT) and serratus anterior (SA) muscles were recorded. A video-based system was used for measuring the movement of the shoulder girdle and scapular kinematics. Differences in scapular kinematics and muscle activities due to the effects of handle heights and weights of the cart were analyzed using two-way ANOVA with repeated measures. The relationships between scapular kinematics and muscle activities were examined by Pearson's correlation coefficients. The changes in upper trapezius and serratus anterior muscle activities increased significantly with increased pushing weights in the one-step pushing phase. The UT/SA ratio on the dominant side decreases significantly with increased handle heights in the one-step pushing phase. The changes in upward rotation, lateral slide and elevation of the scapula decreased with increased pushing loads in the trunk-forward pushing phase. This study indicated that increased pushing loads result in decreased motions of upward rotation, lateral slide and elevation of the scapula; decreased handle heights result in relatively increased activities of the serratus anterior muscles during pushing tasks.

[Forensic identification of floating shoulder injury].

PubMed

Li, Sheng-Ya; Huang, Si-Xing; Zhao, Xing-Bin; Zheng, Xiao-Hong; Zhu, Yi

2006-10-15

To discuss forensic identification of floating shoulder injury (FSI). To analyze fifteen cases of FSI which were accepted from Jan. 1993 to Jan. 2006, including 15 shoulder neck fracture, 13 clavide stem fracture and 2 distal end clavide fracture, the function of shoulder joint was evaluated six months after injure considering the following three aspects: result of forensic examination such as X-ray photograph, CT and MRI, the injurers' symptom, objective sign and joint function, shoulder joint territory, degree of pain and local muscle power. Basing on the curative effect standard of Herscovic, all cases were divided into good. Modest, worst, which included 2, 4, 9 cases respectively; referring the standard of GA35-92, GB18667-2002, all cases were divided into six, seven, eight, nine and ten degree, which included 2,9,2,1,1 cases respectively. As a special powerful injure, FSI always companied with concurrent and multiple injure, and characterized by missed, incorrect and delayed diagnosis and infelicitous treatment, which lead to the high frequency and degree of injure. To prevent missed and incorrect forensic identification, we should have a full realization of the particularity of FSI, and evaluate the function of shoulder all-sidely, objectively and synseticaly.

Effectiveness of telerehabilitation programme following surgery in shoulder impingement syndrome (SIS): study protocol for a randomized controlled non-inferiority trial.

PubMed

Pastora-Bernal, Jose-Manuel; Martín-Valero, Rocío; Barón-López, Francisco Javier; García-Gómez, Oscar

2017-02-23

Shoulder pain is common in society, with high prevalence in the general population. Shoulder impingement syndrome (SIS) is the most frequent cause. Patients suffer pain, muscle weakness and loss of movement in the affected joint. Initial treatment is predominantly conservative. The surgical option has high success rates and is often used when conservative strategy fails. Traditional physiotherapy and post-operative exercises are needed for the recovery of joint range, muscle strength, stability and functionality. Telerehabilitation programmes have shown positive results in some orthopaedic conditions after surgery. Customized telerehabilitation intervention programmes should be developed to recover shoulder function after SIS surgery. The objective of this study is to evaluate the feasibility and effectiveness of a telerehabilitation intervention compared with usual care in patients after subacromial decompression surgery. We will compare an intervention group receiving videoconferences and a telerehabilitation programme to a control group receiving traditional physiotherapy intervention in a single-blind, randomized controlled non-inferiority trial study design. Through this study, we will further develop our preliminary data set and practical experience with the telerehabilitation programmes to evaluate their effectiveness and compare this with traditional intervention. We will also explore patient satisfaction and cost-effectiveness. Patient enrolment is ongoing. ClinicalTrials.gov, NCT02909920 . 14 September 2016.

Pilot study of a robotic protocol to treat shoulder subluxation in patients with chronic stroke

PubMed Central

2013-01-01

Background Shoulder subluxation is a frequent complication of motor impairment after stroke, leading to soft tissue damage, stretching of the joint capsule, rotator cuff injury, and in some cases pain, thus limiting use of the affected extremity beyond weakness. In this pilot study, we determined whether robotic treatment of chronic shoulder subluxation can lead to functional improvement and whether any improvement was robust. Methods 18 patients with chronic stroke (3.9 ± 2.9 years from acute stroke), completed 6 weeks of robotic training using the linear shoulder robot. Training was performed 3 times per week on alternate days. Each session consisted of 3 sets of 320 repetitions of the affected arm, and the robotic protocol alternated between training vertical arm movements, shoulder flexion and extension, in an anti-gravity plane, and training horizontal arm movements, scapular protraction and retraction, in a gravity eliminated plane. Results Training with the linear robot improved shoulder stability, motor power, and resulted in improved functional outcomes that were robust 3 months after training. Conclusion In this uncontrolled pilot study, the robotic protocol effectively treated shoulder subluxation in chronic stroke patients. Treatment of subluxation can lead to improved functional use of the affected arm, likely by increasing motor power in the trained muscles. PMID:23914834

Pilot study of a robotic protocol to treat shoulder subluxation in patients with chronic stroke.

PubMed

Dohle, Carolin I; Rykman, Avrielle; Chang, Johanna; Volpe, Bruce T

2013-08-05

Shoulder subluxation is a frequent complication of motor impairment after stroke, leading to soft tissue damage, stretching of the joint capsule, rotator cuff injury, and in some cases pain, thus limiting use of the affected extremity beyond weakness. In this pilot study, we determined whether robotic treatment of chronic shoulder subluxation can lead to functional improvement and whether any improvement was robust. 18 patients with chronic stroke (3.9 ± 2.9 years from acute stroke), completed 6 weeks of robotic training using the linear shoulder robot. Training was performed 3 times per week on alternate days. Each session consisted of 3 sets of 320 repetitions of the affected arm, and the robotic protocol alternated between training vertical arm movements, shoulder flexion and extension, in an anti-gravity plane, and training horizontal arm movements, scapular protraction and retraction, in a gravity eliminated plane. Training with the linear robot improved shoulder stability, motor power, and resulted in improved functional outcomes that were robust 3 months after training. In this uncontrolled pilot study, the robotic protocol effectively treated shoulder subluxation in chronic stroke patients. Treatment of subluxation can lead to improved functional use of the affected arm, likely by increasing motor power in the trained muscles.

Myofascial involvement of supra- and infraspinatus muscles contributes to ipsilateral shoulder pain after muscle-sparing thoracotomy and video-assisted thoracic surgery.

PubMed

Ohmori, Aki; Iranami, Hiroshi; Fujii, Keisuke; Yamazaki, Akinori; Doko, Yukari

2013-12-01

This study examined the hypothesis that ipsilateral upper extremity elevation for muscle-sparing thoracotomy procedures contributes to the postoperative shoulder pain. Prospective observational study. Medical center. ASA physical status 1-2 patients undergoing elective lung surgeries including pneumonectomy, lobectomy, and segmentectomy performed through either the anterolateral approach or video-assisted thoracotomy surgery. Postoperative observation of ipsilateral shoulder pain. Postoperative examinations of sites of shoulder pain (clavicle, anterior, lateral,or posterior aspect of acromion, posterior neck, supraspinatus, infraspinatus, and these entire areas) with or without trigger points, visual analog scale score of wound pain, and requested counts of analgesics. The number of patients who suffered from postoperative shoulder pain was 37 of 70 (52.9%). Demographic data, anterolateral/VATS ratio, VAS scores, and requested counts of rescue analgesics requirement were similar in the groups of patients with and without postoperative shoulder pain. The segmentectomy caused a significantly higher incidence of postoperative shoulder pain compared with other procedures (p < 0.05). The supra- and infraspinatus were significantly higher areas of painful regions compared to the other sites. The 16 of 37 patients (43.2%) with shoulder pain showed defined trigger points in their painful areas. These results supported the hypothesis that myofascial involvement contributed, to some extent, to shoulder pain after muscle-sparing thoracotomy with ipsilateral upper extremity elevation. Copyright © 2013 Elsevier Inc. All rights reserved.

Quantitative assessment of fatty infiltration and muscle volume of the rotator cuff muscles using 3-dimensional 2-point Dixon magnetic resonance imaging.

PubMed

Matsumura, Noboru; Oguro, Sota; Okuda, Shigeo; Jinzaki, Masahiro; Matsumoto, Morio; Nakamura, Masaya; Nagura, Takeo

2017-10-01

In patients with rotator cuff tears, muscle degeneration is known to be a predictor of irreparable tears and poor outcomes after surgical repair. Fatty infiltration and volume of the whole muscles constituting the rotator cuff were quantitatively assessed using 3-dimensional 2-point Dixon magnetic resonance imaging. Ten shoulders with a partial-thickness tear, 10 shoulders with an isolated supraspinatus tear, and 10 shoulders with a massive tear involving supraspinatus and infraspinatus were compared with 10 control shoulders after matching age and sex. With segmentation of muscle boundaries, the fat fraction value and the volume of the whole rotator cuff muscles were computed. After reliabilities were determined, differences in fat fraction, muscle volume, and fat-free muscle volume were evaluated. Intra-rater and inter-rater reliabilities were regarded as excellent for fat fraction and muscle volume. Tendon rupture adversely increased the fat fraction value of the respective rotator cuff muscle (P < .002). In the massive tear group, muscle volume was significantly decreased in the infraspinatus (P = .035) and increased in the teres minor (P = .039). With subtraction of fat volume, a significant decrease of fat-free volume of the supraspinatus muscle became apparent with a massive tear (P = .003). Three-dimensional measurement could evaluate fatty infiltration and muscular volume with excellent reliabilities. The present study showed that chronic rupture of the tendon adversely increases the fat fraction of the respective muscle and indicates that the residual capacity of the rotator cuff muscles might be overestimated in patients with severe fatty infiltration. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Measurement of muscle thickness of the serratus anterior and lower trapezius using ultrasound imaging in competitive recreational adult swimmers, with and without current shoulder pain.

PubMed

McKenna, Leanda J; de Ronde, Mandy; Le, Minyang; Burke, William; Graves, Anna; Williams, Sian A

2018-02-01

To compare serratus anterior and lower trapezius muscle thickness between swimmers with and without current shoulder pain, and between sides when measured by real-time ultrasound imaging. A single blinded age and gender-matched case-control study with 26 symptomatic and 26 asymptomatic recreational swimmers. Muscle thickness of serratus anterior and lower trapezius were measured using previously validated real-time ultrasound imaging protocols. Serratus anterior thickness was measured in side lying with 90° of glenohumeral flexion at rest and during a scapular protraction contraction. Lower trapezius thickness was measured in prone with 145° of glenohumeral abduction whilst at rest and when holding the weight of the arm. There was no statistically significant difference between the muscle thickness of serratus anterior and lower trapezius between the symptomatic shoulder and the dominance-matched shoulder in the asymptomatic group of swimmers. There was also no significant difference in muscle thickness between the symptomatic side and asymptomatic side within the symptomatic group. There appears to be no difference in serratus anterior and lower trapezius thickness between swimmers who have mild to moderate shoulder pain, who continue to swim and those who do not have shoulder pain. When imaging the serratus anterior and lower trapezius in swimmers with mild shoulder pain, clinicians should expect no differences between sides. If muscle thickness differences between sides are detected in recreational swimmers, this may indicate that the swimmer is participating in other asymmetrical activities or has a higher level of shoulder pain. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Quantify work load and muscle functional activation patterns in neck-shoulder muscles of female sewing machine operators using surface electromyogram.

PubMed

Zhang, Fei-Ruo; He, Li-Hua; Wu, Shan-Shan; Li, Jing-Yun; Ye, Kang-Pin; Wang, Sheng

2011-11-01

Work-related musculoskeletal disorders (WMSDs) have high prevalence in sewing machine operators employed in the garment industry. Long work duration, sustained low level work and precise hand work are the main risk factors of neck-shoulder disorders for sewing machine operators. Surface electromyogram (sEMG) offers a valuable tool to determine muscle activity (internal exposure) and quantify muscular load (external exposure). During sustained and/or repetitive muscle contractions, typical changes of muscle fatigue in sEMG, as an increase in amplitude or a decrease as a shift in spectrum towards lower frequencies, can be observed. In this paper, we measured and quantified the muscle load and muscular activity patterns of neck-shoulder muscles in female sewing machine operators during sustained sewing machine operating tasks using sEMG. A total of 18 healthy women sewing machine operators volunteered to participate in this study. Before their daily sewing machine operating task, we measured the maximal voluntary contractions (MVC) and 20%MVC of bilateral cervical erector spinae (CES) and upper trapezius (UT) respectively, then the sEMG signals of bilateral UT and CES were monitored and recorded continuously during 200 minutes of sustained sewing machine operating simultaneously which equals to 20 time windows with 10 minutes as one time window. After 200 minutes' work, we retest 20%MVC of four neck-shoulder muscles and recorded the sEMG signals. Linear analysis, including amplitude probability distribution frequency (APDF), amplitude analysis parameters such as roof mean square (RMS) and spectrum analysis parameter as median frequency (MF), were used to calculate and indicate muscle load and muscular activity of bilateral CES and UT. During 200 minutes of sewing machine operating, the median load for the left cervical erector spinae (LCES), right cervical erector spinae (RCES), left upper trapezius (LUT) and right upper trapezius (RUT) were 6.78%MVE, 6.94%MVE, 6.47%MVE and 5.68%MVE, respectively. Work load of right muscles are significantly higher than that of the left muscles (P < 0.05); sEMG signal analysis of isometric contractions indicated that the amplitude value before operating was significantly higher than that of after work (P < 0.01), and the spectrum value of bilateral CES and UT were significantly lower than those of after work (P < 0.01); according to the sEMG signal data of 20 time windows, with operating time pass by, the muscle activity patterns of bilateral CES and UT showed dynamic changes, the maximal amplitude of LCES, RCES, LUT occurred at the 20th time window, RUT at 16th time window, spectrum analysis showed that the lower value happened at 7th, 16th, 20th time windows. Female sewing machine operators were exposed to high sustained static load on bilateral neck-shoulder muscles; left neck and shoulder muscles were held in more static positions; the 7th, 16th, and 20th time windows were muscle fatigue period that ergonomics intervention can protocol at these periods.

Modifying a shrug exercise can facilitate the upward rotator muscles of the scapula.

PubMed

Pizzari, Tania; Wickham, James; Balster, Simon; Ganderton, Charlotte; Watson, Lyn

2014-02-01

Scapular dyskinesis, characterised by drooping scapulae and reduced upward rotation, has been implicated in the presentation of a number of shoulder disorders. Traditionally, in shoulder rehabilitation programmes, the shrug exercise has been prescribed to facilitate upward rotation of the scapula by strengthening the upper trapezius muscle. The aim of this research was to compare muscle activation levels during the standard shrug and the upward rotation shrug in a normal and pathological population. Surface electrodes recorded electromyographical activity from upper trapezius, middle trapezius, lower trapezius and serratus anterior muscles in 23 normal participants and 14 participants with multi-directional shoulder instability. Participants completed 10 trials of the standard shrug exercise at 0° of shoulder abduction and the upward rotation shrug exercise at 30° of shoulder abduction in the coronal plane. Muscle activity was expressed as a percentage of maximum voluntary isometric contraction. The four muscles tested performed at a higher intensity during the modified shrug than the standard shrug. Upper trapezius and lower trapezius activity was significantly greater (P < 0.05) in both populations. Though for middle trapezius and serratus anterior muscles, the modified shrug was statistically significant only in the normal population, P = 0.031 and P = <0.001 respectively. The upward rotation shrug is a more effective exercise for eliciting muscle activity of the upper and lower trapezius than the standard shrug in a normal and multi-directional instability population. Clinically, the upward rotation shrug might be useful to address scapular dyskinesis involving drooping shoulders and reduced scapula upward rotation. Copyright © 2013 Elsevier Ltd. All rights reserved.

The impact of shoulder abduction loading on EMG-based intention detection of hand opening and closing after stroke.

PubMed

Lan, Yiyun; Yao, Jun; Dewald, Julius P A

2011-01-01

Many stroke patients are subject to limited hand functions in the paretic arm due to a significant loss of Corticospinal Tract (CST) fibers. A possible solution for this problem is to classify surface Electromyography (EMG) signals generated by hand movements and uses that to implement Functional Electrical Stimulation (FES). However, EMG usually presents an abnormal muscle coactivation pattern shown as increased coupling between muscles within and/or across joints after stroke. The resulting Abnormal Muscle Synergies (AMS) could make the classification more difficult in individuals with stroke, especially when attempting to use the hand together with other joints in the paretic arm. Therefore, this study is aimed at identifying the impact of AMS following stroke on EMG pattern recognition between two hand movements. In an effort to achieve this goal, 7 chronic hemiparetic chronic stroke subjects were recruited and asked to perform hand opening and closing movements at their paretic arm while being either fully supported by a virtual table or loaded with 25% of subject's maximum shoulder abduction force. During the execution of motor tasks EMG signals from the wrist flexors and extensors were simultaneously acquired. Our results showed that increased synergy-induced activity at elbow flexors, induced by increasing shoulder abduction loading, deteriorated the performance of EMG pattern recognition for hand opening for those with a weak grasp strength and EMG activity. However, no such impact on hand closing has yet been observed possibly because finger/wrist flexion is facilitated by the shoulder abduction-induced flexion synergy.

Measurement of the trapezius muscle volume: A new assessment strategy of shoulder dysfunction after neck dissection for the treatment of head and neck cancers.

PubMed

Cho, Jae-Gu; Lee, Naree; Park, Min-Woo; Baek, Seung-Kuk; Kwon, Soon-Young; Jung, Kwang-Yoon; Woo, Jeong-Soo

2015-05-01

The purpose of this study was to determine the actual degree of shoulder muscle change and its relation to symptoms after neck dissection for head and neck cancers. Forty-two patients who underwent unilateral neck dissection were selected. Data obtained from each subject were trapezius muscle volume ratio and a Shoulder Disability Questionnaire (SDQ) score. Patients who had undergone neck dissection with spinal accessory nerve (SAN) preservation were compared with those who had received radical neck dissection. The preservation group was further separated into subgroups by the extent of neck dissection. Trapezius muscle volume ratio was higher and SDQ score was significantly lower in the SAN preservation group compared to the radical neck dissection group. However, the SAN preservation subgroups did not differ from each other. In addition, a good correlation between the muscle volume ratio and SDQ score was observed. With trapezius muscle volume ratio, clinicians may be able to diagnose shoulder dysfunction after neck dissection. Further research on the subject is warranted. This suggests a novel strategy for assessing the degree of shoulder dysfunction. © 2014 Wiley Periodicals, Inc.

Differential activation of parts of the latissimus dorsi with various isometric shoulder exercises.

PubMed

Park, Se-yeon; Yoo, Won-gyu

2014-04-01

As no study has examined whether the branches of the latissimus dorsi are activated differently in different exercises, we investigated intramuscular differences of components of the latissimus dorsi during various shoulder isometric exercises. Seventeen male subjects performed four isometric exercises: shoulder extension, adduction, internal rotation, and shoulder depression. Surface electromyography (sEMG) was used to collect data from the medial and lateral components of the latissimus dorsi during the isometric exercises. Two-way repeated analysis of variance with two within-subject factors (exercise condition and muscle branch) was used to determine the significance of differences between the branches, and which branch was activated more with the exercise variation. The root mean squared sEMG values for the muscles were normalized using the modified isolation equation (%Isolation) and maximum voluntary isometric contraction (%MVIC). Neither the %MVIC nor %Isolation data differed significantly between muscle branches, while there was a significant difference with exercise. %MVIC was significantly higher with shoulder extension, compared to the other isometric exercises. There was a significant correlation between exercise condition and muscle branch in the %Isolation data. Shoulder extension and adduction and internal rotation increased %Isolation of the medial latissimus dorsi more than shoulder depression. Shoulder depression had the highest value of %Isolation of the lateral latissimus dorsi compared to the other isometric exercises. Comparing the medial and lateral latissimus dorsi, the medial component was predominantly activated with shoulder extension, adduction, and internal rotation, and the lateral component with shoulder depression. Shoulder extension is effective for activating the latissimus dorsi regardless of the intramuscular branch. Copyright © 2014 Elsevier Ltd. All rights reserved.

Dynamic Analysis of the Abnormal Isometric Strength Movement Pattern between Shoulder and Elbow Joint in Patients with Hemiplegia.

PubMed

Liu, Yali; Hong, Yuezhen; Ji, Linhong

2018-01-01

Patients with hemiplegia usually have weak muscle selectivity and usually perform strength at a secondary joint (secondary strength) during performing a strength at one joint (primary strength). The abnormal strength pattern between shoulder and elbow joint has been analyzed by the maximum value while the performing process with strength changing from 0 to maximum then to 0 was a dynamic process. The objective of this study was to develop a method to dynamically analyze the strength changing process. Ten patients were asked to perform four group asks (maximum and 50% maximum voluntary strength in shoulder abduction, shoulder adduction, elbow flexion, and elbow extension). Strength and activities from seven muscles were measured. The changes of secondary strength had significant correlation with those of primary strength in all tasks ( R > 0.76, p < 0.01). The antagonistic muscles were moderately influenced by the primary strength ( R > 0.4, p < 0.01). Deltoid muscles, biceps brachii, triceps brachii, and brachioradialis had significant influences on the abnormal strength pattern (all p < 0.01). The dynamic method was proved to be efficient to analyze the different influences of muscles on the abnormal strength pattern. The muscles, deltoid muscles, biceps brachii, triceps brachii, and brachioradialis, much influenced the stereotyped movement pattern between shoulder and elbow joint.

Dynamic Analysis of the Abnormal Isometric Strength Movement Pattern between Shoulder and Elbow Joint in Patients with Hemiplegia

PubMed Central

2018-01-01

Patients with hemiplegia usually have weak muscle selectivity and usually perform strength at a secondary joint (secondary strength) during performing a strength at one joint (primary strength). The abnormal strength pattern between shoulder and elbow joint has been analyzed by the maximum value while the performing process with strength changing from 0 to maximum then to 0 was a dynamic process. The objective of this study was to develop a method to dynamically analyze the strength changing process. Ten patients were asked to perform four group asks (maximum and 50% maximum voluntary strength in shoulder abduction, shoulder adduction, elbow flexion, and elbow extension). Strength and activities from seven muscles were measured. The changes of secondary strength had significant correlation with those of primary strength in all tasks (R > 0.76, p < 0.01). The antagonistic muscles were moderately influenced by the primary strength (R > 0.4, p < 0.01). Deltoid muscles, biceps brachii, triceps brachii, and brachioradialis had significant influences on the abnormal strength pattern (all p < 0.01). The dynamic method was proved to be efficient to analyze the different influences of muscles on the abnormal strength pattern. The muscles, deltoid muscles, biceps brachii, triceps brachii, and brachioradialis, much influenced the stereotyped movement pattern between shoulder and elbow joint. PMID:29610654

Comparing trapezius muscle activity in the different planes of shoulder elevation

PubMed Central

Ishigaki, Tomonobu; Ishida, Tomoya; Samukawa, Mina; Saito, Hiroshi; Hirokawa, Motoki; Ezawa, Yuya; Sugawara, Makoto; Tohyama, Harukazu; Yamanaka, Masanori

2015-01-01

[Purpose] The purpose of this study was to compare the upper, middle, and lower trapezius muscles’ activity in the different planes of shoulder elevation. [Subjects] Twenty male subjects volunteered for this study. [Methods] Surface electromyographic (EMG) activity for each of the three regions of the trapezius muscles in the three different planes of elevation were collected while the participants maintained 30, 60, and 90 degrees of elevation in each plane. The EMG data were normalized with maximum voluntary isometric contraction (%MVIC), and compared among the planes at each angle of elevation. [Results] There were significantly different muscle activities among the elevation planes at each angle. [Conclusion] This study found that the three regions of the trapezius muscles changed their activity depending on the planes of shoulder elevation. These changes in the trapezius muscles could induce appropriate scapular motion to face the glenoid cavity in the correct directions in different planes of shoulder elevation. PMID:26157248

Activation of selected shoulder muscles during unilateral wall and bench press tasks under submaximal isometric effort.

PubMed

Tucci, Helga T; Ciol, Marcia A; de Araújo, Rodrigo C; de Andrade, Rodrigo; Martins, Jaqueline; McQuade, Kevin J; Oliveira, Anamaria S

2011-07-01

Controlled laboratory study. To assess the activation of 7 shoulder muscles under 2 closed kinetic chain (CKC) tasks for the upper extremity using submaximal isometric effort, thus providing relative quantification of muscular isometric effort for these muscles across the CKC exercises, which may be applied to rehabilitation protocols for individuals with shoulder weakness. CKC exercises favor joint congruence, reduce shear load, and promote joint dynamic stability. Additionally, knowledge about glenohumeral and periscapular muscle activity elicited during CKC exercises may help clinicians to design protocols for shoulder rehabilitation. Using surface electromyography, activation level was measured across 7 shoulder muscles in 20 healthy males, during the performance of a submaximal isometric wall press and bench press. Signals were normalized to the maximal voluntary isometric contraction, and, using paired t tests, data were analyzed between the exercises for each muscle. Compared to the wall press, the bench press elicited higher activity for most muscles, except for the upper trapezius. Levels of activity were usually low but were above 20% maximal voluntary isometric contraction for the serratus anterior on both tasks, and for the long head triceps brachii on the bench press. Both the bench press and wall press, as performed in this study, led to relatively low EMG activation levels for the muscles measured and may be considered for use in the early phases of rehabilitation.

Suprascapular neuropathy after intensive progressive resistive exercise: case report.

PubMed

Agre, J C; Ash, N; Cameron, M C; House, J

1987-04-01

A healthy 30-year-old man developed pain in the posterior shoulder region approximately one month after initiating an intensive weightlifting program to increase upper extremity strength. This program especially emphasized shoulder abduction exercises. The pain intensified as he continued and finally he noted weakness of the involved shoulder, which led him to seek medical advice. Examination was normal except for atrophy of the infraspinatus muscle on the involved side and decreased strength of shoulder abduction and external rotation. Electromyographic examination demonstrated 3+ positive sharp waves in the infraspinatus muscle, delayed conduction to the supraspinatus muscle, and absence of an evoked response to the infraspinatus muscle. Surgical decompression of the suprascapular nerve within the suprascapular notch was then performed. Two weeks after surgery the pain was much less and the conduction velocities had improved. Eight months after surgery the patient was free of pain, the conduction velocities had returned to normal, and electromyography revealed reinnervation of the denervated muscle fibers. Intensive shoulder exercise, especially involving repeated forceful abduction movements, should be considered in the etiology of suprascapular neuropathy.

Relationship of Tear Size and Location to Fatty Degeneration of the Rotator Cuff

PubMed Central

Kim, H. Mike; Dahiya, Nirvikar; Teefey, Sharlene A.; Keener, Jay D.; Galatz, Leesa M.; Yamaguchi, Ken

2010-01-01

Background: Fatty degeneration of the rotator cuff muscles may have detrimental effects on both anatomical and functional outcomes following shoulder surgery. The purpose of this study was to investigate the relationship between tear geometry and muscle fatty degeneration in shoulders with a deficient rotator cuff. Methods: Ultrasonograms of both shoulders of 262 patients were reviewed to assess the type of rotator cuff tear and fatty degeneration in the supraspinatus and infraspinatus muscles. The 251 shoulders with a full-thickness tear underwent further evaluation for tear size and location. The relationship of tear size and location to fatty degeneration of the supraspinatus and infraspinatus muscles was investigated with use of statistical comparisons and regression models. Results: Fatty degeneration was found almost exclusively in shoulders with a full-thickness rotator cuff tear. Of the 251 shoulders with a full-thickness tear, eighty-seven (34.7%) had fatty degeneration in either the supraspinatus or infraspinatus, or both. Eighty-two (32.7%) of the 251 full-thickness tears had a distance of 0 mm between the biceps tendon and anterior margin of the tear. Ninety percent of the full-thickness tears with fatty degeneration in both muscles had a distance of 0 mm posterior from the biceps, whereas only 9% of those without fatty degeneration had a distance of 0 mm. Tears with fatty degeneration had significantly greater width and length than those without fatty degeneration (p < 0.0001). Tears with fatty degeneration had a significantly shorter distance posterior from the biceps than those without fatty degeneration (p < 0.0001). The distance posterior from the biceps was found to be the most important predictor for supraspinatus fatty degeneration, whereas tear width and length were found to be the most important predictors for infraspinatus fatty degeneration. Conclusions: Fatty degeneration of the rotator cuff muscles is closely associated with tear size and location. The finding of this study suggests that the integrity of the anterior supraspinatus tendon is important to the development of fatty degeneration. Patients with full-thickness tears that extend through this area may benefit from earlier surgical intervention if fatty degeneration has not already occurred. Additionally, the findings suggest the importance of secure fixation and healing of the anterior aspect of the supraspinatus with surgical repair. PMID:20360505

Serratus Anterior and Lower Trapezius Muscle Activities During Multi-Joint Isotonic Scapular Exercises and Isometric Contractions.

PubMed

Tsuruike, Masaaki; Ellenbecker, Todd

2014-11-14

Context :  Proper scapular function during humeral elevation, such as upward rotation, external rotation, and posterior tilting of the scapula, is necessary to prevent shoulder injury. However, the appropriate intensity of rehabilitation exercise for the periscapular muscles has yet to be clarified. Objective :  To identify the serratus anterior, lower trapezius, infraspinatus, and posterior deltoid muscle activities during 2 free-motion exercises using 3 intensities and to compare these muscle activities with isometric contractions during quadruped shoulder flexion and external rotation and abduction of the glenohumeral joint. Design :  Cross-sectional study. Setting :  Health Science Laboratory. Patients or Other Participants :  A total of 16 uninjured, healthy, active, male college students (age = 19.5 ± 1.2 years, height = 173.1 ± 6.5 cm, weight = 68.8 ± 6.6 kg). Main Outcome Measure(s) :  Mean electromyographic activity normalized by the maximal voluntary isometric contraction was analyzed across 3 intensities and 5 exercises. Intraclass correlation coefficients were calculated for electromyographic activity of the 4 muscles in each free-motion exercise. Results :  Significant interactions in electromyographic activity were observed between intensities and exercises (P < .05). The quadruped shoulder-flexion exercise activated all 4 muscles compared with other exercises. Also, the modified robbery free-motion exercise activated the serratus anterior, lower trapezius, and infraspinatus compared with the lawn-mower free-motion exercise. However, neither exercise showed a difference in posterior deltoid electromyographic activity. Conclusions :  Three intensities exposed the nature of the periscapular muscle activities across the different exercises. The free-motion exercise in periscapular muscle rehabilitation may not modify serratus anterior, lower trapezius, and infraspinatus muscle activities unless knee-joint extension is limited.

Serratus Anterior and Lower Trapezius Muscle Activities During Multi-Joint Isotonic Scapular Exercises and Isometric Contractions

PubMed Central

Tsuruike, Masaaki; Ellenbecker, Todd S.

2015-01-01

Context: Proper scapular function during humeral elevation, such as upward rotation, external rotation, and posterior tilting of the scapula, is necessary to prevent shoulder injury. However, the appropriate intensity of rehabilitation exercise for the periscapular muscles has yet to be clarified. Objective: To identify the serratus anterior, lower trapezius, infraspinatus, and posterior deltoid muscle activities during 2 free-motion exercises using 3 intensities and to compare these muscle activities with isometric contractions during quadruped shoulder flexion and external rotation and abduction of the glenohumeral joint. Design: Cross-sectional study. Setting: Health Science Laboratory. Patients or Other Participants: A total of 16 uninjured, healthy, active, male college students (age = 19.5 ± 1.2 years, height = 173.1 ± 6.5 cm, weight = 68.8 ± 6.6 kg). Main Outcome Measure(s): Mean electromyographic activity normalized by the maximal voluntary isometric contraction was analyzed across 3 intensities and 5 exercises. Intraclass correlation coefficients were calculated for electromyographic activity of the 4 muscles in each free-motion exercise. Results: Significant interactions in electromyographic activity were observed between intensities and exercises (P < .05). The quadruped shoulder-flexion exercise activated all 4 muscles compared with other exercises. Also, the modified robbery free-motion exercise activated the serratus anterior, lower trapezius, and infraspinatus compared with the lawn-mower free-motion exercise. However, neither exercise showed a difference in posterior deltoid electromyographic activity. Conclusions: Three intensities exposed the nature of the periscapular muscle activities across the different exercises. The free-motion exercise in periscapular muscle rehabilitation may not modify serratus anterior, lower trapezius, and infraspinatus muscle activities unless knee-joint extension is limited. PMID:25689561

A unique problem of muscle adaptation from weightlessness: The deceleration deficiency

NASA Technical Reports Server (NTRS)

Stauber, William T.

1989-01-01

Decelerator problems of the knee are emphasized since the lower leg musculature is known to atrophy in response to weightlessness. However, other important decelerator functions are served by the shoulder muscles, in particular the rotator cuff muscles. Problems in these muscles often result in tears and dislocations as seen in baseball pitchers. It is noteworthy that at least one device currently exists that can measure concentric and eccentric muscle loading including a submaximal simulated free weight exercise (i.e., force-controlled) and simultaneously record integrated EMG analysis appropriate for assessment of all muscle functional activities. Studies should be undertaken to provide information as to the performance of maximal and submaximal exercise in space travelers to define potential problems and provide rationale for prevention.

Work-related shoulder-neck complaints in industry: a pilot study.

PubMed

Bjelle, A; Hagberg, M; Michaelson, G

1987-10-01

Twenty-six industrial workers, selected from employment records, were examined with a questionnaire, anthropometric measures, muscle strength measurements and filming during work cycles to study the influence of ergonomic factors on shoulder-neck complaints. No differences were observed when comparing age or anthropometric measurements between the nine workers with and the 17 without shoulder-neck complaints. Significantly weaker shoulder muscles were found in workers with shoulder-neck complaints than in those without. A higher median strain on the shoulders in the working situation of workers with shoulder-neck complaints than in the group with no complaints was suggested from the results of a biomechanical analysis of the different work tasks.

Corticomotor excitability of arm muscles modulates according to static position and orientation of the upper limb.

PubMed

Mogk, Jeremy P M; Rogers, Lynn M; Murray, Wendy M; Perreault, Eric J; Stinear, James W

2014-10-01

We investigated how multi-joint changes in static upper limb posture impact the corticomotor excitability of the posterior deltoid (PD) and biceps brachii (BIC), and evaluated whether postural variations in excitability related directly to changes in target muscle length. The amplitude of individual motor evoked potentials (MEPs) was evaluated in each of thirteen different static postures. Four functional postures were investigated that varied in shoulder and elbow angle, while the forearm was positioned in each of three orientations. Posture-related changes in muscle lengths were assessed using a biomechanical arm model. Additionally, M-waves were evoked in the BIC in each of three forearm orientations to assess the impact of posture on recorded signal characteristics. BIC-MEP amplitudes were altered by shoulder and elbow posture, and demonstrated robust changes according to forearm orientation. Observed changes in BIC-MEP amplitudes exceeded those of the M-waves. PD-MEP amplitudes changed predominantly with shoulder posture, but were not completely independent of influence from forearm orientation. Results provide evidence that overall corticomotor excitability can be modulated according to multi-joint upper limb posture. The ability to alter motor pathway excitability using static limb posture suggests the importance of posture selection during rehabilitation aimed at retraining individual muscle recruitment and/or overall coordination patterns. Published by Elsevier Ireland Ltd.

The isokinetic rotator cuff strength ratios in overhead athletes: Assessment and exercise effect.

PubMed

Berckmans, Kelly; Maenhout, Annelies G; Matthijs, Lien; Pieters, Louise; Castelein, Birgit; Cools, Ann M

2017-09-01

Muscle strength imbalance in the shoulder region can be considered as a predisposing factor in the development of movement dysfunctions, possibly leading to overuse injuries. Repetitive overhead throwing, performed in sports, may result in muscle imbalance between the external (ER) and internal (IR) rotators. Muscle strength measured with an isokinetic device, is reported as a concentric (CON) or eccentric (ECC) force. The balance between an agonist and an antagonist is mentioned as a ratio (CON/CON or ECC/CON). The aim of this systematic literature review is to provide an overview of the existing evidence considering the isokinetic muscle strength ratios of ER and IR of the shoulder in healthy overhead athletes. In addition, the effect of exercise programs on these ratios was investigated. Two online databases (Web of Science and PubMed) were consulted using different search strategies. Articles were selected based on inclusion and exclusion criteria. All included articles were assessed on their methodological quality. There is moderate evidence for a lower functional deceleration ratio (ECC ER/CON IR) at the dominant side. This lower ratio is due to a large overweight of CON IR strength on that side. There is no consensus about which exercise program is the most effective in altering the shoulder isokinetic strength ratios. Copyright © 2017 Elsevier Ltd. All rights reserved.

Control of Leg Movements Driven by EMG Activity of Shoulder Muscles

PubMed Central

La Scaleia, Valentina; Sylos-Labini, Francesca; Hoellinger, Thomas; Wang, Letian; Cheron, Guy; Lacquaniti, Francesco; Ivanenko, Yuri P.

2014-01-01

During human walking, there exists a functional neural coupling between arms and legs, and between cervical and lumbosacral pattern generators. Here, we present a novel approach for associating the electromyographic (EMG) activity from upper limb muscles with leg kinematics. Our methodology takes advantage of the high involvement of shoulder muscles in most locomotor-related movements and of the natural co-ordination between arms and legs. Nine healthy subjects were asked to walk at different constant and variable speeds (3–5 km/h), while EMG activity of shoulder (deltoid) muscles and the kinematics of walking were recorded. To ensure a high level of EMG activity in deltoid, the subjects performed slightly larger arm swinging than they usually do. The temporal structure of the burst-like EMG activity was used to predict the spatiotemporal kinematic pattern of the forthcoming step. A comparison of actual and predicted stride leg kinematics showed a high degree of correspondence (r > 0.9). This algorithm has been also implemented in pilot experiments for controlling avatar walking in a virtual reality setup and an exoskeleton during over-ground stepping. The proposed approach may have important implications for the design of human–machine interfaces and neuroprosthetic technologies such as those of assistive lower limb exoskeletons. PMID:25368569

Control of Leg Movements Driven by EMG Activity of Shoulder Muscles.

PubMed

La Scaleia, Valentina; Sylos-Labini, Francesca; Hoellinger, Thomas; Wang, Letian; Cheron, Guy; Lacquaniti, Francesco; Ivanenko, Yuri P

2014-01-01

During human walking, there exists a functional neural coupling between arms and legs, and between cervical and lumbosacral pattern generators. Here, we present a novel approach for associating the electromyographic (EMG) activity from upper limb muscles with leg kinematics. Our methodology takes advantage of the high involvement of shoulder muscles in most locomotor-related movements and of the natural co-ordination between arms and legs. Nine healthy subjects were asked to walk at different constant and variable speeds (3-5 km/h), while EMG activity of shoulder (deltoid) muscles and the kinematics of walking were recorded. To ensure a high level of EMG activity in deltoid, the subjects performed slightly larger arm swinging than they usually do. The temporal structure of the burst-like EMG activity was used to predict the spatiotemporal kinematic pattern of the forthcoming step. A comparison of actual and predicted stride leg kinematics showed a high degree of correspondence (r > 0.9). This algorithm has been also implemented in pilot experiments for controlling avatar walking in a virtual reality setup and an exoskeleton during over-ground stepping. The proposed approach may have important implications for the design of human-machine interfaces and neuroprosthetic technologies such as those of assistive lower limb exoskeletons.

A comparison of muscle activity in using touchscreen smartphone among young people with and without chronic neck-shoulder pain.

PubMed

Xie, Yanfei; Szeto, Grace P Y; Dai, Jie; Madeleine, Pascal

2016-01-01

This study aimed to examine differences in muscle activity between young people with and without neck-shoulder pain (n = 20 in each group), when they performed texting on a smartphone. Texting was compared between using both hands ('bilateral texting') and with only one hand ('unilateral texting'). Texting tasks were also compared with computer typing. Surface electromyography from three proximal postural muscles and four distal hand/thumb muscles on the right side was recorded. Compared with healthy controls, young people with neck-shoulder pain showed altered motor control consisting of higher muscle activity in the cervical erector spinae and upper trapezius when performing texting and typing tasks. Generally, unilateral texting was associated with higher muscle loading compared with bilateral texting especially in the forearm muscles. Compared with computer typing, smartphone texting was associated with higher activity in neck extensor and thumb muscles but lower activity in upper and lower trapezius as well as wrist extensors. This study demonstrated that symptomatic individuals had increased muscle activity in the neck–shoulder region when texting on a smartphone. Contemporary ergonomic guidelines should include advice on how to interact with handheld electronic devices to achieve a relaxed posture and reduced muscle load in order to reduce the risk of musculoskeletal disorders.

Bilateral Forearm Transplantation in Mexico: 2-Year Outcomes.

PubMed

Iglesias, Martin; Butron, Patricia; Moran-Romero, Mario; Cruz-Reyes, Angel; Alberu-Gomez, Josefina; Leal-Villalpando, Paulino; Bautista-Zamudio, Jorge; Ramirez-Berumen, Maria; Lara-Hinojosa, Euridice; Espinosa-Cruz, Veronica; Gaytan-Cervantes, Rocio; Bravo-Ruiz, Leonardo; Rodriguez-Rojas, Elizabeth; Ramos-Peek, Jaime; Garcia-Alvarez, Miriam; Vega-Boada, Felipe; Sierra-Madero, Juan; Gamboa-Dominguez, Armando; Gonzalez-Sanchez, Judith; Contreras-Barbosa, Sarai; Navarro-Lara, Africa; Vazquez-Lamadrid, Jorge; Guzman-Gonzalez, Juan

2016-01-01

Patients with proximal forearm and arm transplantation have obtained and/or maintained function of the elbow joint and full active range of motion of the extrinsic muscles of the hand, but with diminished protective sensibility and a lack of good function of the intrinsic muscles. These patients have improved function, as measured by the Disabilities of the Arm, Shoulder and Hand questionnaire. We report the case of a 52-year-old man who suffered a high-voltage electrical burn requiring amputation of his upper limbs. He underwent bilateral proximal forearm transplantation in Mexico City in May 2012. At 2-year follow-up, immunosuppressive treatment has not led to metabolic, oncologic, or infectious complications. Keloid scars developed at the graft-recipient interface. There have been 4 acute rejections: the fourth was treated with methylprednisolone, rituximab, and immunoglobulin. Chronic rejection has not been detected. The extrinsic muscles of the wrist and digits have good function. Although the intrinsic muscles demonstrated electrical activity 15 months postoperatively, clinically, they are nonuseful. After 2 years, hand function is sufficient to allow the patient to grasp lightweight and medium-sized objects. The patient's Disabilities of the Arm, Shoulder and Hand questionnaire score improved from 50.00 points to 30.83 points, and his Hand Transplantation Score System rating is good, at 69/73 (right/left) of 100. The patient and his family are very satisfied with the functional and aesthetic outcomes. Upper arm or proximal forearm transplantation is a reconstructive option for patients who have experienced amputation because of trauma.

Does a SLAP lesion affect shoulder muscle recruitment as measured by EMG activity during a rugby tackle?

PubMed Central

2010-01-01

Background The study objective was to assess the influence of a SLAP lesion on onset of EMG activity in shoulder muscles during a front on rugby football tackle within professional rugby players. Methods Mixed cross-sectional study evaluating between and within group differences in EMG onset times. Testing was carried out within the physiotherapy department of a university sports medicine clinic. The test group consisted of 7 players with clinically diagnosed SLAP lesions, later verified on arthroscopy. The reference group consisted of 15 uninjured and full time professional rugby players from within the same playing squad. Controlled tackles were performed against a tackle dummy. Onset of EMG activity was assessed from surface EMG of Pectorialis Major, Biceps Brachii, Latissimus Dorsi, Serratus Anterior and Infraspinatus muscles relative to time of impact. Analysis of differences in activation timing between muscles and limbs (injured versus non-injured side and non injured side versus matched reference group). Results Serratus Anterior was activated prior to all other muscles in all (P = 0.001-0.03) subjects. In the SLAP injured shoulder Biceps was activated later than in the non-injured side. Onset times of all muscles of the non-injured shoulder in the injured player were consistently earlier compared with the reference group. Whereas, within the injured shoulder, all muscle activation timings were later than in the reference group. Conclusions This study shows that in shoulders with a SLAP lesion there is a trend towards delay in activation time of Biceps and other muscles with the exception of an associated earlier onset of activation of Serratus anterior, possibly due to a coping strategy to protect glenohumeral stability and thoraco-scapular stability. This trend was not statistically significant in all cases PMID:20184752

An explorative, cross-sectional study into abnormal muscular coupling during reach in chronic stroke patients

PubMed Central

2010-01-01

Background In many stroke patients arm function is limited, which can be related to an abnormal coupling between shoulder and elbow joints. The extent to which this can be translated to activities of daily life (ADL), in terms of muscle activation during ADL-like movements, is rather unknown. Therefore, the present study examined the occurrence of abnormal coupling on functional, ADL-like reaching movements of chronic stroke patients by comparison with healthy persons. Methods Upward multi-joint reaching movements (20 repetitions at a self-selected speed to resemble ADL) were compared in two conditions: once facilitated by arm weight compensation and once resisted to provoke a potential abnormal coupling. Changes in movement performance (joint angles) and muscle activation (amplitude of activity and co-activation) between conditions were compared between healthy persons and stroke patients using a repeated measures ANOVA. Results The present study showed slight changes in joint excursion and muscle activation of stroke patients due to shoulder elevation resistance during functional reach. Remarkably, in healthy persons similar changes were observed. Even the results of a sub-group of the more impaired stroke patients did not point to an abnormal coupling between shoulder elevation and elbow flexion during functional reach. Conclusions The present findings suggest that in mildly and moderately affected chronic stroke patients ADL-like arm movements are not substantially affected by abnormal synergistic coupling. In this case, it is implied that other major contributors to limitations in functional use of the arm should be identified and targeted individually in rehabilitation, to improve use of the arm in activities of daily living. PMID:20233402

Ipsilateral EEG mu rhythm reflects the excitability of uncrossed pathways projecting to shoulder muscles.

PubMed

Hasegawa, Keita; Kasuga, Shoko; Takasaki, Kenichi; Mizuno, Katsuhiro; Liu, Meigen; Ushiba, Junichi

2017-08-25

Motor planning, imagery or execution is associated with event-related desynchronization (ERD) of mu rhythm oscillations (8-13 Hz) recordable over sensorimotor areas using electroencephalography (EEG). It was shown that motor imagery involving distal muscles, e.g. finger movements, results in contralateral ERD correlating with increased excitability of the contralateral corticospinal tract (c-CST). Following the rationale that purposefully increasing c-CST excitability might facilitate motor recovery after stroke, ERD recently became an attractive target for brain-computer interface (BCI)-based neurorehabilitation training. It was unclear, however, whether ERD would also reflect excitability of the ipsilateral corticospinal tract (i-CST) that mainly innervates proximal muscles involved in e.g. shoulder movements. Such knowledge would be important to optimize and extend ERD-based BCI neurorehabilitation protocols, e.g. to restore shoulder movements after stroke. Here we used single-pulse transcranial magnetic stimulation (TMS) targeting the ipsilateral primary motor cortex to elicit motor evoked potentials (MEPs) of the trapezius muscle. To assess whether ERD reflects excitability of the i-CST, a correlation analysis between between MEP amplitudes and ipsilateral ERD was performed. Experiment 1 consisted of a motor execution task during which 10 healthy volunteers performed elevations of the shoulder girdle or finger pinching while a 128-channel EEG was recorded. Experiment 2 consisted of a motor imagery task during which 16 healthy volunteers imagined shoulder girdle elevations or finger pinching while an EEG was recorded; the participants simultaneously received randomly timed, single-pulse TMS to the ipsilateral primary motor cortex. The spatial pattern and amplitude of ERD and the amplitude of the agonist muscle's TMS-induced MEPs were analyzed. ERDs occurred bilaterally during both execution and imagery of shoulder girdle elevations, but were lateralized to the contralateral hemisphere during finger pinching. We found that trapezius MEPs increased during motor imagery of shoulder elevations and correlated with ipsilateral ERD amplitudes. Ipsilateral ERD during execution and imagery of shoulder girdle elevations appears to reflect the excitability of uncrossed pathways projecting to the shoulder muscles. As such, ipsilateral ERD could be used for neurofeedback training of shoulder movement, aiming at reanimation of the i-CST.

Neural Crest Origins of the Neck and Shoulder

PubMed Central

Matsuoka, Toshiyuki; Ahlberg, Per E.; Kessaris, Nicoletta; Iannarelli, Palma; Dennehy, Ulla; Richardson, William D.; McMahon, Andrew P.; Koentges, Georgy

2005-01-01

Summary The neck and shoulder region of vertebrates has undergone a complex evolutionary history. In order to identify its underlying mechanisms we map the destinations of embryonic neural crest and mesodermal stem cells using novel Cre-recombinase mediated transgenesis. The single-cell resolution of this genetic labelling reveals cryptic cell boundaries traversing seemingly homogeneous skeleton of neck and shoulders. Within this complex assembly of bones and muscles we discern a precise code of connectivity that mesenchymal stem cells of neural crest and mesodermal origin both obey as they form muscle scaffolds. Neural crest anchors the head onto the anterior lining of the shoulder girdle, while a Hox gene controlled mesoderm links trunk muscles to the posterior neck and shoulder skeleton. The skeleton that we identify as neural crest is specifically affected in human Klippel-Feil syndrome, Sprengel’s deformity and Arnold-Chiari I/II malformation, providing first insights into their likely aetiology. We identify genes involved in the cellular modularity of neck and shoulder skeleton and propose a new methodology for determining skeletal homologies that is based on muscle attachments. This has allowed us to trace the whereabouts of the cleithrum, the major shoulder bone of extinct land vertebrate ancestors which appears to survive as the scapular spine in living mammals. PMID:16034409

Acute effect and time course of extension and internal rotation stretching of the shoulder on infraspinatus muscle hardness.

PubMed

Kusano, Ken; Nishishita, Satoru; Nakamura, Masatoshi; Tanaka, Hiroki; Umehara, Jun; Ichihashi, Noriaki

2017-10-01

A decrease in flexibility of the infraspinatus muscle causes limitations in the range of shoulder motion. Static stretching (SS) is a useful method to improve muscle flexibility and joint mobility. Previous researchers investigated effective stretching methods for the infraspinatus. However, few researchers investigated the acute effect of SS on the infraspinatus muscle's flexibility. In addition, the minimum SS time required to increase the infraspinatus muscle's flexibility remains unclear. The aims of this study included investigating the acute effect of SS on the infraspinatus muscle's hardness (an index of muscle flexibility) by measuring shear elastic modulus and determining minimum SS time to decrease the infraspinatus muscle's hardness. This included measuring the effect of SS with extension and internal rotation of the shoulder on the infraspinatus muscle's hardness in 20 healthy men. Hence, shear elastic modulus of the infraspinatus was measured by ultrasonic shear wave elastography before and after every 10 seconds up to 120 seconds of SS. Two-way analysis of variance indicated a significant main effect of SS duration on shear elastic modulus. The post hoc test indicated no significant difference between shear elastic modulus after 10 seconds of SS and that before SS. However, shear elastic modulus immediately after a period ranging from 20 seconds to 120 seconds of SS was significantly lower than that before SS. The results suggested that shoulder extension and internal rotation SS effectively decreased the infraspinatus muscle's hardness. In addition, the results indicated that a period exceeding 20 seconds of SS decreased the infraspinatus muscle's hardness. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

A fundamental model of quasi-static wheelchair biomechanics.

PubMed

Leary, M; Gruijters, J; Mazur, M; Subic, A; Burton, M; Fuss, F K

2012-11-01

The performance of a wheelchair system is a function of user anatomy, including arm segment lengths and muscle parameters, and wheelchair geometry, in particular, seat position relative to the wheel hub. To quantify performance, researchers have proposed a number of predictive models. In particular, the model proposed by Richter is extremely useful for providing initial analysis as it is simple to apply and provides insight into the peak and transient joint torques required to achieve a given angular velocity. The work presented in this paper identifies and corrects a critical error; specifically that the Richter model incorrectly predicts that shoulder torque is due to an anteflexing muscle moment. This identified error was confirmed analytically, graphically and numerically. The authors have developed a corrected, fundamental model which identifies that the shoulder anteflexes only in the first half of the push phase and retroflexes in the second half. The fundamental model has been extended by the authors to obtain novel data on joint and net power as a function of push progress. These outcomes indicate that shoulder power is positive in the first half of the push phase (concentrically contracting anteflexors) and negative in the second half (eccentrically contracting retroflexors). As the eccentric contraction introduces adverse negative power, these considerations are essential when optimising wheelchair design in terms of the user's musculoskeletal system. The proposed fundamental model was applied to assess the effect of vertical seat position on joint torques and power. Increasing the seat height increases the peak positive (concentric) shoulder and elbow torques while reducing the associated (eccentric) peak negative torque. Furthermore, the transition from positive to negative shoulder torque (as well as from positive to negative power) occurs later in the push phase with increasing seat height. These outcomes will aid in the optimisation of manual wheelchair propulsion biomechanics by minimising adverse negative muscle power, and allow joint torques to be manipulated as required to minimise injury or aid in rehabilitation. Copyright © 2012. Published by Elsevier Ltd.

Shoulder isokinetic profile of male handball players of the Brazilian National Team

PubMed Central

Andrade, Marília S.; Vancini, Rodrigo L.; de Lira, Claudio A. B.; Mascarin, Naryana C.; Fachina, Rafael J. F. G.; da Silva, Antonio C.

2013-01-01

Background Data obtained on an isokinetic dynamometer are useful to characterize muscle status and have been reported in muscle imbalance studies in different types of sport. However, few studies have assessed elite handball players to establish reference values. Objective The purpose of this study was to compare, for the dominant (D) and non-dominant (ND) side, the isokinetic profile of shoulder rotator muscle strength between male handball players (H) and asymptomatic non-athletes (NA). Method Isokinetic concentric and eccentric strength tests for D upper limbs were performed by the H group (n=20) and the NA group (n=12). Internal and external rotator muscle peak torque in concentric action was assessed at 60°/s and 300°/s and in eccentric action at 300°/s. We also calculated conventional balance (the ratio of external rotator peak torque to internal rotator peak torque in concentric action) and functional balance (the ratio of external rotator peak torque in eccentric action to internal rotator peak torque in concentric action). Results In the H group, dominant limbs were stronger in concentric action for external rotation at 60 and 300°/s. The conventional balance ratio for the D side was significantly lower at 60 and 300°/s for H compared to NA. The functional ratio for the D side was significantly lower at 300º/s for H compared to NA. Conclusions Compared to asymptomatic non-athletes, handball players presented significant muscular imbalance resulting from daily sports practice, a known risk factor for shoulder injuries. PMID:24271090

Effect of lateralized design on muscle and joint reaction forces for reverse shoulder arthroplasty.

PubMed

Liou, William; Yang, Yang; Petersen-Fitts, Graysen R; Lombardo, Daniel J; Stine, Sasha; Sabesan, Vani J

2017-04-01

Manufacturers of reverse shoulder arthroplasty (RSA) implants have recently designed innovative implants to optimize performance in rotator cuff-deficient shoulders. These advancements are not without tradeoffs and can have negative biomechanical effects. The objective of this study was to develop an integrated finite element analysis-kinematic model to compare the muscle forces and joint reaction forces (JRFs) of 3 different RSA designs. A kinematic model of a normal shoulder joint was adapted from the Delft model and integrated with the well-validated OpenSim shoulder model. Static optimizations then allowed for calculation of the individual muscle forces, moment arms, and JRFs relative to net joint moments. Three-dimensional computer models of 3 RSA designs-humeral lateralized design (HLD), glenoid lateralized design, and Grammont design-were integrated, and parametric studies were performed. Overall, there were decreases in deltoid and rotator cuff muscle forces for all 3 RSA designs. These decreases were greatest in the middle deltoid of the HLD model for abduction and flexion and in the rotator cuff muscles under both internal rotation and external rotation. The JRFs in abduction and flexion decreased similarly for all RSA designs compared with the normal shoulder model, with the greatest decrease seen in the HLD model. These findings demonstrate that the design characteristics implicit in these modified RSA prostheses result in mechanical differences most prominently seen in the deltoid muscle and overall JRFs. Further research using this novel integrated model can help guide continued optimization of RSA design and clinical outcomes. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

The Acute Effect of Cryotherapy on Muscle Strength and Shoulder Proprioception.

PubMed

Torres, Rui; Silva, Filipa; Pedrosa, Vera; Ferreira, João; Lopes, Alexandre

2017-11-01

Cryotherapy, a common intervention used by clinicians, poses several benefits in managing acute injuries. However, cooling muscle tissue can interfere with muscular properties and the sensory-motor system. The aim of this study was to analyze the influence of cryotherapy with a crushed-ice pack on shoulder proprioception concerning joint position sense, force sense, the threshold for detecting passive movement, and maximal force production. A randomized, double-blind controlled trial. 48 healthy women aged 22.6 ± 0.4 y with a mean body mass index of 22.8 ±0.37 kg/m2 and a percentage of body fat of 15.4 ± 1.5%. In the experimental group, a crushed-ice pack was applied to the shoulder for 15 min, whereas participants in the control group applied a sandbag at skin temperature, also for 15 min. An isokinetic dynamometer was used to assess maximal voluntary contraction, force sense, joint position sense, and the threshold for detecting passive movement. Paired sample t tests revealed that maximal voluntary isometric contraction decreased significantly after cryotherapy (P ≤ .001), or approximately 10% of the reduction found in both muscular groups assessed. Shoulder position sense (P < .001) and the threshold for detecting passive movement (P = .01 and P = .01 for lateral and medial shoulder rotator muscles, respectively) also suffered significant impairment. Nevertheless, no significant differences emerged in force sense at 20% and 50% of maximal force reproduction (P = .41 and P = .10 for lateral rotator muscles at 20% and 50%, respectively; and P = .20 and P = .09 for medial rotator muscles at 20% and 50%, respectively). Applying a crushed-ice pack to the shoulder for 15 min negatively affected muscle strength and impaired shoulder proprioception by decreasing joint position sense and the threshold for detecting passive movement.

The relationship of strength and muscle balance to shoulder pain and impingement syndrome in elite quadriplegic wheelchair rugby players.

PubMed

Miyahara, M; Sleivert, G G; Gerrard, D F

1998-04-01

Wheelchair athletes are susceptible to injuries related to overuse of the shoulder, in particular shoulder impingement syndrome. The present study examined the relationship of shoulder pain to demographic details, isokinetic strength and muscle balance in 8 elite quadriplegic rugby players. Demographic data were collected using personal interviews and each subject was clinically examined for signs of impingement syndrome by a physician. In addition each subject underwent bilateral isokinetic strength testing of the shoulder at 60 and 180 deg/s for abduction/adduction and internal/external rotation. A series of step-wise multiple discriminant analysis successfully predicted clinical symptoms from demographic, muscular strength and balance data. In particular, there was a significant deficit in adductor strength and this was related to shoulder pain and wasting of the scapular muscles. This strength deficit may be due to the high level of spinal lesions in the quadriplegic population. The level of spinal lesion may contribute to the aetiology of shoulder pathology in quadriplegia, and differentiate it from that observed in able-bodied athletes who exhibit weak abductors.

Effects of visually demanding near work on trapezius muscle activity.

PubMed

Zetterberg, C; Forsman, M; Richter, H O

2013-10-01

Poor visual ergonomics is associated with visual and neck/shoulder discomfort, but the relation between visual demands and neck/shoulder muscle activity is unclear. The aims of this study were to investigate whether trapezius muscle activity was affected by: (i) eye-lens accommodation; (ii) incongruence between accommodation and convergence; and (iii) presence of neck/shoulder discomfort. Sixty-six participants (33 controls and 33 with neck pain) performed visually demanding near work under four different trial-lens conditions. Results showed that eye-lens accommodation per se did not affect trapezius muscle activity significantly. However, when incongruence between accommodation and convergence was present, a significant positive relationship between eye-lens accommodation and trapezius muscle activity was found. There were no significant group-differences. It was concluded that incongruence between accommodation and convergence is an important factor in the relation between visually demanding near work and trapezius muscle activity. The relatively low demands on accommodation and convergence in the present study imply that visually demanding near work may contribute to increased muscle activity, and over time to the development of near work related neck/shoulder discomfort. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Prevalence and anatomical location of muscle tenderness in adults with nonspecific neck/shoulder pain

PubMed Central

2011-01-01

Background Many adults experience bothersome neck/shoulder pain. While research and treatment strategies often focus on the upper trapezius, other neck/shoulder muscles may be affected as well. The aim of the present study is to evaluate the prevalence and anatomical location of muscle tenderness in adults with nonspecific neck/shoulder pain. Methods Clinical neck/shoulder examination at two large office workplaces in Copenhagen, Denmark. 174 women and 24 men (aged 25-65 years) with nonspecific neck/shoulder pain for a duration of at least 30 days during the previous year and a pain intensity of at least 2 on a modified VAS-scale of 0-10 participated. Exclusion criteria were traumatic injuries or other serious chronic disease. Using a standardized finger pressure of 2 kg, palpable tenderness were performed of eight anatomical neck/shoulder locations in the left and right side on a scale of 'no tenderness', 'some tenderness' and 'severe tenderness'. Results In women, the levator scapulae, neck extensors and infraspinatus showed the highest prevalence of severe tenderness (18-30%). In comparison, the prevalence of severe tenderness in the upper trapezius, occipital border and supraspinatus was 13-19%. Severe tenderness of the medial deltoid was least prevalent (0-1%). In men, the prevalence of severe tenderness in the levator scapulae was 13-21%, and ranged between 0-8% in the remainder of the examined anatomical locations. Conclusions A high prevalence of tenderness exists in several anatomical locations of the neck/shoulder complex among adults with nonspecific neck/shoulder pain. Future research should focus on several neck/shoulder muscles, including the levator scapulae, neck extensors and infraspinatus, and not only the upper trapezius. Trial Registration ISRCTN60264809 PMID:21777478

Prevalence and anatomical location of muscle tenderness in adults with nonspecific neck/shoulder pain.

PubMed

Andersen, Lars L; Hansen, Klaus; Mortensen, Ole S; Zebis, Mette K

2011-07-22

Many adults experience bothersome neck/shoulder pain. While research and treatment strategies often focus on the upper trapezius, other neck/shoulder muscles may be affected as well. The aim of the present study is to evaluate the prevalence and anatomical location of muscle tenderness in adults with nonspecific neck/shoulder pain. Clinical neck/shoulder examination at two large office workplaces in Copenhagen, Denmark. 174 women and 24 men (aged 25-65 years) with nonspecific neck/shoulder pain for a duration of at least 30 days during the previous year and a pain intensity of at least 2 on a modified VAS-scale of 0-10 participated. Exclusion criteria were traumatic injuries or other serious chronic disease. Using a standardized finger pressure of 2 kg, palpable tenderness were performed of eight anatomical neck/shoulder locations in the left and right side on a scale of 'no tenderness', 'some tenderness' and 'severe tenderness'. In women, the levator scapulae, neck extensors and infraspinatus showed the highest prevalence of severe tenderness (18-30%). In comparison, the prevalence of severe tenderness in the upper trapezius, occipital border and supraspinatus was 13-19%. Severe tenderness of the medial deltoid was least prevalent (0-1%). In men, the prevalence of severe tenderness in the levator scapulae was 13-21%, and ranged between 0-8% in the remainder of the examined anatomical locations. A high prevalence of tenderness exists in several anatomical locations of the neck/shoulder complex among adults with nonspecific neck/shoulder pain. Future research should focus on several neck/shoulder muscles, including the levator scapulae, neck extensors and infraspinatus, and not only the upper trapezius. ISRCTN60264809.

Sensorimotor Control of the Shoulder in Professional Volleyball Players with Isolated Infraspinatus Muscle Atrophy.

PubMed

Contemori, Samuele; Biscarini, Andrea; Botti, Fabio Massimo; Busti, Daniele; Panichi, Roberto; Pettorossi, Vito Enrico

2017-06-12

Isolated infraspinatus muscle atrophy (IIMA) only affects the hitting shoulder of overhead-activity athletes, and is caused by suprascapular nerve neuropathy. No study has assessed the static and dynamic stability of the shoulder in overhead professional athletes with IIMA to reveal possible shoulder sensorimotor alterations. To assess the shoulder static stability, dynamic stability, and strength in professional volleyball players with IIMA and in healthy control players. Cross-sectional study. Research laboratory. Twenty-four male professional volleyball players (12 players with diagnosed IIMA and 12 healthy players) recruited from local volleyball teams. Static stability was evaluated with two independent force platforms and dynamic stability was assessed with the "Upper Quarter Y Balance Test". The static stability assessment was conducted in different support (single hand and both hand) and vision (open and closed eyes) conditions. Data from each test were analyzed with ANOVA and paired t-test models, to highlight statistical differences within and between groups. In addition to reduced abduction and external rotation strength, athletes with IIMA consistently demonstrated significant less static (P < 0.001) and dynamic stability (P < 0,001), compared with the contralateral shoulder and with healthy athletes. Closed eyes condition significantly enhanced the static stability deficit of the shoulder with IIMA (P = 0.039 and P = 0.034 for both hand and single hand support, respectively), but had no effect in healthy contralateral and healthy players' shoulders. This study highlights an impairment of the sensorimotor control system of the shoulder with IIMA, which likely results from both proprioceptive and strength deficits. This condition could yield subtle alteration in the functional use of the shoulder and predispose it to acute or overuse injuries. The results of this study may help athletic trainers and physical/physiotherapists to prevent shoulder injuries and create specific proprioceptive and neuromuscular training programs.

THE ACUTE EFFECTS OF CONCENTRIC VERSUS ECCENTRIC MUSCLE FATIGUE ON SHOULDER ACTIVE REPOSITIONING SENSE

PubMed Central

2017-01-01

Purpose/Background Shoulder proprioception is essential in the activities of daily living as well as in sports. Acute muscle fatigue is believed to cause a deterioration of proprioception, increasing the risk of injury. The purpose of this study was to evaluate if fatigue of the shoulder external rotators during eccentric versus concentric activity affects shoulder joint proprioception as determined by active reproduction of position. Study design Quasi-experimental trial. Methods Twenty-two healthy subjects with no recent history of shoulder pathology were randomly allocated to either a concentric or an eccentric exercise group for fatiguing the shoulder external rotators. Proprioception was assessed before and after the fatiguing protocol using an isokinetic dynamometer, by measuring active reproduction of position at 30 ° of shoulder external rotation, reported as absolute angular error. The fatiguing protocol consisted of sets of fifteen consecutive external rotator muscle contractions in either the concentric or eccentric action. The subjects were exercised until there was a 30% decline from the peak torque of the subjects’ maximal voluntary contraction over three consecutive muscle contractions. Results A one-way analysis of variance test revealed no statistical difference in absolute angular error (p > 0.05) between concentric and eccentric groups. Moreover, no statistical difference (p > 0.05) was found in absolute angular error between pre- and post-fatigue in either group. Conclusions Eccentric exercise does not seem to acutely affect shoulder proprioception to a larger extent than concentric exercise. Level of evidence 2b PMID:28515976

Comparison of range of motion and function of subjects with reverse anatomy Bayley-Walker shoulder replacement with those of normal subjects.

PubMed

Masjedi, Milad; Lovell, Cara; Johnson, Garth R

2011-12-01

Patients with rotator cuff tear and degenerative shoulder joint disease commonly experience severe pain and reduced performance during activities of daily living. A popular way to treat these patients is by means of reverse anatomy shoulder prosthesis. Studying the kinematics of subjects with reverse anatomy implant would be useful in order to gain knowledge about functionality of different designs. It is hypothesized that the kinematics of these subjects, in the absence of rotator cuff muscles, differs from that of normal subjects. In this study the upper limb kinematics of 12 subjects with a Bayley-Walker reverse anatomy shoulder prosthesis while performing tasks common in everyday activities and those that represent the range of motion was analyzed and compared to that of 12 normal subjects. Each patient also completed an Oxford Shoulder Score. Substantial reduction in the Bayley-Walker subjects' ranges of motion was observed compared to normal subjects. The mean abduction angle decreased from 109° (±20) for normal subjects to 64° (±25). A similar trend was observed during flexion and axial rotation tasks. Furthermore, the normal group showed less variable ranges of motion performing the standard tasks, whereas for the prosthetic group this varied greatly, which is likely to be dependent on muscle strength. Although the decreased range of motion was prominent, subjects were able to complete most of the tasks by compensating with their elbow and trunk. The most challenging task for Bayley-Walker subjects was lifting an object to head height. Copyright © 2010 Elsevier B.V. All rights reserved.

Locomotor function of forelimb protractor and retractor muscles of dogs: evidence of strut-like behavior at the shoulder.

PubMed

Carrier, David R; Deban, Stephen M; Fischbein, Timna

2008-01-01

The limbs of running mammals are thought to function as inverted struts. When mammals run at constant speed, the ground reaction force vector appears to be directed near the point of rotation of the limb on the body such that there is little or no moment at the joint. If this is true, little or no external work is done at the proximal joints during constant-speed running. This possibility has important implications to the energetics of running and to the coupling of lung ventilation to the locomotor cycle. To test if the forelimb functions as an inverted strut at the shoulder during constant-speed running and to characterize the locomotor function of extrinsic muscles of the forelimb, we monitored changes in the recruitment of six muscles that span the shoulder (the m. pectoralis superficialis descendens, m. pectoralis profundus, m. latissimus dorsi, m. omotransversarius, m. cleidobrachialis and m. trapezius) to controlled manipulations of locomotor forces and moments in trotting dogs (Canis lupus familiaris Linnaeus 1753). Muscle activity was monitored while the dogs trotted at moderate speed (approximately 2 m s(-1)) on a motorized treadmill. Locomotor forces were modified by (1) adding mass to the trunk, (2) inclining the treadmill so that the dogs ran up- and downhill (3) adding mass to the wrists or (4) applying horizontally directed force to the trunk through a leash. When the dogs trotted at constant speed on a level treadmill, the primary protractor muscles of the forelimb exhibited activity during the last part of the ipsilateral support phase and the beginning of swing phase, a pattern that is consistent with the initiation of swing phase but not with active protraction of the limb during the beginning of support phase. Results of the force manipulations were also consistent with the protractor muscles initiating swing phase and contributing to active braking via production of a protractor moment on the forelimb when the dogs decelerate. A similar situation appears to be true for the major retractor muscles of the forelimb. The m. pectoralis profundus and the m. latissimus dorsi were completely silent during the support phase of the ipsilateral limb when the dogs ran unencumbered and exhibited little or no increase in activity when the dogs carried added mass on their backs to increase any retraction torque during the support phase of constant-speed running. The most likely explanation for these observations is that the ground force reaction vector is oriented very close to the fulcrum of the forelimb such that the forelimb functions as a compliant strut at the shoulder when dogs trot at constant speed on level surfaces. Because the moments at the fulcrum of the pectoral girdle appear to be small during the support phase of a trotting step, a case can be made that it is the activity of the extrinsic appendicular muscles that produce the swing phase of the forelimb that explain the coupled phase relationship between ventilatory airflow and the locomotor cycle in trotting dogs.

Reverse shoulder arthroplasty leads to significant biomechanical changes in the remaining rotator cuff.

PubMed

Herrmann, Sebastian; König, Christian; Heller, Markus; Perka, Carsten; Greiner, Stefan

2011-08-16

After reverse shoulder arthroplasty (RSA) external and internal rotation will often remain restricted. A postoperative alteration of the biomechanics in the remaining cuff is discussed as a contributing factor to these functional deficits. In this study, muscle moment arms as well as origin-to-insertion distance (OID) were calculated using three-dimensional models of the shoulder derived from CT scans of seven cadaveric specimens. Moment arms for humeral rotation are significantly smaller for the cranial segments of SSC and all segments of TMIN in abduction angles of 30 degrees and above (p ≤ 0.05). Abduction moment arms were significantly decreased for all segments (p ≤ 0.002). OID was significantly smaller for all muscles at the 15 degree position (p ≤ 0.005), apart from the cranial SSC segment. Reduced rotational moment arms in conjunction with the decrease of OID may be a possible explanation for the clinically observed impaired external and internal rotation.

Neuromuscular assessment in elderly workers with and without work related shoulder/neck trouble: the NEW-study design and physiological findings.

PubMed

Sjøgaard, G; Søgaard, K; Hermens, H J; Sandsjö, L; Läubli, T; Thorn, S; Vollenbroek-Hutten, M M R; Sell, L; Christensen, H; Klipstein, A; Kadefors, R; Merletti, R

2006-01-01

Musculoskeletal disorders in the neck and shoulder area are a major occupational concern in the European countries especially among elderly females. The aim was to assess these disorders based on quantitative EMG indicators and functional tests. 252 female computer users (45-68 years) were recruited from four European countries in two contrast groups: (1) 88 neck/shoulder (NS) cases reporting trouble in the neck and/or shoulder region for more than 30 days during the last year, and (2) 164 NS-controls reporting such trouble for no more than 7 days. Questionnaires, functional/clinical tests, and physiological recordings were performed in workplace related field studies. The results showed no differences in anthropometrics but NS-cases reported more strained head positions and more eye problems than controls. The psychosocial working factors were similar, although, NS-controls had slightly better scores on working conditions, general health, and vitality compared to cases. The NS-cases had lower maximal voluntary contraction (MVC) during shoulder elevation (mean (SD) 310 (122) N) compared to the controls (364 (122) N). During 30% MVC electromyography (EMGrms) in the trapezius muscle was lower in NS-cases (194 (105) muV) than in controls (256 (169) muV), while no differences were found regarding endurance time. Estimated conduction velocity was not different between NS-cases and -controls. Four functional computer tests were performed equally well by NS-cases and -controls, and the corresponding EMG variables also did not differ. A major finding in this large-scale epidemiological study is the significantly lower MVC in NS-cases compared with NS-controls together with lower EMGrms value at 30% MVC, while computer tasks were performed at similar relative muscle activation. The study was unable to reveal quantitative EMG indicators and functional tests that could objectively assess disorders in NS-cases.

Shoulder muscle forces during driving: Sudden steering can load the rotator cuff beyond its repair limit

PubMed Central

Pandis, Petros; Prinold, Joe A.I.; Bull, Anthony M.J.

2015-01-01

Background Driving is one of the most common everyday tasks and the rotator cuff muscles are the primary shoulder stabilisers. Muscle forces during driving are not currently known, yet knowledge of these would influence important clinical advice such as return to activities after surgery. The aim of this study is to quantify shoulder and rotator cuff muscle forces during driving in different postures. Methods A musculoskeletal modelling approach is taken, using a modified driving simulator in combination with an upper limb musculoskeletal model (UK National Shoulder Model). Motion data and external force vectors were model inputs and upper limb muscle and joint forces were the outputs. Findings Comparisons of the predicted glenohumeral joint forces were compared to in vivo literature values, with good agreement demonstrated (61 SD 8% body weight mean peak compared to 60 SD 1% body weight mean peak). High muscle activation was predicted in the rotator cuff muscles; particularly supraspinatus (mean 55% of the maximum and up to 164 SD 27 N). This level of loading is up to 72% of mean failure strength for supraspinatus repairs, and could therefore be dangerous for some cases. Statistically significant and large differences are shown to exist in the joint and muscle forces for different driving positions as well as steering with one or both hands (up to 46% body weight glenohumeral joint force). Interpretation These conclusions should be a key consideration in rehabilitating the shoulder after surgery, preventing specific upper limb injuries and predicting return to driving recommendations. PMID:26139549

Effects of wearing rubber gloves on activities of the forearm and shoulder muscles during different dishwashing stages

PubMed Central

Yoo, Won-Gyu

2015-01-01

[Purpose] The present study examined the effects of wearing rubber gloves on the activities of the forearm and shoulder muscles during two dishwashing stages. [Subjects] This study included 10 young females. [Methods] The participants performed two dishwashing stages (washing and rinsing) with and without rubber gloves. The activities of the wrist flexor and upper trapezius muscles were measured using wireless electromyography. [Results] During the washing stage, the activities of the wrist flexor and upper trapezius muscles were significantly greater without gloves than with gloves when performing the same tasks. However, during the rinsing stage, the activities of these muscles did not differ significantly according to the use of gloves. [Conclusion] Dishwashers should wear gloves during the washing stage to prevent wrist and shoulder pain. PMID:26311980

Clinical effects of deep cervical flexor muscle activation in patients with chronic neck pain

PubMed Central

Kim, Jin Young; Kwag, Kwang Il

2016-01-01

[Purpose] The purpose of this study was to investigate clinical effects of deep cervical flexor (DCF) muscles exercise on pain, Neck Disability Index (NDI), and neck and shoulder postures in patients with chronic neck pain. [Subjects and Methods] Twenty-eight patients with chronic neck pain were randomly assigned into either the general strengthening exercise (GSE) group or the DCF activation group as control and experimental groups, respectively. All exercises were performed three times per week over 4 weeks. NDI and numeric rating scale (NRS) score for pain were determined and radiological assessment of neck-shoulder postures (head tilt angle [HTA], neck flexion angle [NFA], and forward shoulder angle [FSA]) was performed before (baseline), 4 weeks after, and 8 weeks after exercise in order to directly compare the exercise effects between the groups. [Results] In the DCF group, the NDI, NRS score, and neck-shoulder postures (analyzed by uisng HTA, NFA, and FSA) were significantly improved. [Conclusion] DCF activation exercise was effective to alleviate pain, recover functions, and correct forward head posture in the patients with neck pain. Hence, it might be recommended in the rehabilitation of patients with chronic neck pain. PMID:26957772

Muscle load in reaching movements performed by a wheelchair user: a case study.

PubMed

van Drongelen, S; Wolf, S I; Fradet, L

2014-01-01

The aim of this study was to analyse the load on the shoulder muscles during reaching movements that are specific to wheelchair users in relation to the risk of impingement. Three activities of daily living were performed: putting a book on a shelf in front and at the side and putting a pack of water bottles on a table. The AnyBody shoulder model was used to calculate the activity and forces of the shoulder muscles. Handling the pack of bottles caused the highest forces in the deltoideus, trapezius, serratus anterior and rotator cuff muscles. For handling the book, the highest forces were found in the deltoideus (scapular part) and the serratus anterior, especially during the put phase. Handling heavy objects such as a pack of bottles or a wheelchair produces high forces on the rotator cuff muscles and can lead to early fatigue. Therefore, these activities seem to be associated with a high risk of developing impingement syndrome. Implications for Rehabilitation In a single patient, this study demonstrates that the load on the rotator cuff is high during reaching movements. Handling a pack of water bottles, which resembles wheelchair handling, represents an activity associated with a high risk of developing impingement syndrome. Shoulder muscles must be trained in a balanced way to provide stabilization at the shoulder joint and prevent fatigue.

Effects of neck exercise on high-school students' neck-shoulder posture.

PubMed

Lee, Myoung-Hyo; Park, Su-Jin; Kim, Jin-Sang

2013-05-01

[Purpose] This study examined the effects of deep flexor muscle-strengthening exercise on the neck-shoulder posture, and the strength and endurance of the deep flexor muscles of high-school students. [Subjects] The subjects were 30 seventeen-year-old female high-school students who complained about bad posture and chronic neck-shoulder pain. They were randomly divided into an experimental group of 15 subjects, who performed a deep flexor muscle-strengthening exercise and a control group of 15 subjects, who performed a basic stretching exercise. [Methods] The experimental group of 15 subjects performed a deep flexor muscle-strengthening exercise consisting of low-load training of the cranio-cervical flexor muscle, and the control group of 15 subjects performed a basic stretching exercise consisting of seven motions. [Results] The experimental group showed statistically significant changes in head tilt angle, neck flexion angle, forward shoulder angle, and the result of the cranio-cervical flexion test after the training. In contrast, the control group showed no statistically significant changes in these measures following the training. When the results of the groups were compared, statistically significant differences were found for all items between the experimental group and the control group. [Conclusion] Strengthening cranio-cervical flexor muscles is important for the adjustment of neck posture, and maintaining their stability is required to improve neck-shoulder posture.

Hierarchy of stability factors in reverse shoulder arthroplasty.

PubMed

Gutiérrez, Sergio; Keller, Tony S; Levy, Jonathan C; Lee, William E; Luo, Zong-Ping

2008-03-01

Reverse shoulder arthroplasty is being used more frequently to treat irreparable rotator cuff tears in the presence of glenohumeral arthritis and instability. To date, however, design features and functions of reverse shoulder arthroplasty, which may be associated with subluxation and dislocation of these implants, have been poorly understood. We asked: (1) what is the hierarchy of importance of joint compressive force, prosthetic socket depth, and glenosphere size in relation to stability, and (2) is this hierarchy defined by underlying and theoretically predictable joint contact characteristics? We examined the intrinsic stability in terms of the force required to dislocate the humerosocket from the glenosphere of eight commercially available reverse shoulder arthroplasty devices. The hierarchy of factors was led by compressive force followed by socket depth; glenosphere size played a much lesser role in stability of the reverse shoulder arthroplasty device. Similar results were predicted by a mathematical model, suggesting the stability was determined primarily by compressive forces generated by muscles.

Relation between functional mobility and dynapenia in institutionalized frail elderly.

PubMed

Soares, Antonio Vinicius; Marcelino, Elessandra; Maia, Késsia Cristina; Borges, Noé Gomes

2017-01-01

To investigate the relation between functional mobility and dynapenia in institutionalized frail elderly. A descriptive, correlational study involving 26 institutionalized elderly men and women, mean age 82.3±6 years. The instruments employed were the Mini Mental State Examination, the Geriatric Depression Scale, the International Physical Activity Questionnaire, the Timed Up and Go test, a handgrip dynamometer and a portable dynamometer for large muscle groups (shoulder, elbow and hip flexors, knee extensors and ankle dorsiflexors). Significant negative correlation between functional mobility levels assessed by the Timed Up and Go test and dynapenia was observed in all muscle groups evaluated, particularly in knee extensors (r -0.65). A significant negative correlation between muscle strength, particularly knee extensor strength, and functional mobility was found in institutionalized elderly. Data presented indicate that the higher the muscle strength, the shorter the execution time, and this could demonstrate better performance in this functional mobility test.

Feasibility of EMG-Based Control of Shoulder Muscle FNS Via Artificial Neural Network

DTIC Science & Technology

2001-10-25

assuming that just two paralyzed muscles (pectoralis major and latissimus dorsi ) were stimulated. Further, the needed activations of these “stimulated...injuries at C5-C6 typically result in paralysis of several important shoulder muscles (e.g., pectoralis major, latissimus dorsi , and serratus anterior...of several important muscles (e.g., pectoralis major and latissimus dorsi ),but retain at least partial voluntary control over a number of other

Primary and Secondary Consequences of Rotator Cuff Injury on Joint Stabilizing Tissues in the Shoulder.

PubMed

Rahman, Hafizur; Currier, Eric; Johnson, Marshall; Goding, Rick; Johnson, Amy Wagoner; Kersh, Mariana E

2017-11-01

Rotator cuff tears (RCTs) are one of the primary causes of shoulder pain and dysfunction in the upper extremity accounting over 4.5 million physician visits per year with 250,000 rotator cuff repairs being performed annually in the U.S. While the tear is often considered an injury to a specific tendon/tendons and consequently treated as such, there are secondary effects of RCTs that may have significant consequences for shoulder function. Specifically, RCTs have been shown to affect the joint cartilage, bone, the ligaments, as well as the remaining intact tendons of the shoulder joint. Injuries associated with the upper extremities account for the largest percent of workplace injuries. Unfortunately, the variable success rate related to RCTs motivates the need for a better understanding of the biomechanical consequences associated with the shoulder injuries. Understanding the timing of the injury and the secondary anatomic consequences that are likely to have occurred are also of great importance in treatment planning because the approach to the treatment algorithm is influenced by the functional and anatomic state of the rotator cuff and the shoulder complex in general. In this review, we summarized the contribution of RCTs to joint stability in terms of both primary (injured tendon) and secondary (remaining tissues) consequences including anatomic changes in the tissues surrounding the affected tendon/tendons. The mechanical basis of normal shoulder joint function depends on the balance between active muscle forces and passive stabilization from the joint surfaces, capsular ligaments, and labrum. Evaluating the role of all tissues working together as a system for maintaining joint stability during function is important to understand the effects of RCT, specifically in the working population, and may provide insight into root causes of shoulder injury.

Preseason Strength Assessment of the Rotator Muscles and Shoulder Injury in Handball Players.

PubMed

Forthomme, Bénédicte; Croisier, Jean-Louis; Delvaux, François; Kaux, Jean-François; Crielaard, Jean-Michel; Gleizes-Cervera, Sophie

2018-02-01

  Few researchers have identified intrinsic risk factors for shoulder injury in team handball players by analyzing measurements of maximal isokinetic rotator muscle strength.   To identify possible intrinsic risk factors for shoulder injury by analyzing measurements of maximal isokinetic rotator muscle strength.   Cross-sectional study.   Male team handball senior divisions (the highest level) in France and Belgium.   A total of 108 male high-level handball players (age = 24 ± 4 years, height = 189 ± 6 cm, mass = 87 ± 11 kg) were enrolled.   All players completed a preseason questionnaire and performed a bilateral isokinetic assessment of the shoulder rotator muscles. On a monthly questionnaire, players reported any shoulder injury that they sustained during the season.   On the preseason questionnaire, 51 of 108 (47%) participants reported a history of dominant-shoulder injury. A total of 106 participants completed the in-season questionnaire, with 22% (n = 23) reporting a shoulder injury on their dominant side during the subsequent season. Fourteen percent (n = 15) sustained microtraumatic injuries, and 8% (n = 8) described a traumatic injury. Backcourt players had a 3.5-times increased risk of injury during the new season compared with players in other positions. Among the isokinetic results, no risk factor for further injury was identified in handball players with microtraumatic injuries. For traumatic injuries, the concentric maximal strength developed by the internal rotators at high speed (240°/s) in the dominant shoulder was a protective factor against the risk of further injury.   These results can potentially identify intrinsic risk factors for shoulder injury and may be used to determine potential interventions for reducing this risk in handball players.

The "bench-presser's shoulder": an overuse insertional tendinopathy of the pectoralis minor muscle.

PubMed

Bhatia, Deepak N; de Beer, Joe F; van Rooyen, Karin S; Lam, Francis; du Toit, Donald F

2007-08-01

Tendinopathies of the rotator cuff muscles, biceps tendon and pectoralis major muscle are common causes of shoulder pain in athletes. Overuse insertional tendinopathy of pectoralis minor is a previously undescribed cause of shoulder pain in weightlifters/sportsmen. To describe the clinical features, diagnostic tests and results of an overuse insertional tendinopathy of the pectoralis minor muscle. To also present a new technique of ultrasonographic evaluation and injection of the pectoralis minor muscle/tendon based on use of standard anatomical landmarks (subscapularis, coracoid process and axillary artery) as stepwise reference points for ultrasonographic orientation. Between 2005 and 2006, seven sportsmen presenting with this condition were diagnosed and treated at the Cape Shoulder Institute, Cape Town, South Africa. In five patients, the initiating and aggravating factor was performance of the bench-press exercise (hence the term "bench-presser's shoulder"). Medial juxta-coracoid tenderness, a painful active-contraction test and bench-press manoeuvre, and decrease in pain after ultrasound-guided injection of a local anaesthetic agent into the enthesis, in the absence of any other clinically/radiologically apparent pathology, were diagnostic of pectoralis minor insertional tendinopathy. All seven patients were successfully treated with a single ultrasound-guided injection of a corticosteroid into the enthesis of pectoralis minor followed by a period of rest and stretching exercises. This study describes the clinical features and management of pectoralis minor insertional tendinopathy, secondary to the bench-press type of weightlifting. A new pain site-based classification of shoulder pathology in weightlifters is suggested.

Shoulder muscles recruitment during a power backward giant swing on high bar: a wavelet-EMG-analysis.

PubMed

Frère, Julien; Göpfert, Beat; Slawinski, Jean; Tourny-Chollet, Claire

2012-04-01

This study aimed at determining the upper limb muscles coordination during a power backward giant swing (PBGS) and the recruitment pattern of motor units (MU) of co-activated muscles. The wavelet transformation (WT) was applied to the surface electromyographic (EMG) signal of eight shoulder muscles. Total gymnast's body energy and wavelet synergies extracted from the WT-EMG by using a non-negative matrix factorization were analyzed as a function of the body position angle of the gymnast. A cross-correlation analysis of the EMG patterns allowed determining two main groups of co-activated muscles. Two wavelet synergies representing the main spectral features (82% of the variance accounted for) discriminated the recruitment of MU. Although no task-group of MU was found among the muscles, it appeared that a higher proportion of fast MU was recruited within the muscles of the first group during the upper part of the PBGS. The last increase of total body energy before bar release was induced by the recruitment of the muscles of the second group but did not necessitate the recruitment of a higher proportion of fast MU. Such muscle coordination agreed with previous simulations of elements on high bar as well as the findings related to the recruitment of MU. Copyright © 2012 Elsevier B.V. All rights reserved.

Spatiotemporal distribution of location and object effects in the electromyographic activity of upper extremity muscles during reach-to-grasp

PubMed Central

Rouse, Adam G.

2016-01-01

In reaching to grasp an object, proximal muscles that act on the shoulder and elbow classically have been viewed as transporting the hand to the intended location, while distal muscles that act on the fingers simultaneously shape the hand to grasp the object. Prior studies of electromyographic (EMG) activity in upper extremity muscles therefore have focused, by and large, either on proximal muscle activity during reaching to different locations or on distal muscle activity as the subject grasps various objects. Here, we examined the EMG activity of muscles from the shoulder to the hand, as monkeys reached and grasped in a task that dissociated location and object. We quantified the extent to which variation in the EMG activity of each muscle depended on location, on object, and on their interaction—all as a function of time. Although EMG variation depended on both location and object beginning early in the movement, an early phase of substantial location effects in muscles from proximal to distal was followed by a later phase in which object effects predominated throughout the extremity. Interaction effects remained relatively small. Our findings indicate that neural control of reach-to-grasp may occur largely in two sequential phases: the first, serving to project the entire upper extremity toward the intended location, and the second, acting predominantly to shape the entire extremity for grasping the object. PMID:27009156

Influence of body mass index on the outcome of brachial plexus surgery: are there any differences between elbow and shoulder results?

PubMed

Socolovsky, Mariano; Martins, Roberto S; Di Masi, Gilda; Bonilla, Gonzalo; Siqueira, Mario G

2014-12-01

Body mass index (BMI) has recently been identified as a predictor of outcomes following reconstructive surgery of shoulder palsies. In this study, we sought to determine if the same holds true for the reconstruction of elbow flexion. Forty patients who had undergone partial ulnar-to-biceps nerve transfer (Oberlin's procedure) for shoulder palsy were assessed and compared against 18 previously reported patients who had undergone reconstruction for elbow palsies. The British Medical Research Council (BMRC) scale and an index dividing shoulder abduction strength in the affected arm by healthy arm were recorded. All patients had undergone surgery within 12 months of injury and had ≥ 12 months of follow-up. M4 or M3 biceps strength was obtained in 90 % of patients. Final strength on the affected side averaged 5.8 kg, versus 20.2 kg on the normal side, for a mean recovery index score of 0.30. In this sample of 40 patients, BMI did not predict percentage strength or BMRC grade recovery. Neither did age, number of roots involved, the affected side, nor time to surgery. Comparing patients with elbow versus shoulder reconstruction, there were no differences, except that patients undergoing Oberlin's procedure had a statistically longer duration of time between injury and surgical repair (7.4 vs 5.1 months, p < 0.006). Our data suggest that proximal muscle re-innervation is functionally more dependent upon BMI than distal re-innervation, likely because proximal muscles must support the weight of the entire extremity, while more distal muscles do not. BMI should be taken into consideration when planning surgery.

Effects of augmented trunk stabilization with external compression support on shoulder and scapular muscle activity and maximum strength during isometric shoulder abduction.

PubMed

Jang, Hyun-jeong; Kim, Suhn-yeop; Oh, Duck-won

2015-04-01

The aim of the present study was to investigate the effects of augmented trunk stabilization with external compression support (ECS) on the electromyography (EMG) activity of shoulder and scapular muscles and shoulder abductor strength during isometric shoulder abduction. Twenty-six women volunteered for the study. Surface EMG was used to monitor the activity of the upper trapezius (UT), lower trapezius (LT), serratus anterior (SA), and middle deltoid (MD), and shoulder abductor strength was measured using a dynamometer during three experimental conditions: (1) no external support (condition-1), (2) pelvic support (condition-2), and (3) pelvic and thoracic supports (condition-3) in an active therapeutic movement device. EMG activities were significantly lower for UT and higher for MD during condition 3 than during condition 1 (p < 0.05). The MD/UT ratio was significantly higher during condition 3 than during conditions 1 and 2, and higher during condition 2 than during condition 1 (p < 0.05). Shoulder abductor strength was significantly higher during condition 3 than during condition 1 (p < 0.05). These findings suggest that augmented trunk stabilization with the ECS may be advantageous with regard to reducing the compensatory muscle effort of the UT during isometric shoulder abduction and increasing shoulder abductor strength. Copyright © 2014 Elsevier Ltd. All rights reserved.

Can grip strength be used as a surrogate marker to monitor recovery from shoulder fatigue?

PubMed

Hawkes, David; Grant, Michael; McMahon, Jessica; Horsley, Ian; Khaiyat, Omid

2018-06-06

Muscular fatigue impacts on normal shoulder function, which is particularly pertinent to throwing athletes. This study aimed to investigate the relationship between grip strength and shoulder muscle fatigue to evaluate the role of grip strength as a surrogate measure for upper limb performance. Twenty healthy participants were recruited. EMG was recorded from 15 shoulder muscles during different fatiguing contractions: an initial baseline recording (Fat-Baseline); after a shoulder exhausting exercise regime (Fat-Exhaustion); and after a 10 min rest period (Fat-Recovery). Grip strength was similarly measured in the same conditions. Grip strength differed significantly across the testing scenarios (p = 0.012-<0.001). Greater fatigue was seen in anterior deltoid, middle deltoid, posterior deltoid and supraspinatus in the Fat-Exhaustion contraction as compared to the Fat-Baseline contraction (p = <0.001-0.043). Greater fatigue was seen during the Fat-Recovery contraction for the trapezius, serratus anterior and biceps brachii as compared to the Fat-Exhaustion contraction (p = 0.008-0.038). Grip strength decreased following an exhausting exercise protocol but recovered to baseline following a rest period. Conversely, EMG indices of fatigue did not recover. Additional fatigue was seen reflecting a reorganisation of movement strategy. Therefore, susceptibility to injury still exists if grip strength alone is used as a barometer of upper limb performance. Copyright © 2018. Published by Elsevier Ltd.

[The Throwing Shoulder].

PubMed

Wieser, Karl; Gerber, Christian; Meyer, Dominik C

2016-02-03

Repetitive top-performance of overhead athletes induces a tremendous stress for the throwing shoulder. Throwers reach rotational speed of their arm of more than 7000°/s with joint compression and distraction forces of more than 1000 N. This performance is tributary to adaption of the shoulder muscles and the joint itself. These adaptions may, however lead to two specific problems of the throwing shoulder: 1. The posterosuperior internal impingement of the rotator cuff and labrum between glenoid and humeral head during late cooking phase; 2. A decreased internal rotation of the glenohumeral joint (GIRD) with compensatory problems of the scapula-stabilizing muscles. Precise analysis of kinematics and pathomechanics aims to improve understanding and treatment of those specific problems of the throwing shoulder.

Decreased thickness of the lower trapezius muscle in patients with unilateral neck pain.

PubMed

Uthaikhup, Sureeporn; Pensri, Chalomjai; Kawsoiy, Kanokon

2016-09-01

Thickness of the lower trapezius muscle in patients with neck pain has not been established. We examined the thickness of the lower trapezius muscle in patients with and without unilateral neck pain. Twenty women with unilateral (right) neck pain and 20 matched controls participated in the study. Thickness of the lower trapezius muscles was measured bilaterally at rest (0 ° and 120 ° of shoulder abduction) and during contraction (120 ° of shoulder abduction) using ultrasound imaging. The neck pain group had smaller thickness of the lower trapezius muscle on the painful side compared with controls both at rest and during contraction (P < 0.05). However, the percentage change in the lower trapezius thickness from rest to contraction (120 ° of shoulder abduction) was not different between groups (P > 0.05). Patients with neck pain had smaller thickness of the lower trapezius muscle on the painful side compared with healthy controls. Muscle Nerve 54: 439-443, 2016. © 2015 Wiley Periodicals, Inc.

Profile of isokinetic eccentric-to-concentric strength ratios of shoulder rotator muscles in elite female team handball players.

PubMed

Andrade, Marilia Dos Santos; Fleury, Anna Maria; de Lira, Claudio Andre Barbosia; Dubas, Joao Paulo; da Silva, Antonio Carlos

2010-05-01

The purpose of this study was to establish the isokinetic profile of shoulder rotator muscles strength in female handball players. Twenty-seven handball players performed concentric and eccentric strength tests of both dominant and non-dominant upper limbs on an isokinetic dynamometer. Internal and external rotator muscles peak torque was assessed at 1.05, 3.14, and 5.23 rad . s(-1) in concentric mode and at 3.14 and 5.23 rad . s(-1) in eccentric mode. Concentric balance ratio and functional ratio were obtained. Bi-lateral deficiency was compared. Concentric strength for internal and external rotation was significantly greater for the dominant than for the non-dominant limb for all speeds (P < or = 0.0001). For eccentric actions, internal rotator muscles were stronger in the dominant than the non-dominant limb (P < or = 0.0001) at both speeds. Concentric balance and functional balance ratios did not differ between sides at 3.14 rad . s(-1) (P = 0.1631), but at 5.23 rad . s(-1) the functional balance ratio in the dominant limb was lower than for the non-dominant limb (P = 0.0500). Although the dominant side was stronger than the non-dominant side, balance concentric ratios remained the same, with only the functional strength ratio different at 5.23 rad . s(-1). Our results suggest that concentric strength exercises be used for internal and external rotators on the non-dominant side, and functional exercise that improves eccentric rotation strength for prevention programmes.

An electromyography study of muscular endurance during the posterior shoulder endurance test.

PubMed

Evans, Neil A; Dressler, Emily; Uhl, Tim

2018-05-31

The primary purpose was to determine if there is a difference between the median frequency slopes of 5 posterior shoulder muscles during the initial portion of the Posterior Shoulder Endurance Test (PSET) at the 90° and 135° shoulder abduction positions. Fifty-five healthy volunteers (31 females) participated. The median frequency of the posterior deltoid (PD), upper trapezius (UT), middle trapezius (MT), lower trapezius (LT), and infraspinatus (INF) was measured during the PSET at 90° and 135° of shoulder abduction. External torque of 13 ± 1 Nm was used for females and 21 ± 1 Nm for males. A fixed effect multi-variable regression model was used to investigate the median frequency slopes. Males and females were analyzed separately. Median frequency slopes demonstrated fatigue in all 5 of the muscles. The PD fatigued greater than the UT in males (p = 0.0215) and greater than the LT in females (p = 0.008). The time to task failure (TTF) was greater at 90° than 135° for females and males (p = 0.016; p = 0.0193) respectively. The PSET causes fatigue in all of the muscles that were tested, with the PD fatiguing at a greater rate compared to one muscle for each sex. This investigation supports using TTF as a clinical measure of shoulder girdle endurance at 90° shoulder abduction. Copyright © 2018. Published by Elsevier Ltd.

Quality of life, muscle strength, and fatigue perception in patients on suppressive therapy with levothyroxine for differentiated thyroid carcinoma.

PubMed

de Oliveira Chachamovitz, Dhiãnah Santini; dos Santos Vigário, Patrícia; Nogueira Cordeiro, Mônica Fabíola; de Castro, Carmen Lucia Natividade; Vaisman, Mário; dos Santos Teixeira, Patrícia de Fátima

2013-08-01

The aim of this study was to evaluate the fatigue perception, the muscle function, and the health-related quality of life (QoL) in subclinical hyperthyroidism (SCH) induced by levothyroxine in the treatment of differentiated thyroid carcinoma, in comparison with a group of euthyroid (EU) subjects. A cross-sectional study with 38 SCH individuals and 54 EU subjects was performed. They were submitted to Short Form-36 and Chalder questionnaires to evaluate QoL and fatigue, respectively. The tests performed to evaluate muscle function of upper and lower limbs were: maximum quadriceps isometric strength (QS); quadriceps fatigue resistance (T50% QS), QS at 30 seconds (QS30s); quadriceps functional capacity (QFC); maximum isometric handgrip strength (HS); fatigue handgrip resistance (T50% HS), HS at 30 seconds (HS30s); and functional capacity of the shoulder. The SCH patients had worse muscle function, regarding HS (25.19 ± 7.00 vs. 30.45 ± 9.98 kgf in EU, P = 0.009) and functional capacity of the shoulder (41.28 ± 48.36 vs. 56.68 ± 37.44 s in EU, P = 0.004). The self-perception of fatigue by Chalder questionnaire (23.91 ± 5.39 vs. 29.77 ± 7.03, P = 0.000) and the QoL in terms of functional capacity (70.20 ± 21.57 vs. 56.25 ± 28.79, P = 0.025), physical aspects (71.42 ± 36.44 vs. 45.83 ± 42.88, P = 0.004), pain (62.48 ± 22.20 vs. 50.05 ± 24.80, P = 0.035), and emotional aspects (70.74 ± 38.26 vs. 46.29 ± 44.56, P = 0.008) were also worse in SCH. In conclusion, the SCH was associated with alterations in the QoL, reduction in the muscle function of upper limbs, and higher degree of fatigue.

Musculoskeletal dysfunctions associated with swimmers' shoulder.

PubMed

Struyf, Filip; Tate, Angela; Kuppens, Kevin; Feijen, Stef; Michener, Lori A

2017-05-01

Shoulder pain is the most reported area of orthopaedic injury in swimmers. The so-called 'swimmers' shoulder' has been applied to a variety of complaints involving shoulder pain in swimmers without specific reference to contributing mechanisms or structures. Knowledge of dysfunctions associated with swimmers' shoulder can assist clinicians in developing rehabilitation strategies. This literature review aims at providing clinicians insight into the musculoskeletal mechanisms and impairments associated with swimmers' shoulder that could aid them in developing rehabilitation strategies. The following musculoskeletal dysfunctions will be discussed: muscle activity, strength, endurance, muscle control, range of motion, glenohumeral laxity, glenohumeral instability, shoulder posture and scapular dyskinesis. The findings in this review may have implications for swimmers, their coaches, and rehabilitation specialists working with swimmers. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Compensating for intersegmental dynamics across the shoulder, elbow, and wrist joints during feedforward and feedback control.

PubMed

Maeda, Rodrigo S; Cluff, Tyler; Gribble, Paul L; Pruszynski, J Andrew

2017-10-01

Moving the arm is complicated by mechanical interactions that arise between limb segments. Such intersegmental dynamics cause torques applied at one joint to produce movement at multiple joints, and in turn, the only way to create single joint movement is by applying torques at multiple joints. We investigated whether the nervous system accounts for intersegmental limb dynamics across the shoulder, elbow, and wrist joints during self-initiated planar reaching and when countering external mechanical perturbations. Our first experiment tested whether the timing and amplitude of shoulder muscle activity account for interaction torques produced during single-joint elbow movements from different elbow initial orientations and over a range of movement speeds. We found that shoulder muscle activity reliably preceded movement onset and elbow agonist activity, and was scaled to compensate for the magnitude of interaction torques arising because of forearm rotation. Our second experiment tested whether elbow muscles compensate for interaction torques introduced by single-joint wrist movements. We found that elbow muscle activity preceded movement onset and wrist agonist muscle activity, and thus the nervous system predicted interaction torques arising because of hand rotation. Our third and fourth experiments tested whether shoulder muscles compensate for interaction torques introduced by different hand orientations during self-initiated elbow movements and to counter mechanical perturbations that caused pure elbow motion. We found that the nervous system predicted the amplitude and direction of interaction torques, appropriately scaling the amplitude of shoulder muscle activity during self-initiated elbow movements and rapid feedback control. Taken together, our results demonstrate that the nervous system robustly accounts for intersegmental dynamics and that the process is similar across the proximal to distal musculature of the arm as well as between feedforward (i.e., self-initiated) and feedback (i.e., reflexive) control. NEW & NOTEWORTHY Intersegmental dynamics complicate the mapping between applied joint torques and the resulting joint motions. We provide evidence that the nervous system robustly predicts these intersegmental limb dynamics across the shoulder, elbow, and wrist joints during reaching and when countering external perturbations. Copyright © 2017 the American Physiological Society.

Inflamed shoulder tendons (image)

MedlinePlus

Tearing and inflammation of the tendons of the shoulder muscles can occur in sports which require the ... pitching, swimming, and lifting weights. Most often the shoulder will heal if a break is taken from ...

Sensorimotor control and neuromuscular activity of the shoulder in adolescent competitive swimmers with generalized joint hypermobility.

PubMed

Frydendal, Thomas; Eshøj, Henrik; Liaghat, Behnam; Edouard, Pascal; Søgaard, Karen; Juul-Kristensen, Birgit

2018-05-05

Shoulder pain is highly prevalent in competitive swimmers, and generalized joint hypermobility (GJH) is considered a risk factor. Sensorimotor control deficiencies and altered neuromuscular activation of the shoulder may represent underlying factors. To investigate whether competitive swimmers with GJH including shoulder hypermobility (GJHS) differ in shoulder sensorimotor control and muscle activity from those without GJH and no shoulder hypermobility (NGJH). Competitive swimmers (aged 13-17) were recruited. GJHS or NGJH status was determined using the Beighton score (0-9) and Rotès-Quérol test (positive/negative). Inclusion criteria for GJHS were a Beighton score ≥5 and minimum one hypermobile shoulder, while NGJH was defined as a Beighton score ≤3 and no shoulder hypermobility. Three prone lying, upper-extremity weight-bearing shoulder stabilometric tests were performed on a force platform: Bilateral upper-extremity support eyes open (BL-EO) and eyes closed (BL-EC) and unilateral upper-extremity support eyes open (UL-EO). Surface electromyography (SEMG) was measured from the upper trapezius, lower trapezius, serratus anterior, infraspinatus and pectoralis major muscles. SEMG was normalized using maximal voluntary isometric contractions and presented relative to maximal voluntary SEMG (%MVE). Co-contraction index (CCI) was calculated for the following muscle pairs: upper trapezius-lower trapezius, upper trapezius-serratus anterior, and infraspinatus-pectoralis major. Between-group differences in stabilometric parameters, %MVE, and CCI were analyzed with a mixed effects model. Thirty-eight swimmers were enrolled as GJHS (n = 19) or NGJH (n = 19). There were no group differences in stabilometric parameters or CCI. GJHS displayed significantly decreased (29%) pectoralis major activity during BL-EO compared to NGJH (5.35 ± 1.77%MVE vs. 7.51 ± 1.96%MVE; p = 0.043). Adolescent competitive swimmers with GJHS displayed no shoulder sensorimotor control deficiencies and no generally altered shoulder muscle activity pattern, except for decreased pectoralis major activity in BL-EO. Longitudinal studies are needed to investigate whether decreased pectoralis major activation contributes to the development of shoulder pain in swimmers with GJHS. Copyright © 2018 Elsevier B.V. All rights reserved.

Rotator cuff muscle function and its relation to scapular morphology in apes.

PubMed

Larson, Susan G; Stern, Jack T

2013-10-01

It is widely held that many differences among primate species in scapular morphology can be functionally related to differing demands on the shoulder associated with particular locomotor habits. This perspective is largely based on broad scale studies, while more narrow comparisons of scapular form often fail to follow predictions based on inferred differences in shoulder function. For example, the ratio of supraspinous fossa/infraspinous fossa size in apes is commonly viewed as an indicator of the importance of overhead use of the forelimb, yet paradoxically, the African apes, the most terrestrial of the great apes, have higher scapular fossa ratios than the more suspensory orangutan. The recent discovery of several nearly complete early hominin scapular specimens, and their apparent morphological affinities to scapulae of orangutans and gorillas rather than chimpanzees, has led to renewed interest in the comparative analysis of human and extant ape scapular form. To facilitate the functional interpretation of differences in ape scapulae, particularly in regard to relative scapular fossa size, we used electromyography (EMG) to document the activity patterns in all four rotator cuff muscles in orangutans and gibbons, comparing the results with previously published data for chimpanzees. The EMG results indicate that the distinctive contributions of each cuff muscle to locomotion are the same in the three ape species, failing to support inferences of differences in rotator cuff function based on relative scapular fossa size comparisons. It is also shown that relative scapular fossa size is not in fact a good predictor of either the relative masses or cross-sectional areas of the rotator cuff muscles in apes, and relative fossa size gives a false impression of the importance of individual cuff muscles to locomotor differences among apes. A possible explanation for the disparity between fossa and muscle size relates to the underappreciated role of the scapular spine in structural reinforcement of the blade. Copyright © 2013 Elsevier Ltd. All rights reserved.

A comparison of respiratory and peripheral muscle strength, functional exercise capacity, activities of daily living and physical fitness in patients with cystic fibrosis and healthy subjects.

PubMed

Arikan, Hulya; Yatar, İlker; Calik-Kutukcu, Ebru; Aribas, Zeynep; Saglam, Melda; Vardar-Yagli, Naciye; Savci, Sema; Inal-Ince, Deniz; Ozcelik, Ugur; Kiper, Nural

2015-01-01

There are limited reports that compare muscle strength, functional exercise capacity, activities of daily living (ADL) and parameters of physical fitness of cystic fibrosis (CF) patients with healthy peers in the literature. The purpose of this study was to assess and compare respiratory and peripheral muscle strength, functional exercise capacity, ADL and physical fitness in patients with CF and healthy subjects. Nineteen patients with CF (mean forced expiratory volume in one second-FEV1: 86.56±18.36%) and 20 healthy subjects were included in this study. Respiratory (maximal inspiratory pressure-MIP and maximal expiratory pressure-MEP) and peripheral muscle strength (quadriceps, shoulder abductors and hand grip strength) were evaluated. Functional exercise capacity was determined with 6min walk test (6MWT). ADL was assessed with Glittre ADL test and physical fitness was assessed with Munich fitness test (MFT). There were not any statistically significant difference in MIP, %MIP, MEP and %MEP values between two groups (p>0.05). %Peripheral muscle strength (% quadriceps and shoulder abductors strength), 6MWT distance and %6MWT distance were significantly lower in patients with CF than those of healthy subjects (p<0.05). Glittre ADL-test time was significantly longer in patients with CF than healthy subjects (p<0.05). According to Munich fitness test, the number of bouncing a ball, hanging score, distance of standing vertical jumping and standing vertical jumping score were significantly lower in patients with CF than those of healthy subjects (p<0.05). Peripheral muscle strength, functional exercise capacity, ADL performance and speed, coordination, endurance and power components of physical fitness are adversely affected in mild-severe patients with CF compared to healthy peers. Evaluations must be done in comprehensive manner in patients with CF with all stages. Copyright © 2015 Elsevier Ltd. All rights reserved.

Eldercare at Home: Mobility Problems

MedlinePlus

... your shoulders back. You should feel your shoulder blades pull together. Cervical Range of Motion Purpose: To ... ahead. Keep your chin tucked and your shoulder blades back. Tighten your stomach muscles. First, rise up ...

Quantitative evaluation of fatty degeneration of the supraspinatus and infraspinatus muscles using T2 mapping.

PubMed

Matsuki, Keisuke; Watanabe, Atsuya; Ochiai, Shunsuke; Kenmoku, Tomonori; Ochiai, Nobuyasu; Obata, Takayuki; Toyone, Tomoaki; Wada, Yuichi; Okubo, Toshiyuki

2014-05-01

Although fatty degeneration of the rotator cuff muscles has been reported to affect the outcomes of rotator cuff repairs, only a few studies have attempted to quantitatively evaluate this degeneration. T2 mapping is a quantitative magnetic resonance imaging technique that potentially evaluates the concentration of fat in muscles. The purpose of this study was to investigate fatty degeneration of the rotator cuff muscles by using T2 mapping, as well as to evaluate the reliability of T2 measurement. We obtained magnetic resonance images including T2 mapping from 184 shoulders (180 patients; 110 male patients [112 shoulders] and 70 female patients [72 shoulders]; mean age, 62 years [range, 16-84 years]). Eighty-three shoulders had no rotator cuff tear (group A), whereas 101 shoulders had tears, of which 62 were incomplete to medium (group B) and 39 were large to massive (group C). T2 values of the supraspinatus and infraspinatus muscles were measured and compared among groups. Intraobserver and interobserver variabilities also were examined. The mean T2 values of the supraspinatus in groups A, B, and C were 36.3 ± 4.7 milliseconds, 44.2 ± 11.3 milliseconds, and 57.0 ± 18.8 milliseconds, respectively. The mean T2 values of the infraspinatus in groups A, B, and C were 36.1 ± 5.1 milliseconds, 40.0 ± 11.1 milliseconds, and 51.9 ± 18.2 milliseconds, respectively. The T2 value significantly increased with the extent of the tear in both muscles. Both intraobserver and interobserver variabilities were more than 0.99. T2 mapping can be a reliable tool to quantify fatty degeneration of the rotator cuff muscles. Copyright © 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

A Prospective Analysis on Functional Outcomes Following Extended Latissimus Dorsi Flap Breast Reconstruction.

PubMed

Eyjolfsdottir, H; Haraldsdottir, B; Ragnarsdottir, M; Asgeirsson, K S

2017-06-01

To prospectively assess the functional effect of using the extended latissimus dorsi flap in immediate breast reconstructions. A total of 15 consecutive patients undergoing breast reconstruction with extended latissimus dorsi flap participated. Shoulder range of motion, muscle strength, lateral flexion of the torso, and position of scapula were measured pre-operatively and 1, 6, and 12 months post-operatively, in addition to donor-site post-operative complications. At 12 months post-operatively, patients had achieved full range of shoulder movement, when compared to pre-operative values. Lateral flexion of the torso was, however, significantly reduced bilaterally at 1 and 6 months post-operatively (p = 0.001, p = 0.01) and to the not operated side at 12 months (p = 0.01). Muscle strength in flexion-extension-internal rotation was significantly (p = 0.01) reduced on the operated side 12 months post-operatively. All but one patient had numbness around the donor-site scar 12 months post-operatively, 33% had slight adhesions but all were pain free. Although invariably, patients having extended latissimus dorsi flap may expect to achieve full range of shoulder movement, they should be informed of possible functional consequences and the time and effort it takes to recover. Further research is needed to investigate the potential long-term functional implications that extended latissimus dorsi flap may have as a result of changes in the lateral flexion of the torso and scapula position.

Inter-rater Reliability of Sustained Aberrant Movement Patterns as a Clinical Assessment of Muscular Fatigue

PubMed Central

Aerts, Frank; Carrier, Kathy; Alwood, Becky

2016-01-01

Background: The assessment of clinical manifestation of muscle fatigue is an effective procedure in establishing therapeutic exercise dose. Few studies have evaluated physical therapist reliability in establishing muscle fatigue through detection of changes in quality of movement patterns in a live setting. Objective: The purpose of this study is to evaluate the inter-rater reliability of physical therapists’ ability to detect altered movement patterns due to muscle fatigue. Design: A reliability study in a live setting with multiple raters. Participants: Forty-four healthy individuals (ages 19-35) were evaluated by six physical therapists in a live setting. Methods: Participants were evaluated by physical therapists for altered movement patterns during resisted shoulder rotation. Each participant completed a total of four tests: right shoulder internal rotation, right shoulder external rotation, left shoulder internal rotation and left shoulder external rotation. Results: For all tests combined, the inter-rater reliability for a single rater scoring ICC (2,1) was .65 (95%, .60, .71) This corresponds to moderate inter-rater reliability between physical therapists. Limitations: The results of this study apply only to healthy participants and therefore cannot be generalized to a symptomatic population. Conclusion: Moderate inter-rater reliability was found between physical therapists in establishing muscle fatigue through the observation of sustained altered movement patterns during dynamic resistive shoulder internal and external rotation. PMID:27347241

The developing shoulder has a limited capacity to recover after a short duration of neonatal paralysis

PubMed Central

Potter, Ryan; Havlioglu, Necat; Thomopoulos, Stavros

2014-01-01

Mechanical stimuli are required for the proper development of the musculoskeletal system. Removal of muscle forces during fetal or early post-natal timepoints impairs the formation of bone, tendon, and their attachment (the enthesis). The goal of the current study was to examine the capacity of the shoulder to recover after a short duration of neonatal rotator cuff paralysis, a condition mimicking the clinical condition neonatal brachial plexus palsy. We asked if reapplication of muscle load to a transiently paralyzed muscle would allow for full recovery of tissue properties. CD-1 mice were injected with botulinum toxin A to paralyze the supraspinatus muscle from birth through 2 weeks and subsequently allowed to recover. The biomechanics of the enthesis was determined using tensile testing and the morphology of the shoulder joint was determined using micro computed tomography and histology. A recovery period of at least 10 weeks was required to achieve control properties, demonstrating a limited capacity of the shoulder to recover after only two weeks of muscle paralysis. Although care must be taken when extrapolating results from an animal model to the human condition, the results of the current study imply that treatment of neonatal brachial plexus palsy should be aggressive, as even short periods of paralysis could lead to long-term deficiencies in enthesis biomechanics and shoulder morphology. PMID:24831237

Joint Kinetics to Assess the Influence of the Racket on a Tennis Player’s Shoulder

PubMed Central

Creveaux, Thomas; Dumas, Raphaël; Hautier, Christophe; Macé, Pierre; Chèze, Laurence; Rogowski, Isabelle

2013-01-01

This study aimed at investigating the influence of three rackets on shoulder net joint moments, power and muscle activity during the flat tennis serve under field- conditions. A 6-camera Eagle® motion analysis system, operating at 256 Hz, captured racket and dominant upper limb kinematics of the serve in five tennis players under three racket conditions (A: low mass, high balance and polar moment, B: low three moments of inertia, and C: high mass, swingweight and twistweight). The electromyographic activity of six trunk and arm muscles was simultaneously recorded. Shoulder net joint moments and power were computed by 3D inverse dynamics. The results showed that greater shoulder joint power and internal/external rotation peak moments were found to accelerate and decelerate racket A in comparison with the racket C. Moreover, serving with the racket A resulted in less activity in latissimus dorsi muscle during the acceleration phase, and biceps brachii muscle during the follow-through phase when compared with racket C. These initial findings encourage studying the biomechanical measurements to quantify the loads on the body during play in order to reduce them, and then prevent shoulder injuries. Racket specifications may be a critical point for coaches who train players suffering from shoulder pain and chronic upper limb injuries should be considered in relation to the racket specifications of the players. Key Points Light racket required more joint power than heavy one to achieve similar post impact ball velocity. Serving with a light racket resulted in higher shoulder internal and external rotation moments than using a heavy one for similar performance. Chronic shoulder pain should encourage coaches to check for potentially inappropriate racket specifications of their players. PMID:24149804

Treatment of myofascial trigger points in common shoulder disorders by physical therapy: a randomized controlled trial [ISRCTN75722066].

PubMed

Bron, Carel; Wensing, Michel; Franssen, Jo Lm; Oostendorp, Rob Ab

2007-11-05

Shoulder disorders are a common health problem in western societies. Several treatment protocols have been developed for the clinical management of persons with shoulder pain. However available evidence does not support any protocol as being superior over others. Systematic reviews provide some evidence that certain physical therapy interventions (i.e. supervised exercises and mobilisation) are effective in particular shoulder disorders (i.e. rotator cuff disorders, mixed shoulder disorders and adhesive capsulitis), but there is an ongoing need for high quality trials of physical therapy interventions. Usually, physical therapy consists of active exercises intended to strengthen the shoulder muscles as stabilizers of the glenohumeral joint or perform mobilisations to improve restricted mobility of the glenohumeral or adjacent joints (shoulder girdle). It is generally accepted that a-traumatic shoulder problems are the result of impingement of the subacromial structures, such as the bursa or rotator cuff tendons. Myofascial trigger points (MTrPs) in shoulder muscles may also lead to a complex of symptoms that are often seen in patients diagnosed with subacromial impingement or rotator cuff tendinopathy. Little is known about the treatment of MTrPs in patients with shoulder disorders.The primary aim of this study is to investigate whether physical therapy modalities to inactivate MTrPs can reduce symptoms and improve shoulder function in daily activities in a population of chronic a-traumatic shoulder patients when compared to a wait-and-see strategy. In addition we investigate the recurrence rate during a one-year-follow-up period. This paper presents the design for a randomized controlled trial to be conducted between September 2007 - September 2008, evaluating the effectiveness of a physical therapy treatment for non-traumatic shoulder complaints. One hundred subjects are included in this study. All subjects have unilateral shoulder pain for at least six months and are referred to a physical therapy practice specialized in musculoskeletal disorders of the neck-, shoulder-, and arm. After the initial assessment patients are randomly assigned to either an intervention group or a control-group (wait and see). The primary outcome measure is the overall score of the Dutch language version of the DASH (Disabilities of Arm, Shoulder and Hand) questionnaire. Since there is only little evidence for the efficacy of physical therapy interventions in certain shoulder disorders, there is a need for further research. We found only a few studies examining the efficacy of MTrP therapy for shoulder disorders. Therefore we will perform a randomised clinical trial of the effect of physical therapy interventions aimed to inactivate MTrPs, on pain and impairment in shoulder function in a population of chronic a-traumatic shoulder patients. We opted for an intervention strategy that best reflects daily practice. Manual high velocity thrust techniques and dry-needling are excluded. Because in most physical therapy interventions, blinding of the patient and the therapist is not possible, we will perform a randomised, controlled and observer-blinded study. This randomized clinical trial is registered at current controlled trials ISRCTN75722066.

Genetics Home Reference: facioscapulohumeral muscular dystrophy

MedlinePlus

... those of the face (facio-), around the shoulder blades (scapulo-), and in the upper arms (humeral). The ... Weak shoulder muscles tend to make the shoulder blades (scapulae) protrude from the back, a common sign ...

Ergonomic Strategies for Using a Purse

MedlinePlus

... a Heavy Purse • Heavy purses worn over one shoulder cause uneven weight distribution across the back muscles and may restrict blood flow at the shoulder. • Heavy purses and shoulder straps without padding place ...

The gymnast's shoulder MRI and clinical findings.

PubMed

De Carli, A; Mossa, L; Larciprete, M; Ferretti, M; Argento, G; Ferretti, A

2012-02-01

The aim of the study was to evaluate effects of shoulder overuse in elite symptomatic or asymptomatic gymnasts. This was a university-based sport traumatology research, a cohort study, with a control group comparison. Patients included were: 21 elite male gymnasts performing in the Italian National team for at least 10 years and a control group of 10 patients (20 shoulders) of the same age and sex, randomly selected among a healthy non-athletic population who underwent shoulder MRI. Magnetic resonance imaging without contrast were performed to all participants and clinical findings were summarized. Two experienced musculoskeletal radiologists interpreted each MRI scan for multiple variables (rotator cuff tendons, labral signal, capsule), including type of measurements performed on soft tissues (muscles, tendons) to assess global modifications of the shoulders. Signal abnormalities were detected in 36/36 (100%) gymnasts' shoulders, and in 4/20 (20%) of the controls. Sixteen of 36 (44.4%) shoulders had findings consistent with SLAP tears, bilateral in four patients; anteroinferior labrum lesions were identified in 10/36 (27.7%) shoulders, as compared with none (0%) in the controls. Eight of 36 (22%) shoulders had findings consistent with partial- or full-thickness tears of the rotator cuff as compared with none (0%) of the controls. Increased thickness of rotator cuff tendons and hypertrophy of rotator cuff muscles and deltoid muscles were recorded: such reports were symmetrical between dominant and non dominant arms, and increased when compared to controls. Gymnasts' shoulders are significantly different from those of the general population. MRI findings, especially SLAP tears, and hypertrophy are symmetrical. SLAP tears seem to be responsible of most early retirement.

The effect of electrical stimulation in combination with Bobath techniques in the prevention of shoulder subluxation in acute stroke patients.

PubMed

Fil, Ayla; Armutlu, Kadriye; Atay, Ahmet Ozgur; Kerimoglu, Ulku; Elibol, Bulent

2011-01-01

To examine the efficiency of electrical stimulation in combination with Bobath techniques in the prevention of inferior and anterior shoulder subluxation in acute stroke patients. A prospective randomized controlled trial. Intensive care unit and inpatient clinics of neurology in a university hospital. Forty-eight patients with acute stroke, divided equally into control and study groups. Subjects in both groups were treated in accordance with the Bobath concept during the early hospitalization period. In addition to Bobath techniques, electrical stimulation was also applied to the supraspinatus muscle, mid and posterior portions of the deltoid muscle of patients in the study group. Two radiological methods were used to measure the horizontal, vertical and total asymmetry and vertical distance values of the shoulder joint. Motor functions of the arm were evaluated with the Motor Assessment Scale. The hospitalization period was 12.62 ± 2.24 days for the control group and 11.66 ± 1.88 days for the study group. Shoulder subluxation occurred in 9 (37.5%) subjects in the control group, whereas it was not observed in the study group. All shoulder joint displacement values were higher in the control group than in the study group (horizontal asymmetry P = 0.0001, vertical asymmetry P = 0.0001, total asymmetry P = 0.0001, vertical range P = 0.002). Application of electrical stimulation combined with the Bobath approach proved to be efficient in preventing inferior and anterior shoulder subluxation in the acute stages of stroke.

Direction-specific recruitment of rotator cuff muscles during bench press and row.

PubMed

Wattanaprakornkul, Duangjai; Halaki, Mark; Cathers, Ian; Ginn, Karen A

2011-12-01

Recent studies indicate that rotator cuff (RC) muscles are recruited in a reciprocal, direction-specific pattern during shoulder flexion and extension exercises. The main purpose of this study was to determine if similar reciprocal RC recruitment occurs during bench press (flexion-like) and row (extension-like) exercises. In addition, shoulder muscle activity was comprehensively compared between bench press and flexion; row and extension; and bench press and row exercises. Electromyographic (EMG) activity was recorded from 9 shoulder muscles sites in 15 normal volunteers. All exercises were performed at 20, 50 and 70% of subjects' maximal load. EMG data were normalized to standard maximal voluntary contractions. Infraspinatus activity was significantly higher than subscapularis during bench press, with the converse pattern during the row exercise. Significant differences in activity levels were found in pectoralis major, deltoid and trapezius between the bench press and flexion exercises and in lower trapezius between the row and extension exercises. During bench press and row exercises, the recruitment pattern in each active muscle did not vary with load. During bench press and row exercises, RC muscles contract in a reciprocal direction-specific manner in their role as shoulder joint dynamic stabilizers to counterbalance antero-posterior translation forces. Copyright © 2011 Elsevier Ltd. All rights reserved.

Strength Training Using Elastic Bands: Improvement of Muscle Power and Throwing Performance in Young Female Handball Players.

PubMed

Mascarin, Naryana Cristina; de Lira, Claudio Andre Barbosa; Vancini, Rodrigo Luiz; de Castro Pochini, Alberto; da Silva, Antonio Carlos; Dos Santos Andrade, Marilia

2017-05-01

Imbalance in shoulder-rotator muscles has been considered a risk factor for injuries in handball. Strength training programs (STPs) may play an important preventive role. To verify the effects of an STP using elastic bands on shoulder muscles and ball-throwing speed. Randomized and prospective controlled trial. Exercise physiology laboratory. Thirty-nine female handball players were randomly assigned to an experimental (EG, n = 21, 15.3 ± 1.1 y) or a control (CG, n = 18, 15.0 ± 0.8 y) group. The EG performed the STP with elastic-band progressive exercises for 6 wk before regular handball training, and the CG underwent only their regular training. Before and after the STP, both groups underwent a ball-throwing-speed test and isokinetic test to assess shoulder internal- (IR) and external-rotator muscle performance. Average power values for IR muscles presented a significant group-vs-time interaction effect (F = 3.9, P = .05); EG presented significantly higher values after the STP (P = .03). Ball speed presented higher values in EG after the STP in standing (P = .04) and jumping (P = .03) throws. IR peak-torque values and balance in shoulder-rotator muscles presented no group-vs-time interaction effect. STP using elastic bands performed for 6 wk was effective to improve muscle power and ball speed for young female handball players.

An electromyographic analysis of shoulder muscle activation during push-up variations on stable and labile surfaces.

PubMed

Sandhu, Jaspal S; Mahajan, Shruti; Shenoy, Shweta

2008-04-01

Numerous exercises are used to strengthen muscles around the shoulder joint including the push-up and the push-up plus. An important consideration is the addition of surface instability in the form of swiss ball for rehabilitation and strength. The justification for the use of the swiss ball is based on its potential for increasing muscular demand required to maintain postural stability and for improving joint proprioception. Evidence for this is lacking in literature. To compare the myoelectric amplitude of shoulder muscles during push-ups on labile and stable surface. Same subject experimental study. Thirty healthy male subjects in the age group 20-30 years with a mean height of 173.65 cm (+/- SD 2.56) and a mean weight of 69.9 kg (+/-SD 0.2) were taken. Surface electromyogram was recorded from triceps, pectoralis major, serratus anterior and upper trapezius while performing push-up and push-up plus exercises, both on labile and stable surface. Significant increase in muscle activity was observed in pectoralis major and triceps muscle (only during eccentric phase of elbow pushups), while serratus anterior and upper trapezius showed no change in activation level on swiss ball. The addition of a swiss ball is capable of influencing shoulder muscle activity during push-up variations, although the effect is task and muscle dependent.

Manual therapy is an effective treatment for frozen shoulder in diabetics: an observational study.

PubMed

Düzgün, Irem; Baltaci, Gül; Atay, Ozgür Ahmet

2012-01-01

This study aims to compare the efficacy of manual therapy in the frozen shoulder patients with or without diabetes mellitus. Between May 2006 and January 2008, 50 patients (10 males, 40 females; mean age 52 ± 10 years; range 40 to 65 years) orthopedic surgeons referred to the Sports Physiotherapy Unit were included in the study. The patients were divided into two groups, including patients with primary frozen shoulder with type II diabetes mellitus (n=12) and non diabetics (n=38). All patients underwent a rehabilitation program including cold application, manual therapy and exercises twice a week. A total of 16 treatment sessions were performed. The most important part of the manual therapy included scapular mobilization and posterior capsule stretching. The range of motion was measured by goniometry. Functional activity status was assessed by Constant's score. The pain level was evaluated by visual analog scale, while muscle strength was evaluated by hand-held dynamometer. Student t-test was used to compare between the parameters of groups, while Paired sample t-test was used to compare pre- and post-treatment parameters of the patients. The range of motion, functional activity status and muscular strength were improved and the pain level was reduced after rehabilitation in all of the patients in both groups (p<0.05). There was no difference in duration of the treatment between the groups (p>0.05). There were no differences in range of motion, functional activity status, pain level, and muscle strength before and after rehabilitation between the groups (p>0.05). Manual therapy approaches may be safely applied in diabetic patients with frozen shoulder.

On the development of the shoulder girdle in Crocidura russula (Soricidae) and other placental mammals: evolutionary and functional aspects

PubMed Central

Großmann, Martin; Sánchez-Villagra, Marcelo R; Maier, Wolfgang

2002-01-01

The development of the shoulder girdle was studied in embryonic stages and a neonate of Crocidura russula using histological sections and 3-D reconstructions. Neonatal stages of Suncus etruscus and Mesocricetus auratus, both altricial placentals, were also studied. The earliest stage of C. russula, in which the scapula is still partially blastematous, has already a supraspinous fossa. The dorsal portion of the scapular spine does not develop from the anterior margin of the scapula. Its mode of development varies among the placentals studied to date. In some it is completely appositional bone, in others it consists of bone formed mostly by endochondral ossification of a dorsal cartilaginous process stemming from the acromium. During development the supraspinatus muscle increases in size in proportion to the infraspinatus muscle and the humeral head increases in size in relation to the glenoid fossa. Placentals have secondary cartilage in the sternal and acromial ends of the clavicle, a derived feature absent in Marsupialia. Even the most altricial placentals have a more developed shoulder girdle at birth than any newborn marsupial studied to date. PMID:12448772

Anatomy and histochemistry of spread-wing posture in birds. 3. Immunohistochemistry of flight muscles and the "shoulder lock" in albatrosses.

PubMed

Meyers, Ron A; Stakebake, Eric F

2005-01-01

As a postural behavior, gliding and soaring flight in birds requires less energy than flapping flight. Slow tonic and slow twitch muscle fibers are specialized for sustained contraction with high fatigue resistance and are typically found in muscles associated with posture. Albatrosses are the elite of avian gliders; as such, we wanted to learn how their musculoskeletal system enables them to maintain spread-wing posture for prolonged gliding bouts. We used dissection and immunohistochemistry to evaluate muscle function for gliding flight in Laysan and Black-footed albatrosses. Albatrosses possess a locking mechanism at the shoulder composed of a tendinous sheet that extends from origin to insertion throughout the length of the deep layer of the pectoralis muscle. This fascial "strut" passively maintains horizontal wing orientation during gliding and soaring flight. A number of muscles, which likely facilitate gliding posture, are composed exclusively of slow fibers. These include Mm. coracobrachialis cranialis, extensor metacarpi radialis dorsalis, and deep pectoralis. In addition, a number of other muscles, including triceps scapularis, triceps humeralis, supracoracoideus, and extensor metacarpi radialis ventralis, were found to have populations of slow fibers. We believe that this extensive suite of uniformly slow muscles is associated with sustained gliding and is unique to birds that glide and soar for extended periods. These findings suggest that albatrosses utilize a combination of slow muscle fibers and a rigid limiting tendon for maintaining a prolonged, gliding posture.

Functional anatomy of the gibbon forelimb: adaptations to a brachiating lifestyle

PubMed Central

Michilsens, Fana; Vereecke, Evie E; D'Août, Kristiaan; Aerts, Peter

2009-01-01

It has been shown that gibbons are able to brachiate with very low mechanical costs. The conversion of muscle activity into smooth, purposeful movement of the limb depends on the morphometry of muscles and their mechanical action on the skeleton. Despite the gibbon's reputation for excellence in brachiation, little information is available regarding either its gross musculoskeletal anatomy or its more detailed muscle–tendon architecture. We provide quantitative anatomical data on the muscle–tendon architecture (muscle mass, physiological cross-sectional area, fascicle length and tendon length) of the forelimb of four gibbon species, collected by detailed dissections of unfixed cadavers. Data are compared between different gibbon species and with similar published data of non-brachiating primates such as macaques, chimpanzees and humans. No quantitative differences are found between the studied gibbon species. Both their forelimb anatomy and muscle dimensions are comparable when normalized to the same body mass. Gibbons have shoulder flexors, extensors, rotator muscles and elbow flexors with a high power or work-generating capacity and their wrist flexors have a high force-generating capacity. Compared with other primates, the elbow flexors of gibbons are particularly powerful, suggesting that these muscles are particularly important for a brachiating lifestyle. Based on this anatomical study, the shoulder flexors, extensors, rotator muscles, elbow flexors and wrist flexors are expected to contribute the most to brachiation. PMID:19519640

IMPACT OF GRAVITY LOADING ON POST-STROKE REACHING AND ITS RELATIONSHIP TO WEAKNESS

PubMed Central

Beer, Randall F.; Ellis, Michael D.; Holubar, Bradley G.; Dewald, Julius P.A.

2010-01-01

The ability to extend the elbow following stroke depends on the magnitude and direction of torques acting at the shoulder. The mechanisms underlying this link remain unclear. The purpose of this study was to evaluate whether the effects of shoulder loading on elbow function were related to weakness or its distribution in the paretic limb. Ten subjects with longstanding hemiparesis performed movements with the arm either passively supported against gravity by an air bearing, or by activation of shoulder muscles. Isometric maximum voluntary torques at the elbow and shoulder were measured using a load cell. The speed and range of elbow extension movements were negatively impacted by actively supporting the paretic limb against gravity. However, the effects of gravity loading were not related to proximal weakness or abnormalities in the elbow flexor–extensor strength balance. The findings support the existence of abnormal descending motor commands that constrain the ability of stroke survivors to generate elbow extension torque in combination with abduction torque at the shoulder. PMID:17486581

Impact of gravity loading on post-stroke reaching and its relationship to weakness.

PubMed

Beer, Randall F; Ellis, Michael D; Holubar, Bradley G; Dewald, Julius P A

2007-08-01

The ability to extend the elbow following stroke depends on the magnitude and direction of torques acting at the shoulder. The mechanisms underlying this link remain unclear. The purpose of this study was to evaluate whether the effects of shoulder loading on elbow function were related to weakness or its distribution in the paretic limb. Ten subjects with longstanding hemiparesis performed movements with the arm either passively supported against gravity by an air bearing, or by activation of shoulder muscles. Isometric maximum voluntary torques at the elbow and shoulder were measured using a load cell. The speed and range of elbow extension movements were negatively impacted by actively supporting the paretic limb against gravity. However, the effects of gravity loading were not related to proximal weakness or abnormalities in the elbow flexor-extensor strength balance. The findings support the existence of abnormal descending motor commands that constrain the ability of stroke survivors to generate elbow extension torque in combination with abduction torque at the shoulder.

Relation between the Disability of the Arm, Shoulder and Hand Score and Muscle Strength in Post-Cardiac Surgery Patients.

PubMed

Izawa, Kazuhiro P; Kasahara, Yusuke; Hiraki, Koji; Hirano, Yasuyuki; Watanabe, Satoshi

2017-11-27

Background: The Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire is a valid and reliable patient-reported outcome measure. DASH can be assessed by self-reported upper extremity disability and symptoms. We aimed to examine the relationship between the physiological outcome of muscle strength and the DASH score after cardiac surgery. Methods: This cross-sectional study assessed 50 consecutive cardiac patients that were undergoing cardiac surgery. Physiological outcomes of handgrip strength and knee extensor muscle strength and the DASH score were measured at one month after cardiac surgery and were assessed. Results were analyzed using Spearman correlation coefficients. Results: The final analysis comprised 43 patients (men: 32, women: 11; age: 62.1 ± 9.1 years; body mass index: 22.1 ± 4.7 kg/m²; left ventricular ejection fraction: 53.5 ± 13.7%). Respective handgrip strength, knee extensor muscle strength, and DASH score were 27.4 ± 8.3 kgf, 1.6 ± 0.4 Nm/kg, and 13.3 ± 12.3, respectively. The DASH score correlated negatively with handgrip strength ( r = -0.38, p = 0.01) and with knee extensor muscle strength ( r = -0.32, p = 0.04). Conclusion: Physiological outcomes of both handgrip strength and knee extensor muscle strength correlated negatively with the DASH score. The DASH score appears to be a valuable tool with which to assess cardiac patients with poor physiological outcomes, particularly handgrip strength as a measure of upper extremity function, which is probably easier to follow over time than lower extremity function after patients complete cardiac rehabilitation.

Relationship between humeral geometry and shoulder muscle power among suspensory, knuckle-walking, and digitigrade/palmigrade quadrupedal primates.

PubMed

Kikuchi, Yasuhiro; Takemoto, Hironori; Kuraoka, Akio

2012-01-01

Shoulder morphology is functionally related to different patterns of locomotion in primates. To investigate this we performed a quantitative analysis of the relationship between cortical bone thickness (Cbt) of the muscle/tendon attachment site on the humerus and physiological cross-sectional area (PCSA) of the shoulder muscle in primates with different locomotory habits. The deltoid, subscapularis, supraspinatus, and infraspinatus were investigated. A chimpanzee, a gibbon, a baboon, two species of macaque, a lutong, a capuchin, and a squirrel monkey were included in the study. The total length of the humerus was measured and the values were converted into three-dimensional reconstructed data on a computer by computed tomography. The Cbt values were obtained from the volumes divided by the areas of the muscle/tendon attachment sites of the humerus by computer analysis. Muscle mass, muscle fascicle length, and muscle pennation angle were measured and PCSA was calculated using these parameters. A relatively high Cbt and small PCSA were characteristic of the gibbon. The gibbon's high Cbt suggests that passive tension in the muscle/tendon attachment site of suspensory primates (brachiators) may be greater than that of quadrupedal primates, whereas the relatively small PCSA indicates an association with a large amount of internal muscle fascia to endure the passive stress of brachiation. Although chimpanzees undertake some suspensory locomotion, the results for this species resemble those of the digitigrade/palmigrade quadrupedal primates rather than those of the suspensory primate. However, the deltoid and subscapularis in chimpanzee differ from those of the other primates and appear to be affected by the peculiar locomotion of knuckle-walking, i.e. the moment arm of forelimb in chimpanzees is relatively longer than that of digitigrade/palmigrade quadrupedal primates. Hence, a large PCSA in the deltoid and subscapularis may contribute to sustaining the body weight during locomotion. On the other hand, a thin cortical bone relative to a large PCSA was a feature of the cercopithecids, indicating that digitigrade/palmigrade quadrupedal locomotion produces less tension at the muscle/tendon attachment sites compared with that produced by brachiators. © 2011 The Authors. Journal of Anatomy © 2011 Anatomical Society of Great Britain and Ireland.

Outcome of triple-tendon transfer, an Eden-Lange variant, to reconstruct trapezius paralysis.

PubMed

Elhassan, Bassem T; Wagner, Eric R

2015-08-01

This study describes the technique and evaluates the outcome of the triple-tendon (T3) transfer, an Eden-Lange variant, to the scapula to stabilize the scapulothoracic articulation in the treatment of symptomatic trapezius paralysis. T3 transfers were performed in 22 patients with a history of persistent trapezius paralysis secondary to spinal accessory nerve injury. The indications for surgery included shoulder pain and weakness and limited range of motion of the shoulder. The T3 transfer included transfer of the levator scapulae to the lateral aspect of the spine of the scapula, the rhomboid minor to the spine of the scapula just medial to the levator scapulae insertion, and the rhomboid major to the medial spine of the scapula, including all muscles bony insertions. At an average follow-up of 35 months, winging was corrected in all patients, with improvement of shoulder asymmetry. All patients had significant improvement of pain (P < .01) and range of motion, including active shoulder abduction that improved from an average of 71° preoperatively to 118° postoperatively (P < .02) and shoulder flexion from an average of 102° to 150° (P < .01). There were also significant improvements in aggregate Constant Shoulder Score (P < .01), subjective shoulder value (P < .01), and Disabilities of the Arm, Shoulder and Hand score (P < .01). All patients were very satisfied with the outcome of surgery. This study shows that the T3 transfer is effective in stabilizing the scapulothoracic articulation and restoring the function of the trapezius, and thus, in improving pain and shoulder function in patients with symptomatic trapezius paralysis. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

An Accurate and Dynamic Computer Graphics Muscle Model

NASA Technical Reports Server (NTRS)

Levine, David Asher

1997-01-01

A computer based musculo-skeletal model was developed at the University in the departments of Mechanical and Biomedical Engineering. This model accurately represents human shoulder kinematics. The result of this model is the graphical display of bones moving through an appropriate range of motion based on inputs of EMGs and external forces. The need existed to incorporate a geometric muscle model in the larger musculo-skeletal model. Previous muscle models did not accurately represent muscle geometries, nor did they account for the kinematics of tendons. This thesis covers the creation of a new muscle model for use in the above musculo-skeletal model. This muscle model was based on anatomical data from the Visible Human Project (VHP) cadaver study. Two-dimensional digital images from the VHP were analyzed and reconstructed to recreate the three-dimensional muscle geometries. The recreated geometries were smoothed, reduced, and sliced to form data files defining the surfaces of each muscle. The muscle modeling function opened these files during run-time and recreated the muscle surface. The modeling function applied constant volume limitations to the muscle and constant geometry limitations to the tendons.

[Shoulder injuries in golf].

PubMed

Liem, D; Gosheger, G; Schmidt, C

2014-03-01

Due to its growing popularity golf has now come into the focus of orthopedic sports medicine. With a wide range of age groups and playing levels, orthopedic surgeons will encounter a wide range of musculoskeletal problems which are usually the result of overuse rather than trauma. The shoulder joint plays an important role in the golf swing whereby not only the muscles around the glenohumeral joint but also the scapula stabilizing muscles are extremely important for an effective golf swing. Golf is strictly not considered to be an overhead sport; however, the extreme peak positions of the golf swing involve placing the shoulder joint in maximum abduction and adduction positions which can provoke impingement, lesions of the pulley system or even a special form of posterior shoulder instability. Even after complex shoulder operations, such as rotator cuff repair or shoulder arthroplasty, a return to the golf course at nearly the same level of play can be expected.

Relation between functional mobility and dynapenia in institutionalized frail elderly

PubMed Central

Soares, Antonio Vinicius; Marcelino, Elessandra; Maia, Késsia Cristina; Borges, Noé Gomes

2017-01-01

ABSTRACT Objective To investigate the relation between functional mobility and dynapenia in institutionalized frail elderly. Methods A descriptive, correlational study involving 26 institutionalized elderly men and women, mean age 82.3±6 years. The instruments employed were the Mini Mental State Examination, the Geriatric Depression Scale, the International Physical Activity Questionnaire, the Timed Up and Go test, a handgrip dynamometer and a portable dynamometer for large muscle groups (shoulder, elbow and hip flexors, knee extensors and ankle dorsiflexors). Results Significant negative correlation between functional mobility levels assessed by the Timed Up and Go test and dynapenia was observed in all muscle groups evaluated, particularly in knee extensors (r -0.65). Conclusion A significant negative correlation between muscle strength, particularly knee extensor strength, and functional mobility was found in institutionalized elderly. Data presented indicate that the higher the muscle strength, the shorter the execution time, and this could demonstrate better performance in this functional mobility test. PMID:29091148

[Isolated Displaced Fracture of the Acromion - Case Report].

PubMed

Krtička, M; Ira, D

2016-01-01

Displaced fractures of the acromion are rare injuries. A 45-year-old lady presented with an isolated acromion fracture (type III, Kuhn classification) resulting from a direct blow to the top of her right shoulder in a fall while skiing. After standard clinical and radiological examination of the shoulder, an open reduction and internal plate fixation using a postero-superior approach to the scapula was performed. Early rehabilitation of the arm and shoulder was initiated. At 50 days after surgery the patient achieved a full range of motion in her right shoulder and muscle strength equal to that of the contralateral extremity. By 12 weeks radiographic union of the fracture was recorded. The final functional outcome after open reduction and internal plate fixation of the fracture was comparable with results reported in the literature and, in comparison with conservative treatment, the risk of non-union was significantly reduced. acromion fracture, scapula, osteosynthesis.

[Human tolerance to Coriolis acceleration during exertion of different muscle groups].

PubMed

Aĭzikov, G S; Emel'ianov, M D; Ovechkin, V G

1975-01-01

The effect of an arbitrary loading of different muscle groups (shoulder, back, legs) and motor acts on the tolerance to Coriolis accelerations was investigated in 140 experiments in which 40 test subjects participated. The accelerations were cumulated and simulated by the Bryanov scheme. Muscle tension was accompanied by a less expressed vestibulo-vegetative reaction and shortening of the recovery period after the development of motion sickness symptoms. The greatest changes were observed during the performance of complex motor acts and tension of shoulder muscles. Possible mechanisms of these effects are discussed.

ANODAL TRANSCRANIAL DIRECT CURRENT STIMULATION (TDCS) INCREASES ISOMETRIC STRENGTH OF SHOULDER ROTATORS MUSCLES IN HANDBALL PLAYERS.

PubMed

Hazime, Fuad Ahmad; da Cunha, Ronaldo Alves; Soliaman, Renato Rozenblit; Romancini, Ana Clara Bezerra; Pochini, Alberto de Castro; Ejnisman, Benno; Baptista, Abrahão Fontes

2017-06-01

Weakness of the rotator cuff muscles can lead to imbalances in the strength of shoulder external and internal rotators, change the biomechanics of the glenohumeral joint and predispose an athlete to injury. Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that has demonstrated promising results in a variety of health conditions. However few studies addressed its potential approach in the realm of athletics. The purpose of this study was to investigate if transcranial direct current stimulation (tDCS) technique increases the isometric muscle strength of shoulder external and internal rotators in handball athletes. Randomized, double-blind, placebo-controlled, crossover study. Eight female handball players aged between 17 and 21 years (Mean=19.65; SD=2.55) with 7.1 ± 4.8 years of experience in training, participating in regional and national competitions were recruited. Maximal voluntary isometric contraction (MVIC) of shoulder external and internal rotator muscles was evaluated during and after 30 and 60 minutes post one session of anodal and sham current (2mA; 0.057mA/cm 2 ) with a one-week interval between stimulations. Compared to baseline, MVIC of shoulder external and internal rotators significantly increased after real but not sham tDCS. Between-group differences were observed for external and internal rotator muscles. Maximal voluntary isometric contraction of external rotation increased significantly during tDCS, and 30 and 60 minutes post-tDCS for real tDCS compared to that for sham tDCS. For internal rotation MVIC increased significantly during and 60 minutes post-tDCS. The results indicate that transcranial direct current stimulation temporarily increases maximal isometric contractions of the internal and external rotators of the shoulder in handball players. 2.

[Therapeutic effect observation of post-stroke shoulder pain treated with the touching-periosteum needling technique of the meridian muscle region theory].

PubMed

Yuan, Haiguang; Liu, Zhibin; Feng, Weixing

2017-10-12

To evaluate the pain severity, the motor function of the upper limb and the quality of life in the patients of post-stroke shoulder pain treated with the touching-periosteum needling technique of the meridian muscle region theory. One hundred and six cases of post-stroke shoulder pain were randomized into an observation group and a control group, 53 cases in each one. In the observation group, the touching-periosteum needle technique and the rehabilitation training were used on the bases of the theory of meridian muscle region. The points were Jianyuci , Binaoci , Jianliaoci , Jianqianci , Quchi (LI 11), Shousanli (LI 10) and Waiguan (TE 5) on the affected side. The needles were inserted obliquely, at 45°degrees at those extra points to the tendon knots till the needle tips touching periosteum. The needles were manipulated to ensure the qi arrival and then retained for 30 min. The rehabilitation was applied, such as the anti-spasmodic posture, bridge-style movement on the bed, weight transition and balance training, joint activity maintenance training, passive and active movement of shoulder joint, the training for activities of daily living (ADL) and Bobath technique. In the control group, the routine acupuncture and the rehabilitation training were used. The acupints were Jianyu (LI 15), Binao (LI 14), Jianliao (TE 14), Jianqian (Extra), Quchi (LI 11), Shousanli (LI 10) and Waiguan (TE 5). The rehabilitation training was the same as the observation group. The treatment was given once every day, 6 treatments a week. After 20 treatments, the visual analogue scale (VAS), Fugl-Meyer (FMA) score and Barthel (MBI) score were adopted to evaluate the pain severity, the motor function of the upper limb and the ADL. The clinical therapeutic effects were evaluated in the two groups. The VAS scores were reduced after treatment as compared with those before treatment in the two groups, and FMA and MBI scores were all increased as compared with those before treatment, indicating the significant difference statistically ( P <0.05, P <0.01). After treatment, the improvements in the observation group were better than those in the control group (all P <0.05). The curative and remarkably effective rate was 69.8% (37/53) in the observation group, better than 47.2% (25/53) in the control group ( P <0.05). The touching-periosteum needling technique of the meridian muscle region theory obviously improves the pain severity, the motor function of the upper limb and the quality of life in patients of post-stroke shoulder pain. The therapeutic effects are better than the routine acupuncture.

Associations among musculoskeletal impairments, depression, body image and fatigue in breast cancer survivors within the first year after treatment.

PubMed

Cantarero-Villanueva, I; Fernández-Lao, C; Fernández-DE-Las-Peñas, C; Díaz-Rodríguez, L; Sanchez-Cantalejo, E; Arroyo-Morales, M

2011-09-01

The aim of the current study was to investigate the relationship between pressure pain thresholds, shoulder movement, mood state, pain perception, muscle endurance, quality of life and fatigue in breast cancer survivors (BCS). Fifty-nine BCS reporting fatigue were examined at 6 months post-treatment. Women completed the Piper Fatigue Scale, the Breast Cancer-Specific Quality of Life Questionnaire, the Profile of Mood State, and neck-shoulder visual analogue scale. Additionally, shoulder flexion range of motion, the McQuade test (trunk flexor endurance) and pressure pain thresholds over the C5-C6 joint, the deltoid muscle, the second metacarpal and tibialis anterior muscle were assessed. Fatigue was greater in those patients with higher depression (r= 0.45, P < 0.05), higher shoulder pain (r= 0.39, P < 0.05), higher neck pain (r= 0.46, P < 0.01), lower body image (r=-0.34, P < 0.05) and reduced shoulder movement (r=-0.32, P < 0.05). Regression analyses demonstrated that depression, cervical pain intensity, body image and shoulder mobility were associated with fatigue (r= 0.55, P < 0.001). A psychological state characterised with higher depression and reduced body image and a physical impairment with higher cervical pain intensity and reduced shoulder mobility confirm multidimensional character of fatigue in BCS. © 2011 Blackwell Publishing Ltd.

A COMPARISON OF STATIC AND DYNAMIC OPTIMIZATION MUSCLE FORCE PREDICTIONS DURING WHEELCHAIR PROPULSION

PubMed Central

Morrow, Melissa M.; Rankin, Jeffery W.; Neptune, Richard R.; Kaufman, Kenton R.

2014-01-01

The primary purpose of this study was to compare static and dynamic optimization muscle force and work predictions during the push phase of wheelchair propulsion. A secondary purpose was to compare the differences in predicted shoulder and elbow kinetics and kinematics and handrim forces. The forward dynamics simulation minimized differences between simulated and experimental data (obtained from 10 manual wheelchair users) and muscle co-contraction. For direct comparison between models, the shoulder and elbow muscle moment arms and net joint moments from the dynamic optimization were used as inputs into the static optimization routine. RMS errors between model predictions were calculated to quantify model agreement. There was a wide range of individual muscle force agreement that spanned from poor (26.4 % Fmax error in the middle deltoid) to good (6.4 % Fmax error in the anterior deltoid) in the prime movers of the shoulder. The predicted muscle forces from the static optimization were sufficient to create the appropriate motion and joint moments at the shoulder for the push phase of wheelchair propulsion, but showed deviations in the elbow moment, pronation-supination motion and hand rim forces. These results suggest the static approach does not produce results similar enough to be a replacement for forward dynamics simulations, and care should be taken in choosing the appropriate method for a specific task and set of constraints. Dynamic optimization modeling approaches may be required for motions that are greatly influenced by muscle activation dynamics or that require significant co-contraction. PMID:25282075

The effect of over-commitment and reward on trapezius muscle activity and shoulder, head, neck, and torso postures during computer use in the field

PubMed Central

Bruno Garza, Jennifer L.; Eijckelhof, Belinda H.W.; Huysmans, Maaike A.; Catalano, Paul J.; Katz, Jeffrey N.; Johnson, Peter W.; van Dieen, Jaap H.; van der Beek, Allard J.; Dennerlein, Jack T.

2015-01-01

Background Because of reported associations of psychosocial factors and computer related musculoskeletal symptoms, we investigated the effects of a workplace psychosocial factor, reward, in the presence of over-commitment, on trapezius muscle activity and shoulder, head, neck, and torso postures during computer use. Methods We measured 120 office workers across four groups (lowest/highest reward/over-commitment), performing their own computer work at their own workstations over a 2 hour period. Results Median trapezius muscle activity (p=0.04) and median neck flexion (p=0.03) were largest for participants reporting simultaneously low reward and high over-commitment. No differences were observed for other muscle activities or postures. Conclusions These data suggest that the interaction of reward and over-commitment can affect upper extremity muscle activity and postures during computer use in the real work environment. This finding aligns with the hypothesized biomechanical pathway connecting workplace psychosocial factors and musculoskeletal symptoms of the neck and shoulder. PMID:23818000

Individual muscle contributions to push and recovery subtasks during wheelchair propulsion.

PubMed

Rankin, Jeffery W; Richter, W Mark; Neptune, Richard R

2011-04-29

Manual wheelchair propulsion places considerable physical demand on the upper extremity and is one of the primary activities associated with the high prevalence of upper extremity overuse injuries and pain among wheelchair users. As a result, recent effort has focused on determining how various propulsion techniques influence upper extremity demand during wheelchair propulsion. However, an important prerequisite for identifying the relationships between propulsion techniques and upper extremity demand is to understand how individual muscles contribute to the mechanical energetics of wheelchair propulsion. The purpose of this study was to use a forward dynamics simulation of wheelchair propulsion to quantify how individual muscles deliver, absorb and/or transfer mechanical power during propulsion. The analysis showed that muscles contribute to either push (i.e., deliver mechanical power to the handrim) or recovery (i.e., reposition the arm) subtasks, with the shoulder flexors being the primary contributors to the push and the shoulder extensors being the primary contributors to the recovery. In addition, significant activity from the shoulder muscles was required during the transition between push and recovery, which resulted in increased co-contraction and upper extremity demand. Thus, strengthening the shoulder flexors and promoting propulsion techniques that improve transition mechanics have much potential to reduce upper extremity demand and improve rehabilitation outcomes. Copyright © 2011 Elsevier Ltd. All rights reserved.

Electromyographic analysis of rotator cuff muscles in patients with rotator cuff tendinopathy: A systematic review.

PubMed

de Oliveira, Fábio Carlos Lucas; Bouyer, Laurent Julien; Ager, Amanda L; Roy, Jean-Sébastien

2017-08-01

The shoulder is inherently an unstable joint which heavily relies on the neuromuscular activation of the rotator cuff (RC) complex for stability during movement. Currently, there is no consensus regarding how the activity of RC muscles is affected among individuals with a RC tendinopathy (RCTe). This study reviewed the evidence of studies comparing the electromyographic (EMG) activity of any RC muscle of shoulders with a symptomatic RCTe to asymptomatic shoulders. Eight databases were searched. Data from 343 participants (201 symptomatic and 209 asymptomatic shoulders) were analyzed from 10 out of 402 included studies. Strong evidence for the infraspinatus and supraspinatus during isometric contractions and limited evidence for the supraspinatus and infraspinatus during isokinetic contractions suggest that the muscular activity is not altered among individuals with a RCTe during these types of contraction. Very limited evidence indicates reduced muscle activity for the infraspinatus and subscapularis in the presence of a RCTe during isotonic contractions, and no alterations for the supraspinatus or teres minor were identified. Lastly, conflicting to moderate evidence suggests alterations in RC muscle activity during unrestrained movements and swimming. These findings indicate that EMG deficits associated with a RCTe can best be appreciated during unrestrained movements. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evolution and development of the vertebrate neck

PubMed Central

Ericsson, Rolf; Knight, Robert; Johanson, Zerina

2013-01-01

Muscles of the vertebrate neck include the cucullaris and hypobranchials. Although a functional neck first evolved in the lobe-finned fishes (Sarcopterygii) with the separation of the pectoral/shoulder girdle from the skull, the neck muscles themselves have a much earlier origin among the vertebrates. For example, lampreys possess hypobranchial muscles, and may also possess the cucullaris. Recent research in chick has established that these two muscles groups have different origins, the hypobranchial muscles having a somitic origin but the cucullaris muscle deriving from anterior lateral plate mesoderm associated with somites 1–3. Additionally, the cucullaris utilizes genetic pathways more similar to the head than the trunk musculature. Although the latter results are from experiments in the chick, cucullaris homologues occur in a variety of more basal vertebrates such as the sharks and zebrafish. Data are urgently needed from these taxa to determine whether the cucullaris in these groups also derives from lateral plate mesoderm or from the anterior somites, and whether the former or the latter represent the basal vertebrate condition. Other lateral plate mesoderm derivatives include the appendicular skeleton (fins, limbs and supporting girdles). If the cucullaris is a definitive lateral plate-derived structure it may have evolved in conjunction with the shoulder/limb skeleton in vertebrates and thereby provided a greater degree of flexibility to the heads of predatory vertebrates. PMID:22697305

Shoulder Muscle Activation of Novice and Resistance Trained Women during Variations of Dumbbell Press Exercises

PubMed Central

Luczak, Joshua; Bosak, Andy; Riemann, Bryan L.

2013-01-01

Previous research has compared the effects of trunk inclination angle on muscle activation using barbells and Smith machines in men. Whether similar effects occur with the use of dumbbells or in women remains unknown. The purpose was to compare upper extremity surface electromyographical (EMG) activity between dumbbell bench, incline, and shoulder presses. Dominate arm EMG data were recorded for collegiate-aged female resistance trained individuals (n = 12) and novice female resistance trained exercisers (n = 12) from which average EMG amplitude for each repetition phase (concentric, eccentric) was computed. No significant differences were found between experienced and novice resistance trained individuals. For the upper trapezius and anterior deltoid muscles, shoulder press activation was significantly greater than incline press which in turn was significantly greater than bench press across both phases. The bench and incline presses promoted significantly greater pectoralis major sternal activation compared to the shoulder press (both phases). While pectoralis major clavicular activation during the incline press eccentric phase was significantly greater than both the bench and shoulder presses, activation during the bench press concentric phase promoted significantly greater activation than the incline press which in turn was significantly greater than the shoulder press. These results provide evidence for selecting exercises in resistance and rehabilitation programs. PMID:26464884

Participatory ergonomic intervention versus strength training on chronic pain and work disability in slaughterhouse workers: study protocol for a single-blind, randomized controlled trial.

PubMed

Sundstrup, Emil; Jakobsen, Markus D; Andersen, Christoffer H; Jay, Kenneth; Persson, Roger; Aagaard, Per; Andersen, Lars L

2013-02-21

The prevalence of musculoskeletal pain in the shoulder, arm and hand is high among slaughterhouse workers, allegedly due to the highly repetitive and forceful exposure of these body regions during work. Work disability is a common consequence of these pains. Lowering the physical exposure through ergonomics intervention is the traditional strategy to reduce the workload. An alternative strategy could be to increase physical capacity of the worker through strength training. This study investigates the effect of two contrasting interventions, participatory ergonomics versus strength training on pain and work disability in slaughterhouse workers with chronic pain. 66 slaughterhouse workers were allocated to 10 weeks of (1) strength training of the shoulder, arm and hand muscles for 3 x 10 minutes per week, or (2) participatory ergonomics involving counseling on workstation adjustment and optimal use of work tools (~usual care control group). Inclusion criteria were (1) working at a slaughterhouse for at least 30 hours per week, (2) pain intensity in the shoulder, elbow/forearm, or hand/wrist of at least 3 on a 0-10 VAS scale during the last three months, (3) pain lasting for more than 3 months, (4) frequent pain (at least 3 days per week) (5) at least moderate work disability, (6) no strength training during the last year, (7) no ergonomics instruction during the last year.Perceived pain intensity (VAS scale 0-10) of the shoulder, elbow/forearm and hand/wrist (primary outcome) and Disability of the Arm, Shoulder and Hand (Work module, DASH questionnaire) were measured at baseline and 10-week follow-up. Further, total muscle tenderness score and muscle function were assessed during clinical examination at baseline and follow-up. This RCT study will provide experimental evidence of the effectiveness of contrasting work-site interventions aiming at reducing chronic pain and work disability among employees engaged in repetitive and forceful work. ClinicalTrials.gov:NCT01671267.

Reconstructive operations for the upper limb after brachial plexus palsy.

PubMed

Rühmann, Oliver; Schmolke, Stephan; Bohnsack, Michael; Carls, Jörg; Flamme, Christian; Wirth, Carl Joachim

2004-07-01

Limited function due to paralysis following brachial plexus lesions can be improved by secondary operations of the bony and soft tissue. Between April 1994 and December 2000, 109 patients suffering from arm-plexus lesions underwent a total of 144 reconstructive operations guided by our concept of integrated therapy. The average age at the time of surgery was 32 years (range: 15-59). The following operations were performed: shoulder arthrodesis (23), trapezius transfer (74), rotation osteotomy of humerus (9), triceps to biceps transposition (9), transposition of forearm flexors or extensors (8), latissimus transfer (7), pectoralis transfer (1), teres major transfer (1), transposition of flexor carpi ulnaris to the tendons of extensor digitorum (10), and wrist arthrodesis (2). Prospectively, in all patients, the grade of muscle power of the affected upper extremity was evaluated prior to surgery. The follow-up period for all 144 operations was, on average, 22 months (range: 6-74). By means of operative measures, almost all patients obtained an improvement of shoulder function (100%) and stability (>90%), elbow flexion (85%), and hand, finger, and thumb (100%). When muscles malfunction after brachial plexus lesions, one should take into account the individual neuromuscular defect, passive joint function, and bony deformities; different procedures such as muscle transpositions, arthrodeses, and corrective osteotomies can then be performed to improve function of the upper extremity. Each form of operative treatment presents patients with certain benefits and all are integrated into a total treatment plan for the affected extremity.

Effectiveness of home exercise on pain, function, and strength of manual wheelchair users with spinal cord injury: a high-dose shoulder program with telerehabilitation.

PubMed

Van Straaten, Meegan G; Cloud, Beth A; Morrow, Melissa M; Ludewig, Paula M; Zhao, Kristin D

2014-10-01

To test the effectiveness of a high-dose home exercise/telerehabilitation program for manual wheelchair users who have a spinal cord injury (SCI) by determining whether the intervention would reduce pain and increase function, as we hypothesized. A pre-post trial with outcomes measured at 3 time points: baseline, postintervention (12wk), and follow-up (>24 wk). Subjects performed an exercise program at their homes using telerehabilitation for therapist monitoring of technique and exercise advancement. Baseline and postintervention data were collected at a motion analysis laboratory in a tertiary medical center. A convenience sample of manual wheelchair users (N=16, 3 women; average age, 41y; average time in a wheelchair, 16y) with shoulder pain (average pain duration, 9y) and mechanical impingement signs on physical examination. A 12-week home exercise program of rotator cuff and scapular stabilization exercises was given to each participant. The program included a high dose of 3 sets of 30 repetitions, 3 times weekly, and regular physical therapist supervision via videoconferencing. Primary outcomes of pain and function were measured with the Wheelchair User's Shoulder Pain Index (WUSPI), Disabilities of Arm, Shoulder, and Hand (DASH) Index, and Shoulder Rating Questionnaire (SRQ). Secondary outcomes of strength were measured with isometric strength tests of scapulothoracic and glenohumeral muscles, and a static fatigue test of the lower trapezius. Pain was reduced and function improved after the intervention. There was a significant main effect for pain and function between the 3 time points based on the Friedman signed-ranked test, WUSPI (χ(2)2=5.10, P=.014), DASH Index (χ(2)2=5.41, P=.012), and SRQ (χ(2)2=23.71, P≤.001). Wilcoxon signed-rank tests demonstrated that isometric strength measurements of the serratus anterior and scapular retractors increased after the exercise intervention ([t=2.42, P=.04] and [t=4.67, P=.003], respectively). Muscle impulse produced by the lower trapezius during a fatigue task also improved (t=2.2, P=.02). No differences were measured in isometric strength for the lower trapezius, glenohumeral rotators, and abductors between the baseline and 12-week time points. A high-dose scapular stabilizer and rotator cuff strengthening program using telerehabilitation for supervision holds promise for shoulder pain treatment in manual wheelchair users with SCI. Additional work is needed to determine the effectiveness compared with other interventions, as well as the potential for earlier intervention to prevent development of shoulder pain. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Muscle thickness measurements of the lower trapezius with rehabilitative ultrasound imaging are confounded by scapular dyskinesis.

PubMed

Seitz, Amee L; Baxter, Caralyn J; Benya, Kristen

2015-08-01

Alterations in scapular muscle activity have been theorized to contribute to abnormal scapular motion and shoulder pain, but pose challenges to quantify in the clinic. Rehabilitative Ultrasound Imaging (RUSI) has proved useful identifying dysfunction of lumbar regional stabilizing muscle activity, specifically contractile behavior. Although, recent examinations of scapular stabilizing trapezius muscle function using RUSI did not detect alterations individuals with shoulder pain or differences in muscle thickness between varying external loads in asymptomatic individuals, a potential confounder to prior results, scapular dyskinesis has not been controlled. It is unknown if dyskinesis alters scapular muscle thickness during activation measured with RUSI. Thus, the purpose of this study was to compare change in scapular muscle thickness between individuals with and without scapular dyskinesis. Thirty-nine asymptomatic adults with (n = 19) and without (n = 20) scapular dyskinesis, defined with a reliable and validated method, participated. Two separate ultrasound images of the serratus anterior (SA) and lower trapezius (LT) were captured under two randomized conditions, rest and isometric contraction against gravity, and saved for blinded measurement. Change in thickness with contraction was calculated and expressed as a percentage. The dyskinesis group demonstrated a greater increase (p = 0.005) in LT thickness with the isometric contraction than the group without (mean difference = 31.6%; 95%CI = 10.3, 53.0). No differences in SA or resting thickness of either muscle were found between groups. The presence of scapular dyskinesis alters thickness changes of the lower trapezius during activation. Furthermore, potential underlying reasons beyond muscle contractile behavior must be considered. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of Botulinum Toxin on Reducing the Co-contraction of Antagonists in Birth Brachial Plexus Palsy

PubMed Central

Shin, Yong Beom; Chang, Jae Hyeok; Cha, Young Sun; Ko, Hyun-Yoon

2014-01-01

Birth brachial plexus palsy (BBPP) is usually caused by plexus traction during difficult delivery. Although the possibility of complete recovery is relatively high, 5% to 25% of BBPP cases result in prolonged and persistent disability. In particular, muscle imbalance and co-contraction around the shoulder and elbow cause abnormal motor performance, osseous deformities, and joint contracture. Physical and occupational therapies have most commonly been used, but these conventional therapeutic strategies have often been inadequate, in managing the residual muscle imbalance and muscle co-contraction. Therefore, we attempted to improve the functional movements, by using botulinum toxin type A, to reduce the abnormal co-contraction of the antagonist muscles. PMID:24639937

Comparison of shoulder load during power-assisted and purely hand-rim wheelchair propulsion.

PubMed

Kloosterman, Marieke G M; Eising, Hilde; Schaake, Leendert; Buurke, Jaap H; Rietman, Johan S

2012-06-01

Repetitive forces and moments are among the work requirements of hand-rim wheelchair propulsion that are related to shoulder injuries. No previous research has been published about the influence of power-assisted wheelchair propulsion on these work requirements. The purpose of our study was therefore to determine the influence of power-assisted propulsion on shoulder biomechanics and muscle activation patterns. We also explored the theoretical framework for the effectiveness of power-assisted propulsion in preventing shoulder injuries by decreasing the work requirements of hand-rim wheelchair propulsion. Nine non-wheelchair users propelled a hand-rim wheelchair on a treadmill at 0.9 m/s. Shoulder biomechanics, and muscle activation patterns, were compared between propulsion with and without power-assist. Propulsion frequency did not differ significantly between the two conditions (Wilcoxon Signed Rank test/significance level/effect size:4/.314/-.34). During power-assisted propulsion we found significantly decreased maximum shoulder flexion and internal rotation angles (1/.015/-.81 and 0/.008/-.89) and decreased peak force on the rim (0/.008/-.89). This resulted in decreased shoulder flexion, adduction and internal rotation moments (2/.021/-.77; 0/.008/-.89 and 1/.011/-.85) and decreased forces at the shoulder in the posterior, superior and lateral directions (2/.021/-.77; 2/.008/-.89 and 2/.024/-.75). Muscle activation in the pectoralis major, posterior deltoid and triceps brachii was also decreased (2/.038/-.69; 1/.015/-.81 and 1/.021/-.77). Power-assist influenced the work requirements of hand-rim wheelchair propulsion by healthy subjects. It was primarily the kinetics at rim and shoulder which were influenced by power-assisted propulsion. Additional research with actual hand-rim wheelchair users is required before extrapolation to routine clinical practice. Copyright © 2011 Elsevier Ltd. All rights reserved.

Electromyographic activity of selected scapular stabilizers during glenohumeral internal and external rotation contractions.

PubMed

Schachter, Aaron K; McHugh, Malachy P; Tyler, Timothy F; Kreminic, Ian J; Orishimo, Karl F; Johnson, Christopher; Ben-Avi, Simon; Nicholas, Stephen J

2010-09-01

An important synergistic relationship exists between the scapular stabilizers and the glenohumeral rotators. Information on the relative contribution of the scapular stabilizers to glenohumeral rotation would be useful for exercise prescription for overhead athletes and for patients with shoulder pathology. We hypothesized that the scapular stabilizers would be highly active during both maximal and submaximal internal and external rotation. Eight healthy male volunteers (16 shoulders) performed internal and external glenohumeral rotation testing at maximal and submaximal intensities. They also performed a scapular retraction rowing exercise at maximal and submaximal levels. Electromyographic (EMG) signals were recorded from the infraspinatus, pectoralis major, serratus anterior, and middle trapezius. Values were compared among muscle groups, among individual muscles at different intensity levels, and among individual muscles at different points in the arc of motion. For submaximal glenohumeral internal rotation, activity in the scapular stabilizers was not different (P = .1-.83) from activity in the internal rotator throughout the range of motion. For the initial two-thirds of maximal internal rotation, middle trapezius activity and pectoralis major activity were higher (P < .05) than serratus anterior activity. For submaximal external rotation, activity in the scapular stabilizers during the middle phase of the motion was higher (P < .05) than activity in the external rotators. For maximal external rotation these differences were present throughout the motion with middle trapezius activity exceeding 100% maximal voluntary contraction. The scapular stabilizers functioned at a similar or higher intensity than the glenohumeral rotators during internal and external rotation. This highlights the importance of training the scapular stabilizers in upper extremity athletes and in patients with shoulder pathology. (c) 2010 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

Dominant vs. non-dominant shoulder morphology in volleyball players and associations with shoulder pain and spike speed.

PubMed

Challoumas, Dimitrios; Artemiou, Andreas; Dimitrakakis, Georgios

2017-01-01

The aims of our study were to compare the dominant (DOM) and non-dominant (NDOM) shoulders of high-level volleyball athletes and identify possible associations of shoulder adaptations with spike speed (SS) and shoulder pathology. A total of 22 male volleyball players from two teams participating in the first division of the Cypriot championship underwent clinical shoulder tests and simple measurements around their shoulder girdle joints bilaterally. SS was measured with the use of a sports speed radar. Compared with the NDOM side, the DOM scapula was more lateralised, the DOM dorsal capsule demonstrated greater laxity, the DOM dorsal muscles stretching ability was compromised, and the DOM pectoralis muscle was more lengthened. Players with present or past DOM shoulder pain demonstrated greater laxity in their DOM dorsal capsule, tightening of their DOM inferior capsule, and lower SS compared with those without shoulder pain. Dorsal capsule measurements bilaterally were significant predictors of SS. None of the shoulder measurements was associated with team roles or infraspinatus atrophy, while scapular lateralisation was more pronounced with increasing years of experience, and scapular antetilting was greater with increasing age. Adaptations of the DOM shoulder may be linked to pathology and performance. We describe simple shoulder measurements that may have the potential to predict chronic shoulder injury and become part of injury prevention programmes. Detailed biomechanical and large prospective studies are warranted to assess the validity of our findings and reach more definitive conclusions.

Characteristics of upper extremity's muscle strength in Turkish national wheelchair basketball players team.

PubMed

Akınoğlu, Bihter; Kocahan, Tuğba

2017-02-01

The objective of this study was to reveal characteristics of muscle strength of upper extremities of wheelchair (WC) basketball players and to ensure more-specific training program preparation. Isokinetic muscle strength of 12 WC basketball players were assessed by ISOMED 2000 device. The assessment protocol was evaluated at 60°/sec velocity with 5 times repeated force and at 240°/sec with 15 times repeated force. This protocol was carried out individually for shoulder flexion-extension and wrist flexion-extension movements at the right and left extremities. The flexion/extension ratio was determined to be outside of the ratios accepted as normal for primarily shoulder joint and for wrist joint. The extension movement was stronger than flexion movement in the shoulders at both velocities and the flexion movement was stronger than ex-tension movement in the wrist. The repeat times where the peak torque occurred were 2-3 repeats at 60°/sec velocity during flexion and extension movements for the wrist and shoulders, and the peak torque occurred at an average of 5-6 repeats in the shoulders at 240°/sec velocity and it occurred at 3-4 repeats in the wrist. The angles where the peak torque of the shoulder flexion and extension occurred varied between 80°-115° at both velocities, and it varied between 5°-30° angles for the wrist. As this study revealed, determination of muscle strength characteristics of WC athletes and especially using objective isokinetic devices will guide the planning of the appropriate training and exercise programs and preventing sports injuries in long term.

Quantitative Anatomy of the Trapezius Muscle in the Human Fetus.

PubMed

Badura, Mateusz; Grzonkowska, Magdalena; Baumgart, Mariusz; Szpinda, Michał

2016-01-01

The trapezius muscle consists of three parts that are capable of functioning independently. Its superior part together with the levator scapulae and rhomboids elevate the shoulder, the middle part retracts the scapula, while the inferior part lowers the shoulder. The present study aimed to supplement numerical data and to provide growth dynamics of the trapezius in the human fetus. Using methods of anatomical dissection, digital image analysis (NIS Elements AR 3.0), and statistics (Student's t-test, regression analysis), we measured the length, the width and the surface area of the trapezius in 30 fetuses of both sexes (13™ k,17™ … ) aged 13-19 weeks. Neither sex nor laterality differences were found. All the studied parameters of the trapezius increased proportionately with age. The linear functions were computed as follows: y = -103.288 + 10.514 × age (r = 0.957) for total length of the trapezius muscle, y = -67.439 + 6.689 × age (r = 0.856) for length of its descending part, y = -8.493 + 1.033 × age (r = 0.53) for length of its transverse part, y = -27.545 + 2.802 × age (r = 0.791) for length of its ascending part, y = -19.970 + 2.505 × age (r = 0.875) for width of the trapezius muscle, and y = -2670.458 + 212.029 × age (r = 0.915) for its surface area. Neither sex nor laterality differences exist in the numerical data of the trapezius muscle in the human fetus. The descending part of trapezius is the longest, while its transverse part is the shortest. The growth dynamics of the fetal trapezius muscle follows proportionately.

Relation between the Disability of the Arm, Shoulder and Hand Score and Muscle Strength in Post-Cardiac Surgery Patients

PubMed Central

Kasahara, Yusuke; Hiraki, Koji; Hirano, Yasuyuki; Watanabe, Satoshi

2017-01-01

Background: The Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire is a valid and reliable patient-reported outcome measure. DASH can be assessed by self-reported upper extremity disability and symptoms. We aimed to examine the relationship between the physiological outcome of muscle strength and the DASH score after cardiac surgery. Methods: This cross-sectional study assessed 50 consecutive cardiac patients that were undergoing cardiac surgery. Physiological outcomes of handgrip strength and knee extensor muscle strength and the DASH score were measured at one month after cardiac surgery and were assessed. Results were analyzed using Spearman correlation coefficients. Results: The final analysis comprised 43 patients (men: 32, women: 11; age: 62.1 ± 9.1 years; body mass index: 22.1 ± 4.7 kg/m2; left ventricular ejection fraction: 53.5 ± 13.7%). Respective handgrip strength, knee extensor muscle strength, and DASH score were 27.4 ± 8.3 kgf, 1.6 ± 0.4 Nm/kg, and 13.3 ± 12.3, respectively. The DASH score correlated negatively with handgrip strength (r = −0.38, p = 0.01) and with knee extensor muscle strength (r = −0.32, p = 0.04). Conclusion: Physiological outcomes of both handgrip strength and knee extensor muscle strength correlated negatively with the DASH score. The DASH score appears to be a valuable tool with which to assess cardiac patients with poor physiological outcomes, particularly handgrip strength as a measure of upper extremity function, which is probably easier to follow over time than lower extremity function after patients complete cardiac rehabilitation. PMID:29186880

Musculoskeletal disorder risk during automotive assembly: current vs. seated

PubMed Central

Ferguson, Sue A.; Marras, William S.; Allread, W. Gary; Knapik, Gregory G.; Splittstoesser, Riley E.

2013-01-01

Musculoskeletal disorder risk was assessed during automotive assembly processes. The risk associated with current assembly processes was compared to using a cantilever chair intervention. Spine loads and normalized shoulder muscle activity were evaluated during assembly in eight regions of the vehicle. Eight interior cabin regions of the vehicle were classified by reach distance, height from vehicle floor and front to back. The cantilever chair intervention tool was most effective in the far reach regions regardless of the height. In the front far reach regions both spine loads and normalized shoulder muscle activity levels were reduced. In the middle and close reach regions spine loads were reduced, however, shoulder muscle activity was not, thus an additional intervention would be necessary to reduce shoulder risk. In the back far reach region, spine loads were not significantly different between the current and cantilever chair conditions. Thus, the effectiveness of the cantilever chair was dependent on the region of the vehicle. PMID:22036450

The prospective evaluation of changes in fatty infiltration and shoulder strength in nonsurgically treated rotator cuff tears.

PubMed

Nakamura, Yoshihiro; Yokoya, Shin; Harada, Yohei; Shiraishi, Katsunori; Adachi, Nobuo; Ochi, Mitsuo

2017-07-01

The purpose of this study was to evaluate the relationship of fatty infiltration in rotator cuff muscles and shoulder strength in rotator cuff tears and these changes during nonsurgical treatment. Fifty-three shoulders from 47 patients (mean age: 69.9 years) diagnosed with rotator cuff tears by magnetic resonance imaging (MRI) were treated nonsurgically. The degrees of fatty infiltration in supraspinatus (SSP) and infraspinatus (ISP) muscles were graded by the modified Goutallier classification (grade 0-1, grade 2-3, or grade 4). The isometric strength of the abductors (Abd) and external rotators (ER) were examined with a hand dynamometer. We analyzed the correlation of the modified Goutallier classification in SSP and ISP muscles with the strength of Abd and ER at initial visit. In addition, MRI and strength tests were repeated after 24 ± 6 months, and changes in fatty infiltration and strength were examined. Fatty infiltration of SSP and ISP muscles had a negative correlation with the strengths of Abd and ER at initial visit, respectively. Six of 45 shoulders (SSP grade: 0-3) and 7 of 43 shoulders (ISP grade: 0-3) had progression of fatty infiltration. Predictive factor of a progression of fatty infiltration during follow-up was decreased initial strength of Abd. There was no significant change in the strength of Abd, and the strength of ER showed significant improvement between the initial and post-treatment measurements. Even in the subgroup that had progression of fatty infiltration at follow-up, the strength of Abd and ER did not decrease significantly. Although fatty infiltration of the rotator cuff muscles exhibited a negative correlation with muscle strength, fatty infiltration and muscle weakness did not progress at the same rate. Copyright © 2017 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

Does a critical rotator cuff tear stage exist?: a biomechanical study of rotator cuff tear progression in human cadaver shoulders.

PubMed

Oh, Joo Han; Jun, Bong Jae; McGarry, Michelle H; Lee, Thay Q

2011-11-16

It is unknown at which stage of rotator cuff tear the biomechanical environment is altered. The purpose of this study was to determine if a critical rotator cuff tear stage exists that alters glenohumeral joint biomechanics throughout the rotational range of shoulder motion, and to evaluate the biomechanical effect of parascapular muscle-loading. Eight cadaver shoulders were used with a custom testing system. Four progressive rotator cuff tear stages were investigated on the basis of footprint anatomy. Three muscle-loading conditions were examined: rotator cuff only; rotator cuff with deltoid muscle; and rotator cuff, deltoid, pectoralis major, and latissimus dorsi muscles. Testing was performed in the scapular plane with 0°, 30°, and 60° of shoulder abduction. The maximum internal and external rotations were measured with 3.4 Nm of torque. The position of the humeral head apex with respect to the glenoid was calculated with use of a MicroScribe 3DLX digitizing system throughout the rotational range of motion. The abduction capability was determined as the abduction angle achieved with increasing deltoid load. Tear of the entire supraspinatus tendon significantly increased maximum external rotation and significantly decreased abduction capability with higher deltoid loads (p < 0.05). Tear of the entire supraspinatus tendon and half of the infraspinatus tendon significantly shifted the humeral head apex posteriorly at the midrange of rotation and superiorly at maximum internal rotation (p < 0.05). Loading the pectoralis major and latissimus dorsi muscles decreased the amount of humeral head elevation due to deltoid loading. Tear of the entire supraspinatus tendon was the critical stage for increasing rotational range of shoulder motion and for decreased abduction capability. Further tear progression to the infraspinatus muscle was the critical stage for significant changes in humeral head kinematics. The pectoralis major and latissimus dorsi muscles played an important role in stabilizing the humeral head as the rotator cuff tear progressed.

The Effect of Shoulder Muscle Fatigue on Acromiohumeral Distance and Scapular Dyskinesis in Women With Generalized Joint Hypermobility.

PubMed

Alibazi, Razie J; Moghadam, Afsun Nodehi; Cools, Ann M; Bakhshi, Enayatollah; Ahari, Alireza Aziz

2017-12-01

Muscle fatigue is considered to be one cause of shoulder pain, and subjects with generalized joint hypermobility (GJH) are affected more by shoulder pain. The purpose of this study was to examine the effects of muscle fatigue on acromiohumeral distance (AHD) and scapular dyskinesis in women with GJH. Thirty-six asymptomatic participants were assigned to either a GJH (n = 20) or control group (n = 16) using the Beighton scale. Before and after elevation fatigue trials, AHD was measured with ultrasonography at rest and when the arm was in 90° active elevation. A scapular dyskinesis test was used to visually observe alterations in scapular movement. Our results showed that in both groups, the fatigue reduced AHD in the 90° elevation position and increased the presence of scapular dyskinesis; however, no differences were found between the two groups. Although GJH has been identified as a factor for developing musculoskeletal disorders, generalized joint hypermobility did not result in changes to scapular dyskinesis or AHD, even after an elevation fatigue task. More studies are needed to evaluate the effects of muscle fatigue in subjects with GJH and a history of shoulder instability.

Distribution and severity of weakness among patients with polymyositis, dermatomyositis and juvenile dermatomyositis

PubMed Central

Harris-Love, M. O.; Shrader, J. A.; Koziol, D.; Pahlajani, N.; Jain, M.; Smith, M.; Cintas, H. L.; McGarvey, C. L.; James-Newton, L.; Pokrovnichka, A.; Moini, B.; Cabalar, I.; Lovell, D. J.; Wesley, R.; Plotz, P. H.; Miller, F. W.; Hicks, J. E.

2009-01-01

Objective. To describe the distribution and severity of muscle weakness using manual muscle testing (MMT) in 172 patients with PM, DM and juvenile DM (JDM). The secondary objectives included characterizing individual muscle group weakness and determining associations of weakness with functional status and myositis characteristics in this large cohort of patients with myositis. Methods. Strength was assessed for 13 muscle groups using the 10-point MMT and expressed as a total score, subscores based on functional and anatomical regions, and grades for individual muscle groups. Patient characteristics and secondary outcomes, such as clinical course, muscle enzymes, corticosteroid dosage and functional status were evaluated for association with strength using univariate and multivariate analyses. Results. A gradient of proximal weakness was seen, with PM weakest, DM intermediate and JDM strongest among the three myositis clinical groups (P ≤ 0.05). Hip flexors, hip extensors, hip abductors, neck flexors and shoulder abductors were the muscle groups with the greatest weakness among all three clinical groups. Muscle groups were affected symmetrically. Conclusions. Axial and proximal muscle impairment was reflected in the five weakest muscles shared by our cohort of myositis patients. However, differences in the pattern of weakness were observed among all three clinical groups. Our findings suggest a greater severity of proximal weakness in PM in comparison with DM. PMID:19074186

Shoulder Muscular Demand During Lever-Activated Vs Pushrim Wheelchair Propulsion in Persons With Spinal Cord Injury

PubMed Central

Requejo, Philip Santos; Lee, Sharon E; Mulroy, Sara J; Haubert, Lisa Lighthall; Bontrager, Ernest L; Gronley, JoAnne K; Perry, Jacquelin

2008-01-01

Background/Objective: The high demand on the upper limbs during manual wheelchair (WC) use contributes to a high prevalence of shoulder pathology in people with spinal cord injury (SCI). Lever-activated (LEVER) WCs have been presented as a less demanding alternative mode of manual WC propulsion. The objective of this study was to evaluate the shoulder muscle electromyographic activity and propulsion characteristics in manual WC users with SCI propelling a standard pushrim (ST) and LEVER WC design. Methods: Twenty men with complete injuries (ASIA A or B) and tetraplegia (C6, n = 5; C7, n = 7) or paraplegia (n = 8) secondary to SCI propelled ST and LEVER WCs at 3 propulsion conditions on a stationary ergometer: self-selected free, self-selected fast, and simulated graded resistance. Average velocity, cycle distance, and cadence; median and peak electromyographic intensity; and duration of electromyography of anterior deltoid, pectoralis major, supraspinatus, and infraspinatus muscles were compared between LEVER and ST WC propulsion. Results: Significant decreases in pectoralis major and supraspinatus activity were recorded during LEVER compared with ST WC propulsion. However, anterior deltoid and infraspinatus intensities tended to increase during LEVER WC propulsion. Participants with tetraplegia had similar or greater anterior deltoid, pectoralis major, and infraspinatus activity for both ST and LEVER WC propulsion compared with the men with paraplegia. Conclusions: Use of the LEVER WC reduced and shifted the shoulder muscular demands in individuals with paraplegia and tetraplegia. Further studies are needed to determine the impact of LEVER WC propulsion on long-term shoulder function. PMID:19086715

Functional Ability Improved in Essential Tremor by IncobotulinumtoxinA Injections Using Kinematically Determined Biomechanical Patterns – A New Future

PubMed Central

Samotus, Olivia; Rahimi, Fariborz; Lee, Jack; Jog, Mandar

2016-01-01

Objective Effective treatment for functional disability caused by essential tremor is a significant unmet need faced by many clinicians today. Current literature regarding focal therapy by botulinum toxin type A (BoNT-A) injections uses fixed dosing regimens, which cannot be individualized, provides only limited functional benefit and unacceptable muscle weakness commonly occurs. This 38-week open label study, the longest to-date, demonstrates how kinematic technology addressed all these issues by guiding muscle selection. Method Participants (n = 24) were assessed at weeks 0, 6, 16, 22, 32, and 38 and injected with incobotulinumtoxinA at weeks 0, 16, and 32. Clinical assessments including UPDRS tremor items, Fahn-Tolosa-Marin (FTM) tremor rating scale assessing tremor severity, writing and functional ability, quality of life questionnaire (QUEST) and objective kinematic assessments were completed at every visit. Participants performed two postural and two weight-bearing scripted tasks with motion sensors placed over the wrist, elbow and shoulder joints. These sensors captured angular tremor amplitude (RMS units) and acceleration joint motion that was segmented into directional components: flexion-extension (F/E), pronation-supination and radial-ulnar at the wrist, F/E at the elbow, and F/E and adduction-abduction at the shoulder. Injection parameters were determined using kinematics, followed by the clinician’s determination of which muscles would contribute to the specific upper limb tremor biomechanics and dosing per participant. Results Multi-joint biomechanical recordings allowed individualized muscle selection and showed significant improvement in whole-arm function, FTM parts A-C scores, at week 6 which continued throughout the study. By week 38, the total FTM score statistically significantly reduced from 16.2±4.6 at week 0 to 9.5±6.3 (p<0.0005). UPDRS item 21 score rating action tremor was significantly reduced from 2.6±0.5 at week 0 to 1.6±1.1 (p = 0.01) at week 32. Quality of life (QUEST) significantly improved from 40.3±15.8 at week 0 to 31.1±15.3 (p = 0.035) at week 32 and to 27.8±15.3 (p = 0.028) at week 38. Kinematics provided an objective, secondary outcome measure, which showed a significant decrease in tremor amplitude in the wrist and shoulder joints (p<0.05). Eight participants (40%) self-reported mild weakness in injected muscles but had no interference in arm function. Conclusion Kinematic tremor assessments provide the injector unique insight to objectively individualize and personalize injection parameters demonstrating BoNT-A effectively alleviates functional disability caused by essential tremor. Kinematic technology is a promising method for standardizing assessments and for focal upper limb tremor treatment. Trial Registration ClinicalTrials.gov NCT02427646 PMID:27101283

Psychosocial work conditions, perceived stress, perceived muscular tension, and neck/shoulder symptoms among medical secretaries.

PubMed

Larsman, Pernilla; Kadefors, Roland; Sandsjö, Leif

2013-01-01

Unfavorable psychosocial working conditions are hypothesized to lead to perceived stress, which, in turn, can be related to an increased risk of development of neck/shoulder symptoms through increased and sustained muscle activation. The aim of the present study was to test this hypothesized process model among medical secretaries, a female-dominated profession characterized by a high amount of visual display unit use and a high prevalence of neck/shoulder symptoms. In this cross-sectional study, a questionnaire survey was conducted among medical secretaries (n = 200). The proposed process model was tested using a path model framework. The results indicate that high work demands were related to high perceived stress, which in turn was related to a high perceived muscle tension and neck/shoulder symptoms. Low influence at work was not related to perceived stress, but was directly related to a high perceived muscle tension. In general, these cross-sectional results lend tentative support for the hypothesis that adverse psychosocial work conditions (high work demands) may contribute to the development of neck/shoulder symptoms through the mechanism of stress-induced sustained muscular activation. This process model needs to be further tested in longitudinal studies.

Voluntary activation of the trapezius muscle in cases with neck/shoulder pain compared to healthy controls.

PubMed

Bech, Katrine Tholstrup; Larsen, Camilla Marie; Sjøgaard, Gisela; Holtermann, Andreas; Taylor, Janet L; Søgaard, Karen

2017-10-01

Subjects reporting neck/shoulder pain have been shown to generate less force during maximal voluntary isometric contractions (MVC) of the shoulder muscles compared to healthy controls. This has been suggested to be caused by a pain-related decrease in voluntary activation (VA) rather than lack of muscle mass. The aim of the present study was to investigate VA of the trapezius muscle during MVCs in subjects with and without neck/shoulder pain by use of the twitch interpolation technique. Ten cases suffering from pain and ten age and gender matched, healthy controls were included in the study. Upper trapezius muscle thickness was measured using ultrasonography and pain intensity was measured on a 100mm visual analog scale (VAS). VA was calculated from five maximal muscle activation attempts. Superimposed stimuli were delivered to the accessory nerve at peak force and during a 2% MVC following the maximal contraction. Presented as mean±SD for cases and controls, respectively: VAS; 16.0±14.4mm and 2.1±4.1mm (P=0.004), MVC; 545±161N and 664±195N (P=0.016), upper trapezius muscle thickness; 10.9±1.9mm and 10.4±1.5mm (P=0.20), VA; 93.6±14.2% and 96.3±6.0% (P=0.29). In spite of significantly eight-fold higher pain intensity and ∼20% lower MVC for cases compared to controls, no difference was found in VA. Possible explanations for the reduction in MVC could be differences in co-activation of antagonists and synergists as well as muscle quality. Copyright © 2017 Elsevier Ltd. All rights reserved.

Adaptive Alterations in Shoulder Range of Motion and Strength in Young Tennis Players

PubMed Central

Gillet, Benoit; Begon, Mickaël; Sevrez, Violaine; Berger-Vachon, Christian; Rogowski, Isabelle

2017-01-01

Context: Playing tennis requires unilateral and intensive movement of the upper limb, which may lead to functional adaptations of the shoulder and an increased injury risk. Identifying which athletes will be future elite tennis players starts at 5 to 6 years of age. Therefore, highly skilled players practice intensively in their childhood. However, whether these functional changes occur during the prepubertal years has not been established. Objectives: To assess changes in glenohumeral-joint–rotation range of motion and strength of the shoulder-complex muscles in prepubertal elite tennis players. Design: Cross-sectional study. Setting: Tennis training sports facilities. Patients or Other Participants: Sixty-seven male tennis players (age range = 7–13 years) selected by a regional tennis center of excellence were divided into 3 biological age groups relative to their predicted age at peak height velocity: greater than 4 (n = 26; age = 8.7 ± 0.7 years, height = 132.4 ± 12.9 cm, mass = 27.8 ± 3.8 kg), 3 to 4 (n = 21; age = 10.3 ± 0.6 years, height = 144.9 ± 5.7 cm, mass = 34.7 ± 4.0 kg), and 2 (n = 20; age = 12.8 ± 1.4 years, height = 158.5 ± 8.7 cm, mass = 43.0 ± 8.2 kg) years before their age at peak height velocity. Main Outcome Measures(s): We measured the internal- and external-rotation ranges of motion of the glenohumeral joint using a goniometer and calculated the total arc of motion. Maximal isometric strength of 8 shoulder muscles was measured using a handheld dynamometer. Strength values were normalized to body weight and used to calculate 4 agonist-to-antagonist strength ratios. Results: The total arc of motion of the glenohumeral joint decreased gradually with biological age (P ≤ .01) due to the decrease in internal-rotation range of motion (P < .001). Absolute strength increased gradually with biological age (P < .001), but the relative strengths and ratios remained similar. Conclusions: Functional adaptations of the shoulder seen in adolescent and adult tennis players were observed in healthy prepubertal players. This knowledge could help clinicians and coaches more effectively monitor shoulder adaptations to tennis practice during the prepubertal years. PMID:28145740

Electromyographical Comparison of Four Common Shoulder Exercises in Unstable and Stable Shoulders

PubMed Central

Sciascia, Aaron; Kuschinsky, Nina; Nitz, Arthur J.; Mair, Scott D.; Uhl, Tim L.

2012-01-01

This study examines if electromyographic (EMG) amplitude differences exist between patients with shoulder instability and healthy controls performing scaption, prone horizontal abduction, prone external rotation, and push-up plus shoulder rehabilitation exercises. Thirty nine subjects were categorized by a single orthopedic surgeon as having multidirectional instability (n = 10), anterior instability (n = 9), generalized laxity (n = 10), or a healthy shoulder (n = 10). Indwelling and surface electrodes were utilized to measure EMG activity (reported as a % of maximum voluntary isometric contraction (MVIC)) in various shoulder muscles during 4 common shoulder exercises. The exercises studied effectively activated the primary musculature targeted in each exercise equally among all groups. The serratus anterior generated high activity (50–80% MVIC) during a push-up plus, while the infraspinatus and teres major generated moderate-to-high activity (30–80% MVIC) during both the prone horizontal and prone external rotation exercises. Scaption exercise generated moderate activity (20–50% MVIC) in both rotator cuff and scapular musculature. Clinicians should feel confident in prescribing these shoulder-strengthening exercises in patients with shoulder instability as the activation levels are comparable to previous findings regarding EMG amplitudes and should improve the dynamic stabilization capability of both rotator cuff and scapular muscles using exercises designed to address glenohumeral joint instability. PMID:22919499

Therapeutic outcomes of muscular advancement by an arthroscopic-assisted modified Debeyre-Patte procedure for irreparable large and massive rotator cuff tears.

PubMed

Morihara, Toru; Kida, Yoshikazu; Furukawa, Ryuhei; Sukenari, Tsuyoshi; Kabuto, Yukichi; Kurokawa, Masao; Fujiwara, Hiroyoshi; Kubo, Toshikazu

2018-05-01

In cases of the large or massive rotator cuff tears, retear rates after rotator cuff repairs remain high. We introduced an arthroscopic-assisted modified Debeyre-Patte procedure which enables to decrease the tension of torn rotator cuff by sliding supraspinatus and infraspinatus laterally keeping fascia connection to the rhomboids. The objective of this study was to examine the clinical outcomes and retear rates after an arthroscopic-assisted modified Debeyre-Patte procedure for irreparable large and massive rotator cuff tears. Thirty-three rotator cuff tear patients (34 shoulders) were selected. These patients underwent arthroscopic-assisted modified Debeyre-Patte procedures and were observed postoperatively for at least 24 months. Magnetic resonance imaging (MRI) was used to evaluate the preoperative location of the torn rotator cuff stump and fatty infiltration of the muscles composing the rotator cuff, as well as the repaired rotator cuffs. Shoulder functional evaluations through the use of the Constant and Murley scores and the University of California Los Angeles (UCLA) shoulder score were compared before and after surgery, and the preoperative global fatty degeneration index (GFDI) was compared between retear and healed shoulders. MRI showed that 77% of shoulders were healed and 23% exhibited retear postoperatively. The mean preoperative GFDI was 1.99 among the 26 healed shoulders and 2.54 among the 8 retear shoulders (p < .05). When the Goutallier's classification was grade 3 or lower for all 3 cuff muscles for fatty infiltration, the retear rate was 14.3%. The mean Constant and Murley scores in healed and retear groups respectively improved from 34.7 ± 15.8, 30.0 ± 15.1 points (p = 0.47) preoperatively to 70.8 ± 8.3, 53.9 ± 14.0 points (p < .001), and UCLA scores in healed and retear groups from 13.8 ± 3.9, 12.4 ± 5.0 points (p = 0.46) preoperatively to 32.8 ± 2.7, 28.4 ± 3.6 points (p < .001). The clinical outcomes of healed shoulders after the arthroscopic-assisted modified Debeyre-Patte procedure were favorable. If the torn rotator cuff stump is retracted near the glenoid fossa, and the rotator cuff muscle scored Goutallier grade 3 or lower, this modified Debeyre-Patte procedure would be a viable option. Copyright © 2018 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

A critical review on physical factors and functional characteristics that may explain a sex/gender difference in work-related neck/shoulder disorders.

PubMed

Côté, Julie N

2012-01-01

The objective of this paper is to critically review recent literature on physical and functional sex/gender (s/g) differences, with focus on physical determinants associated with neck/shoulder musculoskeletal injuries. It is well known that there are s/g differences in anthropometrical and functional body characteristics (e.g. size and strength). However, s/g differences may be wrongly attributed if data analysis does not include appropriate corrections (e.g. by strength for endurance). Recent literature on motor control shows that there may indeed be s/g differences in muscle coordination and movement strategies during upper limb tasks that are not currently explained by methodological inadequacies. Moreover, recent studies have shown differences between men and women in sensory hypersensitivity characteristics associated with neck/shoulder injuries. Taken together, the literature points to the importance of accounting for possible s/g differences at all levels of the biopsychosocial system in order to better understand sex- and gender-specific issues relevant to workplace health. This article critically reviews recent literature and a conceptual model highlighting s/g differences in physical and functional characteristics related to neck/shoulder musculoskeletal disorders (NSMSD). Findings have implications on understanding how personal factors may affect NSMSD risk. With better understanding, practitioners can make more appropriate decisions to prevent work-related NSMSD.

Compensatory hypertrophy of the teres minor muscle after large rotator cuff tear model in adult male rat.

PubMed

Ichinose, Tsuyoshi; Yamamoto, Atsushi; Kobayashi, Tsutomu; Shitara, Hitoshi; Shimoyama, Daisuke; Iizuka, Haku; Koibuchi, Noriyuki; Takagishi, Kenji

2016-02-01

Rotator cuff tear (RCT) is a common musculoskeletal disorder in the elderly. The large RCT is often irreparable due to the retraction and degeneration of the rotator cuff muscle. The integrity of the teres minor (TM) muscle is thought to affect postoperative functional recovery in some surgical treatments. Hypertrophy of the TM is found in some patients with large RCTs; however, the process underlying this hypertrophy is still unclear. The objective of this study was to determine if compensatory hypertrophy of the TM muscle occurs in a large RCT rat model. Twelve Wistar rats underwent transection of the suprascapular nerve and the supraspinatus and infraspinatus tendons in the left shoulder. The rats were euthanized 4 weeks after the surgery, and the cuff muscles were collected and weighed. The cross-sectional area and the involvement of Akt/mammalian target of rapamycin (mTOR) signaling were examined in the remaining TM muscle. The weight and cross-sectional area of the TM muscle was higher in the operated-on side than in the control side. The phosphorylated Akt/Akt protein ratio was not significantly different between these sides. The phosphorylated-mTOR/mTOR protein ratio was significantly higher on the operated-on side. Transection of the suprascapular nerve and the supraspinatus and infraspinatus tendons activates mTOR signaling in the TM muscle, which results in muscle hypertrophy. The Akt-signaling pathway may not be involved in this process. Nevertheless, activation of mTOR signaling in the TM muscle after RCT may be an effective therapeutic target of a large RCT. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Center of Pressure Displacement of Standing Posture during Rapid Movements Is Reorganised Due to Experimental Lower Extremity Muscle Pain.

PubMed

Shiozawa, Shinichiro; Hirata, Rogerio Pessoto; Graven-Nielsen, Thomas

2015-01-01

Postural control during rapid movements may be impaired due to musculoskeletal pain. The purpose of this study was to investigate the effect of experimental knee-related muscle pain on the center of pressure (CoP) displacement in a reaction time task condition. Nine healthy males performed two reaction time tasks (dominant side shoulder flexion and bilateral heel lift) before, during, and after experimental pain induced in the dominant side vastus medialis or the tibialis anterior muscles by hypertonic saline injections. The CoP displacement was extracted from the ipsilateral and contralateral side by two force plates and the net CoP displacement was calculated. Compared with non-painful sessions, tibialis anterior muscle pain during the peak and peak-to-peak displacement for the CoP during anticipatory postural adjustments (APAs) of the shoulder task reduced the peak-to-peak displacement of the net CoP in the medial-lateral direction (P<0.05). Tibialis anterior and vastus medialis muscle pain during shoulder flexion task reduced the anterior-posterior peak-to-peak displacement in the ipsilateral side (P<0.05). The central nervous system in healthy individuals was sufficiently robust in maintaining the APA characteristics during pain, although the displacement of net and ipsilateral CoP in the medial-lateral and anterior-posterior directions during unilateral fast shoulder movement was altered.

A musculoskeletal shoulder model based on pseudo-inverse and null-space optimization.

PubMed

Terrier, Alexandre; Aeberhard, Martin; Michellod, Yvan; Mullhaupt, Philippe; Gillet, Denis; Farron, Alain; Pioletti, Dominique P

2010-11-01

The goal of the present work was assess the feasibility of using a pseudo-inverse and null-space optimization approach in the modeling of the shoulder biomechanics. The method was applied to a simplified musculoskeletal shoulder model. The mechanical system consisted in the arm, and the external forces were the arm weight, 6 scapulo-humeral muscles and the reaction at the glenohumeral joint, which was considered as a spherical joint. The muscle wrapping was considered around the humeral head assumed spherical. The dynamical equations were solved in a Lagrangian approach. The mathematical redundancy of the mechanical system was solved in two steps: a pseudo-inverse optimization to minimize the square of the muscle stress and a null-space optimization to restrict the muscle force to physiological limits. Several movements were simulated. The mathematical and numerical aspects of the constrained redundancy problem were efficiently solved by the proposed method. The prediction of muscle moment arms was consistent with cadaveric measurements and the joint reaction force was consistent with in vivo measurements. This preliminary work demonstrated that the developed algorithm has a great potential for more complex musculoskeletal modeling of the shoulder joint. In particular it could be further applied to a non-spherical joint model, allowing for the natural translation of the humeral head in the glenoid fossa. Copyright © 2010 IPEM. Published by Elsevier Ltd. All rights reserved.

Ultrasonographic findings of shoulder teno-muscular structures in symptomatic and asymptomatic dogs.

PubMed

Barella, Gabriele; Lodi, Matteo; Faverzani, Stefano

2017-11-14

B-mode sonographic evaluation of shoulder joint in dogs provides qualitative information concerning mainly tendon and muscles structures. Although the sonographic findings of tenomuscular lesions have been described previously, their frequency in symptomatic and asymptomatic patients has not been reported yet. Aim of the study was to describe and compare qualitative ultrasonographic findings of shoulder joint in clinically symptomatic and asymptomatic dogs and to speculate which lesions might be considered major responsible for lameness. Fifty-two dogs with shoulder lameness and 58 asymptomatic dogs (both with unremarkable radiographic findings) underwent ultrasonographic B-mode examination of the scapulohumeral joint. Lesions detected were recorded and statistically compared between groups. Significant differences between groups were observed for the number of ultrasonographic abnormalities detected and for fluid accumulation, biceps brachii tendon (BT) lesions and bone surface irregularities. Sonography was considered useful for the determination of lesions absence and for the detection of BT lesions, fluid accumulation, muscle lacerations and bone surface irregularities. The odds for symptomatic dogs were greater than for asymptomatic patients to ultrasonographically diagnose BT lesions, fluid accumulation and bone surface irregularities. Ultrasound has proven to be a useful tool in the evaluation of tenomusculoskeletal structures of shoulder in dogs with unremarkable radiographic findings. Our results suggest that ultrasonography is useful in the diagnosis of tendon abnormalities, fluid accumulation, muscle lacerations and bone surface irregularities as potential contributors to shoulder lameness in dogs.

Partial rupture of the pectoralis major muscle in athletes.

PubMed

Roi, G S; Respizzi, S; Dworzak, F

1990-02-01

Partial rupture of the pectoralis major muscle is quite a rare event in sports traumatology and information about its treatment is lacking in literature. In this paper the long term effect of conservative non-surgical treatment in two body-builders and one shot-putter is discussed, who reported the partial rupture while performing bench lifts with barbells. Functional recovery was evaluated a few years after the injury (from 4 to 7) with an isokinetic dynamometer (Cybex II, Lumex INC N.Y.), measuring maximal shoulder adduction-abduction torques at different angular speeds (60, 180, and 300 degrees/s). The results were compared with those of five healthy athletes practicing either body-building or weight-lifting. From the present study we conclude the following: the non-invasive treatment of a partial rupture of the pectoralis major muscle may produce almost complete functional recovery; in normal subjects adduction muscles are advantageous in comparison to the abduction ones.

Impact of Posterior Wear on Muscle Length with Reverse Shoulder Arthroplasty.

PubMed

Roche, Christopher P; Diep, Phong; Hamilton, Matthew A; Wright, Thomas W; Flurin, Pierre-Henri; Zuckerman, Joseph D; Routman, Howard D

2015-12-01

The use of reverse total shoulder arthroplasty (rTSA) in patients with posterior glenoid wear can be challenging. Implanting a baseplate in the correct version may require significant eccentric reaming, which further medializes the joint line and results in greater rotator cuff muscle shortening. To restore the joint line, bone graft may be required, though it is associated with additional risks. As an alternative solution, augmented glenoid baseplates offer the potential to restore the joint line and improve rotator cuff muscle tensioning without the need for eccentric reaming or supplemental bone graft. To that end, this computer analysis quantifies the rotator cuff muscle length for standard and augmented rTSA when used in a normal and posteriorly worn glenoid. These results demonstrate that shortening of the rotator cuff occurred for both the standard and posterior augmented reverse shoulder designs with additional muscle shortening occurring in scapula with posteriorly worn glenoids. More anatomic rotator cuff muscle tensioning was observed with augmented glenoid baseplates. The use of posterior augmented glenoid baseplates has the potential to improve stability and better restore active internal and external rotation, a current limitation of rTSA. However, clinical follow-up is necessary to confirm these favorable biomechanical results.

Functional anatomy and muscle moment arms of the thoracic limb of an elite sprinting athlete: the racing greyhound (Canis familiaris).

PubMed

Williams, S B; Wilson, A M; Daynes, J; Peckham, K; Payne, R C

2008-10-01

We provide quantitative muscle-tendon architecture and geometry data for the racing greyhound thoracic limb. Muscle mass, belly length, fascicle lengths, pennation angles and moment arms were measured, as were tendon masses and lengths. Maximum isometric force and maximum power were estimated for muscles, and maximum stress and strain were estimated for tendons. Results are compared with other fast quadrupedal runners, and to previously published data in mixed-breed dogs. The implications of the functional adaptations of the greyhound thoracic limb for sprinting performance are discussed. The thoracic limb was found to benefit from a similar proportion of locomotor muscle mass to the pelvic limb, suggesting that it may be used to some extent in propulsion, or alternatively that stabilisation is very important in this animal. Extrinsic muscles, especially latissimus dorsi and pectoralis profundus, were predicted to be powerful and important for generating net positive work during accelerations. Proximal biarticular muscles show specialisation toward preventing collapse of the shoulder and elbow joints to enable strut-like limb function, or some form of dynamic control. Distal muscles did not appear specialised for elastic energy storage, a functional difference to pelvic limb muscles, and the equivalents in horse thoracic limbs. The greyhound thoracic limb appears to possess substantial differences from both that of more 'sub-maximal specialist' quadrupeds, and from the greyhound pelvic limb.

The impact on post-operative shoulder function of intraoperative nerve monitoring of cranial nerve XI during modified radical neck dissection.

PubMed

Lanišnik, Boštjan; Žitnik, Lidija; Levart, Primož; Žargi, Miha; Rodi, Zoran

2016-12-01

Intraoperative monitoring of the cranial nerve XI (CN XI) may decrease shoulder disability following modified radical neck dissection. Prospective study was designed comparing results of Constant Shoulder Score (CSS), Shoulder Pain and Disability Index (SPADI) and EMG score of the trapezius muscle (mT) before and after surgery. One side of the neck was monitored during surgery with intraoperative nerve monitor. EMG scores of the mT 6 months postoperatively were statistically better on monitored as compared to the non-monitored side of the neck (p = 0.041), while the differences of the CSS and SPADI were not statistically significant. Patients with better EMG scores of the mT at 6 weeks recuperated better and with smaller decrease of the CSS. Intraoperative monitoring is beneficial at the beginning of the surgeon's learning curve and in the process of familiarizing with anatomical variation of the CN XI.

Association between neck and shoulder pain, back pain, low back pain and body composition parameters among the Japanese general population.

PubMed

Iizuka, Yoichi; Iizuka, Haku; Mieda, Tokue; Tajika, Tsuyoshi; Yamamoto, Atsushi; Ohsawa, Takashi; Sasaki, Tsuyoshi; Takagishi, Kenji

2015-11-04

Neck and shoulder pain, back pain and low back pain are common symptoms in Japanese subjects, and it is important to elucidate the pathology and associated factors of these pains due to their frequency and impact on the quality of life (QOL) and activities of daily living (ADL). The purpose of the present study was to investigate whether body composition is associated with these pains. We collected the data of 273 Japanese subjects regarding the presence and the visual analogue scale (VAS) of neck and shoulder pain, back pain, low back pain and body composition parameters calculated using bioelectrical impedance analysis (BIA) technology. Furthermore, we investigated the association between these pains and the body composition using statistical methods. According to a multivariate analysis adjusted for age and gender, lower total body water ratio was significantly associated with the presence of neck and shoulder pain at present (P < 0.05); additionally, total body muscle mass (standardized β = -0.26, 95 % CI, -0.17 - -0.008, P < 0.05), total body water (standardized β = -0.27, 95 % CI, -0.23 - -0.04, P < 0.01), appendicular muscle mass (standardized β = -0.29, 95 % CI, -0.36 - -0.04, P < 0.05), and the appendicular muscle mass index (AMI) (standardized β = -0.24, 95 % CI, -1.18 - -0.20, P <0.01) were negatively correlated with the VAS of neck and shoulder pain, whereas no body composition parameters were significantly associated with back pain, low back pain at present and any type of chronic pain. The present study demonstrated that some body composition parameters regarding body water and body muscle were associated or correlated with the presence or intensity of neck and shoulder pain.

Muscle torque and its relation to technique, tactics, sports level and age group in judo contestants.

PubMed

Lech, Grzegorz; Chwała, Wiesław; Ambroży, Tadeusz; Sterkowicz, Stanisław

2015-03-29

The aim of this study was to perform a comparative analysis of maximal muscle torques at individual stages of development of athletes and to determine the relationship between muscle torques, fighting methods and the level of sports performance. The activity of 25 judo contestants during judo combats and the effectiveness of actions were evaluated. Maximum muscle torques in flexors/extensors of the body trunk, shoulder, elbow, hip and knee joints were measured. The level of significance was set at p≤0.05; for multiple comparisons the Mann-Whitney U test, p≤0.016, was used. Intergroup differences in relative torques in five muscle groups studied (elbow extensors, shoulder flexors, knee flexors, knee extensors, hip flexors) were not significant. In cadets, relative maximum muscle torques in hip extensors correlated with the activity index (Spearman's r=0.756). In juniors, maximum relative torques in elbow flexors and knee flexors correlated with the activity index (r=0.73 and r=0.76, respectively). The effectiveness of actions correlated with relative maximum torque in elbow extensors (r=0.67). In seniors, the relative maximum muscle torque in shoulder flexors correlated with the activity index during the second part of the combat (r=0.821).

Muscle Torque and its Relation to Technique, Tactics, Sports Level and Age Group in Judo Contestants

PubMed Central

Lech, Grzegorz; Chwała, Wiesław; Ambroży, Tadeusz; Sterkowicz, Stanisław

2015-01-01

The aim of this study was to perform a comparative analysis of maximal muscle torques at individual stages of development of athletes and to determine the relationship between muscle torques, fighting methods and the level of sports performance. The activity of 25 judo contestants during judo combats and the effectiveness of actions were evaluated. Maximum muscle torques in flexors/extensors of the body trunk, shoulder, elbow, hip and knee joints were measured. The level of significance was set at p≤0.05; for multiple comparisons the Mann-Whitney U test, p≤0.016, was used. Intergroup differences in relative torques in five muscle groups studied (elbow extensors, shoulder flexors, knee flexors, knee extensors, hip flexors) were not significant. In cadets, relative maximum muscle torques in hip extensors correlated with the activity index (Spearman’s r=0.756). In juniors, maximum relative torques in elbow flexors and knee flexors correlated with the activity index (r=0.73 and r=0.76, respectively). The effectiveness of actions correlated with relative maximum torque in elbow extensors (r=0.67). In seniors, the relative maximum muscle torque in shoulder flexors correlated with the activity index during the second part of the combat (r=0.821). PMID:25964820

An increased response to experimental muscle pain is related to psychological status in women with chronic non-traumatic neck-shoulder pain

PubMed Central

2011-01-01

Background Neck-shoulder pain conditions, e.g., chronic trapezius myalgia, have been associated with sensory disturbances such as increased sensitivity to experimentally induced pain. This study investigated pain sensitivity in terms of bilateral pressure pain thresholds over the trapezius and tibialis anterior muscles and pain responses after a unilateral hypertonic saline infusion into the right legs tibialis anterior muscle and related those parameters to intensity and area size of the clinical pain and to psychological factors (sleeping problems, depression, anxiety, catastrophizing and fear-avoidance). Methods Nineteen women with chronic non-traumatic neck-shoulder pain but without simultaneous anatomically widespread clinical pain (NSP) and 30 age-matched pain-free female control subjects (CON) participated in the study. Results NSP had lower pressure pain thresholds over the trapezius and over the tibialis anterior muscles and experienced hypertonic saline-evoked pain in the tibialis anterior muscle to be significantly more intense and locally more widespread than CON. More intense symptoms of anxiety and depression together with a higher disability level were associated with increased pain responses to experimental pain induction and a larger area size of the clinical neck-shoulder pain at its worst. Conclusion These results indicate that central mechanisms e.g., central sensitization and altered descending control, are involved in chronic neck-shoulder pain since sensory hypersensitivity was found in areas distant to the site of clinical pain. Psychological status was found to interact with the perception, intensity, duration and distribution of induced pain (hypertonic saline) together with the spreading of clinical pain. The duration and intensity of pain correlated negatively with pressure pain thresholds. PMID:21992460

Shoulder Strength and Physical Activity Predictors of Shoulder Pain in People With Paraplegia From Spinal Injury: Prospective Cohort Study

PubMed Central

Hatchett, Patricia; Eberly, Valerie J.; Lighthall Haubert, Lisa; Conners, Sandy; Requejo, Philip S.

2015-01-01

Background Shoulder joint pain is a frequent secondary complaint for people following spinal cord injury (SCI). Objective The purpose of this study was to determine predictors of shoulder joint pain in people with paraplegia. Methods/Design A 3-year longitudinal study was conducted. Participants were people with paraplegia who used a manual wheelchair for at least 50% of their mobility and were asymptomatic for shoulder pain at study entry. Participants were classified as having developed shoulder pain if they experienced an increase of ≥10 points on the Wheelchair User's Shoulder Pain Index in the 3-year follow-up period. Measurements of maximal isometric shoulder torques were collected at study entry (baseline), 18 months, and 3 years. Daily activity was measured using a wheelchair odometer, and self-reported daily transfer and raise frequency data were collected by telephone every 6 weeks. Results Two hundred twenty-three participants were enrolled in the study; 39.8% developed shoulder pain over the 3-year follow-up period. Demographic variables and higher activity levels were not associated with shoulder pain onset. Baseline maximal isometric torque (normalized by body weight) in all shoulder muscle groups was 10% to 15% lower in participants who developed shoulder pain compared with those who remained pain-free. Lower shoulder adduction torque was a significant predictor of shoulder pain development (log-likelihood test=11.38), but the model explained only 7.5% of shoulder pain onset and consequently is of limited clinical utility. Limitations Time since SCI varied widely among participants, and transfer and raise activity was measured by participant recall. Conclusions Participants who developed shoulder pain had decreased muscle strength, particularly in the shoulder adductors, and lower levels of physical activity prior to the onset of shoulder pain. Neither factor was a strong predictor of shoulder pain onset. PMID:25721123

Structural and functional anatomy of the neck musculature of the dog (Canis familiaris)

PubMed Central

Sharir, Amnon; Milgram, Joshua; Shahar, Ron

2006-01-01

The morphometric properties and the anatomical relationships of the entire musculature of the canine cervical spine are reported herein. These data were obtained from the dissection of cadavers of six dogs. Total muscle length, muscle weight, fascicle length and angles of pennation were recorded for each muscle comprising the canine cervical spine. Based upon these properties, physiological cross-section area (PCSA) and architectural index were estimated. When scaled by whole body mass, the values of each of these parameters were found to be similar between all dogs. Muscles that course from the cranial neck to the shoulder girdle or the rib cage (e.g. brachiocephalicus and rhomboideus capitis) were found to have relatively long fascicles and low PCSA values and thus appear to be designed for rapid excursions. By contrast, muscles that primarily support the neck and shoulder against gravitational forces (e.g. serratus ventralis and trapezius) were found to have relatively high PCSA values and short fascicle lengths, and thus have the capacity to generate large forces. Differences of morphometry as well as nomenclature were found between the canine and human neck musculature. Nevertheless, many similarities exist; in particular, both species have similar muscles adapted to force generation or large excursions. We thus conclude that the canine neck may be used as a modelling tool for biomechanical investigations of the human cervical region as long as the differences listed are borne in mind. PMID:16533316

Shoulder Impingement Treatment

MedlinePlus

... imbalance in the rotator cuff or scapular muscles, postural abnormalities, shoulder joint instability, or improper training or ... and corrected. Phase Goals Methods Comments I Pain control Limit overhead activity or anything that causes pain. ...

Electromyographic Activity of Scapular Muscle Control in Free-Motion Exercise

PubMed Central

Nakamura, Yukiko; Tsuruike, Masaaki; Ellenbecker, Todd S.

2016-01-01

Context:  The appropriate resistance intensity to prescribe for shoulder rehabilitative exercise is not completely known. Excessive activation of the deltoid and upper trapezius muscles could be counterproductive for scapulohumeral rhythm during humeral elevation. Objective:  To identify the effects of different exercise intensities on the scapular muscles during a free-motion “robbery” exercise performed in different degrees of shoulder abduction in seated and standing positions. Design:  Descriptive laboratory study. Setting:  Kinesiology Adapted Physical Education Laboratory. Patients or Other Participants:  A total of 15 healthy male college students (age = 20.5 ± 2.2 years, height = 174.5 ± 5.3 cm, mass = 63.8 ± 6.0 kg). Intervention(s):  Participants performed 5 repetitions of a randomized exercise sequence of the robbery exercise in 2 body positions (seated, standing), 2 shoulder-abducted positions (W [20°], 90/90 [90°]) at 3 intensities (0%, 3%, and 7% body weight). Main Outcome Measure(s):  Electromyographic (EMG) activity of the upper trapezius, lower trapezius, serratus anterior, anterior deltoid, and infraspinatus muscles of the upper extremity was collected. All EMG activities were normalized by the maximal voluntary isometric contraction of each corresponding muscle (%). Results:  The serratus anterior, anterior deltoid, and infraspinatus EMG activities were greater at 7% body weight in the seated position compared with the standing position (P < .05). The EMG activities in all 5 muscles were greater in the 90/90 position than in the W position (P < .05). Conclusions:  Scapular muscle activity modulated relative to changes in body posture and resistance intensity. These findings will enable clinicians to prescribe the appropriate level of exercise intensity and positioning during shoulder rehabilitation. PMID:26986055

Strength deficits of the shoulder complex during isokinetic testing in people with chronic stroke

PubMed Central

Nascimento, Lucas R.; Teixeira-Salmela, Luci F.; Polese, Janaine C.; Ada, Louise; Faria, Christina D. C. M.; Laurentino, Glória E. C.

2014-01-01

OBJECTIVES: To examine the strength deficits of the shoulder complex after stroke and to characterize the pattern of weakness according to type of movement and type of isokinetic parameter. METHOD: Twelve chronic stroke survivors and 12 age-matched healthy controls had their shoulder strength measured using a Biodex isokinetic dynamometer. Concentric measures of peak torque and work during shoulder movements were obtained in random order at speeds of 60°/s for both groups and sides. Type of movement was defined as scapulothoracic (protraction and retraction), glenohumeral (shoulder internal and external rotation) or combined (shoulder flexion and extension). Type of isokinetic parameter was defined as maximum (peak torque) or sustained (work). Strength deficits were calculated using the control group as reference. RESULTS: The average strength deficit for the paretic upper limb was 52% for peak torque and 56% for work. Decreases observed in the non-paretic shoulder were 21% and 22%, respectively. Strength deficit of the scapulothoracic muscles was similar to the glenohumeral muscles, with a mean difference of 6% (95% CI -5 to 17). Ability to sustain torque throughout a given range of motion was decreased as much as the peak torque, with a mean difference of 4% (95% CI -2 to 10). CONCLUSIONS: The findings suggest that people after stroke might benefit from strengthening exercises directed at the paretic scapulothoracic muscles in addition to exercises of arm elevation. Clinicians should also prescribe different exercises to improve the ability to generate force and the ability to sustain the torque during a specific range of motion. PMID:25003280

The postural control can be optimized by the first movement initiation condition encountered when submitted to muscle fatigue.

PubMed

Monjo, Florian; Forestier, Nicolas

2017-08-01

We investigated whether and how the movement initiation condition (IC) encountered during the early movements performed following focal muscle fatigue affects the postural control of discrete ballistic movements. For this purpose, subjects performed shoulder flexions in a standing posture at maximal velocity under two movement IC, i.e., in self-paced conditions and submitted to a Stroop-like task in which participants had to trigger fast shoulder flexions at the presentation of incongruent colors. Shoulder flexion kinematics, surface muscle activity of focal and postural muscles as well as center-of-pressure kinematics were recorded. The initial IC and the order in which subjects were submitted to these two conditions were varied within two separate experimental sessions. IC schedule was repeated before and after fatigue protocols involving shoulder flexors. The aim of this fatigue procedure was to affect acceleration-generating capacities of focal muscles. In such conditions, the postural muscle activity preceding and accompanying movement execution is expected to decrease. Following fatigue, when subjects initially moved in self-paced conditions, postural muscle activity decreased and scaled to the lower focal peak acceleration. This postural strategy then transferred to the Stroop-like task. In contrast, when subjects initially moved submitted to the Stroop-like task, postural muscle activity did not decrease and this transferred to self-paced movements. Regarding the center-of-pressure peak velocity, which is indicative of the efficiency of the postural actions generated in stabilizing posture, no difference appeared between the two sessions post-fatigue. This highlights an optimization of the postural actions when subjects first moved in self-paced conditions, smaller postural muscle activation levels resulting in similar postural consequences. In conclusion, the level of neuromuscular activity associated with the postural control is affected and can be optimized by the initial movement IC experienced post-fatigue. Beyond the fundamental contributions arising from these results, we point out potential applications for trainers and sports instructors. Copyright © 2017 Elsevier B.V. All rights reserved.

Shoulder arthrodesis for treatment of flail shoulder in children with polio.

PubMed

Miller, Joshua D; Pinero, Joseph R; Goldstein, Rachel; Yen, Yi-Meng; Eves, William; Otsuka, Norman Y

2011-09-01

Poliomyelitis in children can cause paralysis of shoulder girdle muscles leading to a flail shoulder. Shoulder arthrodesis is indicated as a possible treatment for these children in order to stabilize the shoulder. This retrospective study reviewed all shoulder arthrodesis surgeries owing to complications of polio performed at a major medical institution between 1981 and 1996 to assess position of fusion, radiographic evidence of fusion, complications, and patient satisfaction. A review of medical records identified 11 patients undergoing 13 shoulder arthrodesis procedures, with a mean age of 14.7 years at the time of the procedure. Internal fixation was achieved with large cancellous screws in 8 patients and a Dynamic Compression Plate (DCP) plate in 5 procedures. Average follow-up period was 41 months. Eight patients were placed into a spica cast and 5 used a sling postoperatively. Shoulder arthrodesis surgery in this cohort resulted in an average position of fusion with 42.3 degrees of abduction, 23.8 degrees of flexion, and 26.2 degrees of internal rotation. Twelve of the 13 procedures assessed for radiographic union demonstrated fusion. The most common complications were malrotation and nonunion. Of the 13 procedures, 2 underwent humeral osteotomies for malrotation, and 1 with 6.5 mm cancellous screws required revision with a DCP plate owing to nonunion. Six patients underwent hardware removal, 3 of which were specifically owing to complaints of painful hardware. At final follow-up, no patient reported pain and all expressed satisfaction with their results and improved shoulder function after repair. This study is the largest series of shoulder arthrodesis surgeries for treatment of patients with a flail shoulder from polio to date, providing a more thorough analysis of its efficacy as an indicated treatment. Level III-Retrospective Comparative Study.

Task-specificity of bilateral anticipatory activation of the deep abdominal muscles in healthy and chronic low back pain populations.

PubMed

Massé-Alarie, Hugo; Beaulieu, Louis-David; Preuss, Richard; Schneider, Cyril

2015-02-01

Cross-sectional study of lumbopelvic muscle activation during rapid limb movements in chronic low back pain (CLBP) patients and healthy controls. Controversy exists over whether bilateral anticipatory activation of the deep abdominal muscles represents a normal motor control strategy prior to all rapid limb movements, or if this is simply a task-specific strategy appropriate for only certain movement conditions. To assess the onset timing of the transversus abdominis/internal oblique muscles (TrA/IO) during two rapid limb movement tasks with different postural demands - bilateral shoulder flexion in standing, unilateral hip extension in prone lying - as well as differences between CLBP and controls. Twelve CLBP and 13 controls performed the two tasks in response to an auditory cue. Surface EMG was acquired bilaterally from five muscles, including TrA/IO. In both groups, 50% of bilateral shoulder flexion trials showed bilateral anticipatory TrA/IO activation. This was rare, however, in unilateral hip extension for which only the TrA/IO contralateral to the moving leg showed anticipatory activation. The only significant difference in lumbo-pelvic muscle onset timing between CLBP and controls was a delay in semitendinosus activation during bilateral shoulder flexion in standing. Our data suggest that bilateral anticipatory TrA/IO activation is a task-specific motor control strategy, appropriate for only certain rapid limb movement conditions. Furthermore, the presence of altered semitendinosus onset timing in the CLBP group during bilateral shoulder flexion may be reflective of other possible lumbo-pelvic motor control alterations among this population. Copyright © 2014 Elsevier B.V. All rights reserved.

Effects of pushing height on trunk posture and trunk muscle activity when a cart suddenly starts or stops moving.

PubMed

Lee, Yun-Ju; Hoozemans, Marco J M; van Dieën, Jaap H

2012-01-01

Unexpected sudden (un)loading of the trunk may induce inadequate responses of trunk muscles and uncontrolled trunk motion. These unexpected perturbations may occur in pushing tasks, when the cart suddenly starts moving (unloading) or is blocked by an obstacle (loading). In pushing, handle height affects the user's working posture, which may influence trunk muscle activity and trunk movement in response to the perturbation. Eleven healthy male subjects pushed a 200 kg cart with handles at shoulder and hip height in a start condition (sudden release of brakes) and a stop condition (bumping into an obstacle). Before the perturbation, the baseline of the trunk inclination, internal moment and trunk extensor muscle activity were significantly higher when pushing at hip height than at shoulder height. After the perturbation, the changes in trunk inclination and internal moment were significantly larger when pushing at shoulder height than at hip height in both conditions. The opposite directions of changes in trunk inclination and internal moment suggest that the unexpected perturbations caused uncontrolled trunk motion. Pushing at shoulder height may impose a high risk of low-back injury due to the low trunk stiffness and large involuntary trunk motion occurring after carts suddenly move or stop.

Task variation during simulated, repetitive, low-intensity work--influence on manifestation of shoulder muscle fatigue, perceived discomfort and upper-body postures.

PubMed

Luger, Tessy; Bosch, Tim; Hoozemans, Marco; de Looze, Michiel; Veeger, Dirkjan

2015-01-01

Work-related musculoskeletal disorders are increasing due to industrialisation of work processes. Task variation has been suggested as potential intervention. The objectives of this study were to investigate, first, the influence of task variation on electromyographic (EMG) manifestations of shoulder muscle fatigue and discomfort; second, noticeable postural shoulder changes over time; third, if the association between task variation and EMG might be biased by postural changes. Outcome parameters were recorded using multichannel EMG, Optotrak and the Borg scale. Fourteen participants performed a one-hour repetitive Pegboard task in one continuous and two interrupted conditions with rest and a pick-and-place task, respectively. Manifestations of shoulder muscle fatigue and discomfort feelings were observed throughout the conditions but these were not significantly influenced by task variation. After correction for joint angles, the relation between task variation and EMG was significantly biased but significant effects of task variation remained absent. Comparing a one-hour continuous, repetitive Pegboard task with two interrupted conditions revealed no significant influences of task variation. We did observe that the relation between task variation and EMG was biased by posture and therefore advise taking account for posture when investigating manifestations of muscle fatigue in assembly tasks.

[Influence of body posture in the prevalence of craniomandibular dysfunction].

PubMed

Fuentes, R; Freesmeyer, W; Henríquez, J

1999-09-01

Postural alterations of the shoulders, dorsal spine and hips could have an influence on the development of craniomandibular dysfunctions. To study the influence of body posture on the prevalence of craniomandibular dysfunction. One hundred thirty six dental students and 41 patients assisting to the temporomandibular joints (TMJ) clinic at the Freie Universität at Berlin, were studied. Masticator, cervical muscles, temporomandibular joints and occlusions were clinically examined. The position of shoulders and hips was measured with the use of an acromiopelvimeter. No relationship was found between postural alterations of the hips and shoulders, articular noises and sensibility or pain while palpating the temporomandibular joints. Among students, a relationship between postural alterations of the shoulders and the sensibility or pain while palpating the TMJ, was observed. When all muscles were considered, a significant relationship between asymmetric shoulders or hips and muscular pain while palpating was observed among students. Some symptoms, especially muscular sensibility is more pronounced in people with hip and shoulder asymmetries. This relation is more pronounced in dental students than in patients.

Functional anatomy and muscle moment arms of the thoracic limb of an elite sprinting athlete: the racing greyhound (Canis familiaris)

PubMed Central

Williams, S B; Wilson, A M; Daynes, J; Peckham, K; Payne, R C

2008-01-01

We provide quantitative muscle–tendon architecture and geometry data for the racing greyhound thoracic limb. Muscle mass, belly length, fascicle lengths, pennation angles and moment arms were measured, as were tendon masses and lengths. Maximum isometric force and maximum power were estimated for muscles, and maximum stress and strain were estimated for tendons. Results are compared with other fast quadrupedal runners, and to previously published data in mixed-breed dogs. The implications of the functional adaptations of the greyhound thoracic limb for sprinting performance are discussed. The thoracic limb was found to benefit from a similar proportion of locomotor muscle mass to the pelvic limb, suggesting that it may be used to some extent in propulsion, or alternatively that stabilisation is very important in this animal. Extrinsic muscles, especially latissimus dorsi and pectoralis profundus, were predicted to be powerful and important for generating net positive work during accelerations. Proximal biarticular muscles show specialisation toward preventing collapse of the shoulder and elbow joints to enable strut-like limb function, or some form of dynamic control. Distal muscles did not appear specialised for elastic energy storage, a functional difference to pelvic limb muscles, and the equivalents in horse thoracic limbs. The greyhound thoracic limb appears to possess substantial differences from both that of more ‘sub-maximal specialist’ quadrupeds, and from the greyhound pelvic limb. PMID:19034998

Bi-tangential hybrid IMRT for sparing the shoulder in whole breast irradiation.

PubMed

Farace, P; Deidda, M A; Iamundo de Cumis, I; Iamundo de Curtis, I; Deiana, E; Farigu, R; Lay, G; Porru, S

2013-11-01

A bi-tangential technique is proposed to reduce undesired doses to the shoulder produced by standard tangential irradiation. A total of 6 patients affected by shoulder pain and reduced functional capacity after whole-breast irradiation were retrospectively analysed. The standard tangential plan used for treatment was compared with (1) a single bi-tangential plan where, to spare the shoulder, the lateral open tangent was split into two half-beams at isocentre, with the superior portion rotated by 10-20° medially with respect to the standard lateral beam; (2) a double bi-tangential plan, where both the tangential open beams were split. The planning target volume (PTV) coverage and the dose to the portion of muscles and axilla included in the standard tangential beams were compared. PTV95 % of standard plan (91.9 ± 3.8) was not significantly different from single bi-tangential plan (91.8 ± 3.4); a small but significant (p < 0.01) decrease was observed with the double bi-tangential plan (90.1 ± 3.7). A marked dose reduction to the muscle was produced by the single bi-tangential plan around 30-40 Gy. The application of the double bi-tangential technique further reduced the volume receiving around 20 Gy, but did not markedly affect the higher doses. The dose to the axilla was reduced both in the single and the double bi-tangential plans. The single bi-tangential technique would have been able to reduce the dose to shoulder and axilla, without compromising target coverage. This simple technique is valuable for irradiation after axillary lymph node dissection or in patients without dissection due to negative or low-volume sentinel lymph node disease.

Shoulder muscle volume and fat content in healthy adult volunteers: quantification with DIXON MRI to determine the influence of demographics and handedness.

PubMed

Kälin, Pascal S; Crawford, Rebecca J; Marcon, Magda; Manoliu, Andrei; Bouaicha, Samy; Fischer, Michael A; Ulbrich, Erika J

2018-04-23

We aimed to provide mean values for fat-fraction and volume for full-length bilateral rotator cuff and deltoid muscles in asymptomatic adults selected on the basis of their good musculoskeletal and systemic health, and to understand the influence of gender, age, and arm dominance. Seventy-six volunteers aged 20 to 60 years who were screened for normal BMI and high general health were included in the study. MRI was performed at 3 Tesla using three-point DIXON sequences. Volume and fat-signal fraction of the rotator cuff muscles and the deltoid muscle were determined with semi-automated segmentation of entire muscle lengths. Differences according to age, gender, and handedness per muscle were evaluated. Fat-signal fractions were comparable between genders (mean ± 2 SD, 95% CI, women 7.0 ± 3.0; 6.8-7.2%, men 6.8 ± 2.7; 6.7-7.0%) but did not show convincing changes with age. Higher shoulder muscle volume and lower fat-signal fraction in the dominant arm were shown for teres minor and deltoid (p < 0.01) with similar trends shown for the other rotator cuff muscles. Bilateral fat-signal fractions and volumes based on entire length shoulder muscles in asymptomatic 20-60 year old adults may provide reference for clinicians. Differences shown according to arm dominance should be considered and may rationalize the need for bilateral imaging in determining appropriate management.

A longitudinal study on risk factors for neck and shoulder pain among young adults in the transition from technical school to working life.

PubMed

Hanvold, Therese N; Wærsted, Morten; Mengshoel, Anne Marit; Bjertness, Espen; Twisk, Jos; Veiersted, Kaj Bo

2014-11-01

The study examined the course of neck and shoulder pain among a cohort of technical school students entering working life. We also aimed to identify work-related and individual risk factors for neck and shoulder pain during this transition period. The study was designed as a prospective cohort study following 420 technical school students (167 student hairdressers, 118 student electricians, and 135 media/design students) from school, through their apprenticeship and into working life. Every 4 (th)month over a 6.5 year period (2002-2009), the participant`s neck and shoulder pain for the preceding four weeks was assessed. Mechanical and psychosocial workplace factors as well as individual factors were evaluated at baseline and/or during the follow-up period. Data were analyzed by generalized estimating equations (GEE). We found a significant increase in neck and shoulder pain over time in the transition from technical school to working life. High mechanical workload was associated with neck and shoulder pain among women, while a high level of shoulder muscle endurance capacity was associated with lower rates of neck and shoulder pain among men. Perceived muscle tension and ethnicity were the most consistent predictors for neck and shoulder pain, found among both women and men. Increased neck and shoulder pain was found in the transition from technical school to working life, and both work-related and individual factors were associated with pain development.

What Are the Types of Muscular Dystrophy?

MedlinePlus

... or sitting position Waddle when walking Have difficulty running and jumping Have calf muscles that appear large ... that causes shoulders to appear slanted and shoulder blades to appear "winged" Impaired reflexes only at the ...

Ergonomic Strategies for Using a Briefcase

MedlinePlus

... Carrying a Briefcase • Heavy briefcases worn over one shoulder cause uneven weight distribution across the back muscles and may restrict blood flow at the shoulder. • Heavy briefcases place extra pressure on the nerves ...

Humeral external rotation handling by using the Bobath concept approach affects trunk extensor muscles electromyography in children with cerebral palsy.

PubMed

Grazziotin Dos Santos, C; Pagnussat, Aline S; Simon, A S; Py, Rodrigo; Pinho, Alexandre Severo do; Wagner, Mário B

2014-10-20

This study aimed to investigate the electromyographic activity of cervical and trunk extensors muscles in children with cerebral palsy during two handlings according to the Bobath concept. A crossover trial involving 40 spastic diplegic children was conducted. Electromyography (EMG) was used to measure muscular activity at sitting position (SP), during shoulder internal rotation (IR) and shoulder external rotation (ER) handlings, which were performed using the elbow joint as key point of control. Muscle recordings were performed at the fourth cervical (C4) and at the tenth thoracic (T10) vertebral levels. The Gross Motor Function Classification System (GMFCS) was used to assess whether muscle activity would vary according to different levels of severity. Humeral ER handling induced an increase on EMG signal of trunk extensor muscles at the C4 (P=0.007) and T10 (P<0.001) vertebral levels. No significant effects were observed between SP and humeral IR handling at C4 level; However at T10 region, humeral IR handling induced an increase of EMG signal (P=0.019). Humeral ER resulted in an increase of EMG signal at both levels, suggesting increase of extensor muscle activation. Furthermore, the humeral ER handling caused different responses on EMG signal at T10 vertebra level, according to the GMFCS classification (P=0.017). In summary, an increase of EMG signal was observed during ER handling in both evaluated levels, suggesting an increase of muscle activation. These results indicate that humeral ER handling can be used for diplegic CP children rehabilitation to facilitate cervical and trunk extensor muscles activity in a GMFCS level-dependent manner. Copyright © 2014 Elsevier Ltd. All rights reserved.

Muscle activation patterns in acceleration-based phases during reach-to-grasp movement.

PubMed

Tokuda, Keisuke; Lee, Bumsuk; Shiihara, Yasufumi; Takahashi, Kazuhiro; Wada, Naoki; Shirakura, Kenji; Watanabe, Hideomi

2016-11-01

[Purpose] An earlier study divided reaching activity into characteristic phases based on hand velocity profiles. By synchronizing muscle activities and the acceleration profile, a phasing approach for reaching movement, based on hand acceleration profiles, was attempted in order to elucidate the roles of individual muscle activities in the different phases of the acceleration profile in reaching movements. [Subjects and Methods] Ten healthy volunteer subjects participated in this study. The aim was to electromyographically evaluate muscles around the shoulder, the upper trapezius, the anterior deltoid, the biceps brachii, and the triceps brachii, most of which have been used to evaluate arm motion, as well as the acceleration of the upper limb during simple reaching movement in the reach-to-grasp task. [Results] Analysis showed the kinematic trajectories of the acceleration during a simple biphasic profile of the reaching movement could be divided into four phases: increasing acceleration (IA), decreasing acceleration (DA), increasing deceleration (ID), and decreasing deceleration (DD). Muscles around the shoulder showed different activity patterns, which were closely associated with these acceleration phases. [Conclusion] These results suggest the important role of the four phases, derived from the acceleration trajectory, in the elucidation of the muscular mechanisms which regulate and coordinate the muscles around the shoulder in reaching movements.

[Cuff tear arthropathy – long-term results of reverse total shoulder arthroplasty].

PubMed

Brunner, U; Rückl, K; Fruth, M

2013-07-01

The results after reverse total shoulder arthroplasty for cuff tear arthropathy are superior and the complications fewer than for other etiologies, such as rheumatoid arthritis, fracture, fracture sequelae or even revision. The improvements in function and pain are excellent whereas rotation may be unaffected. Revisions and complications can be encountered in the first 3 years and the survival curve of the prosthesis is still good after 10 years with 90%. Progressive functional and radiological deterioration is observed after 9 years in approximately 30% of the patients without apparent problems with the prosthesis. Notching is progressive with incidence and size over time, without a proven correlation to the functional results but remains a major concern. Modification of the implants, the operative techniques and experience could significantly improve the results and reduce the rate of complications. Lateralization of the center of rotation and smaller inclination angles have a positive effect on the rate of notching and the range of motion, especially for the rotation. New prosthetic designs and operative techniques attempt to implement a combination of the biomechanical improvements. Reverse shoulder arthroplasty remains a challenging operation with a high rate of complications. The results depend on the etiology and the function of the remaining muscles and therefore on the experience and the skill of the surgeon to implement the appropriate biomechanical factors. Because of the concerns regarding the longevity, reverse shoulder arthroplasty should be reserved for the elderly over 70 years of age.

[Normal anatomy and related pathological changes of shoulder on MRI].

PubMed

Zhu, Q; Katsuya, N

2000-04-01

To describe the normal anatomy and common abnormal changes of rotator cuff impingement and tears and recurrent anterior instability of shoulder joint in MRI pictures. MRI was compared in 285 patients with shoulder diseases and 20 patients with symptomatic shoulder diseases. On oblique coronal image, the supraspinatus presented moderate signal intensity and low signal intensity in its tendon-muscle conjunction ranging from the humeral head to the greater tuberosity. The MRI manifestations of impingement lesion of the rotator cuff were as follows: high signal intensity of tendons, changes of their shapes, retraction of tendon-muscle conjunction, and muscle atrophy with high signal intensity. On T1-weighted axial image, the anterior and posterior glenohumeral labrum, the long head biceps tendon were displayed in low signal intensity. The anterior labrum manifested a sharp triangle contour and the posterior labrum a round one. The whole four muscles of the rotator cuff manifested on oblique sagital image. However, it was of less value in detecting the abnormalities of the rotator cuff and the glenohumeral labrum on sagittal imaging. The sensitivity in demonstrating rotator cuff complete tear was 95% for MRI and 91% for arthrography; the specificity was 88% for MRI and 100% for arthrography. The sensitivity and specificity of MRI were 96% and 75% for detecting glenoid labrum abnormalities, and 78% and 88% for detecting labrum tear in anterior recurrent dislocation of the shoulder. Magnetic resonance imaging with its excellent contrast resolution in multiple anatomic planes allows noninvasive visualization of bone and soft tissues in the rotator cuff and labrum.

Glenohumeral Function of the Long Head of the Biceps Muscle

PubMed Central

Chalmers, Peter N.; Cip, Johannes; Trombley, Robert; Cole, Brian J.; Wimmer, Markus A.; Romeo, Anthony A.; Verma, Nikhil N.

2014-01-01

Background: Optimal treatment of superior labral anterior-posterior (SLAP) tears is controversial, in part because the dynamic role of the long head of the biceps muscle (LHBM) in the glenohumeral joint is unclear. The aim of this study was to determine dynamic LHBM behavior during shoulder activity by studying (1) the electromyographic activity of the LHBM during shoulder motion, (2) the effect of elbow immobilization on this activity, and (3) the effect of a load applied to the distal humerus on this activity. Hypothesis: The LHBM would not play a significant role in active glenohumeral range of motion. Study Design: Controlled laboratory study. Methods: Thirteen normal volunteers underwent surface electromyography (EMG) measurement of the LHBM, short head biceps muscle (SHBM), deltoid, infraspinatus, and brachioradialis during shoulder motion from the neutral position (0° of rotation, flexion, and abduction) to 45° of flexion, 90° of flexion, 45° of abduction, and 90° of abduction. These motions were repeated both with and without splint immobilization of the forearm and elbow at 100° of flexion and neutral rotation and with and without a 1-kg weight placed on the lateral distal humerus. Results: Mean EMG activity within the LHBM and the SHBM was low (≤11.6% ± 9.1%). LHBM activity was significant increased by flexion and abduction (P < .049 in all cases), while SHBM activity was not. EMG activity from the middle head of the deltoid was significantly increased by loading with the shoulder positioned away from the body (ie, in abduction or flexion). When compared with the unloaded state, the addition of a distal humeral load significantly increased LHBM activity in 45° of abduction (P = .028) and 90° of flexion (P = .033) despite forearm and elbow immobilization. The SHBM showed similar trends. Conclusion: In normal volunteers with forearm and elbow immobilization and application of a load to the distal humerus, LHBM EMG activity is increased by both glenohumeral flexion and abduction, suggesting that this muscle plays a dynamic role in glenohumeral motion with higher demand activities. Clinical Relevance: Biceps tenodesis may result in dynamic change within the glenohumeral joint with higher demand activities. PMID:26535304

Participatory ergonomic intervention versus strength training on chronic pain and work disability in slaughterhouse workers: study protocol for a single-blind, randomized controlled trial

PubMed Central

2013-01-01

Background The prevalence of musculoskeletal pain in the shoulder, arm and hand is high among slaughterhouse workers, allegedly due to the highly repetitive and forceful exposure of these body regions during work. Work disability is a common consequence of these pains. Lowering the physical exposure through ergonomics intervention is the traditional strategy to reduce the workload. An alternative strategy could be to increase physical capacity of the worker through strength training. This study investigates the effect of two contrasting interventions, participatory ergonomics versus strength training on pain and work disability in slaughterhouse workers with chronic pain. Methods/design 66 slaughterhouse workers were allocated to 10 weeks of (1) strength training of the shoulder, arm and hand muscles for 3 x 10 minutes per week, or (2) participatory ergonomics involving counseling on workstation adjustment and optimal use of work tools (~usual care control group). Inclusion criteria were (1) working at a slaughterhouse for at least 30 hours per week, (2) pain intensity in the shoulder, elbow/forearm, or hand/wrist of at least 3 on a 0–10 VAS scale during the last three months, (3) pain lasting for more than 3 months, (4) frequent pain (at least 3 days per week) (5) at least moderate work disability, (6) no strength training during the last year, (7) no ergonomics instruction during the last year. Perceived pain intensity (VAS scale 0–10) of the shoulder, elbow/forearm and hand/wrist (primary outcome) and Disability of the Arm, Shoulder and Hand (Work module, DASH questionnaire) were measured at baseline and 10-week follow-up. Further, total muscle tenderness score and muscle function were assessed during clinical examination at baseline and follow-up. Discussion This RCT study will provide experimental evidence of the effectiveness of contrasting work-site interventions aiming at reducing chronic pain and work disability among employees engaged in repetitive and forceful work. Trial registration ClinicalTrials.gov:NCT01671267 PMID:23433448

The musculoskeletal consequences of breast reconstruction using the latissimus dorsi muscle for women following mastectomy for breast cancer: A critical review.

PubMed

Blackburn, N E; Mc Veigh, J G; Mc Caughan, E; Wilson, I M

2018-03-01

Breast reconstruction using the latissimus dorsi (LD) flap following mastectomy is an important management option in breast cancer. However, one common, but often ignored, complication following LD flap is shoulder dysfunction. The aim of this critical review was to comprehensively assess the musculoskeletal impact of LD breast reconstruction and evaluate the functional outcome following surgery. Five electronic databases were searched including; Medline, Embase, CINAHL Plus (Cumulative Index to Nursing and Allied Health), PubMed and Web of Science. Databases were searched from 2006 to 2016, and only full text, English language articles were included. Twenty-two observational studies and two surveys were reviewed with sample sizes ranging from six to 206 participants. The majority of studies had small sample sizes and were retrospective in nature. Nevertheless, there is evidence to suggest that there is some degree of weakness and reduced mobility at the shoulder following LD muscle transfer. The literature demonstrates that there is considerable morbidity in the immediate post-operative period with functional recovery varying between studies. The majority of work tends to be limited and often gives conflicting results; therefore, further investigation is required in order to determine underlying factors that contribute to a reduction in function and activities of daily living. © 2017 John Wiley & Sons Ltd.

Ultrasound-Guided Percutaneous Electrolysis and Eccentric Exercises for Subacromial Pain Syndrome: A Randomized Clinical Trial

PubMed Central

Arias-Buría, José L.; Truyols-Domínguez, Sebastián; Valero-Alcaide, Raquel; Salom-Moreno, Jaime; Atín-Arratibel, María A.; Fernández-de-las-Peñas, César

2015-01-01

Objective. To compare effects of ultrasound- (US-) guided percutaneous electrolysis combined with an eccentric exercise program of the rotator cuff muscles in subacromial pain syndrome. Methods. Thirty-six patients were randomized and assigned into US-guided percutaneous electrolysis (n = 17) group or exercise (n = 19) group. Patients were asked to perform an eccentric exercise program of the rotator cuff muscles twice every day for 4 weeks. Participants assigned to US-guided percutaneous electrolysis group also received the application of galvanic current through acupuncture needle on each session once a week (total 4 sessions). Shoulder pain (NPRS) and disability (DASH) were assessed at baseline, after 2 sessions, and 1 week after the last session. Results. The ANOVA revealed significant Group∗Time interactions for shoulder pain and disability (all, P < 0.01): individuals receiving US-guided percutaneous electrolysis combined with the eccentric exercises experienced greater improvement than those receiving eccentric exercise alone. Conclusions. US-guided percutaneous electrolysis combined with eccentric exercises resulted in small better outcomes at short term compared to when only eccentric exercises were applied in subacromial pain syndrome. The effect was statistically and clinically significant for shoulder pain but below minimal clinical difference for function. Future studies should investigate the long-term effects and potential placebo effect of this intervention. PMID:26649058

Comparison of the effects of local cryotherapy and passive cross-body stretch on extensibility in subjects with posterior shoulder tightness.

PubMed

Park, Kyue-Nam; Kwon, Oh-Yun; Weon, Jong-Hyuck; Choung, Sung-Dae; Kim, Si-Hyun

2014-01-01

The objective was to compare the immediate effects of local cryotherapy (LC) and passive cross-body stretch on the extensibility of the posterior shoulder muscle in individuals with posterior shoulder tightness. Eighty-seven healthy subjects with a between-shoulder difference in internal rotation (IR) range of motion (ROM) greater than 10° were randomly divided into three groups: LC group, stretching group, and control group (n = 29 in each group). Subjects in the LC group received LC on infraspinatus and posterior deltoid muscles and subjects in the stretching group performed passive cross-body stretch. Stretch sensation was measured at the end range of passive IR and horizontal adduction (HA) using numerical rating scale, and the pressure pain threshold (PPT) at the infraspinatus and posterior deltoid muscles was measured using pressure algometry. Passive and active ROM of IR and HA of the glenohumeral joint were measured using an inclinometer. All measurements were performed at pre-intervention, post- intervention, and 10-min follow-up. Stretch sensation was significantly decreased and PPT was significantly increased in the LC and stretching groups at post-intervention, and these effects were maintained at 10-min follow-up, compared to the control group. Both the LC group and stretching group had a significantly greater increase in passive and active ROM of IR and HA, compared to the control group at post-intervention and 10-min follow-up. However, there were no significant differences in stretch sensation, PPT, or ROM of IR and HA between the LC group and stretching group. LC can be used to decrease the stretch sensation and increase PPT and ROM of IR and HA as much as a stretching exercise. LC could be an alternative method for increasing the restricted ROM of glenohumeral IR and HA for individuals with posterior shoulder tightness, especially for patients and sports players who have severe stretching discomfort. Key PointsLocal cryotherapy (LC) decreased the uncomfortable stretch sensation, and increased the pressure pain threshold (PPT) of infraspinatus and posterior deltoid muscles in subjects with posterior shoulder tightness.Decreased stretch sensation by LC without passive stretching could improve the passive and active ROM of internal rotation and horizontal adduction in subjects with posterior shoulder tightness, similar to cross-body stretch.LC can be an alternative method to increase extensibility when individuals with posterior shoulder tightness have high stretch sensitivity and low PPT in the infraspinatus and posterior deltoid muscles.

Comparison of the Effects of Local Cryotherapy and Passive Cross-Body Stretch on Extensibility in Subjects with Posterior Shoulder Tightness

PubMed Central

Park, Kyue-nam; Kwon, Oh-yun; Weon, Jong-hyuck; Choung, Sung-dae; Kim, Si-hyun

2014-01-01

The objective was to compare the immediate effects of local cryotherapy (LC) and passive cross-body stretch on the extensibility of the posterior shoulder muscle in individuals with posterior shoulder tightness. Eighty-seven healthy subjects with a between-shoulder difference in internal rotation (IR) range of motion (ROM) greater than 10° were randomly divided into three groups: LC group, stretching group, and control group (n = 29 in each group). Subjects in the LC group received LC on infraspinatus and posterior deltoid muscles and subjects in the stretching group performed passive cross-body stretch. Stretch sensation was measured at the end range of passive IR and horizontal adduction (HA) using numerical rating scale, and the pressure pain threshold (PPT) at the infraspinatus and posterior deltoid muscles was measured using pressure algometry. Passive and active ROM of IR and HA of the glenohumeral joint were measured using an inclinometer. All measurements were performed at pre-intervention, post- intervention, and 10-min follow-up. Stretch sensation was significantly decreased and PPT was significantly increased in the LC and stretching groups at post-intervention, and these effects were maintained at 10-min follow-up, compared to the control group. Both the LC group and stretching group had a significantly greater increase in passive and active ROM of IR and HA, compared to the control group at post-intervention and 10-min follow-up. However, there were no significant differences in stretch sensation, PPT, or ROM of IR and HA between the LC group and stretching group. LC can be used to decrease the stretch sensation and increase PPT and ROM of IR and HA as much as a stretching exercise. LC could be an alternative method for increasing the restricted ROM of glenohumeral IR and HA for individuals with posterior shoulder tightness, especially for patients and sports players who have severe stretching discomfort. Key Points Local cryotherapy (LC) decreased the uncomfortable stretch sensation, and increased the pressure pain threshold (PPT) of infraspinatus and posterior deltoid muscles in subjects with posterior shoulder tightness. Decreased stretch sensation by LC without passive stretching could improve the passive and active ROM of internal rotation and horizontal adduction in subjects with posterior shoulder tightness, similar to cross-body stretch. LC can be an alternative method to increase extensibility when individuals with posterior shoulder tightness have high stretch sensitivity and low PPT in the infraspinatus and posterior deltoid muscles. PMID:24570610

Magnetic resonance imaging-controlled results of the pectoralis major tendon transfer for irreparable anterosuperior rotator cuff tears performed with standard and modified fixation techniques.

PubMed

Lederer, Stefan; Auffarth, Alexander; Bogner, Robert; Tauber, Mark; Mayer, Michael; Karpik, Stefanie; Matis, Nicholas; Resch, Herbert

2011-10-01

Irreparable ruptures of the subscapularis tendon lead to impaired function of the shoulder joint. In such cases, transfer of the pectoralis major tendon has led to encouraging results. The procedure fails periodically, typically associated with insufficient in-growth of the transferred tissue. We hypothesized that tendon harvest with chips of cancellous bone would improve the tendon-bone interface. Of 62 consecutive pectoralis tendon transfers, 54 shoulders were followed-up at an average of 35 months. In all shoulders, the transferred tendon was rerouted behind the conjoint tendon and fixed by transosseous sutures. In 29 shoulders, the tendon was harvested with a cuff of cancellous bone. In 25 shoulders, the conventional technique with sharp detachment of the tendon was used. Apart from detailed clinical examination of all shoulders, a magnetic resonance image (MRI) was available in 52 shoulders. The overall Constant score had improved from an average of 38.8 points preoperatively to 63.4 points at follow-up. Shoulders treated with the new fixation technique scored 64.4 compared with 62.2 for the conventional fixations. The MRI showed intact tendons and muscles in 80.8% of shoulders. In 7 shoulders (13.5%), the transferred tendon was ruptured. Two of these were treated with the new fixation technique. Mean patient satisfaction score was 8.2 points. A secure method of fixation that avoids secondary ruptures despite insufficiency of the transferred tendon is of great importance. Also the rerouting of the transferred tendon under the conjoined tendon is essential to imitate the natural force vector and the function of an intact subscapularis tendon. Patients in this investigation were also monitored by MRI to verify the integrity of the transferred tendon. As a salvage procedure, the pectoralis major tendon transfer provides good results in most cases. Sufficient in-growth of the transferred tissue is essential for the success of the procedure. This seems to be facilitated by both methods. Copyright © 2011 Journal of Shoulder and Elbow Surgery Board of Trustees. All rights reserved.

Effects of inactivation of the anterior interpositus nucleus on the kinematic and dynamic control of multijoint movement.

PubMed

Cooper, S E; Martin, J H; Ghez, C

2000-10-01

We previously showed that inactivating the anterior interpositus nucleus in cats disrupts prehension; paw paths, normally straight and accurate, become curved, hypometric, and more variable. In the present study, we determined the joint kinematic and dynamic origins of this impairment. Animals were restrained in a hammock and trained to reach and grasp a cube of meat from a narrow food well at varied heights; movements were monitored using the MacReflex analysis system. The anterior interpositus nucleus was inactivated by microinjection of the GABA agonist muscimol (0.25-0.5 microgram in 0.5 microliter saline). For each joint, we computed the torque due to gravity, inertial resistance (termed self torque), interjoint interactions (termed interaction torque), and the combined effects of active muscle contraction and passive soft tissue stretch (termed generalized muscle torque). Inactivation produced significant reductions in the amplitude, velocity, and acceleration of elbow flexion. However, these movements continued to scale normally with target height. Shoulder extension was reduced by inactivation but wrist angular displacement and velocity were not. Inactivation also produced changes in the temporal coordination between elbow, shoulder, and wrist kinematics. Dynamic analysis showed that elbow flexion both before and during inactivation was produced by the combined action of muscle and interaction torque, but that the timing depended on muscle torque. Elbow interaction and muscle torques were scaled to target height both before and during inactivation. Inactivation produced significant reductions in elbow flexor interaction and muscle torques. The duration of elbow flexor muscle torque was prolonged to compensate for the reduction in flexor interaction torque. Shoulder extension was produced by extensor interaction and muscle torques both before and during inactivation. Inactivation produced a reduction in shoulder extension, primarily by reduced interaction torque, but without compensation. Wrist plantarflexion, which occurred during elbow flexion, was driven by plantarflexor interaction and gravitational torques both before and during inactivation. Muscle torque acted in the opposite direction with a phase lead to restrain the plantarflexor interaction torque. During inactivation, there was a reduction in plantarflexor interaction torque and a loss of the phase lead of the muscle torque. Our findings implicate the C1/C3 anterior interpositus zone of the cerebellum in the anticipatory control of intersegmental dynamics during reaching, which zone is required for coordinating the motions of the shoulder and wrist with those of the elbow. In contrast, this cerebellar zone does not play a role in scaling the movement to match a target.

The clinical aspects of the upper extremity exoskeleton "EXAR" use

NASA Astrophysics Data System (ADS)

Vorobiev, A. A.; Krivonozhkina, P. S.; Andryushchenko, F. A.; Zasypkina, O. A.

2015-11-01

The article considers some of indications and contraindications for the use of the exoskeleton "EXAR". Our experience with the present construction use shows that the exoskeleton "EXAR" is able to make up the following lost or disturbed muscle functions:- an arm raise; a drawing of the arm aside from the trunk;- a bending of the arm in shoulder or elbow joints.

Muscle strength and fatigue in newly diagnosed patients with myasthenia gravis.

PubMed

Vinge, Lotte; Andersen, Henning

2016-10-01

Dynamometry is increasingly used as an objective measurement of muscle strength in neurological diseases. No study has applied dynamometry in untreated newly diagnosed patients with myasthenia gravis (MG). Isometric muscle strength at the shoulder, knee, and ankle was determined in 21 MG patients before and after initial anti-myasthenic treatment. Isometric strength was compared with MG evaluation scales. Muscle strength was reduced for knee extensors and shoulder abductors but normal for ankle extensors. Isometric muscle strength did not correlate significantly with manual muscle testing (MG Composite). Dynamometry revealed improved muscle strength of up to 50% (median 17%; range -1.8-49.8) despite no change in the MG Composite score. Dynamometry appears to be a more sensitive method of identifying changes in limb strength than MG evaluation scales. This supports the use of dynamometry in MG patients, especially for evaluation of the effect of anti-myasthenic treatment. Muscle Nerve 54: 709-714, 2016. © 2016 Wiley Periodicals, Inc.

Shoulder instability: evaluation with MR imaging.

PubMed

Seeger, L L; Gold, R H; Bassett, L W

1988-09-01

Instability of the glenohumeral joint is a common cause of chronic shoulder pain and disability. One or more episodes of subluxation or dislocation may result in a tear, detachment, or attenuation of the glenoid labrum, stripping of the joint capsule from the scapula, or trauma to the tendons or muscles of the rotator cuff. A series of 27 shoulders examined with magnetic resonance (MR) imaging showed changes of glenohumeral instability, which were confirmed with open or arthroscopic surgery. MR imaging was capable of displaying common types of pathologic conditions resulting from instability, including labral trauma, capsular detachment, and retraction of the subscapularis muscle. MR imaging is a valuable diagnostic tool for the evaluation of glenohumeral instability.

A novel cadaveric model for anterior-inferior shoulder dislocation using forcible apprehension positioning.

PubMed

McMahon, Patrick J; Chow, Stephen; Sciaroni, Laura; Yang, Bruce Y; Lee, Thay Q

2003-01-01

A novel cadaveric model for anterior-inferior shoulder dislocation using forcible apprehension positioning is presented. This model simulates an in vivo mechanism and yields capsulolabral lesions. The scapulae of 14 cadaveric entire upper limbs (82 +/- 9 years, mean +/- standard deviation) were each rigidly fixed to a custom shoulder-testing device. A pneumatic system was used with pulleys and cables to simulate the rotator cuff and the deltoid muscles (anterior and middle portions). The glenohumeral joint was then positioned in the apprehension position of abduction, external rotation, and horizontal abduction. A 6-degree-of-freedom load cell (Assurance Technologies, Garner, North Carolina) measured the joint reaction force that was then resolved into three orthogonal components of compression force, anteriorly directed force, and superiorly directed force. With the use of a thrust bearing, the humerus was moved along a rail with a servomotor-controlled system at 50 mm/s that resulted in horizontal abduction. Force that developed passively in the pectoralis major muscle was recorded with an independent uniaxial load cell. Each of the glenohumeral joints dislocated anterior-inferior, six with avulsion of the capsulolabrum from the anterior-inferior glenoid bone and eight with capsulolabral stretching. Pectoralis major muscle force as well as the joint reaction force increased with horizontal abduction until dislocation. At dislocation, the magnitude of the pectoralis major muscle force, 609.6 N +/- 65.2 N was similar to the compression force, 569.6 N +/- 37.8 N. A cadaveric model yielded an anterior dislocation with a mechanism of forcible apprehension positioning when the appropriate shoulder muscles were simulated and a passive pectoralis major muscle was included. Capsulolabral lesions resulted, similar to those observed in vivo.

Functional outcomes of traumatic and non-traumatic rotator cuff tears after arthroscopic repair

PubMed Central

Abechain, José Jorge Kitagaki; Godinho, Glaydson Gomes; Matsunaga, Fabio Teruo; Netto, Nicola Archetti; Daou, Julia Pozzetti; Tamaoki, Marcel Jun Sugawara

2017-01-01

AIM To compare the functional outcomes of traumatic and non-traumatic rotator cuff tears after arthroscopic repair. METHODS Eighty-seven patients with rotator cuff tears following arthroscopic treatment were divided into traumatic and non-traumatic tear groups. Postoperative muscle strength and outcomes using the modified University of California, Los Angeles score were evaluated. Sex, age, affected limb and dominant limb were correlated between groups. Muscle strength of the repaired and unaffected shoulders was compared. Rotator cuff injury size was measured. RESULTS Of the 87 patients who underwent rotator cuff repairs, 35 had traumatic tears and 52 had non-traumatic tears. In patients with non-traumatic tears, the average age was 59 years, 74.5% were female, 96.1% were right-hand dominant and 92.3% had their dominant shoulder affected. Patients with traumatic tears were 59.5 years old on average, 51.4% were female, 91.4% were right-hand dominant and 88.5% had their dominant shoulder affected. No difference existed in the mean modified University of California, Los Angeles score between patients with traumatic tears (33.7) compared with those with non-traumatic tears (32.8). No strength differences were observed between groups: The strength difference between the non-affected and affected sides was 1.21 kg in the non-traumatic group and 1.39 kg in the traumatic group (P = 0.576), while the strength ratio between the non-affected/affected sides was 0.805 in the non-traumatic group and 0.729 in the traumatic group (P = 0.224). CONCLUSION The functional results of traumatic rotator cuff repairs are similar to non-traumatic tears. Both outcomes are satisfactory. PMID:28875129

Effect of power-assisted hand-rim wheelchair propulsion on shoulder load in experienced wheelchair users: A pilot study with an instrumented wheelchair.

PubMed

Kloosterman, Marieke G M; Buurke, Jaap H; de Vries, Wiebe; Van der Woude, Lucas H V; Rietman, Johan S

2015-10-01

This study aims to compare hand-rim and power-assisted hand-rim propulsion on potential risk factors for shoulder overuse injuries: intensity and repetition of shoulder loading and force generation in the extremes of shoulder motion. Eleven experienced hand-rim wheelchair users propelled an instrumented wheelchair on a treadmill while upper-extremity kinematic, kinetic and surface electromyographical data was collected during propulsion with and without power-assist. As a result during power-assisted propulsion the peak resultant force exerted at the hand-rim decreased and was performed with significantly less abduction and internal rotation at the shoulder. At shoulder level the anterior directed force and internal rotation and flexion moments decreased significantly. In addition, posterior and the minimal inferior directed forces and the external rotation moment significantly increased. The stroke angle decreased significantly, as did maximum shoulder flexion, extension, abduction and internal rotation. Stroke-frequency significantly increased. Muscle activation in the anterior deltoid and pectoralis major also decreased significantly. In conclusion, compared to hand-rim propulsion power-assisted propulsion seems effective in reducing potential risk factors of overuse injuries with the highest gain on decreased range of motion of the shoulder joint, lower peak propulsion force on the rim and reduced muscle activity. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

Effects of hand grip exercise on shoulder joint internal rotation and external rotation peak torque.

PubMed

Lee, Dong-Rour; Jong-Soon Kim, Laurentius

2016-08-10

The goal of this study is to analyze the effects of hand grip training on shoulder joint internal rotation (IR)/external rotation (ER) peak torque for healthy people. The research was conducted on 23 healthy adults in their 20 s-30 s who volunteered to participate in the experiment. Hand grip power test was performed on both hands of the research subjects before/after the test to study changes in hand grip power. Isokinetic machine was used to measure the concentric IRPT (internal rotation peak torque) and concentric ERPT (external rotation peak torque) at the velocity of 60°/sec, 90°/sec, and 180°/sec before/after the test. Hand grip training was performed daily on the subject's right hand only for four weeks according to exercise program. Finally, hand grip power of both hands and the maximum torque values of shoulder joint IR/ER were measured before/after the test and analyzed. There was a statistically significant difference in the hand grip power of the right hand, which was subject to hand grip training, after the experiment. Also, statistically significant difference for shoulder ERPT was found at 60°/sec. Hand grip training has a positive effect on shoulder joint IRPT/ERPT and therefore can help strengthen muscles around the shoulder without using weight on the shoulder. Consequently, hand grip training would help maintain strengthen the muscles around the shoulder in the early phase of rehabilitation process after shoulder surgery.

Facioscapulohumeral muscular dystrophy

MedlinePlus

... due to weakness of the cheek muscles Decreased facial expression due to weakness of facial muscles Depressed or angry facial expression Difficulty pronouncing words Difficulty reaching above the shoulder ...

Variation in the insertion of the latissimus dorsi & its clinical importance.

PubMed

Bhatt, C R; Prajapati, B; Patil, D S; Patel, V D; Singh, Binodkumar G P; Mehta, C D

2013-01-01

The latissimus dorsi is the larger, flat, dorso-lateral muscle on the trunk, posterior to the arm, and partly covered by the trapezius on its median dorsal region. Origin of the latissimus dorsi is from spinous processes of thoracic T7-T12, thoracolumbar fascia, iliac crest and inferior 3 or 4 ribs, inferior angle of scapula and insertion on floor of intertubercular groove of the humerus. We have studied 50 cadavers in the different medical colleges in which we found 2% case of anterior and posterior slip of the muscle fibers with their extension up to the pectoralis major and teres major respectively. Usually, latissimus dorsi involve in extension, adduction, transverse extension also known as horizontal abduction, flexion from an extended position, and internal rotation of the shoulder joint. It also has a synergistic role in extension and lateral flexion of the lumbar spine. The latissimus dorsi may be used for the tendon graft surgeries. Tight latissimus dorsi has been shown to be one cause of chronic shoulder pain and chronic back pain. Because the latissimus dorsi connects the spine to the humerus, tightness in this muscle can manifest as either sub-optimal glenohumeral joint function (which leads to chronic shoulder pain) or tendinitis in the tendinous fasciae connecting the latissimus dorsi to the thoracic and lumbar spine. Latissimus dorsi used for pedicle transplant rotator cuff repair reconstruction of breast, face, scalp and cranium defect. The extra slip of the latissimus dorsi may puzzle any transplant operations. We as anatomist discuss the clinical implication of the extra slip of latissimus dorsi.

Variation in the insertion of the latissimus dorsi & its clinical importance

PubMed Central

Bhatt, C.R.; Prajapati, B.; Patil, D.S.; Patel, V.D.; Singh, Binodkumar G.P.; Mehta, C.D.

2013-01-01

The latissimus dorsi is the larger, flat, dorso-lateral muscle on the trunk, posterior to the arm, and partly covered by the trapezius on its median dorsal region. Origin of the latissimus dorsi is from spinous processes of thoracic T7–T12, thoracolumbar fascia, iliac crest and inferior 3 or 4 ribs, inferior angle of scapula and insertion on floor of intertubercular groove of the humerus. We have studied 50 cadavers in the different medical colleges in which we found 2% case of anterior and posterior slip of the muscle fibers with their extension up to the pectoralis major and teres major respectively. Usually, latissimus dorsi involve in extension, adduction, transverse extension also known as horizontal abduction, flexion from an extended position, and internal rotation of the shoulder joint. It also has a synergistic role in extension and lateral flexion of the lumbar spine. The latissimus dorsi may be used for the tendon graft surgeries. Tight latissimus dorsi has been shown to be one cause of chronic shoulder pain and chronic back pain. Because the latissimus dorsi connects the spine to the humerus, tightness in this muscle can manifest as either sub-optimal glenohumeral joint function (which leads to chronic shoulder pain) or tendinitis in the tendinous fasciae connecting the latissimus dorsi to the thoracic and lumbar spine. Latissimus dorsi used for pedicle transplant rotator cuff repair reconstruction of breast, face, scalp and cranium defect. The extra slip of the latissimus dorsi may puzzle any transplant operations. We as anatomist discuss the clinical implication of the extra slip of latissimus dorsi. PMID:24403744

Development of a Deltoid Shoulder Muscle Model for Rhesus Monkey Spaceflight Studies

NASA Technical Reports Server (NTRS)

Riley, Danny A.; Macias, Melissa Y.; Anders, Scott; Slocum, Glenn R.

1995-01-01

The acromiodeltoid shoulder muscle was demonstrated to be a suitable model for spaceflight studies. The muscle contains a mixture of fast and slow fibers, permitting analysis of muscle fiber type specific changes. Two biopsy sites per muscle were identified that provided samples not degraded by the biopsy procedure. Both sites contained sufficient numbers fibers for determining changes in fiber type percentages and size. There was adequate bilateral symmetry regarding fiber type composition in the left and right muscles such that a total of four times points can be compared. The ESOP cage did not cause atrophy of deltoid muscle fibers; this means that microgravity-induced atrophy should be detectable. As expected, muscle excision stimulated muscle IgM and IgG muscle autoantibody production. Nonrestrained control animals suppressed this response whereas restrained monkeys showed an abnormally pronounced response indicative a compromised immune system. The presence of ESOP cage-induced changes in the immune response may mask spaceflight-induced effects. The ESOP cage modified the dominant hand operation of the PTS. These results demonstrate the importance of high fidelity ground based controls.

The Primer for Sports Medicine Professionals on Imaging

PubMed Central

Farshad-Amacker, Nadja A.; Jain Palrecha, Sapna; Farshad, Mazda

2013-01-01

Because of its inherent superior soft tissue contrast and lack of ionizing radiation, magnetic resonance imaging (MRI) is highly suited to study the complex anatomy of the shoulder joint, particularly when assessing the relatively high incidence of shoulder injuries in young, athletic patients. This review aims to serve as a primer for understanding shoulder MRI in an algorithmical approach, including MRI protocol and technique, normal anatomy and anatomical variations of the shoulder, pathologic conditions of the rotator cuff tendons and muscles, the long head of the biceps tendon, shoulder impingement, labral and glenohumeral ligament pathology, MR findings in shoulder instability, adhesive capsulitis, and osteoarthritis. PMID:24381700

Intrarater reliability of the Humac NORM isokinetic dynamometer for strength measurements of the knee and shoulder muscles.

PubMed

Habets, Bas; Staal, J Bart; Tijssen, Marsha; van Cingel, Robert

2018-01-10

To determine the intrarater reliability of the Humac NORM isokinetic dynamometer for concentric and eccentric strength tests of knee and shoulder muscles. 54 participants (50% female, average age 20.9 ± 3.1 years) performed concentric and eccentric strength measures of the knee extensors and flexors, and the shoulder internal and external rotators on two different Humac NORM isokinetic dynamometers, which were situated at two different centers. The knee extensors and flexors were tested concentrically at 60° and 180°/s, and eccentrically at 60° s. Concentric strength of the shoulder internal and external rotators, and eccentric strength of the external rotators were measured at 60° and 120°/s. We calculated intraclass correlation coefficients (ICCs), standard error of measurement, standard error of measurement expressed as a %, and the smallest detectable change to determine reliability and measurement error. ICCs for the knee tests ranged from 0.74 to 0.89, whereas ICC values for the shoulder tests ranged from 0.72 to 0.94. Measurement error was highest for the concentric test of the knee extensors and lowest for the concentric test of shoulder external rotators.

Is bipolar latissimus dorsi transfer a reliable option to restore elbow flexion in children with arthrogryposis? A review of 13 tendon transfers.

PubMed

Zargarbashi, Ramin; Nabian, Mohammad Hossein; Werthel, Jean-David; Valenti, Philippe

2017-11-01

Scant data are published about different available therapeutic options for restoration of active elbow flexion in arthrogryposis with varying degrees of improvement. In this retrospective study we evaluated medium-term effects of bipolar latissimus dorsi transfer in patients with arthrogryposis. Pedicled latissimus dorsi bipolar muscle transfer was used to restore elbow flexion in 11 patients (13 limbs) with arthrogryposis. Elbow and shoulder range of motions and strength of elbow flexion were measured preoperatively and at the last follow-up. The functional use of the upper limb was examined by observation of activities of daily living and presence of adaptive mechanisms. General satisfaction was assessed at the final follow-up. The patients were a mean age of 5.69 ± 2.49 years. The follow-up period was 27.31 ± 17.8 months. At the last examination, according to transferred muscle function and elbow range of motion, function of 12 limbs was graded as excellent and good, and 1 was graded poor. The active postoperative elbow range of motion was 97.7° ± 34.5°. The general satisfaction of the patients with the surgical results was 92.3%. Activities of daily living were improved in 10 of 13 limbs, but adaptive mechanisms were detected in all patients except 2 at the last follow-up. We suggest pedicled bipolar latissimus dorsi transfer as a reliable therapeutic option to restore active elbow flexion in arthrogryposis with acceptable results regarding regaining range of motion and patient satisfaction. Functional passive elbow range of motion and good quality of latissimus dorsi muscle preoperatively is mandatory. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

The effect of in vivo rotator cuff muscle contraction on glenohumeral joint translation: An ultrasonographic and electromyographic study.

PubMed

Rathi, Sangeeta; Taylor, Nicholas F; Green, Rodney A

2016-12-08

The proposed stabilizing mechanism of rotator cuff muscles is to limit excessive humeral head translation. However, an accurate measurement of glenohumeral joint translation in vivo has been challenging. We aimed to measure the effect of rotator cuff muscle contraction on glenohumeral joint translation using real time ultrasound (RTUS) and electromyography. Twenty healthy adults with no history of shoulder pathology were recruited. Six intramuscular electrodes were inserted in the rotator cuff muscles (supraspinatus, upper and lower infraspinatus, teres minor, upper and lower subscapularis). Anterior and posterior glenohumeral translations were measured in testing conditions (with and without translation force, with and without isometric internal and external rotation), in two positions (shoulder neutral, abduction) and views (anterior, posterior). There was reduced glenohumeral translation with rotator cuff muscle contraction in the neutral anterior (F 2,38 =17.8, p<0.01), neutral posterior (F 1.6,31.0 =44.3, p<0.01) and abducted posterior (F 1.5,28.8 =5.2, p<0.02) positions. There were also differences between the amount of translation limited by anterior and posterior rotator cuff muscles in response to anterior and posterior translation forces (p<0.05), indicating that their activity was, to a certain extent, direction specific. For example, in both neutral and abducted positions, contraction of the posterior rotator cuff muscles, infraspinatus and teres minor, appeared to tether anterior translation of the humeral head. Our results confirm that the rotator cuff functions as a stabilizer of the glenohumeral joint by limiting humeral head translation and this is likely to be in a direction-specific manner. Copyright © 2016 Elsevier Ltd. All rights reserved.

An inverse dynamic analysis on the influence of upper limb gravity compensation during reaching.

PubMed

Essers, J M N Hans; Meijer, Kenneth; Murgia, Alessio; Bergsma, Arjen; Verstegen, Paul

2013-06-01

Muscular dystrophies (MDs) are characterized by progressive muscle wasting and weakness. Several studies have been conducted to investigate the influence of arm supports in an attempt to restore arm function. Lowering the load allows the user to employ the residual muscle force for movement as well as for posture stabilization. In this pilot study three conditions were investigated during a reaching task performed by three healthy subjects and three MD subjects: a control condition involving reaching; a similar movement with gravity compensation using braces to support the forearm; an identical reaching movement in simulated zero-gravity. In the control condition the highest values of shoulder moments were present, with a maximum of about 6 Nm for shoulder flexion and abduction. In the gravity compensation and zero gravity conditions the maximum shoulder moments were decreased by more than 70% and instead of increasing during reaching, they remained almost unvaried, fluctuating around an offset value less than 1 Nm. Similarly, the elbow moments in the control condition were the highest with a peak around 3.3 Nm for elbow flexion, while the moments were substantially reduced in the remaining two conditions, fluctuating around offset values between 0 to 0.5 Nm. In conclusion, gravity compensation by lower arm support is effective in healthy subjects and MD subjects and lowers the amount of shoulder and elbow moments by an amount comparable to a zero gravity environment. However the influence of gravity compensation still needs to be investigated on more people with MDs in order to quantify any beneficial effect on this population.

Effect of two contrasting interventions on upper limb chronic pain and disability: a randomized controlled trial.

PubMed

Sundstrup, Emil; Jakobsen, Markus D; Andersen, Christoffer H; Jay, Kenneth; Persson, Roger; Aagaard, Per; Andersen, Lars L

2014-01-01

Chronic pain and disability of the arm, shoulder, and hand severely affect labor market participation. Ergonomic training and education is the default strategy to reduce physical exposure and thereby prevent aggravation of pain. An alternative strategy could be to increase physical capacity of the worker by physical conditioning. To investigate the effect of 2 contrasting interventions, conventional ergonomic training (usual care) versus resistance training, on pain and disability in individuals with upper limb chronic pain exposed to highly repetitive and forceful manual work. Examiner-blinded, parallel-group randomized controlled trial with allocation concealment. Slaughterhouses located in Denmark, Europe. Sixty-six adults with chronic pain in the shoulder, elbow/forearm, or hand/wrist and work disability were randomly allocated to 10 weeks of specific resistance training for the shoulder, arm, and hand muscles for 3 x 10 minutes per week, or ergonomic training and education (usual care control group). Pain intensity (average of shoulder, arm, and hand, scale 0 - 10) was the primary outcome, and disability (Work module of DASH questionnaire) as well as isometric shoulder and wrist muscle strength were secondary outcomes. Pain intensity, disability, and muscle strength improved more following resistance training than usual care (P < 0.001, P = 0.05, P <0.0001, respectively [corrected]). Pain intensity decreased by 1.5 points (95% confidence interval -2.0 to -0.9) following resistance training compared with usual care, corresponding to an effect size of 0.91 (Cohen's d). Blinding of participants is not possible in behavioral interventions. However, at baseline outcome expectations of the 2 interventions were similar. Resistance training at the workplace results in clinical relevant improvements in pain, disability, and muscle strength in adults with upper limb chronic pain exposed to highly repetitive and forceful manual work. NCT01671267.

Laboratory or field tests for evaluating firefighters' work capacity?

PubMed

Lindberg, Ann-Sofie; Oksa, Juha; Malm, Christer

2014-01-01

Muscle strength is important for firefighters work capacity. Laboratory tests used for measurements of muscle strength, however, are complicated, expensive and time consuming. The aims of the present study were to investigate correlations between physical capacity within commonly occurring and physically demanding firefighting work tasks and both laboratory and field tests in full time (N = 8) and part-time (N = 10) male firefighters and civilian men (N = 8) and women (N = 12), and also to give recommendations as to which field tests might be useful for evaluating firefighters' physical work capacity. Laboratory tests of isokinetic maximal (IM) and endurance (IE) muscle power and dynamic balance, field tests including maximal and endurance muscle performance, and simulated firefighting work tasks were performed. Correlations with work capacity were analyzed with Spearman's rank correlation coefficient (rs). The highest significant (p<0.01) correlations with laboratory and field tests were for Cutting: IE trunk extension (rs = 0.72) and maximal hand grip strength (rs = 0.67), for Stairs: IE shoulder flexion (rs = -0.81) and barbell shoulder press (rs = -0.77), for Pulling: IE shoulder extension (rs = -0.82) and bench press (rs = -0.85), for Demolition: IE knee extension (rs = 0.75) and bench press (rs = 0.83), for Rescue: IE shoulder flexion (rs = -0.83) and bench press (rs = -0.82), and for the Terrain work task: IE trunk flexion (rs = -0.58) and upright barbell row (rs = -0.70). In conclusion, field tests may be used instead of laboratory tests. Maximal hand grip strength, bench press, chin ups, dips, upright barbell row, standing broad jump, and barbell shoulder press were strongly correlated (rs≥0.7) with work capacity and are therefore recommended for evaluating firefighters work capacity.

Effect of brief daily resistance training on rapid force development in painful neck and shoulder muscles: randomized controlled trial

PubMed Central

Jay, Kenneth; schraefel, mc; Andersen, Christoffer H; Ebbesen, Frederik S; Christiansen, David H; Skotte, Jørgen; Zebis, Mette K; Andersen, Lars L

2013-01-01

Objective: To determine the effect of small daily amounts of progressive resistance training on rapid force development of painful neck/shoulder muscles. Methods: 198 generally healthy adults with frequent neck/shoulder muscle pain (mean: age 43·1 years, computer use 93% of work time, 88% women, duration of pain 186 day during the previous year) were randomly allocated to 2- or 12 min of daily progressive resistance training with elastic tubing or to a control group receiving weekly information on general health. A blinded assessor took measures at baseline and at 10-week follow-up; participants performed maximal voluntary contractions at a static 90-degree shoulder joint angle. Rapid force development was determined as the rate of torque development and maximal muscle strength was determined as the peak torque. Results: Compared with the control group, rate of torque development increased 31·0 Nm s−1 [95% confidence interval: (1·33–11·80)] in the 2-min group and 33·2 Nm s−1 (1·66–12·33) in the 12-min group from baseline to 10-week follow-up, corresponding to an increase of 16·0% and 18·2% for the two groups, respectively. The increase was significantly different compared to controls (P<0·05) for both training groups. Maximal muscle strength increased only ∼5–6% [mean and 95% confidence interval for 2- and 12-min groups to control, respectively: 2·5 Nm (0·05–0·73) and 2·2 Nm (0·01–0·70)]. No significant differences between the 2- and 12-min groups were evident. A weak but significant relationship existed between changes in rapid force development and pain (r = 0·27, P<0·01), but not between changes in maximal muscle strength and pain. Conclusion: Small daily amounts of progressive resistance training in adults with frequent neck/shoulder pain increases rapid force development and, to a less extent, maximal force capacity. PMID:23758661

Development of a Finite Element Model of the Human Shoulder to Investigate the Mechanical Responses and Injuries in Side Impact

NASA Astrophysics Data System (ADS)

Iwamoto, Masami; Miki, Kazuo; Yang, King H.

Previous studies in both fields of automotive safety and orthopedic surgery have hypothesized that immobilization of the shoulder caused by the shoulder injury could be related to multiple rib fractures, which are frequently life threatening. Therefore, for more effective occupant protection, it is important to understand the relationship between shoulder injury and multiple rib fractures in side impact. The purpose of this study is to develop a finite element model of the human shoulder in order to understand this relationship. The shoulder model included three bones (the humerus, scapula and clavicle) and major ligaments and muscles around the shoulder. The model also included approaches to represent bone fractures and joint dislocations. The relationships between shoulder injury and immobilization of the shoulder are discussed using model responses for lateral shoulder impact. It is also discussed how the injury can be related to multiple rib fractures.

Restoration of Elbow Flexion in Patients With Complete Traumatic and Obstetric Brachial Plexus Injury After Functional Free Gracilis Muscle Transfer: Our Experience and Management.

PubMed

Nath, Rahul K; Boutros, Sean G; Somasundaram, Chandra

2017-01-01

Background: Functional free gracilis muscle transfer is an operative procedure for elbow reconstruction in patients with complete brachial plexus nerve and avulsion injuries and in delayed or prolonged nerve denervation, as well as in patients with inadequate upper extremity function after primary nerve reconstruction. Methods: We retrospectively reviewed our patient records and identified 24 patients with complete brachial plexus nerve injury (13 obstetric, 11 males and 2 females; 11 traumatic, 9 males and 2 females) whose affected arm and shoulder were totally paralyzed and their voluntary elbow flexion or the biceps function was poor preoperatively (mean M0-1/5 in MRC grade). These patients had undergone the functional free gracilis muscle transfer procedure at our clinic since 2005. Results: Ninety-two percent of all patients showed recovery and improvement. Successful free gracilis muscle transfer is defined as antigravity biceps muscle strength of M3-4/5 and higher, which was observed in 16 (8 obstetric and 8 traumatic) of our 24 patients (67%) in this study at least 1 year after functional free gracilis muscle transfer. This is statistically significant ( P < .000001) in comparison with their mean preoperative score (M0-1/5). There was no improvement in motor level of the biceps muscle (M0/5) in 2 patients (1 from each group). The donor site of these 24 patients showed no deficit in motor and sensory functions. Conclusions: Taken together, a significant number (92%) of patients in both obstetric and traumatic brachial plexus injury groups had recovery and improvement and most of these patients (64%) achieved antigravity and elbow flexion at least 1 year after free gracilis muscle transfer at our clinic.

Restoration of Elbow Flexion in Patients With Complete Traumatic and Obstetric Brachial Plexus Injury After Functional Free Gracilis Muscle Transfer: Our Experience and Management

PubMed Central

Boutros, Sean G.; Somasundaram, Chandra

2017-01-01

Background: Functional free gracilis muscle transfer is an operative procedure for elbow reconstruction in patients with complete brachial plexus nerve and avulsion injuries and in delayed or prolonged nerve denervation, as well as in patients with inadequate upper extremity function after primary nerve reconstruction. Methods: We retrospectively reviewed our patient records and identified 24 patients with complete brachial plexus nerve injury (13 obstetric, 11 males and 2 females; 11 traumatic, 9 males and 2 females) whose affected arm and shoulder were totally paralyzed and their voluntary elbow flexion or the biceps function was poor preoperatively (mean M0-1/5 in MRC grade). These patients had undergone the functional free gracilis muscle transfer procedure at our clinic since 2005. Results: Ninety-two percent of all patients showed recovery and improvement. Successful free gracilis muscle transfer is defined as antigravity biceps muscle strength of M3-4/5 and higher, which was observed in 16 (8 obstetric and 8 traumatic) of our 24 patients (67%) in this study at least 1 year after functional free gracilis muscle transfer. This is statistically significant (P < .000001) in comparison with their mean preoperative score (M0-1/5). There was no improvement in motor level of the biceps muscle (M0/5) in 2 patients (1 from each group). The donor site of these 24 patients showed no deficit in motor and sensory functions. Conclusions: Taken together, a significant number (92%) of patients in both obstetric and traumatic brachial plexus injury groups had recovery and improvement and most of these patients (64%) achieved antigravity and elbow flexion at least 1 year after free gracilis muscle transfer at our clinic. PMID:29213347

Effect of pain-free range exercise on shoulder pain and range of motion in an amateur skier.

PubMed

Yoo, Won-Gyu

2016-12-01

[Purpose] This study prescribed pain-free range exercises for a female amateur skier who complained of limitations in her shoulder range of motion, and pain caused by protective spasms; the tester evaluated the effects of such exercise on pain. [Subject and Methods] A 23-year-old female who complained of pain of 3 weeks in duration in the right glenohumoral and scapulothoracic joints was enrolled. [Results] After pain-free range exercises, the visual analog pain score was 2 and the shoulder flexion and abduction angles improved compared to the initial values. [Conclusion] Thus, this study suggests muscle-strengthening exercises within the pain-free range, rather than simple pain treatments, as therapy for acute muscle injuries in skiers.

Rotator cuff strength in recurrent anterior shoulder instability.

PubMed

Edouard, Pascal; Degache, Francis; Beguin, Laurent; Samozino, Pierre; Gresta, Giorgio; Fayolle-Minon, Isabelle; Farizon, Frédéric; Calmels, Paul

2011-04-20

Although rotator-cuff muscle contraction plays an important role in stabilizing the glenohumeral joint, little is known about the role of these muscles in the pathophysiology of recurrent anterior instability. We intended to analyze the association between isokinetic internal rotator and external rotator muscle strength and glenohumeral joint instability in patients with recurrent anterior instability that was not previously treated surgically. We enrolled thirty-seven patients with unilateral recurrent anterior posttraumatic shoulder dislocation and eleven healthy nonathletic subjects in this controlled study. The association between internal rotator and external rotator strength and shoulder instability was analyzed by side-to-side comparisons and comparisons with a control group. Isokinetic internal rotator and external rotator strength was evaluated with a Con-Trex dynamometer, with the subject seated and the shoulder abducted 45° in the scapular plane. Tests were performed at 180°/s, 120°/s, and 60°/s in concentric mode for both sides. Peak torque normalized to body weight and external rotator to internal rotator ratio were calculated for each angular velocity. Clinical and isokinetic evaluation was done by the same rehabilitation physician. The association between shoulder instability and internal rotator and external rotator strength was associated with side-to-side differences (p < 0.05). Compared with a control group, strength values were lower on the pathological shoulder side of the patients with shoulder instability than on the healthy contralateral shoulder of control subjects at 180°/s and 120°/s (p < 0.05). The side-to-side differences were increased when the nondominant upper-extremity side was involved and were decreased when the dominant side was involved. There was no association between glenohumeral joint instability and external rotator to internal rotator ratio. Internal rotator and external rotator weakness was associated with recurrent anterior instability, and side-to-side differences depended on the side of hand dominance. Use of a control group may help in the analysis of the influence of constraints on shoulder strength. Further prospective studies are necessary to determine whether the weakness is a cause or an effect of the instability.

Shoulder girdle muscle activity and fatigue in traditional and improved design carpet weaving workstations.

PubMed

Allahyari, Teimour; Mortazavi, Narges; Khalkhali, Hamid Reza; Sanjari, Mohammad Ali

2016-01-01

Work-related musculoskeletal disorders in the neck and shoulder regions are common among carpet weavers. Working for prolonged hours in a static and awkward posture could result in an increased muscle activity and may lead to musculoskeletal disorders. Ergonomic workstation improvements can reduce muscle fatigue and the risk of musculoskeletal disorders. The aim of this study is to assess and to compare upper trapezius and middle deltoid muscle activity in 2 traditional and improved design carpet weaving workstations. These 2 workstations were simulated in a laboratory and 12 women carpet weavers worked for 3 h. Electromyography (EMG) signals were recorded during work in bilateral upper trapezius and bilateral middle deltoid. The root mean square (RMS) and median frequency (MF) values were calculated and used to assess muscle load and fatigue. Repeated measure ANOVA was performed to assess the effect of independent variables on muscular activity and fatigue. The participants were asked to report shoulder region fatigue on the Borg's Category-Ratio scale (Borg CR-10). Root mean square values in workstation A are significantly higher than in workstation B. Furthermore, EMG amplitude was higher in bilateral trapezius than in bilateral deltoid. However, muscle fatigue was not observed in any of the workstations. The results of the study revealed that muscle load in a traditional workstation was high, but fatigue was not observed. Further studies investigating other muscles involved in carpet weaving tasks are recommended. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

Muscle fatigue in fibromyalgia is in the brain, not in the muscles: a case-control study of perceived versus objective muscle fatigue.

PubMed

Bandak, Elisabeth; Amris, Kirstine; Bliddal, Henning; Danneskiold-Samsøe, Bente; Henriksen, Marius

2013-06-01

To investigate relationships between perceived and objectively measured muscle fatigue during exhausting muscle contractions in women with fibromyalgia (FM) compared with healthy controls (HC). Women with FM and HC completed an isometric muscle exhaustion task at 90° shoulder abduction. Surface electromyographic (EMG) activity in the deltoid muscle was recorded together with self-reported level of muscle fatigue. 25 participants with FM and 23 HC were included. Average time to exhaustion was 254 s shorter in participants with FM than in HC. Participants with FM did not exhibit the same level of objective signs of muscle fatigue, seen as fewer changes in the EMG activity, as the HC during the exhaustion task. The task did not provoke pain in the HC, while participants with FM reported a doubling of pain. Women with FM had shorter exhaustion times and showed fewer objective signs of muscle fatigue during an exhausting isometric shoulder abduction compared with younger HC. This indicates that perceived muscle fatigue may be of central origin and supports the notion of central nervous dysfunction as basic pathological changes in FM.

Assessing physical function in adult acquired major upper-limb amputees by combining the Disabilities of the Arm, Shoulder and Hand (DASH) Outcome Questionnaire and clinical examination.

PubMed

Ostlie, Kristin; Franklin, Rosemary J; Skjeldal, Ola H; Skrondal, Anders; Magnus, Per

2011-10-01

To describe physical function in adult acquired major upper-limb amputees (ULAs) by combining self-assessed arm function and physical measures obtained by clinical examinations; to estimate associations between background factors and self-assessed arm function in ULAs; and to assess whether clinical examination findings may be used to detect reduced arm function in unilateral ULAs. postal questionnaires and clinical examinations. Norwegian ULA population. Clinical examinations performed at 3 clinics. Questionnaires: population-based sample (n=224; 57.4% response rate). Clinical examinations: combined referred sample and convenience sample of questionnaire responders (n=70; 83.3% of those invited). SURVEY inclusion criteria: adult acquired major upper-limb amputation, resident in Norway, mastering of spoken and written Norwegian. Not applicable. The Disabilities of the Arm, Shoulder and Hand (DASH) Outcome Questionnaire, and clinical examination of joint motion and muscle strength with and without prostheses. Mean DASH score was 22.7 (95% confidence interval [CI], 20.3-25.0); in bilateral amputees, 35.7 (95% CI, 23.0-48.4); and in unilateral amputees, 22.1 (95% CI, 19.8-24.5). A lower unilateral DASH score (better function) was associated with paid employment (vs not in paid employment: adjusted regression coefficient [aB]=-5.40, P=.033; vs students: aB=-13.88, P=.022), increasing postamputation time (aB=-.27, P=.001), and Norwegian ethnicity (aB=-14.45, P<.001). At clinical examination, we found a high frequency of impaired neck mobility and varying frequencies of impaired joint motion and strength at the shoulder, elbow, and forearm level. Prosthesis wear was associated with impaired joint motion in all upper-limb joints (P<.006) and with reduced shoulder abduction strength (P=.002). Impaired without-prosthesis joint motion in shoulder flexion (ipsilateral: aB=12.19, P=.001) and shoulder abduction (ipsilateral: aB=12.01, P=.005; contralateral: aB=28.82, P=.004) was associated with increased DASH scores. Upper-limb loss clearly affects physical function. DASH score limitation profiles may be useful in individual clinical assessments. Targeted clinical examination may indicate patients with extra rehabilitational needs. Such examinations may be of special importance in relation to prosthesis function. Copyright © 2011 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Andreas Vesalius' five hundreth anniversary: initiation of the rotator cuff concept.

PubMed

Brinkman, Romy J; Hage, J Joris

2015-12-01

The rotator cuff concept refers to the four scapulohumeral muscles that stabilize and rotate the humerus relative to the scapula. To date, the first description of the rotator cuff remained unidentified. In light of the 500th birthday of Andreas Vesalius (1515-1564) we searched his 1543 masterwork "Fabrica Corporis Humani Libri Septem" for references to the morphology and function of the rotator cuff muscles. Even though he distinguished three rather than four scapulohumeral muscles, Vesalius recognized the need for structures that prevent dislocation of the shoulder inherent to the morphology of the humeral caput and scapular socket. He recorded "three strong ligaments" and the "three muscles that rotate the arm" of which the tendons completely "embrace the ligaments of the joint" as such structures. Vesalius defined the rotator cuff concept avant la lettre.

Development of a 3D workspace shoulder assessment tool incorporating electromyography and an inertial measurement unit-a preliminary study.

PubMed

Aslani, Navid; Noroozi, Siamak; Davenport, Philip; Hartley, Richard; Dupac, Mihai; Sewell, Philip

2018-06-01

Traditional shoulder range of movement (ROM) measurement tools suffer from inaccuracy or from long experimental setup times. Recently, it has been demonstrated that relatively low-cost wearable inertial measurement unit (IMU) sensors can overcome many of the limitations of traditional motion tracking systems. The aim of this study is to develop and evaluate a single IMU combined with an electromyography (EMG) sensor to monitor the 3D reachable workspace with simultaneous measurement of deltoid muscle activity across the shoulder ROM. Six volunteer subjects with healthy shoulders and one participant with a 'frozen' shoulder were recruited to the study. Arm movement in 3D space was plotted in spherical coordinates while the relative EMG intensity of any arm position is presented graphically. The results showed that there was an average ROM surface area of 27291 ± 538 deg 2 among all six healthy individuals and a ROM surface area of 13571 ± 308 deg 2 for the subject with frozen shoulder. All three sections of the deltoid show greater EMG activity at higher elevation angles. Using such tools enables individuals, surgeons and physiotherapists to measure the maximum envelope of motion in conjunction with muscle activity in order to provide an objective assessment of shoulder performance in the voluntary 3D workspace. Graphical abstract The aim of this study is to develop and evaluate a single IMU combined with an electromyography (EMG) sensor to monitor the 3D reachable workspace with simultaneous measurement of deltoid muscle activity across the shoulder ROM. The assessment tool consists of an IMU sensor, an EMG sensor, a microcontroller and a Bluetooth module. The assessment tool was attached to subjects arm. Individuals were instructed to move their arms with the elbow fully extended. They were then asked to provide the maximal voluntary elevation envelope of the arm in 3D space in multiple attempts starting from a small movement envelope going to the biggest possible in four consecutive circuits. The results showed that there was an average ROM surface area of 27291 ± 538 deg2 among all six healthy individuals and a ROM surface area of 13571 ± 308 deg2 for the subject with frozen shoulder. All three sections of the deltoid show greater EMG activity at higher elevation angles. Using such tools enables individuals, surgeons and physiotherapists to measure the maximum envelope of motion in conjunction with muscle activity in order to provide an objective assessment of shoulder performance in the voluntary 3D workspace.

Biomechanical analysis of the circular friction hand massage.

PubMed

Ryu, Jeseong; Son, Jongsang; Ahn, Soonjae; Shin, Isu; Kim, Youngho

2015-01-01

A massage can be beneficial to relieve muscle tension on the neck and shoulder area. Various massage systems have been developed, but their motions are not uniform throughout different body parts nor specifically targeted to the neck and shoulder areas. Pressure pattern and finger movement trajectories of the circular friction hand massage on trapezius, levator scapulae, and deltoid muscles were determined to develop a massage system that can mimic the motion and the pressure of the circular friction massage. During the massage, finger movement trajectories were measured using a 3D motion capture system, and finger pressures were simultaneously obtained using a grip pressure sensor. Results showed that each muscle had different finger movement trajectory and pressure pattern. The trapezius muscle experienced a higher pressure, longer massage time (duration of pressurization), and larger pressure-time integral than the other muscles. These results could be useful to design a better massage system simulating human finger movements.

The side of chronic low back pain matters: evidence from the primary motor cortex excitability and the postural adjustments of multifidi muscles.

PubMed

Massé-Alarie, Hugo; Beaulieu, Louis-David; Preuss, Richard; Schneider, Cyril

2017-03-01

Hemispheric lateralization of pain processing was reported with overactivation of the right frontal lobe. Specifically in chronic low back pain (CLBP), functional changes in the left primary motor cortex (M1) with impaired anticipatory postural activation (APA) of trunk muscles have been observed. Given the connections between frontal and M1 areas for motor planning, it is hypothesized that the pain side could differently influence M1 function and APA of paravertebral multifidus (MF) muscles. This study aimed at testing whether people with right- versus left-sided CLBP showed different M1 excitability and APA. Thirty-five individuals with lateralized CLBP (19 right-sided and 16 left-sided) and 13 pain-free subjects (normative values) were tested for the excitability of MF M1 area (active motor threshold-AMT) with transcranial magnetic stimulation and for the latency of MF APA during bilateral shoulder flexion and during unilateral hip extension in prone lying. In the right-sided CLBP group, the AMT of both M1 areas was lower than in the left-sided group and the pain-free subjects; the latency of MF APA was shorter in bilateral shoulder flexion and in the left hip extension tasks as compared to the left-sided group. In CLBP, an earlier MF APA was correlated with lower AMT in both tasks. People with right-sided CLBP presented with increased M1 excitability in both hemispheres and earlier MF APA. These results likely rely on cortical motor adaptation related to the tasks and axial muscles tested. Future studies should investigate whether CLBP side-related differences have a clinical impact, e.g. in diagnosis and intervention.

Scapular kinematics and shoulder elevation in a traditional push-up.

PubMed

Suprak, David N; Bohannon, Jennifer; Morales, Gabriel; Stroschein, Joseph; San Juan, Jun G

2013-01-01

Proper scapulothoracic motion is critical for the health and function of the shoulder and represents a principal focus in the rehabilitation setting. Variants of the traditional push-up are used frequently to help restore proper scapular kinematics. To date, substantial research has focused on muscle activation levels of rotator cuff and scapular-stabilizing musculature, whereas a dearth of literature exists regarding scapular kinematics during push-up variants. To examine the effect of shoulder position on scapular kinematics across the range of motion (ROM) of a traditional push-up. Cross-sectional study. University laboratory. Sixteen healthy participants without a history of upper extremity or spine injury requiring rehabilitation or surgery. Participants performed a traditional push-up while kinematic measurements were acquired from multiple upper extremity segments. The 3 shoulder position conditions were (1) self-selected position, (2) shoulder adducted upon ascent (at side), and (3) shoulder elevated to approximately 90°. Scapular posterior tilt, upward rotation, and external rotation were examined across elbow-extension ROM and compared across conditions. Posterior tilt was greater in the self-selected and at-side conditions than in the elevated condition and increased linearly with elbow extension. External rotation was greater in the self-selected and at-side conditions compared with that in the elevated condition. In the at-side condition, upward rotation began lower than in the other conditions at the start of the concentric phase but increased above the others soon after the elbow started to extend. Performing a traditional push-up with the shoulders elevated may place the scapula in a position of impingement. Clinicians should be cognizant of shoulder elevation when prescribing and monitoring exercise progression. The results of this study will provide further direction for clinicians in prescribing rehabilitation exercises for the upper extremity, especially closed chain exercises for shoulder conditions.

Effects of 8 Weeks’ Specific Physical Training on the Rotator Cuff Muscle Strength and Technique of Javelin Throwers

PubMed Central

Kim, Hyeyoung; Lee, Youngsun; Shin, Insik; Kim, Kitae; Moon, Jeheon

2014-01-01

[Purpose] For maximum efficiency and to prevent injury during javelin throwing, it is critical to maintain muscle balance and coordination of the rotator cuff and the glenohumeral joint. In this study, we investigated the change in the rotator cuff muscle strength, throw distance and technique of javelin throwers after they had performed a specific physical training that combined elements of weight training, function movement screen training, and core training. [Subjects] Ten javelin throwers participated in this study: six university athletes in the experimental group and four national-level athletes in the control group. [Methods] The experimental group performed 8 weeks of the specific physical training. To evaluate the effects of the training, measurements were performed before and after the training for the experimental group. Measurements comprised anthropometry, isokinetic muscle strength measurements, the function movement screen test, and movement analysis. [Results] After the specific physical training, the function movement screen score and external and internal rotator muscle strength showed statistically significant increases. Among kinematic factors, only pull distance showed improvement after training. [Conclusion] Eight weeks of specific physical training for dynamic stabilizer muscles enhanced the rotator cuff muscle strength, core stability, throw distance, and flexibility of javelin throwers. These results suggest that specific physical training can be useful for preventing shoulder injuries and improving the performance for javelin throwers. PMID:25364111

Effects of 8 weeks' specific physical training on the rotator cuff muscle strength and technique of javelin throwers.

PubMed

Kim, Hyeyoung; Lee, Youngsun; Shin, Insik; Kim, Kitae; Moon, Jeheon

2014-10-01

[Purpose] For maximum efficiency and to prevent injury during javelin throwing, it is critical to maintain muscle balance and coordination of the rotator cuff and the glenohumeral joint. In this study, we investigated the change in the rotator cuff muscle strength, throw distance and technique of javelin throwers after they had performed a specific physical training that combined elements of weight training, function movement screen training, and core training. [Subjects] Ten javelin throwers participated in this study: six university athletes in the experimental group and four national-level athletes in the control group. [Methods] The experimental group performed 8 weeks of the specific physical training. To evaluate the effects of the training, measurements were performed before and after the training for the experimental group. Measurements comprised anthropometry, isokinetic muscle strength measurements, the function movement screen test, and movement analysis. [Results] After the specific physical training, the function movement screen score and external and internal rotator muscle strength showed statistically significant increases. Among kinematic factors, only pull distance showed improvement after training. [Conclusion] Eight weeks of specific physical training for dynamic stabilizer muscles enhanced the rotator cuff muscle strength, core stability, throw distance, and flexibility of javelin throwers. These results suggest that specific physical training can be useful for preventing shoulder injuries and improving the performance for javelin throwers.

Interposition Dermal Matrix Xenografts: A Successful Alternative to Traditional Treatment of Massive Rotator Cuff Tears.

PubMed

Neumann, Julie A; Zgonis, Miltiadis H; Rickert, Kathleen D; Bradley, Kendall E; Kremen, Thomas J; Boggess, Blake R; Toth, Alison P

2017-05-01

Management of massive rotator cuff tears in shoulders without glenohumeral arthritis remains problematic for surgeons. Repairs of massive rotator cuff tears have failure rates of 20% to 94% at 1 to 2 years postoperatively as demonstrated with arthrography, ultrasound, and magnetic resonance imaging. Additionally, inconsistent outcomes have been reported with debridement alone of massive rotator cuff tears, and limitations have been seen with other current methods of operative intervention, including arthroplasty and tendon transfers. The use of interposition porcine acellular dermal matrix xenograft in patients with massive rotator cuff tears will result in improved subjective outcomes, postoperative pain, function, range of motion, and strength. Case series; Level of evidence, 4. Sixty patients (61 shoulders) were prospectively observed for a mean of 50.3 months (range, 24-63 months) after repair of massive rotator cuff tears with porcine acellular dermal matrix xenograft as an interposition graft. Subjective outcome data were obtained with visual analog scale for pain score (0-10, 0 = no pain) and Modified American Shoulder and Elbow Surgeons (MASES) score. Active range of motion in flexion, external rotation, and internal rotation were recorded. Strength in the supraspinatus and infraspinatus muscles was assessed manually on a 10-point scale and by handheld dynamometer. Ultrasound was used to assess the integrity of the repair during latest follow-up. Mean visual analog scale pain score decreased from 4.0 preoperatively to 1.0 postoperatively ( P < .001). Mean active forward flexion improved from 140.7° to 160.4° ( P < .001), external rotation at 0° of abduction from 55.6° to 70.1° ( P = .001), and internal rotation at 90° of abduction from 52.0° to 76.2° ( P < .001). Supraspinatus manual strength increased from 7.7 to 8.8 ( P < .001) and infraspinatus manual strength from 7.7 to 9.3 ( P < .001). Mean dynamometric strength in forward flexion was 77.7 N in nonoperative shoulders (shoulder that did not undergo surgery) and 67.8 N ( P < .001) in operative shoulders (shoulder that underwent rotator cuff repair with interposition porcine dermal matrix xenograft). Mean dynamometric strength in external rotation was 54.5 N in nonoperative shoulders and 50.1 N in operative shoulders ( P = .04). Average postoperative MASES score was 87.8. Musculoskeletal ultrasound showed that 91.8% (56 of 61) of repairs were fully intact; 3.3% (2 of 61), partially intact; and 4.9% (3 of 61), not intact. Patients who underwent repair of massive rotator cuff tears with interposition porcine acellular dermal matrix graft have good subjective function as assessed by the MASES score. Patients have significant improvement in pain, range of motion, and manual muscle strength. Postoperative ultrasound demonstrated that the repair was completely intact in 91.8% of patients, a vast improvement compared with results previously reported for primary repairs of massive rotator cuff tears.

Biomechanical effects of mobile computer location in a vehicle cab.

PubMed

Saginus, Kyle A; Marklin, Richard W; Seeley, Patricia; Simoneau, Guy G; Freier, Stephen

2011-10-01

The objective of this research is to determine the best location to place a conventional mobile computer supported by a commercially available mount in a light truck cab. U.S. and Canadian electric utility companies are in the process of integrating mobile computers into their fleet vehicle cabs. There are no publications on the effect of mobile computer location in a vehicle cab on biomechanical loading, performance, and subjective assessment. The authors tested four locations of mobile computers in a light truck cab in a laboratory study to determine how location affected muscle activity of the lower back and shoulders; joint angles of the shoulders, elbows, and wrist; user performance; and subjective assessment. A total of 22 participants were tested in this study. Placing the mobile computer closer to the steering wheel reduced low back and shoulder muscle activity. Joint angles of the shoulders, elbows, and wrists were also closer to neutral angle. Biomechanical modeling revealed substantially less spinal compression and trunk muscle force. In general, there were no practical differences in performance between the locations. Subjective assessment indicated that users preferred the mobile computer to be as close as possible to the steering wheel. Locating the mobile computer close to the steering wheel reduces risk of injuries, such as low back pain and shoulder tendonitis. Results from the study can guide electric utility companies in the installation of mobile computers into vehicle cabs. Results may also be generalized to other industries that use trucklike vehicles, such as construction.

Does taping in addition to physiotherapy improve the outcomes in subacromial impingement syndrome? A systematic review.

PubMed

Saracoglu, Ismail; Emuk, Yusuf; Taspinar, Ferruh

2018-04-01

Taping is used with or without other interventions for many purposes, especially to manage pain and improve functional activity in patients with shoulder pain. The aim of this review was to determine whether any taping technique in addition to physiotherapy care is more effective than physiotherapy care alone in patients with shoulder impingement syndrome. A systematic search of Cochrane Database of Systematic Review, MEDLINE (EBSCO), Physiotherapy Evidence Database (PEDro), CINAHL (EBSCO), PUBMED, AMED, EMBASE (OVID), The Kinesio Kinesio® Taping Method, Kinesio® Tex Tape UK and International websites ( www.kinesiotaping.co.uk ; www.kinesiotaping.com ) was conducted to June 2015. The outcome measures were pain, disability, range of motion and muscle strength. As data were not suitable for meta-analysis, narrative synthesis were applied. Three randomized controlled trials and one controlled trial (135 patients) were included. The results were conflicting and weak on the effectiveness of taping as an adjunct therapy for improvement of pain, disability, range of motion and muscle strength. Clinical taping in addition to physiotherapy interventions (e.g. exercise, electrotherapy, and manual therapy) might be an optional modality for managing patients with shoulder impingement syndrome, especially for the initial stage of the treatment; however, we need further robust, placebo controlled and consistent studies to prove whether it is more effective than physiotherapy interventions without taping.

How sensitive is the deltoid moment arm to humeral offset changes with reverse total shoulder arthroplasty?

PubMed

Walker, David R; Kinney, Allison L; Wright, Thomas W; Banks, Scott A

2016-06-01

Reverse total shoulder arthroplasty commonly treats cuff-deficient or osteoarthritic shoulders not amenable to rotator cuff repair. This study investigates deltoid moment arm sensitivity to variations in the joint center and humeral offset of 3 representative reverse total shoulder arthroplasty subjects. We hypothesized that a superior joint implant placement may exist, indicated by muscle moment arms, compared with the current actual surgical implant configuration. Moment arms for the anterior, lateral, and posterior aspects of the deltoid muscle were determined for 1521 perturbations of the humeral offset location away from the surgical placement in a subject-specific musculoskeletal model with motion defined by subject-specific in vivo abduction kinematics. The humeral offset was varied from its surgical position ±4 mm in the anterior/posterior direction, ±12 mm in the medial/lateral direction, and -10 to 14 mm in the superior/inferior direction. The anterior deltoid moment arm varied in humeral offset and center of rotation up to 20 mm, primarily in the medial/lateral and superior/inferior directions. The lateral deltoid moment arm varied in humeral offset up to 20 mm, primarily in the medial/lateral and anterior/posterior directions. The posterior deltoid moment arm varied up to 15 mm, primarily in early abduction, and was most sensitive to humeral offset changes in the superior/inferior direction. High variations in muscle moment arms were found for all 3 deltoid components, presenting an opportunity to dramatically change the deltoid moment arms through surgical placement of the reverse shoulder components and by varying the overall offset of the humerus. Basic Science Study; Computer Modeling. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Effect of a 6-week strengthening program on shoulder and scapular-stabilizer strength and scapular kinematics in division I collegiate swimmers.

PubMed

Hibberd, Elizabeth E; Oyama, Saki; Spang, Jeffrey T; Prentice, William; Myers, Joseph B

2012-08-01

Shoulder injuries are common in swimmers because of the demands of the sport. Muscle imbalances frequently exist due to the biomechanics of the sport, which predispose swimmers to injury. To date, an effective shoulder-injury-prevention program for competitive swimmers has not been established. To assess the effectiveness of a 6-wk strengthening and stretching intervention program on improving glenohumeral and scapular muscle strength and scapular kinematics in collegiate swimmers. Randomized control trial. University biomechanics research laboratory. Forty-four Division I collegiate swimmers. The intervention program was completed 3 times per week for 6 wk. The program included strengthening exercises completed using resistance tubing-scapular retraction (Ts), scapular retraction with upward rotation (Ys), scapular retraction with downward rotation (Ws), shoulder flexion, low rows, throwing acceleration and deceleration, scapular punches, shoulder internal rotation at 90° abduction, and external rotation at 90° abduction-and 2 stretching exercises: corner stretch and sleeper stretch. Scapular kinematics and glenohumeral and scapular muscle strength assessed preintervention and postintervention. There were no significant between-groups differences in strength variables at pre/post tests, although shoulder-extension and internal-rotation strength significantly increased in all subjects regardless of group assignment. Scapular kinematic data revealed increased scapular internal rotation, protraction, and elevation in all subjects at posttesting but no significant effect of group on the individual kinematic variables. The current strengthening and stretching program was not effective in altering strength and scapular kinematic variables but may serve as a framework for future programs. Adding more stretching exercises, eliminating exercises that overlap with weight-room training and swim training, and timing of implementation may yield a more beneficial program for collegiate swimmers.

Botulinum toxin type a injections for cervical and shoulder girdle myofascial pain using an enriched protocol design.

PubMed

Nicol, Andrea L; Wu, Irene I; Ferrante, F Michael

2014-06-01

Myofascial pain syndrome is a regional condition of muscle pain and stiffness and is classically characterized by the presence of trigger points in affected musculature. Botulinum toxin type A (BoNT-A) has been shown to have antinociceptive properties and elicit sustained muscle relaxation, thereby possibly affording even greater relief than traditional strategies. Our goal was to determine whether direct injection of BoNT-A into painful muscle groups is effective for cervical and shoulder girdle myofascial pain. An enriched protocol design was used, wherein 114 patients with cervical and shoulder girdle myofascial pain underwent injection of BoNT-A to determine their response to the drug. Fifty-four responders were then enrolled in a 12-week, randomized, double-blind, placebo-controlled trial. Pain scales and quality of life measures were assessed at baseline and at routine follow-up visits until completion of the study after 26 weeks. Injection of BoNT-A into painful muscle groups improved average visual numerical pain scores in subjects who received a second dose of BoNT-A compared to placebo (P = 0.019 [0.26, 2.78]). Subjects who received a second dose of BoNT-A had a reduced number of headaches per week (P = 0.04 [0.07, 4.55]). Brief Pain Inventory interference scores for general activity and sleep were improved (P = 0.046 [0.038, 3.700] and 0.02 [0.37, 4.33], respectively) in those who received a second dose of BoNT-A. BoNT-A injected directly into painful muscle groups improves average pain scores and certain aspects of quality of life in patients experiencing severe cervical and shoulder girdle myofascial pain.

Multi-muscle FES force control of the human arm for arbitrary goals.

PubMed

Schearer, Eric M; Liao, Yu-Wei; Perreault, Eric J; Tresch, Matthew C; Memberg, William D; Kirsch, Robert F; Lynch, Kevin M

2014-05-01

We present a method for controlling a neuroprosthesis for a paralyzed human arm using functional electrical stimulation (FES) and characterize the errors of the controller. The subject has surgically implanted electrodes for stimulating muscles in her shoulder and arm. Using input/output data, a model mapping muscle stimulations to isometric endpoint forces measured at the subject's hand was identified. We inverted the model of this redundant and coupled multiple-input multiple-output system by minimizing muscle activations and used this inverse for feedforward control. The magnitude of the total root mean square error over a grid in the volume of achievable isometric endpoint force targets was 11% of the total range of achievable forces. Major sources of error were random error due to trial-to-trial variability and model bias due to nonstationary system properties. Because the muscles working collectively are the actuators of the skeletal system, the quantification of errors in force control guides designs of motion controllers for multi-joint, multi-muscle FES systems that can achieve arbitrary goals.

Relationship between scapular muscle and core endurance in healthy subjects.

PubMed

Hazar Kanik, Zeynep; Pala, Omer Osman; Gunaydin, Gurkan; Sozlu, Ugur; Alkan, Zeynep Beyza; Basar, Selda; Citaker, Seyit

2017-01-01

Scapular muscle endurance and core endurance reportedly influence shoulder injury risk. The exact relationship between scapular muscle endurance and core endurance, and how they impact one another in the healthy subjects remain unclear. To investigate the relationship between scapular muscle endurance and core endurance in healthy subjects. Fifty healthy volunteers (23 males, 27 females; mean age 20.42 ± 1.04 years) were participated in this study. Endurance of the serratus anterior and trapezius muscles was assessed using the scapular muscle endurance test. Sorensen test (endurance of trunk extensor muscles), trunk flexor endurance test, and side bridge test (endurance of lateral core muscles) were conducted to assess the core endurance. Pearson's product moment correlations examined relationships between scapular muscle endurance and each of the core endurance tests scores. Scapular muscle endurance test scores showed a positive correlation with the side bridge test scores (r = 0.414; p = 0.003). No significant correlation was found between scapular muscle endurance test scores and the other core endurance tests scores (p > 0.05). There appears to be a link between the scapular muscle endurance and lateral core muscles in healthy subjects; however, more research is needed to provide a definitive answer on the nature of this relationship. Further studies involving patients with shoulder pathology are warranted.

Load emphasizes muscle effort minimization during selection of arm movement direction

PubMed Central

2012-01-01

Background Directional preferences during center-out horizontal shoulder-elbow movements were previously established for both the dominant and non-dominant arm with the use of a free-stroke drawing task that required random selection of movement directions. While the preferred directions were mirror-symmetrical in both arms, they were attributed to a tendency specific for the dominant arm to simplify control of interaction torque by actively accelerating one joint and producing largely passive motion at the other joint. No conclusive evidence has been obtained in support of muscle effort minimization as a contributing factor to the directional preferences. Here, we tested whether distal load changes directional preferences, making the influence of muscle effort minimization on the selection of movement direction more apparent. Methods The free-stroke drawing task was performed by the dominant and non-dominant arm with no load and with 0.454 kg load at the wrist. Motion of each arm was limited to rotation of the shoulder and elbow in the horizontal plane. Directional histograms of strokes produced by the fingertip were calculated to assess directional preferences in each arm and load condition. Possible causes for directional preferences were further investigated by studying optimization across directions of a number of cost functions. Results Preferences in both arms to move in the diagonal directions were revealed. The previously suggested tendency to actively accelerate one joint and produce passive motion at the other joint was supported in both arms and load conditions. However, the load increased the tendency to produce strokes in the transverse diagonal directions (perpendicular to the forearm orientation) in both arms. Increases in required muscle effort caused by the load suggested that the higher frequency of movements in the transverse directions represented increased influence of muscle effort minimization on the selection of movement direction. This interpretation was supported by cost function optimization results. Conclusions While without load, the contribution of muscle effort minimization was minor, and therefore, not apparent, the load revealed this contribution by enhancing it. Unlike control of interaction torque, the revealed tendency to minimize muscle effort was independent of arm dominance. PMID:23035925

Muscular Dystrophy

MedlinePlus

... be affected. Limb-girdle muscular dystrophy (LGMD) affects boys and girls equally, weakening muscles in the shoulders and upper ... weakness and poor muscle tone. Occurring in both girls and boys, it can have different symptoms. It varies in ...

Development and evaluation of a soft wearable weight support device for reducing muscle fatigue on shoulder

PubMed Central

Cho, Kyu-Jin

2017-01-01

Compensating the weight of human limbs is important in reducing muscle fatigue experienced by manual laborers. In this study, a compact and lightweight soft wearable weight support device was developed and evaluated. The device supports gravitational force on the shoulder at any arm posture, although there are some limitations in its assistive performance. The device actuator consists of a cam-rod structure, a tendon-driven mechanism, and a rubber band. The desired assistive torque is translated to the shoulder joint along a tendon routing structure. Device performance was evaluated by measuring muscle activation in with-assist and without-assist conditions. Muscle activation on the deltoid was measured by surface electromyography. An experimental protocol consisting of a series of exercises was executed with six healthy subjects. The subjects raised and lowered their arm from 0 to 100 degrees for 30 times under eight conditions, which were combined with-assist and without-assist conditions, and holding the horizontal angle of the arm at 0, 30, 60, or 90 degrees against the sagittal plane. Surface electromyography data were pre-processed and analyzed using a root mean square method. When muscle fatigue occurs, the root mean square of the surface electromyography increases nonlinearly. This was calculated using the standard deviation of the root mean square. Three of six subjects showed decreased variation of the root mean square between the exercises in the with-assist condition. One subject’s result was significantly reduced (by about 57.6%) in the with-assist condition. In contrast, two subjects did not show significant difference between measurements taken in the with-assist and without-assist conditions. One subject was dropped from the experiment because the device did not fit the subject’s body. In conclusion, the effectiveness of the soft wearable weight support device in supporting shoulder movements was verified through the decreased variation of muscle activation. PMID:28291825

Development and evaluation of a soft wearable weight support device for reducing muscle fatigue on shoulder.

PubMed

Park, Daegeun; Cho, Kyu-Jin

2017-01-01

Compensating the weight of human limbs is important in reducing muscle fatigue experienced by manual laborers. In this study, a compact and lightweight soft wearable weight support device was developed and evaluated. The device supports gravitational force on the shoulder at any arm posture, although there are some limitations in its assistive performance. The device actuator consists of a cam-rod structure, a tendon-driven mechanism, and a rubber band. The desired assistive torque is translated to the shoulder joint along a tendon routing structure. Device performance was evaluated by measuring muscle activation in with-assist and without-assist conditions. Muscle activation on the deltoid was measured by surface electromyography. An experimental protocol consisting of a series of exercises was executed with six healthy subjects. The subjects raised and lowered their arm from 0 to 100 degrees for 30 times under eight conditions, which were combined with-assist and without-assist conditions, and holding the horizontal angle of the arm at 0, 30, 60, or 90 degrees against the sagittal plane. Surface electromyography data were pre-processed and analyzed using a root mean square method. When muscle fatigue occurs, the root mean square of the surface electromyography increases nonlinearly. This was calculated using the standard deviation of the root mean square. Three of six subjects showed decreased variation of the root mean square between the exercises in the with-assist condition. One subject's result was significantly reduced (by about 57.6%) in the with-assist condition. In contrast, two subjects did not show significant difference between measurements taken in the with-assist and without-assist conditions. One subject was dropped from the experiment because the device did not fit the subject's body. In conclusion, the effectiveness of the soft wearable weight support device in supporting shoulder movements was verified through the decreased variation of muscle activation.

Effects of non-paretic arm exercises using a tubing band on abdominal muscle activity in stroke patients.

PubMed

Lee, Dong-Kyu; Kang, Min-Hyeok; Kim, Ji-Won; Kim, Yang-Gon; Park, Ji-Hyuk; Oh, Jae-Seop

2013-01-01

Abdominal strengthening exercises are important for stroke patients; however, there is a lack of research on therapeutic exercises for increasing abdominal muscle activity in stroke patients. We investigated the effects of non-paretic arm exercises using a tubing band on abdominal muscle activity in stroke patients. In total, 18 hemiplegic subjects (13 males, 5 females) were recruited. All subjects performed non-paretic arm exercises involving three different shoulder movements (extension, flexion, and horizontal abduction) using an elastic tubing band. Surface electromyography (EMG) signals were recorded from the rectus abdominis (RA), external oblique (EO), and internal oblique (IO) muscles bilaterally during non-paretic arm exercises. EMG activities of abdominal muscles during non-paretic arm extension and horizontal abduction were increased significantly versus shoulder flexion when subjects performed the arm exercise in a seated position. Muscle activity of the EO was significantly greater in the paretic than the non-paretic side during non-paretic arm extension and horizontal abduction. We suggest that non-paretic arm extension and horizontal abduction exercises using an elastic tubing band may be effective in increasing abdominal muscle activity.

A slouched body posture decreases arm mobility and changes muscle recruitment in the neck and shoulder region.

PubMed

Malmström, Eva-Maj; Olsson, Joakim; Baldetorp, Johan; Fransson, Per-Anders

2015-12-01

Long-term use of unfavorable postures, congenital deformations and degenerative processes associated with aging or disease may generate an increased thoracic curvature resulting in pain and disability. We wanted to examine whether a slouched postural alignment with increased thoracic kyphosis changes the shoulder kinematics and muscle activity in upper trapezius (UT), lower trapezius (LT) and serratus anterior (SA) during arm elevation. The aim was to determine if a slouched posture influences range of motion, muscle activation patterns, maximal muscle activity and the total muscle work required when performing arm elevations. Twelve male subjects (23.3 ± 1.5 years) performed maximum arm elevations in upright and slouched postures. A combined 3D movement and EMG system recorded arm movements and spine curvature simultaneously with EMG activity in the UT, LT and SA. Slouched posture affected the biomechanical conditions by significantly decreasing maximum arm elevation by ~15° (p < 0.001) and decreasing arm movement velocity by ~8 % during movements upwards (p < 0.001) and downwards (p = 0.034). The peak muscle activity increased in all muscles: UT (p = 0.034, +32.3 %), LT (p = 0.001, +48.6 %) and SA (p = 0.007, +20.9 %). The total muscle work increased significantly in the slouched posture during movements upwards: UT (p = 0.003, +36.6 %), LT (p < 0.001, +89.0 %), SA (p = 0.002, +19.4 %) and downwards: UT (p = 0.012, +29.8 %) and LT (p < 0.001, +122.5 %). An increased thoracic kyphosis was found associated with marked increased physical costs when performing arm movements. Hence, patients suffering from neck-shoulder pain and disability should be investigated and treated for defective thoracic curvature issues.

Treatment related impairments in arm and shoulder in patients with breast cancer: a systematic review.

PubMed

Hidding, Janine T; Beurskens, Carien H G; van der Wees, Philip J; van Laarhoven, Hanneke W M; Nijhuis-van der Sanden, Maria W G

2014-01-01

Breast cancer is the most common type of cancer in women in the developed world. As a result of breast cancer treatment, many patients suffer from serious complaints in their arm and shoulder, leading to limitations in activities of daily living and participation. In this systematic literature review we present an overview of the adverse effects of the integrated breast cancer treatment related to impairment in functions and structures in the upper extremity and upper body and limitations in daily activities. Patients at highest risk were defined. We conducted a systematic literature search using the databases of PubMed, Embase, CINAHL and Cochrane from 2000 to October 2012, according to the PRISMA guidelines. Included were studies with patients with stage I-III breast cancer, treated with surgery and additional treatments (radiotherapy, chemotherapy and hormonal therapy). The following health outcomes were extracted: reduced joint mobility, reduced muscle strength, pain, lymphedema and limitations in daily activities. Outcomes were divided in within the first 12 months and >12 months post-operatively. Patients treated with ALND are at the highest risk of developing impairments of the arm and shoulder. Reduced ROM and muscle strength, pain, lymphedema and decreased degree of activities in daily living were reported most frequently in relation to ALND. Lumpectomy was related to a decline in the level of activities of daily living. Radiotherapy and hormonal therapy were the main risk factors for pain. Patients treated with ALND require special attention to detect and consequently address impairments in the arm and shoulder. Patients with pain should be monitored carefully, because pain limits the degree of daily activities. Future research has to describe a complete overview of the medical treatment and analyze outcome in relation to the treatment. Utilization of uniform validated measurement instruments has to be encouraged.

Rotator cuff strength balance in glovebox workers

DOE PAGES

Lawton, Cindy M.; Weaver, Amelia M.; Chan, Martha Kwan Yi; ...

2016-11-23

Gloveboxes are essential to the pharmaceutical, semi-conductor, nuclear, and biochemical industries. While gloveboxes serve as effective containment systems, they are often difficult to work in and present a number of ergonomic hazards. One such hazard is injury to the rotator cuff, a group of tendons and muscles in the shoulder, connecting the upper arm to the shoulder blade. Rotator cuff integrity is critical to shoulder health. This study compared the rotator cuff muscle strength ratios of glovebox workers to the healthy norm. Descriptive statistics were collected using a short questionnaire. Handheld dynamometry was used to quantify the ratio of forcesmore » produced for shoulder internal and external rotation. Results showed this population to have shoulder strength ratios significantly different from the healthy norm. Strength ratios were found to be a sound predictor of symptom incidence. The deviation from the normal ratio demonstrates the need for solutions designed to reduce the workload on the rotator cuff musculature in order to improve health and safety. Assessment of strength ratios can be used to screen for risk of symptom development. As a result, this increases technical knowledge and augments operational safety.« less

Rotator cuff strength balance in glovebox workers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lawton, Cindy M.; Weaver, Amelia M.; Chan, Martha Kwan Yi

Gloveboxes are essential to the pharmaceutical, semi-conductor, nuclear, and biochemical industries. While gloveboxes serve as effective containment systems, they are often difficult to work in and present a number of ergonomic hazards. One such hazard is injury to the rotator cuff, a group of tendons and muscles in the shoulder, connecting the upper arm to the shoulder blade. Rotator cuff integrity is critical to shoulder health. This study compared the rotator cuff muscle strength ratios of glovebox workers to the healthy norm. Descriptive statistics were collected using a short questionnaire. Handheld dynamometry was used to quantify the ratio of forcesmore » produced for shoulder internal and external rotation. Results showed this population to have shoulder strength ratios significantly different from the healthy norm. Strength ratios were found to be a sound predictor of symptom incidence. The deviation from the normal ratio demonstrates the need for solutions designed to reduce the workload on the rotator cuff musculature in order to improve health and safety. Assessment of strength ratios can be used to screen for risk of symptom development. As a result, this increases technical knowledge and augments operational safety.« less

Overhead work and shoulder-neck pain in orchard farmers harvesting pears and apples.

PubMed

Sakakibara, H; Miyao, M; Kondo, T; Yamada, S

1995-04-01

The effects of overhead work were studied by comparing orchard farmers' musculoskeletal symptoms while bagging pears with those same symptoms while bagging apples. The subjects were 52 Japanese female farmers, who were examined twice an evening in late June for bagging pears, and during another evening of late July for bagging apples, when each task had been almost finished. They were questioned about musculoskeletal complaints of stiffness and pain during each job, and examined for muscle tenderness and pain from joint movement. Arm elevation angles during the work were measured for each type of bagging. The prevalence of stiffness and pain in the neck and shoulder, muscle tenderness in the shoulder regions, and pain in neck motion were found to be significantly higher when bagging pears than apples. Musculoskeletal symptoms of parts other than the neck and shoulder did not differ between the two types of bagging. The working posture of elevating the arm more than 90 degrees was assumed to account for 75% of the time bagging pears, against 40% for bagging apples. Overhead work requiring arm elevation and head extension was considered to be closely related with shoulder-neck disorders among farmers.

Cardiopulmonary fitness and muscle strength in patients with osteogenesis imperfecta type I.

PubMed

Takken, Tim; Terlingen, Heike C; Helders, Paul J M; Pruijs, Hans; Van der Ent, Cornelis K; Engelbert, Raoul H H

2004-12-01

To evaluate cardiopulmonary function, muscle strength, and cardiopulmonary fitness (VO 2 peak) in patients with osteogenesis imperfecta (OI). In 17 patients with OI type I (mean age 13.3 +/- 3.9 years) cardiopulmonary function was assessed at rest using spirometry, plethysmography, electrocardiography, and echocardiography. Exercise capacity was measured using a maximal exercise test on a bicycle ergometer and an expired gas analysis system. Muscle strength in shoulder abductors, hip flexors, ankle dorsal flexor, and grip strength were measured. All results were compared with reference values. Cardiopulmonary function at rest was within normal ranges, but when it was compared with normal height for age and sex, vital capacities were reduced. Mean absolute and relative VO 2 peak were respectively -1.17 (+/- 0.67) and -1.41 (+/- 1.52) standard deviations lower compared with reference values ( P < .01). Muscle strength also was significantly reduced in patients with OI, ranging from -1.24 +/- 1.40 to -2.88 +/- 2.67 standard deviations lower compared with reference values. In patients with OI type I, no pulmonary or cardiac abnormalities at rest were found. The exercise tolerance and muscle strength were significantly reduced in patients with OI, which might account for their increased levels of fatigue during activities of daily living.

Neuromuscular responses during aquatic resistance exercise with different devices and depths.

PubMed

Colado, Juan C; Borreani, Sebastien; Pinto, Stephanie Santana; Tella, Victor; Martin, Fernando; Flandez, Jorge; Kruel, Luiz F

2013-12-01

Little research has been reported regarding the effects of using different devices and immersion depths during the performance of resistance exercises in a water environment. The purpose of this study was to compare muscular activation of upper extremity and core muscles during shoulder extensions performed at maximum velocity with different devices and at different depths. Volunteers (N = 24) young fit male university students performed 3 repetitions of shoulder extensions at maximum velocity using 4 different devices and at 2 different depths. The maximum amplitude of the electromyographic root mean square of the latissimus dorsi (LD), rectus abdominis, and erector lumbar spinae was recorded. Electromyographic signals were normalized to the maximum voluntary isometric contraction. No significant (p > 0.05) differences were found in the neuromuscular responses between the different devices used during the performance of shoulder extension at xiphoid process depth. Regarding the comparisons of muscle activity between the 2 depths analyzed in this study, only the LD showed a significantly (p ≤ 0.05) higher activity at the xiphoid process depth compared with that at the clavicle depth. Therefore, if maximum muscle activation of the extremities is required, the xiphoid depth is a better choice than clavicle depth, and the kind of device is not relevant. Regarding core muscles, neither the kind of device nor the immersion depth modifies muscle activation.

Increased Upper Trapezius Muscle Stiffness in Overhead Athletes with Rotator Cuff Tendinopathy

PubMed Central

Leong, Hio Teng; Hug, François; Fu, Siu Ngor

2016-01-01

Although excessive tension of the upper trapezius (UT) is thought to contribute to rotator cuff tendinopathy, no study examined UT tension in athletes with and without rotator cuff tendinopathy. Here we used UT shear modulus measured using ultrasound shear wave elastography as an index of muscle stiffness/tension. The aims of this study were twofold: 1) to determine whether the UT muscle shear modulus is altered in athletes with rotator cuff tendinopathy compared to asymptomatic athletes, and 2) to detect optimal cut-off points of UT shear modulus in identifying athletes with rotator cuff tendinopathy. Forty-three male volleyball players (17 asymptomatic and 26 with rotator cuff tendinopathy, mean age = 22.9±3.5 years) participated in the study. UT shear modulus was quantified during active arm holding at 30° and 60° of shoulder abduction and passive arm positioning at 0°, 30° and 60° of shoulder abduction. During the active tasks, the UT shear modulus was higher in athletes with rotator cuff tendinopathy than the asymptomatic athletes (p = 0.002), regardless the arm position. During the passive tasks, athletes with rotator cuff tendinopathy exhibited a higher UT shear modulus than asymptomatic athletes only at 0° of shoulder abduction (13.0±2.5 kPa vs 10.2±1.8 kPa, p = 0.001). When considering the active task, an optimal cut-off shear modulus of 12.0 kPa at 30° of shoulder abduction (sensitivity = 0.84, specificity = 0.57, AUC = 0.757, p = 0.008) and 9.5 kPa at 60° of shoulder abduction (sensitivity = 0.88, specificity = 0.67, AUC = 0.816, p = 0.002) was detected. When considering the passive task at 0° of shoulder abduction, a cut-off of 12.2 kPa was found (sensitivity = 0.73, AUC = 0.817, p = 0.001). Findings from the present study show that monitoring passive and active UT muscle shear modulus may provide important information for the prevention/rehabilitation of rotator cuff tendinopathy. PMID:27159276

Increased Upper Trapezius Muscle Stiffness in Overhead Athletes with Rotator Cuff Tendinopathy.

PubMed

Leong, Hio Teng; Hug, François; Fu, Siu Ngor

2016-01-01

Although excessive tension of the upper trapezius (UT) is thought to contribute to rotator cuff tendinopathy, no study examined UT tension in athletes with and without rotator cuff tendinopathy. Here we used UT shear modulus measured using ultrasound shear wave elastography as an index of muscle stiffness/tension. The aims of this study were twofold: 1) to determine whether the UT muscle shear modulus is altered in athletes with rotator cuff tendinopathy compared to asymptomatic athletes, and 2) to detect optimal cut-off points of UT shear modulus in identifying athletes with rotator cuff tendinopathy. Forty-three male volleyball players (17 asymptomatic and 26 with rotator cuff tendinopathy, mean age = 22.9±3.5 years) participated in the study. UT shear modulus was quantified during active arm holding at 30° and 60° of shoulder abduction and passive arm positioning at 0°, 30° and 60° of shoulder abduction. During the active tasks, the UT shear modulus was higher in athletes with rotator cuff tendinopathy than the asymptomatic athletes (p = 0.002), regardless the arm position. During the passive tasks, athletes with rotator cuff tendinopathy exhibited a higher UT shear modulus than asymptomatic athletes only at 0° of shoulder abduction (13.0±2.5 kPa vs 10.2±1.8 kPa, p = 0.001). When considering the active task, an optimal cut-off shear modulus of 12.0 kPa at 30° of shoulder abduction (sensitivity = 0.84, specificity = 0.57, AUC = 0.757, p = 0.008) and 9.5 kPa at 60° of shoulder abduction (sensitivity = 0.88, specificity = 0.67, AUC = 0.816, p = 0.002) was detected. When considering the passive task at 0° of shoulder abduction, a cut-off of 12.2 kPa was found (sensitivity = 0.73, AUC = 0.817, p = 0.001). Findings from the present study show that monitoring passive and active UT muscle shear modulus may provide important information for the prevention/rehabilitation of rotator cuff tendinopathy.

Deregulation of the Protocadherin Gene FAT1 Alters Muscle Shapes: Implications for the Pathogenesis of Facioscapulohumeral Dystrophy

PubMed Central

Caruso, Nathalie; Herberth, Balàzs; Bartoli, Marc; Puppo, Francesca; Dumonceaux, Julie; Zimmermann, Angela; Denadai, Simon; Lebossé, Marie; Roche, Stephane; Geng, Linda; Magdinier, Frederique; Attarian, Shahram; Bernard, Rafaelle; Maina, Flavio; Levy, Nicolas; Helmbacher, Françoise

2013-01-01

Generation of skeletal muscles with forms adapted to their function is essential for normal movement. Muscle shape is patterned by the coordinated polarity of collectively migrating myoblasts. Constitutive inactivation of the protocadherin gene Fat1 uncoupled individual myoblast polarity within chains, altering the shape of selective groups of muscles in the shoulder and face. These shape abnormalities were followed by early onset regionalised muscle defects in adult Fat1-deficient mice. Tissue-specific ablation of Fat1 driven by Pax3-cre reproduced muscle shape defects in limb but not face muscles, indicating a cell-autonomous contribution of Fat1 in migrating muscle precursors. Strikingly, the topography of muscle abnormalities caused by Fat1 loss-of-function resembles that of human patients with facioscapulohumeral dystrophy (FSHD). FAT1 lies near the critical locus involved in causing FSHD, and Fat1 mutant mice also show retinal vasculopathy, mimicking another symptom of FSHD, and showed abnormal inner ear patterning, predictive of deafness, reminiscent of another burden of FSHD. Muscle-specific reduction of FAT1 expression and promoter silencing was observed in foetal FSHD1 cases. CGH array-based studies identified deletion polymorphisms within a putative regulatory enhancer of FAT1, predictive of tissue-specific depletion of FAT1 expression, which preferentially segregate with FSHD. Our study identifies FAT1 as a critical determinant of muscle form, misregulation of which associates with FSHD. PMID:23785297

Throwing Injuries of the Shoulder.

ERIC Educational Resources Information Center

McCue, Frank C., III; and Others

The majority of shoulder injuries occurring in throwing sports involve the soft tissue structures. Injuries often occur when the unit is overstretched to a point near its greatest length, involving the elastic tissues. The other injury mechanism involves the contractural unit of the muscle, which occurs near the midpoint of contractions, involving…

Use of botulinum toxin type A in the management of neonatal brachial plexus palsy.

PubMed

Michaud, Linda J; Louden, Emily J; Lippert, William C; Allgier, Allison J; Foad, Susan L; Mehlman, Charles T

2014-12-01

To evaluate functional outcomes and the impact on surgical interventions after the use of botulinum neurotoxin type A (BoNT-A) for muscle imbalance, cocontractions, or contractures with neonatal brachial plexus palsy. A retrospective cohort study. A brachial plexus center in a tertiary children's hospital. Fifty-nine patients with neonatal brachial plexus palsy (75 injection procedures, 91 muscles and/or muscle groups) received BoNT-A injections (mean age at injection, 36.2 months; range, 6-123 months; 31 boys; 30 right-sided injuries, 28 left-sided injuries, 1 bilateral injury). Data collected retrospectively from medical records, from procedure notes and clinic visits before BoNT-A use, at ≤6 months follow-up (BoNT-A active [BA]) and at ≥7 months follow-up (BoNT-A not active [BNA]) included demographics, injection indication, side, and site(s), previous surgical history, occupational therapy and/or physical therapy plan, and outcome measurements. Outcomes assessed before and after injections included active and passive range of motion, Mallet and Toronto scores, parent comments about arm function, preinjection surgical considerations, and postinjection surgical history. Injection procedures included 51 to shoulder internal rotators, 15 triceps, 15 pronator teres, 9 biceps, and 1 flexor carpi ulnaris. Active and passive shoulder external rotation (SER) range of motion improved after shoulder internal rotator injections (P = .0003 and P = .002, respectively), as did Mallet scores with BA; the latter were sustained with BNA. Surgical intervention was averted, modified, or deferred after BoNT-A in 45% (n = 20) under surgical consideration before BoNT-A. Active elbow flexion improved in 67% (P = .005), sustained BNA (P = .004) after triceps injections; 2 of 7 patients averted surgery. Active supination improved with BA (P = .002), with gains sustained BNA (P = .016). Passive elbow extension improved after biceps injections by an average 17° (P = .004) BA, although not sustained BNA. BoNT-A is an effective adjunct to therapy and surgery in managing muscle imbalance, cocontractions, and contractures in neonatal brachial plexus palsy. Use of BoNT-A can result in averting, modifying, or deferring surgical interventions in a number of affected children. Copyright © 2014 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Mouse shoulder morphology responds to locomotor activity and the kinematic differences of climbing and running.

PubMed

Green, David J; Richmond, Brian G; Miran, Sara L

2012-12-01

Mechanical loads play a significant role in determining long bone shape and strength, but less work has explored how these loads influence flat bones like the scapula, which has been shown to vary with locomotor preference among primate taxa. Here, we tested the effects of voluntary running and climbing exercise in mice to examine how the mechanical loads borne from different locomotor patterns influence shoulder morphological development. Ninety-nine female wild-type mice were distributed equally among sedentary control, activity-wheel running, and vertical climbing experimental conditions. Running mice had the lowest body masses, larger intrinsic shoulder muscles, and the most pronounced differences in scapular size and shape relative to the other groups. Climbing mouse scapular morphology also differed significantly from the control individuals, but these differences were not as marked as those between the running and control mice. This might be attributable in part to greater levels of activity in the wheel-runners relative to the climbers. Additionally, climbing mice held their bodies closer to the substrate and maintained more flexed limbs and posterior hand positions compared with the kinematics of running. As a result, climbers differed significantly from both the running and control mice in developing a relatively broader infraspinous region, which is likely related to preferential recruitment of the infraspinatus and teres minor muscles to maintain flexed shoulder postures. The results of this study demonstrate that variation in activity level and type of locomotor regime over a significant portion of the life history influences muscle and bone development in the shoulder. Copyright © 2012 Wiley Periodicals, Inc.

Effects of Stimulating Hip and Trunk Muscles on Seated Stability, Posture and Reach after Spinal Cord Injury

PubMed Central

Triolo, Ronald J.; Bailey, Stephanie Nogan; Miller, Michael E.; Lombardo, Lisa M.; Audu, Musa L.

2014-01-01

Objective To determine the stimulated strength of the paralyzed gluteal and paraspinal muscles and their effects on the seated function of individuals with paralysis. Design Case series with subjects acting as their own concurrent controls. Setting Hospital-based clinical biomechanics laboratory. Participants Eight users of implanted neuroprostheses for lower extremity function with low-cervical or thoracic level injuries. Interventions Dynamometry and digital motion capture both with and without stimulation to the hip and trunk muscles. Main Outcome Measure(s) Isometric trunk extension moment at 0, 15 and 30 degrees of flexion; seated stability in terms of simulated isokinetic rowing; pelvic tilt, shoulder height, loaded and unloaded bimanual reaching to different heights, and subjective ratings of difficulty during unsupported sitting. Results Stimulation produced significant increases in mean trunk extension moment (9.2±9.5Nm, p=0.0001) and rowing force (27.4±23.1N, p=0.0123) over baseline volitional values. Similarly, stimulation induced positive changes in average pelvic tilt (16.7±15.7deg) and shoulder height (2.2±2.5cm) during quiet sitting and bimanual reaching, and increased mean reach distance (5.5±6.6cm) over all subjects, target heights and loading conditions. Subjects consistently rated tasks with stimulation easier than voluntary effort alone. Conclusions In spite of considerable inter-subject variability, stabilizing the paralyzed trunk with electrical stimulation can positively impact seated posture, extend forward reach and allow exertion of larger forces on objects in the environment. PMID:23500182

Assessing the influence of a passive, upper extremity exoskeletal vest for tasks requiring arm elevation: Part I - "Expected" effects on discomfort, shoulder muscle activity, and work task performance.

PubMed

Kim, Sunwook; Nussbaum, Maury A; Mokhlespour Esfahani, Mohammad Iman; Alemi, Mohammad Mehdi; Alabdulkarim, Saad; Rashedi, Ehsan

2018-03-07

Use of exoskeletal vests (designed to support overhead work) can be an effective intervention approach for tasks involving arm elevation, yet little is known on the potential beneficial impacts of their use on physical demands and task performance. This laboratory study (n = 12) evaluated the effects of a prototype exoskeletal vest during simulated repetitive overhead drilling and light assembly tasks. Anticipated or expected benefits were assessed, in terms of perceived discomfort, shoulder muscle activity, and task performance. Using the exoskeletal vest did not substantially influence perceived discomfort, but did decrease normalized shoulder muscle activity levels (e.g., ≤ 45% reduction in peak activity). Drilling task completion time decreased by nearly 20% with the vest, but the number of errors increased. Overall, exoskeletal vest use has the potential to be a new intervention for work requiring arm elevation; however, additional investigations are needed regarding potential unexpected or adverse influences (see Part II). Copyright © 2018 Elsevier Ltd. All rights reserved.

Laboratory or Field Tests for Evaluating Firefighters' Work Capacity?

PubMed Central

Lindberg, Ann-Sofie; Oksa, Juha; Malm, Christer

2014-01-01

Muscle strength is important for firefighters work capacity. Laboratory tests used for measurements of muscle strength, however, are complicated, expensive and time consuming. The aims of the present study were to investigate correlations between physical capacity within commonly occurring and physically demanding firefighting work tasks and both laboratory and field tests in full time (N = 8) and part-time (N = 10) male firefighters and civilian men (N = 8) and women (N = 12), and also to give recommendations as to which field tests might be useful for evaluating firefighters' physical work capacity. Laboratory tests of isokinetic maximal (IM) and endurance (IE) muscle power and dynamic balance, field tests including maximal and endurance muscle performance, and simulated firefighting work tasks were performed. Correlations with work capacity were analyzed with Spearman's rank correlation coefficient (rs). The highest significant (p<0.01) correlations with laboratory and field tests were for Cutting: IE trunk extension (rs = 0.72) and maximal hand grip strength (rs = 0.67), for Stairs: IE shoulder flexion (rs = −0.81) and barbell shoulder press (rs = −0.77), for Pulling: IE shoulder extension (rs = −0.82) and bench press (rs = −0.85), for Demolition: IE knee extension (rs = 0.75) and bench press (rs = 0.83), for Rescue: IE shoulder flexion (rs = −0.83) and bench press (rs = −0.82), and for the Terrain work task: IE trunk flexion (rs = −0.58) and upright barbell row (rs = −0.70). In conclusion, field tests may be used instead of laboratory tests. Maximal hand grip strength, bench press, chin ups, dips, upright barbell row, standing broad jump, and barbell shoulder press were strongly correlated (rs≥0.7) with work capacity and are therefore recommended for evaluating firefighters work capacity. PMID:24614596

Metastasis of osteosarcoma to the trapezius muscle: a case report

PubMed Central

2014-01-01

Metastasis of a primary osteosarcoma to the muscles is extremely rare. As there have been few reported cases, the necessity of surgical treatment for such metastatic lesions remains controversial. We present the case of a primary osteosarcoma with development of a solitary metastasis to the trapezius muscle during chemotherapy for pulmonary metastasis. The patient was a 51-year-old man diagnosed with osteosarcoma of the right tibia. After undergoing chemotherapy and femoral amputation, he developed pulmonary metastasis. Chemotherapy was reinitiated, however, after approximately 1 year a palpable tumor was identified in the patient’s right shoulder. This tumor grew and was associated with pain in the right shoulder. It was surgically removed 3 years after the re-initiation of chemotherapy. The pathological diagnosis was osteosarcoma with metastasis to the trapezius muscle. Although the patient died of respiratory failure due to pulmonary metastasis 14 months after resection of the metastatic lesion in the trapezius muscle, no new extrapulmonary metastasis was observed after the resection. PMID:24893571

Metastasis of osteosarcoma to the trapezius muscle: a case report.

PubMed

Sakamoto, Yuichiro; Yokouchi, Masahiro; Nagano, Satoshi; Shimada, Hirofumi; Nakamura, Shunsuke; Setoguchi, Takao; Kawamura, Ichiro; Ishidou, Yasuhiro; Tanimoto, Akihide; Komiya, Setsuro

2014-06-04

Metastasis of a primary osteosarcoma to the muscles is extremely rare. As there have been few reported cases, the necessity of surgical treatment for such metastatic lesions remains controversial. We present the case of a primary osteosarcoma with development of a solitary metastasis to the trapezius muscle during chemotherapy for pulmonary metastasis. The patient was a 51-year-old man diagnosed with osteosarcoma of the right tibia. After undergoing chemotherapy and femoral amputation, he developed pulmonary metastasis. Chemotherapy was reinitiated, however, after approximately 1 year a palpable tumor was identified in the patient's right shoulder. This tumor grew and was associated with pain in the right shoulder. It was surgically removed 3 years after the re-initiation of chemotherapy. The pathological diagnosis was osteosarcoma with metastasis to the trapezius muscle. Although the patient died of respiratory failure due to pulmonary metastasis 14 months after resection of the metastatic lesion in the trapezius muscle, no new extrapulmonary metastasis was observed after the resection.

Muscle trigger point therapy in tension-type headache.

PubMed

Alonso-Blanco, Cristina; de-la-Llave-Rincón, Ana Isabel; Fernández-de-las-Peñas, César

2012-03-01

Recent evidence suggests that active trigger points (TrPs) in neck and shoulder muscles contribute to tension-type headache. Active TrPs within the suboccipital, upper trapezius, sternocleidomastoid, temporalis, superior oblique and lateral rectus muscles have been associated with chronic and episodic tension-type headache forms. It seems that the pain profile of this headache may be provoked by referred pain from active TrPs in the posterior cervical, head and shoulder muscles. In fact, the presence of active TrPs has been related to a higher degree of sensitization in tension-type headache. Different therapeutic approaches are proposed for proper TrP management. Preliminary evidence indicates that inactivation of TrPs may be effective for the management of tension-type headache, particularly in a subgroup of patients who may respond positively to this approach. Different treatment approaches targeted to TrP inactivation are discussed in the current paper, focusing on tension-type headache. New studies are needed to further delineate the relationship between muscle TrP inactivation and tension-type headache.

Becker muscular dystrophy

MedlinePlus

The health care provider will do a nervous system (neurological) and muscle exam. A careful medical history is also important, ... the legs and pelvis, then moves to the muscles of the shoulders, ... respiratory system Tests that may be done include: CPK blood ...

Shear wave mapping of skeletal muscle using shear wave wavefront reconstruction based on ultrasound color flow imaging

NASA Astrophysics Data System (ADS)

Yamakoshi, Yoshiki; Yamamoto, Atsushi; Kasahara, Toshihiro; Iijima, Tomohiro; Yuminaka, Yasushi

2015-07-01

We have proposed a quantitative shear wave imaging technique for continuous shear wave excitation. Shear wave wavefront is observed directly by color flow imaging using a general-purpose ultrasonic imaging system. In this study, the proposed method is applied to experiments in vivo, and shear wave maps, namely, the shear wave phase map, which shows the shear wave propagation inside the medium, and the shear wave velocity map, are observed for the skeletal muscle in the shoulder. To excite the shear wave inside the skeletal muscle of the shoulder, a hybrid ultrasonic wave transducer, which combines a small vibrator with an ultrasonic wave probe, is adopted. The shear wave velocity of supraspinatus muscle, which is measured by the proposed method, is 4.11 ± 0.06 m/s (N = 4). This value is consistent with those obtained by the acoustic radiation force impulse method.

Effects of kinesiotaping added to a rehabilitation programme for patients with rotator cuff tendinopathy: protocol for a single-blind, randomised controlled trial addressing symptoms, functional limitations and underlying deficits.

PubMed

de Oliveira, Fábio Carlos Lucas; de Fontenay, Benoît Pairot; Bouyer, Laurent Julien; Desmeules, François; Roy, Jean-Sébastien

2017-09-24

Rotator cuff tendinopathy (RCTe) is the most frequent cause of shoulder pain, resulting in considerable losses to society and public resources. Muscle imbalance and inadequate sensorimotor control are deficits often associated with RCTe. Kinesiotaping (KT) is widely used by clinicians for rehabilitation of RCTe. While previous studies have examined the immediate effects of KT on shoulder injuries or the effects of KT as an isolated method of treatment, no published study has addressed its mid-term and long-term effects when combined with a rehabilitation programme for patients with RCTe. The primary objective of this randomised controlled trial (RCT) will be to assess the efficacy of therapeutic KT, added to a rehabilitation programme, in reducing pain and disabilities in individuals with RCTe. Secondary objectives will look at the effects of KT on the underlying factors involved in shoulder control, such as muscular activity, acromiohumeral distance (AHD) and range of motion (ROM). A single-blind RCT will be conducted. Fifty-two participants, randomly allocated to one of two groups (KT or no-KT), will take part in a 6-week rehabilitation programme. The KT group will receive KT added to the rehabilitation programme, whereas the no-KT group will receive only the rehabilitation programme. Measurements will be taken at baseline, week 3, week 6, week 12 and 6 months. Primary outcomes will be symptoms and functional limitations assessed by the Disabilities of the Arm, Shoulder and Hand questionnaire. Secondary outcomes will include shoulder ROM, AHD at rest and at 60° of abduction, and muscle activation during arm elevation. The added effects of KT will be assessed through a two-way analysis of variance for repeated measures. Ethics approval was obtained from the Ethics Committee of Quebec Rehabilitation Institute of the Centre Integrated University Health and Social Services. Results will be disseminated through international publications in peer-reviewed journals, in addition to international conference presentations. Protocol was registered at ClinicalTrials.gov (NCT02881021) on 25 August 2016. The WHO Trial Registration Data Set can also be found as an online supplementary file. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Effects of kinesiotaping added to a rehabilitation programme for patients with rotator cuff tendinopathy: protocol for a single-blind, randomised controlled trial addressing symptoms, functional limitations and underlying deficits

PubMed Central

de Fontenay, Benoît Pairot; Bouyer, Laurent Julien; Desmeules, François; Roy, Jean-Sébastien

2017-01-01

Introduction Rotator cuff tendinopathy (RCTe) is the most frequent cause of shoulder pain, resulting in considerable losses to society and public resources. Muscle imbalance and inadequate sensorimotor control are deficits often associated with RCTe. Kinesiotaping (KT) is widely used by clinicians for rehabilitation of RCTe. While previous studies have examined the immediate effects of KT on shoulder injuries or the effects of KT as an isolated method of treatment, no published study has addressed its mid-term and long-term effects when combined with a rehabilitation programme for patients with RCTe. The primary objective of this randomised controlled trial (RCT) will be to assess the efficacy of therapeutic KT, added to a rehabilitation programme, in reducing pain and disabilities in individuals with RCTe. Secondary objectives will look at the effects of KT on the underlying factors involved in shoulder control, such as muscular activity, acromiohumeral distance (AHD) and range of motion (ROM). Methods and analysis A single-blind RCT will be conducted. Fifty-two participants, randomly allocated to one of two groups (KT or no-KT), will take part in a 6-week rehabilitation programme. The KT group will receive KT added to the rehabilitation programme, whereas the no-KT group will receive only the rehabilitation programme. Measurements will be taken at baseline, week 3, week 6, week 12 and 6 months. Primary outcomes will be symptoms and functional limitations assessed by the Disabilities of the Arm, Shoulder and Hand questionnaire. Secondary outcomes will include shoulder ROM, AHD at rest and at 60° of abduction, and muscle activation during arm elevation. The added effects of KT will be assessed through a two-way analysis of variance for repeated measures. Ethics and dissemination Ethics approval was obtained from the Ethics Committee of Quebec Rehabilitation Institute of the Centre Integrated University Health and Social Services. Results will be disseminated through international publications in peer-reviewed journals, in addition to international conference presentations. Trial registration number Protocol was registered at ClinicalTrials.gov (NCT02881021) on 25 August 2016. The WHO Trial Registration Data Set can also be found as an online supplementary file. PMID:28947462

EMG median frequency changes in the neck-shoulder stabilizers of symptomatic office workers when challenged by different physical stressors.

PubMed

Szeto, Grace Pui Yuk; Straker, Leon Melville; O'Sullivan, Peter Bruce

2005-12-01

The problem of work-related neck and upper limb disorders among computer users has been reported extensively in the literature, and commonly cited risk factors include static posture, speed and force of keyboard operation. The present study examined changes in median frequency (MF) of the neck-shoulder muscles in symptomatic and asymptomatic office workers when they were exposed to these three physical stressors. A quasi-experimental Case-Control design was used to examine MF changes in two groups of female office workers when they were subjected to controlled doses of computer work involving prolonged static posture, increased typing speed and increased typing force. The MF of four major neck-shoulder muscles were examined bilaterally and compared between groups. The MF changes over time-at-task did not clearly illustrate any muscle fatigue mechanism. However, Case Group consistently showed trends for higher MF than the Control Group, and this pattern was observed in response to all three physical stressors. The consistent group differences in MF suggest different muscle recruitment strategies between symptomatic and asymptomatic office workers. These results implied that symptomatic individuals had altered motor control, which may have important implications in understanding the etiology of work-related musculoskeletal disorders.

Comparing Trigger Point Dry Needling and Manual Pressure Technique for the Management of Myofascial Neck/Shoulder Pain: A Randomized Clinical Trial.

PubMed

De Meulemeester, Kayleigh E; Castelein, Birgit; Coppieters, Iris; Barbe, Tom; Cools, Ann; Cagnie, Barbara

2017-01-01

The aim of this study was to investigate short-term and long-term treatment effects of dry needling (DN) and manual pressure (MP) technique with the primary goal of determining if DN has better effects on disability, pain, and muscle characteristics in treating myofascial neck/shoulder pain in women. In this randomized clinical trial, 42 female office workers with myofascial neck/shoulder pain were randomly allocated to either a DN or MP group and received 4 treatments. They were evaluated with the Neck Disability Index, general numeric rating scale, pressure pain threshold, and muscle characteristics before and after treatment. For each outcome parameter, a linear mixed-model analysis was applied to reveal group-by-time interaction effects or main effects for the factor "time." No significant differences were found between DN and MP. In both groups, significant improvement in the Neck Disability Index was observed after 4 treatments and 3 months (P < .001); the general numerical rating scale also significantly decreased after 3 months. After the 4-week treatment program, there was a significant improvement in pain pressure threshold, muscle elasticity, and stiffness. Both treatment techniques lead to short-term and long-term treatment effects. Dry needling was found to be no more effective than MP in the treatment of myofascial neck/shoulder pain. Copyright © 2016. Published by Elsevier Inc.

High-Intensity Strength Training Improves Function of Chronically Painful Muscles: Case-Control and RCT Studies

PubMed Central

Andersen, Christoffer H.; Skotte, Jørgen H.; Suetta, Charlotte; Søgaard, Karen; Saltin, Bengt; Sjøgaard, Gisela

2014-01-01

Aim. This study investigates consequences of chronic neck pain on muscle function and the rehabilitating effects of contrasting interventions. Methods. Women with trapezius myalgia (MYA, n = 42) and healthy controls (CON, n = 20) participated in a case-control study. Subsequently MYA were randomized to 10 weeks of specific strength training (SST, n = 18), general fitness training (GFT, n = 16), or a reference group without physical training (REF, n = 8). Participants performed tests of 100 consecutive cycles of 2 s isometric maximal voluntary contractions (MVC) of shoulder elevation followed by 2 s relaxation at baseline and 10-week follow-up. Results. In the case-control study, peak force, rate of force development, and rate of force relaxation as well as EMG amplitude were lower in MYA than CON throughout all 100 MVC. Muscle fiber capillarization was not significantly different between MYA and CON. In the intervention study, SST improved all force parameters significantly more than the two other groups, to levels comparable to that of CON. This was seen along with muscle fiber hypertrophy and increased capillarization. Conclusion. Women with trapezius myalgia have lower strength capacity during repetitive MVC of the trapezius muscle than healthy controls. High-intensity strength training effectively improves strength capacity during repetitive MVC of the painful trapezius muscle. PMID:24707475

[Effect of disease severity on upper extremity muscle strength, exercise capacity, and activities of daily living in individuals with pulmonary arterial hypertension].

PubMed

Özcan Kahraman, Buse; Özsoy, İsmail; Acar, Serap; Özpelit, Ebru; Akdeniz, Bahri; Sevinç, Can; Savcı, Sema

2017-07-01

Pulmonary arterial hypertension (PAH) is a rare disease. Although muscle strength, exercise capacity, quality of life, and activities of daily living of patients with PAH are affected, it is not known how they are affected by disease severity. The purpose of the present study was to investigate effects of disease severity on upper extremity muscle strength, exercise capacity, and performance of activities of daily living in patients with PAH. Twenty-five patients with disease severity classified according to the New York Heart Association (NYHA) as functional class II (n=14) or class III (n=11) were included in the study. Upper-extremity exercise capacity and limitations in performing activities of daily living were assessed with 6-minute pegboard and ring test (6PBRT) and the Milliken activities of daily living scale (MAS), respectively. Shoulder flexion, elbow extension, elbow flexion muscle strength, and handgrip strength were measured with dynamometer. There were no significant differences in age, gender, body mass index, or mean pulmonary artery pressure between groups (p>0.05). The 6PBRT, MAS, and elbow flexion (right) and grip strength (right and left) results were significantly lower in NYHA III group than in NYHA II group (p=0.004, p=0.002, p=0.043, p=0.002 and p=0.003, respectively). There was no significant difference in shoulder flexion, elbow flexion (left), or elbow extension between groups (p>0.05). Results suggest that upper extremity exercise capacity, elbow flexion muscle strength (right), and handgrip strength decrease and that limitations in activities of daily living grow as disease severity increases in patients with PAH. When planning rehabilitation programs, disease severity should be considered and evaluations and treatments for the upper extremities should be included.

Effects of the humeral tray component positioning for onlay reverse shoulder arthroplasty design: a biomechanical analysis.

PubMed

Berhouet, Julien; Kontaxis, Andreas; Gulotta, Lawrence V; Craig, Edward; Warren, Russel; Dines, Joshua; Dines, David

2015-04-01

Recent shoulder prostheses have introduced a concept of a universal humeral stem component platform that has an onlay humeral tray for the reverse total shoulder arthroplasty (RTSA). No studies have reported how humeral tray positioning can affect the biomechanics of RTSA. The Newcastle Shoulder Model was used to investigate the biomechanical effect of humeral tray positioning in the Biomet Comprehensive Total Shoulder System (Biomet, Warsaw, IN, USA) RTSA. Five humeral tray configuration positions were tested: no offset, and 5 mm offset in the anterior, posterior, medial, and lateral positions. Superior and inferior impingement were evaluated for abduction, scapular plane elevation, forward flexion, and external/internal rotation with the elbow at the side (adduction) and at 90° of shoulder abduction. Muscle lengths and moment arms (elevating and rotational) were calculated for the deltoid, the infraspinatus, the teres minor, and the subscapularis. Inferior impingement was not affected by the humeral tray position. There was less superior impingement during abduction, scapular plane elevation, and rotation with the shoulder when the tray was placed laterally or posteriorly. The subscapularis rotational moment arm was increased with a posterior offset, whereas infraspinatus and teres minor rotational moment arms were increased with an anterior offset. Very little change was observed for the deltoid elevating moment arm or for its muscle length. Positioning the humeral tray with posterior offset offers a biomechanical advantage for patients needing RTSA by decreasing superior impingement and increasing the internal rotational moment arm of the subscapularis, without creating inferior impingement. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Two aspects of feedforward postural control: anticipatory postural adjustments and anticipatory synergy adjustments.

PubMed

Klous, Miriam; Mikulic, Pavle; Latash, Mark L

2011-05-01

We used the framework of the uncontrolled manifold hypothesis to explore the relations between anticipatory synergy adjustments (ASAs) and anticipatory postural adjustments (APAs) during feedforward control of vertical posture. ASAs represent a drop in the index of a multimuscle-mode synergy stabilizing the coordinate of the center of pressure in preparation to an action. ASAs reflect early changes of an index of covariation among variables reflecting muscle activation, whereas APAs reflect early changes in muscle activation levels averaged across trials. The assumed purpose of ASAs is to modify stability of performance variables, whereas the purpose of APAs is to change magnitudes of those variables. We hypothesized that ASAs would be seen before APAs and that this finding would be consistent with regard to the muscle-mode composition defined on the basis of different tasks and phases of action. Subjects performed a voluntary body sway task and a quick, bilateral shoulder flexion task under self-paced and reaction time conditions. Surface muscle activity of 12 leg and trunk muscles was analyzed to identify sets of 4 muscle modes for each task and for different phases within the shoulder flexion task. Variance components in the muscle-mode space and indexes of multimuscle-mode synergy stabilizing shift of the center of pressure were computed. ASAs were seen ∼ 100-150 ms prior to the task initiation, before APAs. The results were consistent with respect to different sets of muscle modes defined over the two tasks and different shoulder flexion phases. We conclude that the preparation for a self-triggered postural perturbation is associated with two types of anticipatory adjustments, ASAs and APAs. They reflect different feedforward processes within the hypothetical hierarchical control scheme, resulting in changes in patterns of covariation of elemental variables and in their patterns averaged across trials, respectively. The results show that synergies quantified using dissimilar sets of muscle modes show similar feedforward changes in preparation to action.

Successful outcome of modified quad surgical procedure in preteen and teen patients with brachial plexus birth palsy.

PubMed

Nath, Rahul K; Somasundaram, Chandra

2012-01-01

To evaluate the outcome of modified Quad procedure in preteen and teen patients with brachial plexus birth palsy. We have previously demonstrated a significant improvement in shoulder abduction, resulting from the modified Quad procedure in children (mean age 2.5 years; range, 0.5-9 years) with obstetric brachial plexus injury. We describe in this report the outcome of 16 patients (6 girls and 10 boys; 7 preteen and 9 teen) who have undergone the modified Quad procedure for the correction of the shoulder function, specifically abduction. The patients underwent transfer of the latissimus dorsi and teres major muscles, release of contractures of subscapularis pectoralis major and minor, and axillary nerve decompression and neurolysis (the modified Quad procedure). Mean age of these patients at surgery was 13.5 years (range, 10.1-17.9 years). The mean preoperative total Mallet score was 14.8 (range, 10-20), and active abduction was 84° (range, 20°-140°). At a mean follow-up of 1.5 years, the mean postoperative total Mallet score increased to 19.7 (range, 13-25, P < .0001), and the mean active abduction improved to 132° (range, 40°-180°, P < .0003). The modified Quad procedure greatly improves not only the active abduction but also other shoulder functions in preteen and teen patients, as this outcome is the combined result of decompression and neurolysis of the axillary nerve and the release of the contracted internal rotators of the shoulder.

Reinvestigation of the dysfunction in neck and shoulder girdle muscles as the reason of cervicogenic headache among office workers.

PubMed

Huber, Juliusz; Lisiński, Przemysław; Polowczyk, Agnieszka

2013-05-01

Dysfunction of cervical and shoulder girdle muscles as reason of cervicogenic headache (CEH) was reinvestigated with clinical and neurophysiological studies. Forty office workers were randomized into two groups to verify efficiency of supervised kinesiotherapy (N = 20) aimed with improvement of muscle's activity and headache symptoms releasing. Headache intensity was evaluated with visual analog scale (VAS), range of cervical movement (ROM) with goniometer, trigger points (TrPs) incidence with palpation and muscle's strength with Lovett's scale. Reaction of patients for muscle's elongation was also evaluated. Surface electromyographical recordings were bilaterally analyzed at rest (rEMG) and during maximal contraction (mcEMG). Deficits of cervical flexion and muscles strength were found in all patients. TrPs occurred predominantly in painful trapezius muscle. Incidence of trigger points coexisted with intensity of CEH. Results indicated on muscles dysfunction which improved only after supervised therapy. Positive correlations between increase in rEMG amplitudes and high VAS scores, high-amplitude rEMG recordings incidence and increased number of TrPs were found. Negative correlation was detected between amplitude in mcEMG and amplitude of rEMG recordings. Dysfunction of trapezius muscle was most responsible for CEH etiology. Proposed algorithm of kinesiotherapy was effective as complementary method of the CEH patients treatment.

The role of botulinum toxin in the neuro-rehabilitation of young patients with brachial plexus birth palsy.

PubMed

Desiato, M T; Risina, B

2001-01-01

To favour the active movements of the shoulder abductor/external rotator, elbow extensor and supinator muscles, through the partial inhibition of the uninvolved antagonistic muscles, in the Brachial Plexus birth Palsy (BPP). The type A Botulinum Neuro Toxin (BNT-Dysport, Ipsen) was injected in 50 outpatients (mean age: 4.7 +/- 3.4 years) with BPP according to the criteria: early and current neuro-rehabilitation (Reflex Locomotion-RL), age <14 years, no cognitive impairment. Repeat injections (1.9 +/- 0.8) were performed in 30 patients. The range of active movements increased at the maximal benefit phase, compared to the baseline values (p < 0.05-0.01). The gain of shoulder's abduction was directly related to the youngest age (r = 0.6). An expanded compliance of the injected muscles and a faster response to the RL, in respect to that experienced in the pre-BNT sessions, was detected. The Global Clinical Rating Scale disclosed the temporal profile of the clinical outcome, with step-like increases of the function in 70% of the patients, and a 'plateau' trait in the remaining ones (+29.8 +/- 10.5%). The video-taped recordings showed an improvement in the global movements. The employment of BNT in the management of young patients with BPP has beneficial effects in the integration of the bodily scheme.

New approach to evaluate late arm impairment and effects of dragon boat activity in breast cancer survivors.

PubMed

Melchiorri, Giovanni; Viero, Valerio; Triossi, Tamara; Sorge, Roberto; Tancredi, Virginia; Cafaro, Domenico; Andreis, Caterina; Vulpiani, Maria Chiara; Saraceni, Vincenzo Maria

2017-11-01

To verify the applicability of a new approach based on the strength curves (SCs) methodology in late arm impairment in breast cancer (BC) survivors and to evaluate the effects of dragon boat (DB) activity on the late regaining of the muscle strength, upper limb impairment, and quality of life in patients undergoing surgery for BC.Retrospective observational study on 64 subjects (54.5 ± 9.7 years), 47 of them had undergone unilateral mastectomy surgery and were evaluated for late arm impairment. A clinical evaluation of the shoulder and compilation of functional assessment (DASH, Rowe, Constant-Murley) and quality of life (SF-36) scales were carried out. Assessment of muscle strength with SC obtained with isometric assessments and serratus anterior muscle test were performed.Differences between the SC are evident between healthy and operated subjects. Among the 3 groups of operated subjects the difference in strength is maximum at 0°. Statistically significant difference was found between operated and nonoperated only in SF-36 scale. No significant difference was found between groups for shoulder instability and winged scapula.The SC can be used in the study of upper limb impairment after surgery for BC: measurements carried out at 1st degrees of the range of motion are more useful for clinicians. DB activity is useful to reduce the late arm impairment.

Postoperative physical therapy program for latissimus dorsi and teres major tendons transfer to rotator cuff in children with obstetrical brachial plexus injury.

PubMed

Safoury, Yasser A; Eldesoky, Mohamed T; Abutaleb, Enas E; Atteya, Mohamed R; Gabr, Ahmed M

2017-04-01

The transfer of latissimus dorsi and teres major tendons to rotator cuff have been developed to rebalance the muscular dysfunction and improve shoulder range of motion in children with obstetrical brachial plexus palsy (OBPP). No previous study reported the ideal postoperative physical therapy program for these cases. The aim of the present study was to design appropriate postoperative physical therapy (PT) program after latissimus dorsi and teres major tendons transfer to rotator cuff in OBPP to improve upper limb function. Time series design. The patients were recruited from outpatient clinic of Kasr EL Aini Hospital, Cairo, Egypt. Forty seven OBPP infants (4.64±1.21 years with a range of 2.5 to 7 years, 21male and26 female) were allocated to one group. All patients had functional limitation in the involved arm due to muscle paralysis and contracture. Twenty-five patients had C5-C6 nerve root lesions while 22 had C5-C6-C7 nerve root lesions. The children underwent the surgical procedures of the transfer of latissimus dorsi and teres major tendons to rotator cuff. After the surgery the children participated in a designed physical therapy program for 6 months. Active shoulder abduction, flexion and external rotation range of motion (ROM) were assessed by electrogoniometer, and functional assessments were measured using the modified Mallet scale. All measurements were taken preoperative, 6 weeks, 3 months, and 6 months postoperatively after the application of the designed PT program. Repeated measure analysis of variance (ANOVA) followed by Bonferroni post-hoc test were used to show the improvement in all measured variables. Analysis revealed that shoulder abduction, flexion and external rotation ROM and shoulder function measured by modified Mallet scale were significantly improved (P<0.0001) after the designed postoperative PT program. It can be concluded that the combination treatment of surgical procedure and the postoperative physical therapy program seem to be effective in improving shoulder and arm functions in children with OBPP. This study describes a detailed physical therapy program after latissimus dorsi and teres major tendons transfer to rotator cuff in OBPP.

Handgrip strength deficits best explain limitations in performing bimanual activities after stroke.

PubMed

Basílio, Marluce Lopes; de Faria-Fortini, Iza; Polese, Janaine Cunha; Scianni, Aline A; Faria, Christina Dcm; Teixeira-Salmela, Luci Fuscaldi

2016-04-01

[Purpose] To evaluate the relationships between residual strength deficits (RSD) of the upper limb muscles and the performance in bimanual activities and to determine which muscular group would best explain the performance in bimanual activities of chronic stroke individuals. [Subjects and Methods] Strength measures of handgrip, wrist extensor, elbow flexor/extensor, and shoulder flexor muscles of 107 subjects were obtained and expressed as RSD. The performance in bimanual activities was assessed by the ABILHAND questionnaire. [Results] The correlations between the RSD of handgrip and wrist extensor muscles with the ABILHAND scores were negative and moderate, whereas those with the elbow flexor/extensor and shoulder flexor muscles were negative and low. Regression analysis showed that the RSD of handgrip and wrist extensor muscles explained 38% of the variance in the ABILHAND scores. Handgrip RSD alone explained 33% of the variance. [Conclusion] The RSD of the upper limb muscles were negatively associated with the performance in bimanual activities and the RSD of handgrip muscles were the most relevant variable. It is possible that stroke subjects would benefit from interventions aiming at improving handgrip strength, when the goal is to increase the performance in bimanual activities.

Risk Factors Associated With Shoulder Pain and Disability Across the Lifespan of Competitive Swimmers

PubMed Central

Tate, Angela; Turner, Gregory N.; Knab, Sarah E.; Jorgensen, Colbie; Strittmatter, Andrew; Michener, Lori A.

2012-01-01

Context: The prevalence of shoulder pain among competitive swimmers is high, but no guidelines exist to reduce shoulder injuries. Elucidating differences between swimmers with and without shoulder pain can serve as a basis for the development of a program to prevent shoulder injury that might lead to pain and dysfunction. Objective: To determine whether physical characteristics, exposure, or training variables differ between swimmers with and without shoulder pain or disability. Design: Cross-sectional study. Setting: Multisite swimming centers. Patients or Other Participants: A total of 236 competitive female swimmers aged 8 to 77 years. Data Collection and Analysis: Participants completed the Penn Shoulder Score and underwent testing of core endurance, range of motion, muscle force production, and pectoralis minor muscle length and the Scapular Dyskinesis Test. Swimmers were grouped by age for analysis: ages 8 to 11 years (n = 42), 12 to 14 years (n = 43), 15 to 19 years (high school, n = 84), and 23 to 77 years (masters, n = 67). Comparisons were made between groups with and without pain and disability using independent t tests for continuous data and χ2 analyses and Fisher exact tests for categorical data. Results: Nine (21.4%) swimmers aged 8 to 11 years, 8 (18.6%) swimmers aged 12 to 14 years, 19 (22.6%) high school swimmers, and 13 (19.4%) masters swimmers had shoulder pain and disability. Differences that were found in 2 or more age groups between athletes with and without shoulder pain and disability included greater swimming exposure, a higher incidence of previous traumatic injury and patient-rated shoulder instability, and reduced participation in another sport in the symptomatic groups (P < .05). Reduced shoulder flexion motion, weakness of the middle trapezius and internal rotation, shorter pectoralis minor and latissimus, participation in water polo, and decreased core endurance were found in symptomatic females in single varying age groups (P < .05). Conclusions: Female competitive swimmers have shoulder pain and disability throughout their lives. Given that exposure and physical examination findings varied between athletes with and without substantial pain and disability, a program to prevent shoulder injury that might lead to pain and dysfunction appears warranted and might include exposure reduction, cross-training, pectoral and posterior shoulder stretching, strengthening, and core endurance training. PMID:22488280

Shoulder and Lower Back Joint Reaction Forces in Seated Double Poling.

PubMed

Lund Ohlsson, Marie; Danvind, Jonas; Holmberg, L Joakim

2018-04-13

Overuse injuries in the shoulders and lower back are hypothesized to be common in cross-country sit-skiing. Athletes with reduced trunk muscle control mainly sits with their knees higher than hips (KH). To reduce spinal flexion, a position with the knees below the hips (KL) was enabled for these athletes using a frontal trunk support. The aim of the study was to compare the shoulder joint (glenohumeral joint) and L4-L5 joint reactions between the sitting positions KL and KH. Five able-bodied female athletes performed submaximal and maximal exercise tests in the sitting positions KL and KH on a ski-ergometer. Measured pole forces and 3-dimensional kinematics served as input for inverse-dynamics simulations to compute the muscle forces and joint reactions in the shoulder and L4-L5 joint. This was the first musculoskeletal simulation study of seated double poling. The results showed that the KH position was favorable for higher performance and decreased values of the shoulder joint reactions for female able-bodied athletes with full trunk control. The KL position was favorable for lower L4-L5 joint reactions and might therefore reduce the risk of lower back injuries. These results indicate that it is hard to optimize both performance and safety in the same sit-ski.

Factors that Influence Functional Outcome after Total or Subtotal Scapulectomy: Japanese Musculoskeletal Oncology Group (JMOG) Study

PubMed Central

Hayashi, Katsuhiro; Iwata, Shintaro; Ogose, Akira; Kawai, Akira; Ueda, Takafumi; Otsuka, Takanobu; Tsuchiya, Hiroyuki

2014-01-01

Background Scapulectomy requires not only joint resection but also wide resection of the shoulder girdle muscles. Even the significance of reconstruction has not yet been determined because of the difficulties in comparing the different conditions. The purpose of this study was to investigate factors that influence functional outcomes after scapulectomy in a multicenter study. Methods This retrospective study comprised 48 patients who underwent total or subtotal scapulectomy and were followed for at least one year after surgery. Patients were registered at the Japanese Musculoskeletal Oncology Group affiliated hospitals. Soft tissue reconstruction for joint stabilization was performed when there was enough remaining tissue for reconstruction of the rotator cuff and tendons. In 23 cases, humeral suspension was performed. The average follow-up period was 61.9 months. Multivariate analysis was performed using the patient’s background to determine which factors influence the Enneking functional score or active range of motion. Results The average functional score was 21.1 out of 30. Active shoulder range of motion was 42.7 degree in flexion, 39.7 degree in abduction, 49.6 degree of internal rotation and 16.8 degree of external rotation. The amount of remaining bone influenced functional outcome, which means that preserving the glenoid or the acromion lead to better function compared to total scapulectomy (p<0.01). Factors that influenced each functional measure include the amount of remaining bone, soft tissue reconstruction, the length of the resected humerus and nerve resection (p<0.05). Conclusion Although shoulder function was almost eliminated following total or subtotal scapulectomy, minimal resection of bone, and soft tissue reconstruction should lead to better function. PMID:24937254

[Case-control study on shoulder pain caused by hook palte for the treatment of acromioclavicular joint dislocation].

PubMed

Yang, Ying-guo; Cai, Xiao-bing; Wang, Xiao-min; Zhu, Yong-gan; Pan, He-yong

2015-06-01

To explore causes of shoulder pain and propose prevention measures in treating acromioclavicular joint dislocation. From January 2005 to January 2013, 86 patients with acromioclavicular joint dislocation (Tossy III) were treated with hook plate fixation, and were divided into two groups. Bsaed on recovery of shoulder function mostly, the patients who suffered from rest pain, motion pain were named as shoulder pain group, while the patients without pain were named as painless group. In shoulder pain group, there were 21 cases including 15 males and and 6 females ranging the age from 22 to 62 years old with an average of (40.6±11.2) years old. There were 8 cases were on the left side and 13 cases were on the right side. In painless group, there were 65 cases including 36 males and and 29 females ranging the age from 19 to 65 years old with an average of (40.0±11.3) years old. There were 33 cases were on the left side and 32 cases were on the right side. The time from injury to operation ranged from 3 h to 8 d with an average of 34.6 h. Shoulder function of all patients were normal before injuried. Postoperative pain, activity of daily living (ADL), range of motion, deltoid muscle strength were compared. Anteflexion,rear protraction, abduction and upthrow of shoulder joint were also compared. Postoperative complications between two groups were observed and compared. All patients were followed up from 12 to 48 months with an average of 18.5 months. Constant-Murley score were used to evaluate clinical efficacy at the least following up, and 13 cases got an excellent results, 5 moderate, 2 good and 1 poor in shoulder pain group ; while 61 cases were obtained excellent results, 3 moderate and 1 good in painless group. There were significantly differences between two groups in Constant-Murley score and activity of shoulder joint (P<0.05). In shoulder pain group, 3 cases were disconnected, 1 case occurred stress fracture, 9 cases were subacromial impingement syndrome, 5 cases occurred subluxation, 1 case occurred plate breakage and 11 cases were acromioclavicular arthritis. Chosing individual clavicular hook plate, fulfilling anatomic reset, paying attention to the repair of articular capsule ligament, and reducing hook and bone antagonism between stress is the key point of preventing and decreasing postoperative shoulder pain.

Multimodal assessment of sensorimotor shoulder function in patients with untreated anterior shoulder instability and asymptomatic handball players.

PubMed

Mornieux, Guillaume; Hirschmüller, Anja; Gollhofer, Albert; Südkamp, Norbert P; Maier, Dirk

2018-04-01

Functional evaluation of sensorimotor function of the shoulder joint is important for guidance of sports-specific training, prevention and rehabilitation of shoulder instability. Such assessment should be multimodal and comprise all qualities of sensorimotor shoulder function. This study evaluates feasibility of such multimodal assessment of glenohumeral sensorimotor function in patients with shoulder instability and handball players. Nine patients with untreated anterior instability of their dominant shoulder and 15 asymptomatic recreational handball players performed proprioceptive joint position sense and dynamic stabilization evaluations on an isokinetic device, as well as a functional throwing performance task. Outcome measures were analysed individually and equally weighted in a Shoulder-Specific Sensorimotor Index (S-SMI). Finally, isokinetic strength evaluations were conducted. We observed comparable sensorimotor functions of unstable dominant shoulders compared to healthy, contralateral shoulders (e.g. P=0.59 for S-SMI). Handball players demonstrated superior sensorimotor function of their dominant shoulders exhibiting a significantly higher throwing performance and S-SMI (P<0.001 and P=0.002, respectively), but comparable internal rotator peak torques for both shoulders (P>0.22). The present study proves feasibility of multimodal assessment of shoulder sensorimotor function in overhead athletes and patients with symptomatic anterior shoulder instability. Untreated shoulder instability led to a loss of dominance-related sensorimotor superiority indicating functional internal rotation deficiency. Dominant shoulders of handball players showed a superior overall sensorimotor function but weakness of dominant internal rotation constituting a risk factor for occurrence of posterior superior impingement syndrome. The S-SMI could serve as a diagnostic tool for guidance of sports-specific training, prevention and rehabilitation of shoulder instability.

Augmentation of partially regenerated nerves by end-to-side side-to-side grafting neurotization: experience based on eight late obstetric brachial plexus cases

PubMed Central

2006-01-01

Objective The effect of end-to-side neurotization of partially regenerated recipient nerves on improving motor power in late obstetric brachial plexus lesions, so-called nerve augmentation, was investigated. Methods Eight cases aged 3 – 7 years were operated upon and followed up for 4 years (C5,6 rupture C7,8T1 avulsion: 5; C5,6,7,8 rupture T1 avulsion:1; C5,6,8T1 rupture C7 avulsion:1; C5,6,7 ruptureC8 T1 compression: one 3 year presentation after former neurotization at 3 months). Grade 1–3 muscles were neurotized. Grade0 muscles were neurotized, if the electromyogram showed scattered motor unit action potentials on voluntary contraction without interference pattern. Donor nerves included: the phrenic, accessory, descending and ascending loops of the ansa cervicalis, 3rd and 4th intercostals and contralateral C7. Results Superior proximal to distal regeneration was observed firstly. Differential regeneration of muscles supplied by the same nerve was observed secondly (superior supraspinatus to infraspinatus regeneration). Differential regeneration of antagonistic muscles was observed thirdly (superior biceps to triceps and pronator teres to supinator recovery). Differential regeneration of fibres within the same muscle was observed fourthly (superior anterior and middle to posterior deltoid regeneration). Differential regeneration of muscles having different preoperative motor powers was noted fifthly; improvement to Grade 3 or more occurred more in Grade2 than in Grade0 or Grade1 muscles. Improvements of cocontractions and of shoulder, forearm and wrist deformities were noted sixthly. The shoulder, elbow and hand scores improved in 4 cases. Limitations The sample size is small. Controls are necessary to rule out any natural improvement of the lesion. There is intra- and interobserver variability in testing muscle power and cocontractions. Conclusion Nerve augmentation improves cocontractions and muscle power in the biceps, pectoral muscles, supraspinatus, anterior and lateral deltoids, triceps and in Grade2 or more forearm muscles. As it is less expected to improve infraspinatus power, it should be associated with a humeral derotation osteotomy and tendon transfer. Function to non improving Grade 0 or 1 forearm muscles should be restored by muscle transplantation. Level of evidence Level IV, prospective case series. PMID:17147803

[Pattern of paralysis and reconstructive operations after traumatic brachial plexus lesions].

PubMed

Rühmann, O; Schmolke, S; Carls, J; Wirth, C J

2002-12-01

The aim of this study was to evaluate persistent patterns of paralysis after traumatic brachial plexus lesions. As a result, consecutive reconstructive operations according to our differential therapy concept are presented. Between 04/1994 and 12/2000 in 104 patients with brachial plexus palsy, the grade of muscle power of the affected upper extremities was evaluated prospectively. The neuromuscular patterns of defect showed, in most cases, insufficient muscle power grades of 0-2 for the deltoid muscle (90%), supraspinatus muscle (82%), infraspinatus muscle (93%), elbow flexors (67% to 77%), hand and finger extensors (69% to 71%), and the abductor and extensors of the thumb (67% to 70%). In corresponding frequency, the following operations were performed between 04/1994 and 06/2002: shoulder arthrodesis (n 26), trapezius transfer (n 80), rotation osteotomy of humerus (n 10), triceps to biceps transposition (n 11), transposition of forearm flexors or extensors/Steindler operation (n 12), latissimus transfer (n 7), pectoralis transfer (n 1), teres major transfer (n 1), transposition of forearm flexors to the tendons of extensor digitorum (n 19) and of the extensor pollicis longus (n 9), and wrist arthrodesis (n 5). On malfunction of muscles following brachial plexus lesions, taking into account the individual neuromuscular defect, passive joint function, and bony deformities, different procedures such as muscle transposition, arthrodesis, and corrective osteotomy can be performed to improve function of the upper extremity.

Three-dimensional shoulder kinematics normalize after rotator cuff repair.

PubMed

Kolk, Arjen; de Witte, Pieter Bas; Henseler, Jan Ferdinand; van Zwet, Erik W; van Arkel, Ewoud R A; van der Zwaal, Peer; Nelissen, Rob G H H; de Groot, Jurriaan H

2016-06-01

Patients with a rotator cuff (RC) tear often exhibit scapular dyskinesia with increased scapular lateral rotation and decreased glenohumeral elevation with arm abduction. We hypothesized that in patients with an RC tear, scapular lateral rotation, and thus glenohumeral elevation, will be restored to normal after RC repair. Shoulder kinematics were quantitatively analyzed in 26 patients with an electromagnetic tracking device (Flock of Birds) before and 1 year after RC repair in this observational case series. We focused on humeral range of motion and scapular kinematics during abduction. The asymptomatic contralateral shoulder was used as the control. Changes in scapular kinematics were associated with the gain in range of motion. Shoulder kinematics were analyzed using a linear mixed model. Mean arm abduction and forward flexion improved after surgery by 20° (95% confidence interval [CI], 2.7°-36.5°; P = .025) and 13° (95% CI, 1.2°-36.5°; P = .044), respectively. Kinematic analyses showed decreases in mean scapular protraction (ie, internal rotation) and lateral rotation (ie, upward rotation) during abduction by 3° (95% CI, 0.0°-5.2°; P = .046) and 4° (95% CI, 1.6°-8.4°; P = .042), respectively. Glenohumeral elevation increased by 5° (95% CI, 0.6°-9.7°; P = .028) at 80°. Humeral range of motion increased when scapular lateral rotation decreased and posterior tilt increased. Scapular kinematics normalize after RC repair toward a symmetrical scapular motion pattern as observed in the asymptomatic contralateral shoulder. The observed changes in scapular kinematics are associated with an increased overall range of motion and suggest restored function of shoulder muscles. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Activity of Shoulder Stabilizers and Prime Movers During an Unstable Overhead Press.

PubMed

Williams, Martin R; Hendricks, Dustin S; Dannen, Michael J; Arnold, Andrea M; Lawrence, Michael A

2018-06-08

Williams, MR Jr, Hendricks, DS, Dannen, MJ, Arnold, AM, and Lawrence, MA. Activity of shoulder stabilizers and prime movers during an unstable overhead press. J Strength Cond Res XX(X): 000-000, 2018-Overhead reaching is a common movement that relies heavily on muscles for dynamic stability. Stabilizer muscle activation increased during squatting and bench pressing with an unstable load, but the overhead press (OHP) has yet to be examined. The purpose of this study is to compare muscle activity of the shoulder stabilizers and prime movers and excursions of the center of pressure (CoP) during the OHP in 2 unstable and one stable conditions. Twelve men (aged 25.3 ± 2.7 years, mass: 91.5 ± 8.4 kg, height: 1.81 ± 0.06 m) pressed 50% of their 1 repetition maximum for 10 repetitions over 3 conditions: a straight stable barbell (SS), a straight unstable (SU) barbell with kettlebells suspend by elastic bands, and an unstable Earthquake (EU) bar with kettlebells suspended by elastic bands. Activity of the shoulder stabilizers and prime movers were measured via surface and indwelling electromyography. Center of pressure excursion of the right foot was also measured. A multivariate analysis was used to determine significant differences between conditions. Pressing with the EQ increased activation of the biceps brachii, erector spinae, latissimus dorsi, pectoralis major, rectus abdominus, rhomboids, and serratus anterior over the SS condition, whereas only the SU condition increased activation in the erector spinae and latissimus dorsi muscles. The EQ condition produced greater CoP excursion (35.3 ± 7.9% foot length) compared with the SU (28.0 ± 7.2% foot length) and SS (22.2 ± 6.3% foot length) conditions. Therefore, the EU condition may be an effective exercise to activate scapular stabilizers.

Axillary Sonography of the Shoulder: An Adjunctive Approach.

PubMed

Michelin, Paul; Legrand, Julie; Lee, Kenneth S; Leleup, Grégoire; Etancelin, Mathilde; Banse, Christopher; Dacher, Jean-Nicolas; Duparc, Fabrice

2018-03-25

Sonography of the shoulder is widely used to assess various disorders, including tendinous diseases of the rotator cuff and the long head of the biceps brachii muscle. The shoulder is commonly explored through anterior, superior, and posterior approaches, but the inferior axillary approach is rarely considered in the literature. However, this technique allows the direct visualization of relevant anatomic structures. The aim of this pictorial essay is, first, to technically describe this approach and the normal musculoskeletal sonographic anatomy of the region and, second, to present the sonographic findings of shoulder disorders that may be helpfully explored this technique. © 2018 by the American Institute of Ultrasound in Medicine.

Comparison of four different reduction methods for anterior dislocation of the shoulder.

PubMed

Guler, Olcay; Ekinci, Safak; Akyildiz, Faruk; Tirmik, Uzeyir; Cakmak, Selami; Ugras, Akin; Piskin, Ahmet; Mahirogullari, Mahir

2015-05-28

Shoulder dislocations account for almost 50% of all major joint dislocations and are mainly anterior. The aim is a comparative retrospective study of different reduction maneuvers without anesthesia to reduce the dislocated shoulder. Patients were treated with different reduction maneuvers, including various forms of traction and external rotation, in the emergency departments of four training hospitals between 2009 and 2012. Each of the four hospitals had different treatment protocols for reduction and applying one of four maneuvers: Spaso, Chair, Kocher, and Matsen methods. Thirty-nine patients were treated by the Spaso method, 47 by the Chair reduction method, 40 by the Kocher method, and 27 patients by Matsen's traction-countertraction method. All patients' demographic data were recorded. Dislocation number, reduction time, time interval between dislocation and reduction, and associated complications, pre- and post-reduction period, were recorded prospectively. No anesthetic method was used for the reduction. All of the methods used included traction and some external rotation. The Chair method had the shortest reduction time. All surgeons involved in the study agreed that the Kocher and Matsen methods needed more force for the reduction. Patients could contract their muscles because of the pain in these two methods. The Spaso method includes flexion of the shoulder and blocks muscle contraction somewhat. The Chair method was found to be the easiest because the patients could not contract their muscles while sitting on a chair with the affected arm at their side. We suggest that the Chair method is an effective and fast reduction maneuver that may be an alternative for the treatment of anterior shoulder dislocations. Further prospective studies with larger sample size are needed to compare safety of different reduction techniques.

Arthroscopic release of the long head of the biceps tendon: functional outcome and clinical results.

PubMed

Kelly, Anne M; Drakos, Mark C; Fealy, Stephen; Taylor, Samuel A; O'Brien, Stephen J

2005-02-01

Treatment of chronic, refractory biceps tendinitis remains controversial. The authors sought to evaluate clinical and functional outcomes of arthroscopic release of the long head of the biceps tendon. In specific cases of refractory biceps tendinitis, site-specific release of the long head of the biceps tendon may yield relief of pain and symptoms. Case series; Level of evidence, 4. Fifty-four patients diagnosed with biceps tendinitis underwent arthroscopic release of the long head of the biceps tendon as an isolated procedure or as part of a concomitant shoulder procedure over a 2-year period. Patients were not excluded for concomitant shoulder abnormality, including degenerative joint disease, rotator cuff tears, Bankart lesions, or instability. Nine of 40 patients had an isolated arthroscopic release of the biceps tendon. At a minimum of 2 years, the American Shoulder and Elbow Surgeons; the University of California, Los Angeles; and the L'Insalata shoulder questionnaires as well as ipsilateral and contralateral metrics were used for evaluation. The L'Insalata; University of California, Los Angeles; and American Shoulder and Elbow Surgeons scores were 77.6, 27.6, and 75.6, respectively. Seventy percent had a Popeye sign at rest or during active elbow flexion; 82.7% of men and 36.5% of women had a positive Popeye sign (P < .05); 68% were rated as good, very good, or excellent. No patient reported arm pain at rest distally or proximally; 38% of patients complained of fatigue discomfort (soreness) isolated to the biceps muscle after resisted elbow flexion. Arthroscopic release of the long head of the biceps tendon is an appropriate and reliable intervention for patients with chronic, refractory biceps tendinitis. Cosmetic deformity presenting as a positive Popeye sign and fatigue discomfort were the primary complaints. Although tenotomy is not the ideal intervention for patients of all ages with various shoulder abnormalities, data suggest that it may be an acceptable surgical intervention for a specifically selected cohort of individuals.

Rotator cuff degeneration of the healthy shoulder in patients with unilateral arm amputation is not worsened by overuse.

PubMed

Gumina, S; Candela, V; Mariani, L; Venditto, T; Catalano, C; Castellano, S; Santilli, V; Giannicola, G; Castagna, A

2018-01-01

In order to evaluate whether overuse has a significant role in rotator cuff tear (RCT) aetiology, we evaluated both shoulders of patients with old unilateral arm amputation expecting a higher rate of RC degeneration in the healthy side. Nineteen males and six females (mean age: 57.3 ± 10.1) with an old (>20 years) unilateral arm amputation were submitted to an MRI of both shoulders. Tendon status and muscle tropism were evaluated according to Sugaya and Fuchs classifications, respectively; the acromion humeral distance was measured. Statistical analysis was performed to verify the prevalence of Sugaya and Fuchs categories in each sides. A significant prevalence of Sugaya type II in the amputated side (p = 0.02) and of type I in the healthy side (p < 0.001) was found. Rotator cuff was healthy in 28 and 52% of amputated and non-amputated side, respectively. The mean acromio-humeral distances of the amputated and healthy side were 0.8 cm (SD: 0.1) and 0.9 cm (SD: 0.1), respectively, (p = 0.02). A significant prevalence of Fuchs type II category in the healthy side (p < 0.001) was found. Fuchs III/IV were observed in 40 and 12% of amputated and healthy side, respectively. The present study resizes the role of overuse on the aetiology of RCT. Cuff tear prevalence in not amputated shoulders, inevitably submitted to functional overload, was not higher than that of coetaneous subjects with two functional upper limbs. Shoulder non-use is a risk factor for rotator cuff tear. As the prevalence of rotator cuff degeneration/tear is higher in the amputee side, non-use is a more relevant risk factor than overuse. In the daily clinical practice, patients with rotator cuff tear should be encouraged to shoulder movement because rotator cuff tendon status could be worsened by disuse. III.

Triceps brachii muscle reconstruction with a latissimus dorsi muscle flap in a dog.

PubMed

Pavletic, Michael M; Kalis, Russell; Tribou, Patricia; Mouser, Pam J

2015-01-15

A 6-year-old spayed female Border Collie was examined for a severe deformity of the right forelimb. Three months prior to examination, the patient awkwardly fell off the couch and became acutely lame in the right forelimb, progressing to non-weight bearing over the following 72 hours. On physical examination, the dog carried the limb caudally against the thoracic wall, with the shoulder flexed and elbow in extension. The right triceps brachii muscle was atrophied and contracted, resulting in a resistant tension band effect that precluded manipulation of the right elbow joint. The physical changes in the triceps muscle were considered the primary cause of the patient's loss of limb function. Surgical treatment by means of elevation and transposition of the ipsilateral latissimus dorsi muscle was performed. The exposed triceps brachii muscles were transected 3 cm proximal to the tendons of insertion. Via a separate incision, the right latissimus dorsi muscle was elevated and tunneled subcutaneously beneath the interposing skin between the 2 surgical incisions. The muscle was then positioned and sutured to the proximal and distal borders of the divided triceps muscle group. Two weeks later, physical therapy was initiated. After 2 months, the patient regularly walked on the limb most of the time (9/10 steps). The surgical procedure for elevation and transposition of the latissimus dorsi muscle was relatively simple to perform. Physical therapy was an essential component to achieving the successful functional outcome in this case. This technique may be considered for treatment of similar patients in which the triceps muscle group is severely compromised.

Clinical Muscle Testing Compared with Whole-Body Magnetic Resonance Imaging in Facio-scapulo-humeral Muscular Dystrophy.

PubMed

Regula, J U; Jestaedt, L; Jende, F; Bartsch, A; Meinck, H-M; Weber, M-A

2016-12-01

The objective of this study was to evaluate the clinical usefulness of whole-body magnetic resonance imaging (MRI) in facio-scapulo-humeral muscular dystrophy (FSHD). In 20 patients with genetically proven FSHD1, we prospectively assessed muscular involvement and correlated the results of semi-quantitative manual muscle testing and other parameters such as disease duration, creatine kinase (CK) levels and repeat length of the D4Z4 locus with whole-body MRI. Clinical muscle testing revealed the trapezius, pectoralis and infraspinatus as the most severely affected muscles in the shoulder, and the knee flexors and gluteus medius in the hip girdle. MRI revealed the trapezius and serratus anterior muscles in the shoulder, and the hamstrings and adductor muscles in the hip girdle, as the most severely affected muscle groups. Overall, degrees of fatty degeneration on MRI scans correlated significantly with clinical weakness. Moreover, we could detect clear affection of the trunk muscles. Corresponding to earlier reports, asymmetric involvement was frequent in both clinical examination and MRI scoring. Moreover, MRI revealed inhomogeneous muscle degeneration in a considerable proportion of both, muscles and patients. Both clinical and MRI scores significantly correlated to disease duration, but not to fragment size or CK levels. Fatty degeneration in whole-body MRI correlates well to clinical muscle testing of the extremities but gives more information on deeper or trunk muscles. It shows structural changes in muscular disorders and may become an excellent tool for assessment of muscle involvement and follow-up studies.

Impact of movement training on upper limb motor strategies in persons with shoulder impingement syndrome

PubMed Central

Roy, Jean-Sébastien; Moffet, Hélène; McFadyen, Bradford J; Lirette, Richard

2009-01-01

Background Movement deficits, such as changes in the magnitude of scapulohumeral and scapulathoracic muscle activations or perturbations in the kinematics of the glenohumeral, sternoclavicular and scapulothoracic joints, have been observed in people with shoulder impingement syndrome. Movement training has been suggested as a mean to contribute to the improvement of the motor performance in persons with musculoskeletal impairments. However, the impact of movement training on the movement deficits of persons with shoulder impingement syndrome is still unknown. The aim of this study was to evaluate the short-term effects of supervised movement training with feedback on the motor strategies of persons with shoulder impingement syndrome. Methods Thirty-three subjects with shoulder impingement were recruited. They were involved in two visits, one day apart. During the first visit, supervised movement training with feedback was performed. The upper limb motor strategies were evaluated before, during, immediately after and 24 hours after movement training. They were characterized during reaching movements in the frontal plane by EMG activity of seven shoulder muscles and total excursion and final position of the wrist, elbow, shoulder, clavicle and trunk. Movement training consisted of reaching movements performed under the supervision of a physiotherapist who gave feedback aimed at restoring shoulder movements. One-way repeated measures ANOVAs were run to analyze the effect of movement training. Results During, immediately after and 24 hours after movement training with feedback, the EMG activity was significantly decreased compared to the baseline level. For the kinematics, total joint excursion of the trunk and final joint position of the trunk, shoulder and clavicle were significantly improved during and immediately after training compared to baseline. Twenty-four hours after supervised movement training, the kinematics of trunk, shoulder and clavicle were back to the baseline level. Conclusion Movement training with feedback brought changes in motor strategies and improved temporarily some aspects of the kinematics. However, one training session was not enough to bring permanent improvement in the kinematic patterns. These results demonstrate the potential of movement training in the rehabilitation of movement deficits associated with shoulder impingement syndrome. PMID:19445724

Muscular imbalance and shoulder pain in volleyball attackers.

PubMed Central

Kugler, A; Krüger-Franke, M; Reininger, S; Trouillier, H H; Rosemeyer, B

1996-01-01

OBJECTIVE: In overhead sports such as volleyball, baseball, or tennis shoulder problems are very common. The aim of this study was to identify features which may correlate with shoulder problems in volleyball attackers. METHODS: 30 competitive volleyball attackers (mean age 25 years) were included in the study; 15 were suffering from shoulder pain and 15 had no history of shoulder pain. The results were compared with those of a control group of 15 recreational athletes without any overhead sports activities. RESULTS: Volleyball attackers have a different muscular and capsular pattern at the playing shoulder compared to the opposite shoulder. Their playing shoulder is depressed, the scapula lateralised, and the dorsal muscles and the posterior and inferior part of the shoulder capsule shortened. These differences were of more significance in volleyball attackers with shoulder pain than in volleyball players without shoulder pain. In contrast to recreational athletes without any overhead sports activity, there were no significant difference in the comparison of the two shoulders. The histories, clinical and sonographic findings did not reveal further typical features for volleyball attackers with shoulder pain. CONCLUSIONS: Muscular balance of the shoulder girdle is very important in this sport. It is therefore imperative to include adequate stretching and muscular training programme for the prevention, as well as for therapy, of shoulder pain in volleyball attackers. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:8889124

The science of rotator cuff tears: translating animal models to clinical recommendations using simulation analysis.

PubMed

Mannava, Sandeep; Plate, Johannes F; Tuohy, Christopher J; Seyler, Thorsten M; Whitlock, Patrick W; Curl, Walton W; Smith, Thomas L; Saul, Katherine R

2013-07-01

The purpose of this article is to review basic science studies using various animal models for rotator cuff research and to describe structural, biomechanical, and functional changes to muscle following rotator cuff tears. The use of computational simulations to translate the findings from animal models to human scale is further detailed. A comprehensive review was performed of the basic science literature describing the use of animal models and simulation analysis to examine muscle function following rotator cuff injury and repair in the ageing population. The findings from various studies of rotator cuff pathology emphasize the importance of preventing permanent muscular changes with detrimental results. In vivo muscle function, electromyography, and passive muscle-tendon unit properties were studied before and after supraspinatus tenotomy in a rodent rotator cuff injury model (acute vs chronic). Then, a series of simulation experiments were conducted using a validated computational human musculoskeletal shoulder model to assess both passive and active tension of rotator cuff repairs based on surgical positioning. Outcomes of rotator cuff repair may be improved by earlier surgical intervention, with lower surgical repair tensions and fewer electromyographic neuromuscular changes. An integrated approach of animal experiments, computer simulation analyses, and clinical studies may allow us to gain a fundamental understanding of the underlying pathology and interpret the results for clinical translation.

Clinical and radiological outcomes after reverse shoulder arthroplasty in patients with failed deltoid or latissimus dorsi transfers. A review of ten cases.

PubMed

Valenti, Philippe; Maqdes, Ali; Werthel, Jean-David

2017-10-01

The purpose of this study was to report clinical and radiological results of reverse shoulder arthroplasty (RSA) after failure of either a deltoid and/or a latissimus dorsi transfer. Between 2001 and 2011, ten patients (average age, 61 years) underwent primary RSA after a failed tendon transfer for irreparable postero-superior rotator cuff tear (five deltoid muscle transfers, four latissimus dorsi transfers and one both). Average follow-up was 48 months. Outcome measures included pain, range of motion and postoperative Constant-Murley score. Pain score improved significantly from a mean 8.3 to a mean 0.3. Mean shoulder elevation improved from 66 to 134°, and absolute Constant-Murley scores increased from 25.8 to 62.8 The mean improvement in external rotation was limited to 7.5°. Subjectively, six patients rated the result as much better and three rated it as better than before surgery. Failure of the tendon transfer with deterioration of the functional outcomes can be salvaged with a RSA with no impact on the expected outcome.

The biomechanical demands of manual scaling on the shoulders & neck of dental hygienists.

PubMed

La Delfa, Nicholas J; Grondin, Diane E; Cox, Jocelyn; Potvin, Jim R; Howarth, Samuel J

2017-01-01

The purpose of this study was to evaluate the postural and muscular demands placed on the shoulders and neck of dental hygienists when performing a simulated manual scaling task. Nineteen healthy female dental hygienists performed 30-min of simulated manual scaling on a manikin head in a laboratory setting. Surface electromyography was used to monitor muscle activity from several neck and shoulder muscles, and neck and arm elevation kinematics were evaluated using motion capture. The simulated scaling task resulted in a large range of neck and arm elevation angles and excessive low-level muscular demands in the neck extensor and scapular stabilising muscles. The physical demands varied depending on the working position of the hygienists relative to the manikin head. These findings are valuable in guiding future ergonomics interventions aimed at reducing the physical exposures of dental hygiene work. Practitioner Summary: Given that this study evaluates the physical demands of manual scaling, a procedure that is fundamental to dental hygiene work, the findings are valuable to identify ergonomics interventions to reduce the prevalence of work-related injuries, disability and the potential for early retirement among this occupational group.

Beyond the Bottom of the Foot: Topographic Organization of the Foot Dorsum in Walking.

PubMed

Klarner, Taryn; Pearcey, Gregory E P; Sun, Yao; Barss, Trevor S; Kaupp, Chelsea; Munro, Bridget; Frank, Nick; Zehr, E Paul

2017-12-01

Sensory feedback from the foot dorsum during walking has only been studied globally by whole nerve stimulation. Stimulating the main nerve innervating the dorsal surface produces a functional stumble corrective response that is phase-dependently modulated. We speculated that effects evoked by activation of discrete skin regions on the foot dorsum would be topographically organized, as with the foot sole. Nonnoxious electrical stimulation was delivered to five discrete locations on the dorsal surface of the foot during treadmill walking. Muscle activity from muscles acting at the ankle, knee, hip, and shoulder were recorded along with ankle, knee, and hip kinematics and kinetic information from forces under the foot. All data were sorted on the basis of stimulus occurrence in 12 step cycle phases, before being averaged together within a phase for subsequent analysis. Results reveal dynamic changes in reflex amplitudes and kinematics that are site specific and phase dependent. Most responses from discrete sites on the foot dorsum were seen in the swing phase suggesting function to conform foot trajectory to maintain stability of the moving limb. In general, responses from lateral stimulation differed from medial stimulation, and effects were largest from stimulation at the distal end of the foot at the metatarsals; that is, in anatomical locations where actual impact with an object in the environment is most likely during swing. Responses to stimulation extend to include muscles at the hip and shoulder. We reveal that afferent feedback from specific cutaneous locations on the foot dorsum influences stance and swing phase corrective responses. This emphasizes the critical importance of feedback from the entire foot surface in locomotor control and has application for rehabilitation after neurological injury and in footwear development.

Scapular muscle activity in a variety of plyometric exercises.

PubMed

Maenhout, Annelies; Benzoor, Maya; Werin, Maria; Cools, Ann

2016-04-01

Plyometric shoulder exercises are commonly used to progress from slow analytical strength training to more demanding high speed power training in the return to play phase after shoulder injury. The aim of this study was first, to investigate scapular muscle activity in plyometric exercises to support exercise selection in practice and second, to enhance understanding of how scapular muscles are recruited during the back and forth movement phase of these exercises. Thirty-two healthy subjects performed 10 plyometric exercises while surface EMG-activity of the scapular muscles (upper (UT), middle (MT) and lower trapezius (LT) and serratus anterior (SA)) was registered. A high speed camera tracked start and end of the back and forth movement. Mean scapular EMG activity during the 10 exercises ranged from 14.50% to 76.26%MVC for UT, from 15.19% to 96.55%MVC for MT, from 13.18% to 94.35%MVC for LT and from 13.50% to 98.50%MVC for SA. Anova for repeated measures showed significant differences in scapular muscle activity between exercises (p<0.001) and between the back and forth movement (p<0.001) within exercises. Plyometric shoulder exercises require moderate (31-60%MVC) to high (>60%MVC) scapular muscle activity. Highest MT/LT activity was present in prone plyometric external rotation and flexion. Highest SA activity was found in plyometric external rotation and flexion with Xco and plyometric push up on Bosu. Specific exercises can be selected that recruit minimal levels of UT activity (<15%): side lying plyometric external rotation and horizontal abduction or plyometric push up on the Bosu. The results of this study support exercise selection for clinical practice. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluating biomechanics of user-selected sitting and standing computer workstation.

PubMed

Lin, Michael Y; Barbir, Ana; Dennerlein, Jack T

2017-11-01

A standing computer workstation has now become a popular modern work place intervention to reduce sedentary behavior at work. However, user's interaction related to a standing computer workstation and its differences with a sitting workstation need to be understood to assist in developing recommendations for use and set up. The study compared the differences in upper extremity posture and muscle activity between user-selected sitting and standing workstation setups. Twenty participants (10 females, 10 males) volunteered for the study. 3-D posture, surface electromyography, and user-reported discomfort were measured while completing simulated tasks with each participant's self-selected workstation setups. Sitting computer workstation associated with more non-neutral shoulder postures and greater shoulder muscle activity, while standing computer workstation induced greater wrist adduction angle and greater extensor carpi radialis muscle activity. Sitting computer workstation also associated with greater shoulder abduction postural variation (90th-10th percentile) while standing computer workstation associated with greater variation for should rotation and wrist extension. Users reported similar overall discomfort levels within the first 10 min of work but had more than twice as much discomfort while standing than sitting after 45 min; with most discomfort reported in the low back for standing and shoulder for sitting. These different measures provide understanding in users' different interactions with sitting and standing and by alternating between the two configurations in short bouts may be a way of changing the loading pattern on the upper extremity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Functional capacity and muscular abnormalities in subclinical hypothyroidism.

PubMed

Reuters, Vaneska S; Teixeira, Patrícia de Fátima S; Vigário, Patrícia S; Almeida, Cloyra P; Buescu, Alexandre; Ferreira, Márcia M; de Castro, Carmen L N; Gold, Jaime; Vaisman, Mario

2009-10-01

Neuromuscular abnormalities and low exercise tolerance are frequently observed in overt hypothyroidism, but it remains controversial if they can also occur in subclinical hypothyroidism (sHT). The aim of this study is to evaluate neuromuscular symptoms, muscle strength, and exercise capacity in sHT, compared with healthy euthyroid individuals. A cross-sectional study was performed with 44 sHT and 24 euthyroid outpatients from a university hospital. Neuromuscular symptoms were questioned. Muscle strength was tested for neck, shoulder, arm, and hip muscle groups, using manual muscle testing (MMT). Quadriceps muscle strength was tested with a chair dynamometer and inspiratory muscle strength (IS) by a manuvacuometer. Functional capacity was estimated based on the peak of oxygen uptake (mL/kg/min), using the Bruce treadmill protocol. Cramps (54.8% versus 25.0%; P < 0.05), weakness (45.2% versus 12.6; P < 0.05), myalgia (47.6% versus 25.0%; P = 0.07), and altered MMT (30.8% versus 8.3%; P = 0.040) were more frequent in sHT. Quadriceps strength and IS were not impaired in sHT and the same was observed for functional capacity. IS was significantly lower in patients complaining of fatigue and weakness (P < 0.05) and tended to be lower in those with altered MMT (P = 0.090). Neuromuscular complaints and altered MMT were significantly more frequent in sHT than in controls, and IS was lower in patients with these abnormalities. Results suggest that altered muscle strength by MMT and the coexistence of neuromuscular complaints in patients with sHT may indicate neuromuscular dysfunction.

Alternative pre-rigor foreshank positioning can improve beef shoulder muscle tenderness.

PubMed

Grayson, A L; Lawrence, T E

2013-09-01

Thirty beef carcasses were harvested and the foreshank of each side was independently positioned (cranial, natural, parallel, or caudal) 1h post-mortem to determine the effect of foreshank angle at rigor mortis on the sarcomere length and tenderness of six beef shoulder muscles. The infraspinatus (IS), pectoralis profundus (PP), serratus ventralis (SV), supraspinatus (SS), teres major (TM) and triceps brachii (TB) were excised 48 h post-mortem for Warner-Bratzler shear force (WBSF) and sarcomere length evaluations. All muscles except the SS had altered (P<0.05) sarcomere lengths between positions; the cranial position resulted in the longest sarcomeres for the SV and TB muscles whilst the natural position had longer sarcomeres for the PP and TM muscles. The SV from the cranial position had lower (P<0.05) shear than the caudal position and TB from the natural position had lower (P<0.05) shear than the parallel or caudal positions. Sarcomere length was moderately correlated (r=-0.63; P<0.01) to shear force. Copyright © 2013 Elsevier Ltd. All rights reserved.

Early motor learning changes in upper-limb dynamics and shoulder complex loading during handrim wheelchair propulsion.

PubMed

Vegter, Riemer J K; Hartog, Johanneke; de Groot, Sonja; Lamoth, Claudine J; Bekker, Michel J; van der Scheer, Jan W; van der Woude, Lucas H V; Veeger, Dirkjan H E J

2015-03-10

To propel in an energy-efficient manner, handrim wheelchair users must learn to control the bimanually applied forces onto the rims, preserving both speed and direction of locomotion. Previous studies have found an increase in mechanical efficiency due to motor learning associated with changes in propulsion technique, but it is unclear in what way the propulsion technique impacts the load on the shoulder complex. The purpose of this study was to evaluate mechanical efficiency, propulsion technique and load on the shoulder complex during the initial stage of motor learning. 15 naive able-bodied participants received 12-minutes uninstructed wheelchair practice on a motor driven treadmill, consisting of three 4-minute blocks separated by two minutes rest. Practice was performed at a fixed belt speed (v = 1.1 m/s) and constant low-intensity power output (0.2 W/kg). Energy consumption, kinematics and kinetics of propulsion technique were continuously measured. The Delft Shoulder Model was used to calculate net joint moments, muscle activity and glenohumeral reaction force. With practice mechanical efficiency increased and propulsion technique changed, reflected by a reduced push frequency and increased work per push, performed over a larger contact angle, with more tangentially applied force and reduced power losses before and after each push. Contrary to our expectations, the above mentioned propulsion technique changes were found together with an increased load on the shoulder complex reflected by higher net moments, a higher total muscle power and higher peak and mean glenohumeral reaction forces. It appears that the early stages of motor learning in handrim wheelchair propulsion are indeed associated with improved technique and efficiency due to optimization of the kinematics and dynamics of the upper extremity. This process goes at the cost of an increased muscular effort and mechanical loading of the shoulder complex. This seems to be associated with an unchanged stable function of the trunk and could be due to the early learning phase where participants still have to learn to effectively use the full movement amplitude available within the wheelchair-user combination. Apparently whole body energy efficiency has priority over mechanical loading in the early stages of learning to propel a handrim wheelchair.

Rotator cuff tears: An evidence based approach

PubMed Central

Sambandam, Senthil Nathan; Khanna, Vishesh; Gul, Arif; Mounasamy, Varatharaj

2015-01-01

Lesions of the rotator cuff (RC) are a common occurrence affecting millions of people across all parts of the globe. RC tears are also rampantly prevalent with an age-dependent increase in numbers. Other associated factors include a history of trauma, limb dominance, contralateral shoulder, smoking-status, hypercholesterolemia, posture and occupational dispositions. The challenge lies in early diagnosis since a high proportion of patients are asymptomatic. Pain and decreasing shoulder power and function should alert the heedful practitioner in recognizing promptly the onset or aggravation of existing RC tears. Partial-thickness tears (PTT) can be bursal-sided or articular-sided tears. Over the course of time, PTT enlarge and propagate into full-thickness tears (FTT) and develop distinct chronic pathological changes due to muscle retraction, fatty infiltration and muscle atrophy. These lead to a reduction in tendon elasticity and viability. Eventually, the glenohumeral joint experiences a series of degenerative alterations - cuff tear arthropathy. To avert this, a vigilant clinician must utilize and corroborate clinical skill and radiological findings to identify tear progression. Modern radio-diagnostic means of ultrasonography and magnetic resonance imaging provide excellent visualization of structural details and are crucial in determining further course of action for these patients. Physical therapy along with activity modifications, anti-inflammatory and analgesic medications form the pillars of nonoperative treatment. Elderly patients with minimal functional demands can be managed conservatively and reassessed at frequent intervals. Regular monitoring helps in isolating patients who require surgical interventions. Early surgery should be considered in younger, active and symptomatic, healthy patients. In addition to being cost-effective, this helps in providing a functional shoulder with a stable cuff. An easily reproducible technique of maximal strength and sturdiness should by chosen among the armamentarium of the shoulder surgeon. Grade 1 PTTs do well with debridement while more severe lesions mandate repair either by trans-tendon technique or repair following conversion into FTT. Early repair of repairable FTT can avoid appearance and progression of disability and weakness. The choice of surgery varies from surgeon-to-surgeon with arthroscopy taking the lead in the current scenario. The double-row repairs have an edge over the single-row technique in some patients especially those with massive tears. Stronger, cost-effective and improved functional scores can be obtained by the former. Both early and delayed postoperative rehabilitation programmes have led to comparable outcomes. Guarded results may be anticipated in patients in extremes of age, presence of comorbidities and severe tear patters. Overall, satisfactory results are obtained with timely diagnosis and execution of the appropriate treatment modality. PMID:26716086

Treatment Strategy for Irreparable Rotator Cuff Tears

PubMed Central

Oh, Joo Han; Rhee, Sung Min

2018-01-01

Recently, patients with shoulder pain have increased rapidly. Of all shoulder disorders, rotator cuff tears (RCTs) are most prevalent in the middle-aged and older adults, which is the primary reason for shoulder surgery in the population. Some authors have reported that up to 30% of total RCTs can be classified as irreparable due to the massive tear size and severe muscle atrophy. In this review article, we provide an overview of treatment methods for irreparable massive RCTs and discuss proper surgical strategies for RCTs that require operative management. PMID:29854334

A comparison of trapezius muscle activities of different shoulder abduction angles and rotation conditions during prone horizontal abduction

PubMed Central

Lim, Jin Yong; Lee, Jung Seok; Mun, Byeong Mu; Kim, Tae Ho

2015-01-01

[Purpose] This study examined the differences in the activities of three parts of the trapezius muscle—the upper trapezius (UT), middle trapezius (MT), and lower trapezius (LT)—among three different rotation conditions of the shoulders, while subjects performed prone horizontal abduction (PHA) at 30°, 60°, 90°, and 120° of abduction. [Subjects and Methods] The subjects of this experimental study were 16 healthy male adults. Surface electromyography was used to collect data on the activity of each part of the trapezius. A two-way analysis of variance was used to compare the activities of each area of the trapezius—the UT, MT, and LT—among internal rotation (IR), the neutral position (NP), and external rotation (ER) of the shoulders during PHA with shoulder abduction of 30°, 60°, 90°, and 120°. [Results] Activity of the UT, MT, and LT significantly increased as the shoulder abduction angle increased during PHA. There was a significant difference only in the activity of the LT, with change in shoulder rotation. In addition, the muscle activity of the LT was highest during shoulder IR at 120°. [Conclusion] Although activity of the LT was the highest during IR at 120 abduction, PHA accompanied by ER at an abduction angle of 120° would be effective at eliciting high activity in the LT when PHA is performed. Nonetheless, at an early stage of rehabilitation, PHA accompanied by ER at low abduction angles of 30° and 60° would be desirable to elicit low activity of the UT and high activity of the LT. PMID:25642047

Reliability of rehabilitative ultrasonographic imaging for muscle thickness measurement of the rhomboid major.

PubMed

Jeong, Ju Ri; Ko, Young Jun; Ha, Hyun Geun; Lee, Wan Hee

2016-03-01

This study was to establish inter-rater and intrarater reliability of the rehabilitative ultrasonographic imaging (RUSI) technique for muscle thickness measurement of the rhomboid major at rest and with the shoulder abducted to 90°. Twenty-four young adults (eight men, 16 women; right-handed; mean age [±SD], 24·4 years [±2·6]) with no history of neck, shoulder, or arm pain were recruited. Rhomboid major muscle images were obtained in the resting position and with shoulder in 90° abduction using an ultrasonography system with a 7·5-MHz linear transducer. In these two positions, the examiners found the site at which the transducer could be placed. Two examiners obtained the images of all participants in three test sessions at random. Intraclass correlation coefficients (ICC) were used to estimate reliability. All ICCs (95% CI) were >0·75, ranging from 0·93 to 0·98, which indicates good reliability. The ICCs for inter-rater reliability ranged from 0·75 to 0·94. For the absolute value of the difference in the intra-examiner reliability between the right and left ratios, the ICCs ranged from 0·58 to 0·91. In this study, the intra- and interexaminer reliability of muscle thickness measurements of the rhomboid major were good. Therefore, we suggest that muscle thickness measurements of the rhomboid major obtained with the RUSI technique would be useful for clinical rehabilitative assessment. © 2014 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Ultrasound elastography-based assessment of the elasticity of the supraspinatus muscle in impingement syndrome: does elastography has any diagnostic value?

PubMed

Demirel, Adnan; Baykara, Murat; Koca, Tuba Tülay; Berk, Ejder

2018-06-01

Ultrasound elastography (UE) is a new ultrasound-based imaging technique that provides information about elasticity and stiffness of tissues. This cross-sectional study aimed to identify the diagnostic importance of UE in supraspinatus impingement syndrome. Forty-one subjects, aged 38-70 years, were included in the study. UE was used to determine the elasticity of the supraspinatus muscle. The strain ratio was calculated as the evaluation criteria to measure the elasticity of the muscle. High strain ratio indicated low elasticity. The measurements were made by the blinded radiologist while the patients sat with their shoulder in a neutral position. The diagnostic value of the strain ratio was evaluated using the receiver operating characteristic (ROC) analysis. The mean strain value of the supraspinatus muscle on the intact and pathological shoulders determined by UE was 0.74 ± 0.33 and 0.31 ± 0.24, respectively. A low strain ratio value in the supraspinatus muscle on the side with impingement syndrome was measured. When the test variable was evaluated as "strain ratio" according to ROC curve analysis, it was found to be above the reference line [0.849 (> 0.5)] (P = 0.00). When the cutoff value was selected as 0.495, the sensitivity and specificity were found to be 75.6 and 78% (the strain ratio value > 0.495), respectively. Measurement of strain ratio with UE can be used as a noninvasive, inexpensive, and practical diagnostic test for the shoulder impingement disease.

Muscular and metabolic responses to different Nordic walking techniques, when style matters.

PubMed

Pellegrini, Barbara; Boccia, Gennaro; Zoppirolli, Chiara; Rosa, Raffaela; Stella, Federico; Bortolan, Lorenzo; Rainoldi, Alberto; Schena, Federico

2018-01-01

Due to poling action and upper body engagement, Nordic walking (NW) has additional health benefits with respect to conventional walking. The aim of this study was to evaluate the differences in muscle activation and metabolic responses between NW, performed with the technique suggested by NW instructors, and with some modifications in the way to move upper limb and poles. Ten NW instructors volunteered to walk on a treadmill at 5.5 km•h-1 in five conditions: walking (W), Nordic walking (NW), NW with a weak poling action (NWweak), with straight-upper limbs moving the shoulders (NWshoulder) and with elbow flexion-extension pattern and shoulder freezed (NWelbow). Poling forces, body segments and poles movement, upper and lower body muscle activation, as well as metabolic parameters were measured.All modified NW techniques elicited lower muscular activation and metabolic responses with respect to the suggested NW technique (P < 0.05). All NW techniques elicited higher muscular activation and metabolic responses than W. All parameters observed with the NWweak were lower than NW. A decreased activation of shoulder extensor muscles and increased activation of anterior deltoid muscle were the main features of NWshoulder. Lower triceps brachii muscle activation and reduced propulsive poling action with respect to NW were seen for NWelbow, resulting also in shorter steps.Nordic walking instructors, sport technicians and practitioners should be aware that any deviation from the technique usually suggested might lead to lower benefits. However it is worth to note that any walking technique with poles elicits higher metabolic responses and muscular activation than walking.

What is the effect of a shoulder-strengthening program to prevent shoulder pain among junior female team handball players?

PubMed Central

Sommervold, Maria; Østerås, Håvard

2017-01-01

Background Excessively high stresses are applied to the shoulder joint of handball players, mainly caused by overhead throwing. Shoulder pain is a significant problem among junior female team handball players and both male and female top-level team handball players in Norway. Method A randomized selection was performed among the best female junior teams (J 16) in the Trøndelag region of Norway in the 2014–2015 season. Three teams were randomized to the intervention group and three teams to the control group. Players in the intervention group (n=53) participated in a seven-month, three-times-a-week shoulder-muscle strength-training program, while those in the control group (n=53) participated in a comparable handball training, but did not conduct any specific strength training during the season. Results A strength-training program had no effect on the prevention of shoulder pain. Overall, the players reported shoulder pain, but graded the pain low on visual analog scale (VAS). Both the intervention group and the control group reported pain under 1 on VAS at baseline and posttest, and there was no significant difference within or between the groups when it came to the intensity of pain reported on VAS. A significant difference (p<0.048) was found between the groups on the sport-specific part of the quick-Disability of the Arm, Shoulder and Hand (DASH) form, but it did not fulfill the minimal demand to change and the players scored it low, something that indicates little functional problems when it comes to team handball. The intervention group was significantly stronger (p<0.008) on the push-ups test compared to the control group on the posttest. The intervention group increased the number of push-ups from 3.1 to 6.4, while the control group went from 2.3 to 3.6. Aside from this, there were no significant differences in between the groups. Conclusion A shoulder-strengthening program had no effect on the prevention of shoulder pain among junior female team handball players. PMID:28435335

What is the effect of a shoulder-strengthening program to prevent shoulder pain among junior female team handball players?

PubMed

Sommervold, Maria; Østerås, Håvard

2017-01-01

Excessively high stresses are applied to the shoulder joint of handball players, mainly caused by overhead throwing. Shoulder pain is a significant problem among junior female team handball players and both male and female top-level team handball players in Norway. A randomized selection was performed among the best female junior teams (J 16) in the Trøndelag region of Norway in the 2014-2015 season. Three teams were randomized to the intervention group and three teams to the control group. Players in the intervention group (n=53) participated in a seven-month, three-times-a-week shoulder-muscle strength-training program, while those in the control group (n=53) participated in a comparable handball training, but did not conduct any specific strength training during the season. A strength-training program had no effect on the prevention of shoulder pain. Overall, the players reported shoulder pain, but graded the pain low on visual analog scale (VAS). Both the intervention group and the control group reported pain under 1 on VAS at baseline and posttest, and there was no significant difference within or between the groups when it came to the intensity of pain reported on VAS. A significant difference ( p <0.048) was found between the groups on the sport-specific part of the quick-Disability of the Arm, Shoulder and Hand (DASH) form, but it did not fulfill the minimal demand to change and the players scored it low, something that indicates little functional problems when it comes to team handball. The intervention group was significantly stronger ( p <0.008) on the push-ups test compared to the control group on the posttest. The intervention group increased the number of push-ups from 3.1 to 6.4, while the control group went from 2.3 to 3.6. Aside from this, there were no significant differences in between the groups. A shoulder-strengthening program had no effect on the prevention of shoulder pain among junior female team handball players.

Electromyography (EMG) analysis on impact of classroom chair and table usage among primary school students in Perlis

NASA Astrophysics Data System (ADS)

Jing, Ewe Hui; Shan, Lim Shaiu; Effendi, M. S. M.; Rosli, Muhamad Farizuan

2017-09-01

The existing design of primary school classroom chair and table had brought low back pain, neck pain and shoulder pain problems respectively among students in primary school. The purpose of this study is to relate the electromyography (EMG) analysis with the most critical area of the body during sitting and writing. Six male and six female primary school students from SK Seri Perlis with no back pain, neck pain and shoulder pain problems involved were invited as respondents in this study. EMG experiment was carried out by first determined the critical point at T9 and L3 from thoracic and lumbar segment respectively for ECG electrode placement and performed with a series of sitting trials for analysis. The sitting trials performed were slouch to lumbopelvic sitting and slouch to thoracic sitting follow by instruction. Next, the electrode placement was identified at C2-C3 on cervical spine for neck and at midpoint between C7 to the lateral edge of acromion spanning for shoulder respectively. These points were identified for a series of writing task performing for the EMG analysis. There were two type of writing task which included writing by looking at the whiteboard and paper placed on the table. The subjects were instructed to rest during the experiment when necessary. During lumbopelvic sitting posture, the average muscle activation on lumbar area was at the highest peak. The peak indicated that there was critical effect from the experimental finding. The performance of writing task from whiteboard gave rise a higher impact on neck muscle while writing task from paper had a greater impact on shoulder muscle. The critical affected muscle on these areas was proven on these written tasks. The EMG experiment showed that the existing design of primary school classroom chair and table had brought impact on lumbar, neck and shoulder towards the students who were using. A future recommendation suggests that to redesign primary school classroom chair and table which develop with prototype for improvement of EMG result testing.

Reliability of magnetic resonance imaging assessment of rotator cuff: the ROW study.

PubMed

Jain, Nitin B; Collins, Jamie; Newman, Joel S; Katz, Jeffrey N; Losina, Elena; Higgins, Laurence D

2015-03-01

Physiatrists encounter patients with rotator cuff disorders, and imaging is frequently an important component of their diagnostic assessment. However, there is a paucity of literature on the reliability of magnetic resonance imaging (MRI) assessment between shoulder specialists and musculoskeletal radiologists. We assessed inter- and intrarater reliability of MRI characteristics of the rotator cuff. Cross-sectional secondary analyses in a prospective cohort study. Academic tertiary care centers. Subjects with shoulder pain were recruited from orthopedic and physiatry clinics. Two shoulder-fellowship-trained physicians (a physiatrist and a shoulder surgeon) jointly performed a blinded composite MRI review by consensus of 31 subjects with shoulder pain. Subsequently, MRI was reviewed by one fellowship-trained musculoskeletal radiologist. We calculated the Cohen kappa coefficients and percentage agreement among the 2 reviews (composite review of 2 shoulder specialists versus that of the musculoskeletal radiologist). Intrarater reliability was assessed among the shoulder specialists by performing a repeated blinded composite MRI review. In addition to this repeated composite review, only one of the physiatry shoulder specialists performed an additional review. Interrater reliability (shoulder specialists versus musculoskeletal radiologist) was substantial for the presence or absence of tear (kappa 0.90 [95% confidence interval {CI}, 0.72-1.00]), tear thickness (kappa 0.84 [95% CI, 0.70-0.99]), longitudinal size of tear (kappa 0.75 [95% CI, 0.44-1.00]), fatty infiltration (kappa 0.62 [95% CI, 0.45-0.79]), and muscle atrophy (kappa 0.68 [95% CI, 0.50-0.86]). There was only fair interrater reliability of the transverse size of tear (kappa 0.20 [95% CI, 0.00-0.51]). The kappa for intrarater reliability was high for tear thickness (0.88 [95% CI, 0.72-1.00]), longitudinal tear size (0.61 [95% CI, 0.22-0.99]), fatty infiltration (0.89 [95% CI, 0.80,-0.98]), and muscle atrophy (0.87 [95% CI, 0.76-0.98]). Intrarater reliability for the individual shoulder specialist was similar to that of the composite reviews. There was high interrater and intrarater reliability for most findings on shoulder MRI. Analysis of our data supports the reliability of MRI assessment by shoulder specialists for rotator cuff disorders. Copyright © 2015 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Ultrasonography of the equine shoulder: technique and normal appearance.

PubMed

Tnibar, M A; Auer, J A; Bakkali, S

1999-01-01

This study was intended to document normal ultrasonographic appearance of the equine shoulder and anatomic landmarks useful in clinical imaging. Both forelimbs of five equine cadavers and both forelimbs of six live adult horses were used. To facilitate understanding of the images, a zoning system assigned to the biceps brachii and to the infraspinatus tendon was developed. Ultrasonography was performed with a real-time B-mode semiportable sector scanner using 7.5- and 5-MHz transducers. On one cadaver limb, magnetic resonance imaging (MRI) was performed using a system at 1.5 Tesla, T1-weighted spin-echo sequence. Ultrasonography images were compared to frozen specimens and MRI images to correlate the ultrasonographic findings to the gross anatomy of the shoulder. Ultrasonography allowed easy evaluation of the biceps brachii and the infraspinatus tendon and their bursae, the supraspinatus muscle and tendons, the superficial muscles of the shoulder, and the underlying humerus and scapula. Only the lateral and, partially, the caudal aspects of the humeral head could be visualized with ultrasound. Ultrasonographic appearance, orientation, and anatomic relationships of these structures are described. Ultrasonographic findings correlated well with MRI images and with gross anatomy in the cadavers' limbs.

Shoulder strength imbalances as injury risk in handball.

PubMed

Edouard, P; Degache, F; Oullion, R; Plessis, J-Y; Gleizes-Cervera, S; Calmels, P

2013-07-01

This study was conducted to analyze whether internal (IR) and external (ER) rotator shoulder muscles weakness and/or imbalance collected through a preseason assessment could be predictors of subsequent shoulder injury during a season in handball players. In preseason, 16 female elite handball players (HPG) and 14 healthy female nonathletes (CG) underwent isokinetic IR and ER strength test with use of a Con-Trex® dynamometer in a seated position with 45° shoulder abduction in scapular plane, at 60, 120 and 240°/s in concentric and at 60°/s in eccentric, for both sides. An imbalanced muscular strength profile was determined using -statistically selected cut-offs from CG values. For HPG, all newly incurred shoulder injuries were reported during the season. There were significant differences between HPG and CG only for dominant eccentric IR strength, ER/IR ratio at 240°/s and for IRecc/ERcon ratio. In HPG, IR and ER strength was higher, and ER/IR ratios lower for dominant than for nondominant side. The relative risk was 2.57 (95%CI: 1.60-3.54; P<0.05) if handball players had an imbalanced muscular strength profile. In youth female handball players IR and ER muscle strength increases on the dominant side without ER/IR imbalances; and higher injury risk was associated with imbalanced muscular strength profile. © Georg Thieme Verlag KG Stuttgart · New York.

Evaluation of a dynamic arm support for seated and standing tasks: a laboratory study of electromyography and subjective feedback.

PubMed

Odell, Dan; Barr, Alan; Goldberg, Robert; Chung, Jeffrey; Rempel, David

2007-04-01

The goal of this study was to determine whether a new dynamic arm support system reduced shoulder and arm muscle load for seated and standing hand/ arm tasks. The new system provides support for both horizontal and vertical arm motion. A total of 11 participants performed ten tasks (five seated and five standing) both with and without the arm support. Outcomes were assessed with electromyography and subjective feedback. Muscle activity was measured over the dominant side supraspinatus, triceps and forearm extensor muscles. Significant (p < 0.01) reductions in static muscle activity were observed in one of ten tasks performed with the support device for the supraspinatus muscle, in five tasks for the triceps and in one task for forearm extensor muscles. Likewise, a significant improvement in subjective measures was reported with the support device for 'ease of task' for two of ten tasks, for 'forearm comfort' for three of ten tasks and for 'shoulder effort' for six of ten tasks. The results suggest that a dynamic forearm support may improve subjective comfort and reduce static muscle loads in the upper extremity for tasks that involve horizontal movement of the arms. For rapid motions, the value of the support is limited due to internal inertia and friction.

Integration of active pauses and pattern of muscular activity during computer work.

PubMed

St-Onge, Nancy; Samani, Afshin; Madeleine, Pascal

2017-09-01

Submaximal isometric muscle contractions have been reported to increase variability of muscle activation during computer work; however, other types of active contractions may be more beneficial. Our objective was to determine which type of active pause vs. rest is more efficient in changing muscle activity pattern during a computer task. Asymptomatic regular computer users performed a standardised 20-min computer task four times, integrating a different type of pause: sub-maximal isometric contraction, dynamic contraction, postural exercise and rest. Surface electromyographic (SEMG) activity was recorded bilaterally from five neck/shoulder muscles. Root-mean-square decreased with isometric pauses in the cervical paraspinals, upper trapezius and middle trapezius, whereas it increased with rest. Variability in the pattern of muscular activity was not affected by any type of pause. Overall, no detrimental effects on the level of SEMG during active pauses were found suggesting that they could be implemented without a cost on activation level or variability. Practitioner Summary: We aimed to determine which type of active pause vs. rest is best in changing muscle activity pattern during a computer task. Asymptomatic computer users performed a standardised computer task integrating different types of pauses. Muscle activation decreased with isometric pauses in neck/shoulder muscles, suggesting their implementation during computer work.

Massage Therapy and Frequency of Chronic Tension Headaches

PubMed Central

Quinn, Christopher; Chandler, Clint; Moraska, Albert

2002-01-01

Objectives. The effect of massage therapy on chronic nonmigraine headache was investigated. Methods. Chronic tension headache sufferers received structured massage therapy treatment directed toward neck and shoulder muscles. Headache frequency, duration, and intensity were recorded and compared with baseline measures. Results. Compared with baseline values, headache frequency was significantly reduced within the first week of the massage protocol. The reduction of headache frequency continued for the remainder of the study (P = .009). The duration of headaches tended to decrease during the massage treatment period (P = .058). Headache intensity was unaffected by massage (P = .19). Conclusions. The muscle-specific massage therapy technique used in this study has the potential to be a functional, nonpharmacological intervention for reducing the incidence of chronic tension headache. PMID:12356617

Successful Outcome of Modified Quad Surgical Procedure in Preteen and Teen Patients with Brachial Plexus Birth Palsy

PubMed Central

Nath, Rahul K.; Somasundaram, Chandra

2012-01-01

Objective: To evaluate the outcome of modified Quad procedure in preteen and teen patients with brachial plexus birth palsy. Background: We have previously demonstrated a significant improvement in shoulder abduction, resulting from the modified Quad procedure in children (mean age 2.5 years; range, 0.5–9 years) with obstetric brachial plexus injury. Methods: We describe in this report the outcome of 16 patients (6 girls and 10 boys; 7 preteen and 9 teen) who have undergone the modified Quad procedure for the correction of the shoulder function, specifically abduction. The patients underwent transfer of the latissimus dorsi and teres major muscles, release of contractures of subscapularis pectoralis major and minor, and axillary nerve decompression and neurolysis (the modified Quad procedure). Mean age of these patients at surgery was 13.5 years (range, 10.1–17.9 years). Results: The mean preoperative total Mallet score was 14.8 (range, 10–20), and active abduction was 84° (range, 20°–140°). At a mean follow-up of 1.5 years, the mean postoperative total Mallet score increased to 19.7 (range, 13–25, P < .0001), and the mean active abduction improved to 132° (range, 40°–180°, P < .0003). Conclusion: The modified Quad procedure greatly improves not only the active abduction but also other shoulder functions in preteen and teen patients, as this outcome is the combined result of decompression and neurolysis of the axillary nerve and the release of the contracted internal rotators of the shoulder. PMID:23308301

Subdeltoid/subacromial bursitis associated with influenza vaccination.

PubMed

Cook, Ian F

2014-01-01

A 76-year-old male presented with subacromial/subdeltoid bursitis following influenza vaccine administration into the left deltoid muscle. This shoulder injury related to vaccine administration (SIRVA) could have been prevented by the use of a safe, evidence based protocol for the intramuscular injection of the deltoid muscle.

Muscle atrophy and fatty infiltration after an acute rotator cuff repair in a sheep model

PubMed Central

Luan, Tammy; Liu, Xuhui; Easley, Jeremiah T.; Ravishankar, Bharat; Puttlitz, Christian; Feeley, Brian T.

2015-01-01

Summary Introduction rotator cuff tears (RCTs) are the most common tendon injury seen in orthopedic patients. Muscle atrophy and fatty infiltration of the muscle are crucial factors that dictate the outcome following rotator cuff surgery. Though less studied in humans, rotator cuff muscle fibrosis has been seen in animal models as well and may influence outcomes as well. The purpose of this study was to determine if the rotator cuff would develop muscle changes even in the setting of an acute repair in a sheep model. We hypothesized that fatty infiltration and fibrosis would be present even after an acute repair six months after initial surgery. Methods twelve female adult sheep underwent an acute rotator cuff tear and immediate repair on the right shoulder. The left shoulder served as a control and did not undergo a tear or a repair. Six months following acute rotator cuff repairs, sheep muscles were harvested to study atrophy, fatty infiltration, and fibrosis by histological analysis, western blotting, and reverse transcription polymerase chain reaction (RT-PCR). Results the repair group demonstrated an increase expression of muscle atrophy, fatty infiltration, and fibrosis related genes. Significantly increased adipocytes, muscle fatty infiltration, and collagen deposition was observed in rotator cuff muscles in the tendon repair group compared to the control group. Conclusions rotator cuff muscle undergoes degradation changes including fatty infiltration and fibrosis even after the tendons are repair immediately after rupture. Level of Evidence Basic Science Study. PMID:26261789

Efficacy and safety of guaifenesin for upper back, neck, and shoulder pain: a Phase II proof-of-concept, multicenter, placebo-controlled, repeat-dose, parallel-group study.

PubMed

Collaku, Agron; Yue, Yong; Reed, Kenneth

2017-01-01

Guaifenesin, an over-the-counter (OTC) expectorant, has exhibited muscle relaxant effects preclinically and clinically. This proof-of-principle study explored whether OTC doses of guaifenesin can provide relief from acute upper back, neck, or shoulder muscle spasm and pain. This multicenter, placebo-controlled, repeat-dose, parallel study randomly assigned adults experiencing acute pain and muscle spasm in their upper back, neck, or shoulder to guaifenesin 600 or 1200 mg or matched placebo twice daily (BID) in a 2:2:1:1 ratio for 7 days. The primary end point was the change from baseline in muscle spasm relief, measured using an 11-point numeric rating scale (0=not present to 10=unbearable) recorded twice daily and averaged over the 7-day treatment period. Analyses were performed using a linear mixed model that included treatment as a fixed effect and site as a random effect. A total of 77 subjects were included in the 4 treatment groups. Least squares mean muscle spasm score over 7 days was 1.77 with guaifenesin 1200 mg, 1.42 with its matched placebo, 1.53 with guaifenesin 600 mg, and 1.74 with its matched placebo. Treatment with guaifenesin 1200 mg BID provided 25% greater reduction in mean muscle spasm over its matched placebo and 16% greater reduction than guaifenesin 600 mg BID. These differences were not statistically significant. Based on comparisons of absolute mean values, a consistent directional change in effect was observed, suggesting some benefit from placebo to lower-to-upper doses of guaifenesin with regard to muscle spasm, tension, pain, discomfort, and relaxation. No severe or serious adverse events were reported. Results suggest the potential for OTC dose of guaifenesin 1200 mg BID to provide symptomatic relief of upper back musculoskeletal pain and spasm. Confirmation of this preliminary result in a larger, adequately powered study is needed.

Efficacy and safety of guaifenesin for upper back, neck, and shoulder pain: a Phase II proof-of-concept, multicenter, placebo-controlled, repeat-dose, parallel-group study

PubMed Central

Collaku, Agron; Yue, Yong; Reed, Kenneth

2017-01-01

Background/objective Guaifenesin, an over-the-counter (OTC) expectorant, has exhibited muscle relaxant effects preclinically and clinically. This proof-of-principle study explored whether OTC doses of guaifenesin can provide relief from acute upper back, neck, or shoulder muscle spasm and pain. Methods This multicenter, placebo-controlled, repeat-dose, parallel study randomly assigned adults experiencing acute pain and muscle spasm in their upper back, neck, or shoulder to guaifenesin 600 or 1200 mg or matched placebo twice daily (BID) in a 2:2:1:1 ratio for 7 days. The primary end point was the change from baseline in muscle spasm relief, measured using an 11-point numeric rating scale (0=not present to 10=unbearable) recorded twice daily and averaged over the 7-day treatment period. Analyses were performed using a linear mixed model that included treatment as a fixed effect and site as a random effect. Results A total of 77 subjects were included in the 4 treatment groups. Least squares mean muscle spasm score over 7 days was 1.77 with guaifenesin 1200 mg, 1.42 with its matched placebo, 1.53 with guaifenesin 600 mg, and 1.74 with its matched placebo. Treatment with guaifenesin 1200 mg BID provided 25% greater reduction in mean muscle spasm over its matched placebo and 16% greater reduction than guaifenesin 600 mg BID. These differences were not statistically significant. Based on comparisons of absolute mean values, a consistent directional change in effect was observed, suggesting some benefit from placebo to lower-to-upper doses of guaifenesin with regard to muscle spasm, tension, pain, discomfort, and relaxation. No severe or serious adverse events were reported. Conclusion Results suggest the potential for OTC dose of guaifenesin 1200 mg BID to provide symptomatic relief of upper back musculoskeletal pain and spasm. Confirmation of this preliminary result in a larger, adequately powered study is needed. PMID:28356767

Muscle forces analysis in the shoulder mechanism during wheelchair propulsion.

PubMed

Lin, Hwai-Ting; Su, Fong-Chin; Wu, Hong-Wen; An, Kai-Nan

2004-01-01

This study combines an ergometric wheelchair, a six-camera video motion capture system and a prototype computer graphics based musculoskeletal model (CGMM) to predict shoulder joint loading, muscle contraction force per muscle and the sequence of muscular actions during wheelchair propulsion, and also to provide an animated computer graphics model of the relative interactions. Five healthy male subjects with no history of upper extremity injury participated. A conventional manual wheelchair was equipped with a six-component load cell to collect three-dimensional forces and moments experienced by the wheel, allowing real-time measurement of hand/rim force applied by subjects during normal wheelchair operation. An ExpertVision six-camera video motion capture system collected trajectory data of markers attached on anatomical positions. The CGMM was used to simulate and animate muscle action by using an optimization technique combining observed muscular motions with physiological constraints to estimate muscle contraction forces during wheelchair propulsion. The CGMM provides results that satisfactorily match the predictions of previous work, disregarding minor differences which presumably result from differing experimental conditions, measurement technologies and subjects. Specifically, the CGMM shows that the supraspinatus, infraspinatus, anterior deltoid, pectoralis major and biceps long head are the prime movers during the propulsion phase. The middle and posterior deltoid and supraspinatus muscles are responsible for arm return during the recovery phase. CGMM modelling shows that the rotator cuff and pectoralis major play an important role during wheelchair propulsion, confirming the known risk of injury for these muscles during wheelchair propulsion. The CGMM successfully transforms six-camera video motion capture data into a technically useful and visually interesting animated video model of the shoulder musculoskeletal system. The CGMM further yields accurate estimates of muscular forces during motion, indicating that this prototype modelling and analysis technique will aid in study, analysis and therapy of the mechanics and underlying pathomechanics involved in various musculoskeletal overuse syndromes.

The value of electrical stimulation as an exercise training modality

NASA Technical Reports Server (NTRS)

Currier, Dean P.; Ray, J. Michael; Nyland, John; Noteboom, Tim

1994-01-01

Voluntary exercise is the traditional way of improving performance of the human body in both the healthy and unhealthy states. Physiological responses to voluntary exercise are well documented. It benefits the functions of bone, joints, connective tissue, and muscle. In recent years, research has shown that neuromuscular electrical stimulation (NMES) simulates voluntary exercise in many ways. Generically, NMES can perform three major functions: suppression of pain, improve healing of soft tissues, and produce muscle contractions. Low frequency NMES may gate or disrupt the sensory input to the central nervous system which results in masking or control of pain. At the same time NMES may contribute to the activation of endorphins, serotonin, vasoactive intestinal polypeptides, and ACTH which control pain and may even cause improved athletic performances. Soft tissue conditions such as wounds and inflammations have responded very favorably to NMES. NMES of various amplitudes can induce muscle contractions ranging from weak to intense levels. NMES seems to have made its greatest gains in rehabilitation where directed muscle contractions may improve joint ranges of motion correct joint contractures that result from shortening muscles; control abnormal movements through facilitating recruitment or excitation into the alpha motoneuron in orthopedically, neurologically, or healthy subjects with intense sensory, kinesthetic, and proprioceptive information; provide a conservative approach to management of spasticity in neurological patients; by stimulation of the antagonist muscle to a spastic muscle stimulation of the agonist muscle, and sensory habituation; serve as an orthotic substitute to conventional bracing used with stroke patients in lieu of dorsiflexor muscles in preventing step page gait and for shoulder muscles to maintain glenohumeral alignment to prevent subluxation; and of course NMES is used in maintaining or improving the performance or torque producing capability of muscle. NMES in exercise training is our major concern.

[Evaluation of the capacity of work using upper limbs after radical latero-cervical surgery].

PubMed

Capodaglio, P; Strada, M R; Grilli, C; Lodola, E; Panigazzi, M; Bernardo, G; Bazzini, G

1998-01-01

Evaluation of arm work capacity after radical neck surgery. The aim of this paper is to describe an approach for the assessment of work capacity in patients who underwent radical neck surgery, including those treated with radiation therapy. Nine male patients, who underwent radical neck surgery 2 months before being referred to our Unit, participated in the study. In addition to manual muscle strength test, we performed the following functional evaluations: 0-100 Constant scale for shoulder function; maximal shoulder strength in adduction/abduction and intrarotation/extrarotation; instrumental. We measured maximal isokinetic strength (10 repetitions) with a computerized dynamometer (Lido WorkSET) set at 100 degrees/sec. During the rehabilitation phase, the patients' mechanical parameters, the perception of effort, pain or discomfort, and the range of movement were monitored while performing daily/occupational task individually chosen on the simulator (Lido WorkSET) under isotonic conditions. On this basis, patients were encouraged to return to levels of daily physical activities compatible with the individual tolerable work load. The second evaluation at 2 month confirmed that the integrated rehabilitation protocol successfully increased patients' capacities and "trust" in their physical capacity. According to the literature, the use of isokinetic and isotonic exercise programs appears to decrease shoulder rehabilitation time. In our experience an excellent compliance has been noted. One of the advantages of the method proposed is to provide quantitative reports of the functional capacity and therefore to facilitate return-to-work of patients who underwent radical neck surgery.

Manual muscle testing and hand-held dynamometry in people with inflammatory myopathy: An intra- and interrater reliability and validity study

PubMed Central

Baschung Pfister, Pierrette; Sterkele, Iris; Maurer, Britta; de Bie, Rob A.; Knols, Ruud H.

2018-01-01

Manual muscle testing (MMT) and hand-held dynamometry (HHD) are commonly used in people with inflammatory myopathy (IM), but their clinimetric properties have not yet been sufficiently studied. To evaluate the reliability and validity of MMT and HHD, maximum isometric strength was measured in eight muscle groups across three measurement events. To evaluate reliability of HHD, intra-class correlation coefficients (ICC), the standard error of measurements (SEM) and smallest detectable changes (SDC) were calculated. To measure reliability of MMT linear Cohen`s Kappa was computed for single muscle groups and ICC for total score. Additionally, correlations between MMT8 and HHD were evaluated with Spearman Correlation Coefficients. Fifty people with myositis (56±14 years, 76% female) were included in the study. Intra-and interrater reliability of HHD yielded excellent ICCs (0.75–0.97) for all muscle groups, except for interrater reliability of ankle extension (0.61). The corresponding SEMs% ranged from 8 to 28% and the SDCs% from 23 to 65%. MMT8 total score revealed excellent intra-and interrater reliability (ICC>0.9). Intrarater reliability of single muscle groups was substantial for shoulder and hip abduction, elbow and neck flexion, and hip extension (0.64–0.69); moderate for wrist (0.53) and knee extension (0.49) and fair for ankle extension (0.35). Interrater reliability was moderate for neck flexion (0.54) and hip abduction (0.44); fair for shoulder abduction, elbow flexion, wrist and ankle extension (0.20–0.33); and slight for knee extension (0.08). Correlations between the two tests were low for wrist, knee, ankle, and hip extension; moderate for elbow flexion, neck flexion and hip abduction; and good for shoulder abduction. In conclusion, the MMT8 total score is a reliable assessment to consider general muscle weakness in people with myositis but not for single muscle groups. In contrast, our results confirm that HHD can be recommended to evaluate strength of single muscle groups. PMID:29596450

Assessing the interplay between the shoulders and low back during manual patient handling techniques in a nursing setting.

PubMed

Belbeck, Alicia; Cudlip, Alan C; Dickerson, Clark R

2014-01-01

The purpose of this research was to quantify shoulder demands during freestyle manual patient handling (MPH) tasks and determine whether approaches intended to prevent low back injury increased shoulder demands. Twenty females completed 5 MPH tasks found commonly in hospital settings before and after a training session using current workplace MPH guidelines. Most normalized muscle activity indices and ratings of perceived exertion decreased following training at both the low back and shoulders, but were more pronounced at the low back. There was little evidence to suggest that mechanical demands were transferred from the low back to the shoulders following the training session. The study generally supports continued use of the recommended MPH techniques, but indicates that several tasks generate high muscular demands and should be avoided if possible.

Ultrasound elastography-based assessment of the elasticity of the supraspinatus muscle and tendon during muscle contraction.

PubMed

Muraki, Takayuki; Ishikawa, Hiroaki; Morise, Shuhei; Yamamoto, Nobuyuki; Sano, Hirotaka; Itoi, Eiji; Izumi, Shin-ichi

2015-01-01

Although elasticity of the supraspinatus muscle and tendon is a useful parameter to represent the conditions of the supraspinatus muscle and tendon, assessment of the elasticity in clinical settings has not been established. The purpose of this study was to determine the elasticity of the supraspinatus muscle belly and tendon under different muscle contraction conditions using ultrasound real-time tissue elastography (RTE). Twenty-three healthy individuals participated in this study. Ultrasound RTE was used for elasticity measurements of the muscle belly and tendon of the supraspinatus muscle. The elasticity was defined as the ratio of strain in the tissues to that in an acoustic coupler (reference). A greater ratio indicated that the tissue was softer. Measurements were performed with study subjects in the lateral decubitus position at 10° of shoulder abduction under conditions of (1) no contraction, (2) isometric contraction without a weight, and (3) isometric contraction with a 1-kg weight. The intraclass correlation coefficient (ICC1,3) of 3 measurements under each condition ranged from 0.931 to 0.998, showing high intraobserver reliability. Strain ratios for both the supraspinatus muscle belly and tendon significantly decreased with increases in muscle contraction (P < .001). Ultrasound RTE with the acoustic coupler has the potential to noninvasively detect changes in the elasticity of the supraspinatus muscle belly and tendon that accompany varying levels of muscle contraction in clinical practice. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Neuronal Correlates of Functional Coupling between Reach- and Grasp-Related Components of Muscle Activity

PubMed Central

Geed, Shashwati; McCurdy, Martha L.; van Kan, Peter L. E.

2017-01-01

Coordinated reach-to-grasp movements require precise spatiotemporal synchrony between proximal forelimb muscles (shoulder, elbow) that transport the hand toward a target during reach, and distal muscles (wrist, digit) that simultaneously preshape and orient the hand for grasp. The precise mechanisms through which the redundant neuromuscular circuitry coordinates reach with grasp, however, remain unclear. Recently, Geed and Van Kan (2016) demonstrated, using exploratory factor analysis (EFA), that limited numbers of global, template-like transport/preshape- and grasp-related muscle components underlie the complexity and variability of intramuscular electromyograms (EMGs) of up to 21 distal and proximal muscles recorded while monkeys performed reach-to-grasp tasks. Importantly, transport/preshape- and grasp-related muscle components showed invariant spatiotemporal coupling, which provides a potential mechanism for coordinating forelimb muscles during reach-to-grasp movements. In the present study, we tested whether ensemble discharges of forelimb neurons in the cerebellar nucleus interpositus (NI) and its target, the magnocellular red nucleus (RNm), a source of rubrospinal fibers, function as neuronal correlates of the transport/preshape- and grasp-related muscle components we identified. EFA applied to single-unit discharges of populations of NI and RNm neurons recorded while the same monkeys that were used previously performed the same reach-to-grasp tasks, revealed neuronal components in the ensemble discharges of both NI and RNm neuronal populations with characteristics broadly similar to muscle components. Subsets of NI and RNm neuronal components were strongly and significantly crosscorrelated with subsets of muscle components, suggesting that similar functional units of reach-to-grasp behavior are expressed by NI and RNm neuronal populations and forelimb muscles. Importantly, like transport/preshape- and grasp-related muscle components, their NI and RNm neuronal correlates showed invariant spatiotemporal coupling. Clinical and lesion studies have reported disruption of coupling between reach and grasp following cerebellar damage; the present results expand on those studies by identifying a neuronal mechanism that may underlie cerebellar contributions to spatiotemporal coordination of distal and proximal limb muscles during reaching to grasp. We conclude that finding similar functional units of behavior expressed at multiple levels of information processing along interposito-rubrospinal pathways and forelimb muscles supports the hypothesis that functionally related populations of NI and RNm neurons act synergistically in the control of complex coordinated motor behaviors. PMID:28270752

Electromyographic study of the upper extremity during bilateral sanding: unresisted and resisted conditions.

PubMed

Spaulding, S J; Robinson, K L

1984-04-01

Electromyographic information was obtained from seven right shoulder complex muscles in nine subjects (three normal, three paraplegic, and three quadriplegic) during the occupational therapy activity of bilateral sanding on an incline board, an activity that has been recommended as a treatment modality to strengthen the triceps brachii. Electromyography revealed that the anterior and middle portions of the deltoid were the muscles most responsible for the subjects' arm movements during both resisted and unresisted bilateral sanding . Triceps lateralis and medialis were also active during the up phase, but not as consistently as the deltoid. Pectoralis major and biceps brachii were not extensively active in most subjects. The small size and heterogeneity of the subject sample limits the generalizations of our findings. However, graded resisted bilateral sanding does appear to be an appropriate activity for strengthening the shoulder muscle group, especially the deltoid and triceps brachii, in the tested patient populations.

Neck and shoulder muscle activity and posture among helicopter pilots and crew-members during military helicopter flight.

PubMed

Murray, Mike; Lange, Britt; Chreiteh, Shadi Samir; Olsen, Henrik Baare; Nørnberg, Bo Riebeling; Boyle, Eleanor; Søgaard, Karen; Sjøgaard, Gisela

2016-04-01

Neck pain among helicopter pilots and crew-members is common. This study quantified the physical workload on neck and shoulder muscles using electromyography (EMG) measures during helicopter flight. Nine standardized sorties were performed, encompassing: cruising from location A to location B (AB) and performing search and rescue (SAR). SAR was performed with Night Vision Goggles (NVG), while AB was performed with (AB+NVG) and without NVG (AB-NVG). EMG was recorded for: trapezius (TRA), upper neck extensors (UNE), and sternocleido-mastoid (SCM). Maximal voluntary contractions (MVC) were performed for normalization of EMG (MVE). Neck posture of pilots and crew-members was monitored and pain intensity of neck, shoulder, and back was recorded. Mean muscle activity for UNE was ∼10% MVE and significantly higher than TRA and SCM, and SCM was significantly lower than TRA. There was no significant difference between AB-NVG and AB+NVG. Muscle activity in the UNE was significantly higher during SAR+NVG than AB-NVG. Sortie time (%) with non-neutral neck posture for SAR+NVG and AB-NVG was: 80.4%, 74.5% (flexed), 55.5%, 47.9% (rotated), 4.5%, 3.7% (lateral flexed). Neck pain intensity increased significantly from pre- (0.7±1.3) to post-sortie (1.6±1.9) for pilots (p=0.028). If sustained, UNE activity of ∼10% MVE is high, and implies a risk for neck disorders. Copyright © 2016 Elsevier Ltd. All rights reserved.

Nerve transfers in tetraplegia I: Background and technique

PubMed Central

Brown, Justin M.

2011-01-01

Background: The recovery of hand function is consistently rated as the highest priority for persons with tetraplegia. Recovering even partial arm and hand function can have an enormous impact on independence and quality of life of an individual. Currently, tendon transfers are the accepted modality for improving hand function. In this procedure, the distal end of a functional muscle is cut and reattached at the insertion site of a nonfunctional muscle. The tendon transfer sacrifices the function at a lesser location to provide function at a more important location. Nerve transfers are conceptually similar to tendon transfers and involve cutting and connecting a healthy but less critical nerve to a more important but paralyzed nerve to restore its function. Methods: We present a case of a 28-year-old patient with a C5-level ASIA B (international classification level 1) injury who underwent nerve transfers to restore arm and hand function. Intact peripheral innervation was confirmed in the paralyzed muscle groups corresponding to finger flexors and extensors, wrist flexors and extensors, and triceps bilaterally. Volitional control and good strength were present in the biceps and brachialis muscles, the deltoid, and the trapezius. The patient underwent nerve transfers to restore finger flexion and extension, wrist flexion and extension, and elbow extension. Intraoperative motor-evoked potentials and direct nerve stimulation were used to identify donor and recipient nerve branches. Results: The patient tolerated the procedure well, with a preserved function in both elbow flexion and shoulder abduction. Conclusions: Nerve transfers are a technically feasible means of restoring the upper extremity function in tetraplegia in cases that may not be amenable to tendon transfers. PMID:21918736

Muscular strength profile in Tunisian male national judo team.

PubMed

Ghrairi, Mourad; Hammouda, Omar; Malliaropoulos, Nikos

2014-04-01

it is well established that muscle strength is a determinant factor in judo. However, little data are available for African athletes. Therefore, the aim of this study was to provide reference data of the muscular strength profile (MSP) for an African team, Tunisian judo team. the study was conducted among ten international judo athletes from Tunisia. To determine their MSP, we used an isokinetic dynamometer to assess Hamstrings, Quadriceps of both knees and external, internal rotators of both shoulders. The angular velocities of the assessments were; 90, 180, 240°/s for the knees and 60, 120°/s for the shoulders. MSP was determined based on two parameters; the maximum peak torque (PT) of each muscle and the ratio agonistic/antagonistic muscles (R). The knee extensors and flexors in the "supporting leg" had higher PT than in the "attacking leg"; respectively, 245N.m versus 237 (p<0.05) and 147 N.m versus 145 (p>0.05). R was normal for both legs. Furthermore, both rotators of the dominant shoulder had higher PT; 84 N.m versus 71 for the internal rotators (p<0.05) and 34,7 N.m versus 29,0 for the lateral rotators (p<0.05). Inversely, R was higher in the non-dominant side; 45% versus 35, p<0.05). the MSP of the selected elites Tunisian judo athletes was characterized by 3 major features; a strength of the quadriceps in the standing leg significantly higher than in the attacking leg, a normal muscular balance Hamstrings/quadriceps in both legs and a strength of the shoulder' rotators higher in the dominant side.

Shoulder Dynamic Control Ratio and Rotation Range of Motion in Female Junior Elite Handball Players and Controls.

PubMed

van Cingel, Robert; Habets, Bas; Willemsen, Linn; Staal, Bart

2018-03-01

To compare glenohumeral range of motion and shoulder rotator muscle strength in healthy female junior elite handball players and controls. Cross-sectional case-control study. Sports medical center. Forty elite female handball players and 30 controls active in nonoverhead sports participated in this study. Passive external rotator (ER), internal rotator (IR), and total range of motion (TROM) of the dominant and nondominant arm were examined with a goniometer. An isokinetic dynamometer was used to evaluate concentric and eccentric rotator muscle strength at 60 and 120 degrees/s with dynamic control ratio (DCR = ERecc:IRcon) as the main outcome parameter. Except for the ER range of motion in the nondominant arm, no significant differences were found between groups for IR, ER of the dominant arm, and the TROM. Within the handball group, the side-to-side difference for IR of the dominant arm was -1.4 degrees. The ER and the TROM of the dominant arm were significantly larger, 6.3 and 4.9 degrees, respectively. For both groups, the DCR values were above 1 and no significant differences were found between the dominant and nondominant arm. The DCR values in the handball group were significantly lower than in the control group. Based on the adopted definitions for muscle imbalance, glenohumeral internal range of motion deficit and TROM deficit our elite female handball players seem not at risk for shoulder injuries. Prospective studies are needed to support the belief that a DCR below 1 places the shoulder at risk for injury.

Nerve supply of the subscapularis during anterior shoulder surgery: definition of a potential risk area.

PubMed

Leschinger, Tim; Hackl, Michael; Zeifang, Felix; Scaal, Martin; Müller, Lars Peter; Wegmann, Kilian

2017-01-01

The purpose of the study was to evaluate the position of the subscapular nerves relative to surgical landmarks during exposure and to analyze the pattern of innervation of the subscapularis to avoid injury during anterior shoulder surgery. 20 embalmed human cadaveric shoulder specimens were used in the study. The muscular insertions of the subscapular nerves were marked and their closest branches to the musculotendinous junction and the coracoid process were measured in horizontal and vertical distances. In addition, the innervation pattern of each specimen was documented. 14/20 specimens showed an innervation of the subscapularis with an upper, middle and lower subscapular nerve branch. Even though the nerve branches were in average more than 2 cm medial to the musculotendinous junction, minimal distances of 1.1-1.3 cm were found. The mean vertical distance as measured from the medial base of the coracoid to the nerve innervation point into the muscle was 0.7 cm for the upper nerve branch, 2.2 cm for the middle nerve branch and 4.4 cm for the lower nerve branch. The subscapularis has a variable nerve supply, which increases the risk of muscle denervation during open shoulder surgery. Dissection or release should be avoided at the anterior aspect of the subscapularis muscle more than 1 cm medial to the musculotendinous junction. In approaches with a horizontal incision of the subscapularis, splitting should be performed at a vertical distance of 3.2-3.6 cm to the coracoid base to avoid iatrogenic subscapular nerve injuries.

[A field study on the work load and muscle fatigue at neck-shoulder in female sewing machine operators by using surface electromyography].

PubMed

Zhang, Fei-ruo; Wang, Sheng; He, Li-hua; Zhang, Ying; Wu, Shan-shan; Li, Jing-yun; Hu, Guang-yi; Ye, Kang-ping

2011-03-01

To study neck and shoulder work-related muscle fatigue of female sewing machine operators. 18 health female sewing machine operators without musculoskeletal disorders work in Beijing garment industry factory as volunteers in participate of this study. The maximal voluntary contraction (MVC) and 20% MVC of bilateral upper trapezium and cervical erectors spinae was tested before sewing operations, then the whole 20 time windows (1 time window = 10 min) sewing machine operations was monitored and the surface electromyography (sEMG) signals simultaneously was recorded after monitoring the 20%MVC was tested. Use amplitude analysis method to reduction recorded EMG signals. During work, the median load for the left cervical erector spinae (LCES), right cervical erector spinae (RCES), left upper trapezium (LUT) and right upper trapezium (RUT) respectively was 6.78 ± 1.05, 6.94 ± 1.12, 5.68 ± 2.56 and 6.47 ± 3.22, work load of right is higher than the left; static load analysis indicated the value of RMS(20%MVC) before work was higher than that value after work, the increase of right CES and UT RMS(20%MVC) was more; the largest 20%MVE of bilateral CES occurred at 20th time window, and that of bilateral UT happened at 16th. The work load of female sewing machine operators is sustained "static" load, and work load of right neck-shoulder is higher than left, right neck-shoulder muscle is more fatigable and much serious once fatigued.

Intramuscular migration of calcium hydroxyapatite crystal deposits involving the rotator cuff tendons of the shoulder: report of 11 patients.

PubMed

Pereira, Bruno P G; Chang, Eric Y; Resnick, Donald L; Pathria, Mini N

2016-01-01

The intent of the study is to describe an unusual pattern of intramuscular migration of calcific deposits related to hydroxyapatite deposition disease (HADD) involving the rotator cuff, to illustrate the characteristic imaging features of this phenomenon, and to discuss the clinical significance of such migration. A series of cases of intramuscular accumulation of calcium hydroxyapatite crystals collected over a 7-year period at multiple hospitals within the same academic institution were retrospectively reviewed. The patient group was composed of seven men and four women, ranging in age from 51 to 79 years, with a mean age of 63 years. All subjects presented with acute shoulder pain. The majority of subjects reported the spontaneous onset of the symptoms (64%), while others reported weight lifting (27%) and a fall on the arm (9%) as the mechanisms of injury. The right shoulder was affected in 73% of the subjects. The supraspinatus was the most commonly affected muscle (82%), followed by the infraspinatus muscle (36%). Knowledge of the imaging features of intramuscular migration of hydroxyapatite deposits is important in order to avoid the erroneous diagnosis of other causes of muscle edema and inflammation such as myotendinous injury, myositis, subacute denervation, and neoplasm.

Biomechanics of Reverse Shoulder Arthroplasty: 
Current Concepts.

PubMed

Lorenzetti, Adam J; Stone, Geoffrey P; Simon, Peter; Frankle, Mark A

2016-01-01

The evolution of reverse shoulder arthroplasty has provided surgeons with new solutions for many complex shoulder problems. A primary goal of orthopaedics is the restoration or re-creation of functional anatomy to reduce pain and improve function, which can be accomplished by either repairing injured structures or replacing them as anatomically as possible. If reconstructible tissue is lacking or not available, which is seen in patients who have complex shoulder conditions such as an irreparable rotator cuff-deficient shoulder, cuff tear arthropathy, or severe glenoid bone loss, substantial problems may arise. Historically, hemiarthroplasty or glenoid grafting with total shoulder arthroplasty yielded inconsistent and unsatisfactory results. Underlying pathologies in patients who have an irreparable rotator cuff-deficient shoulder, cuff tear arthropathy, or severe glenoid bone loss can considerably alter the mechanical function of the shoulder and create treatment dilemmas that are difficult to overcome. A better biomechanical understanding of these pathologic adaptations has improved treatment options. In the past three decades, reverse total shoulder arthroplasty was developed to treat these complex shoulder conditions not by specifically re-creating the anatomy but by using the remaining functional tissue to improve shoulder balance. Reverse total shoulder arthroplasty has achieved reliable improvements in both pain and function. Initial implant designs lacked scientific evidence to support the design rationale, and many implants failed because surgeons did not completely understand the forces involved or the pathology being treated. Implant function and clinical results will continue to improve as surgeons' biomechanical understanding of shoulder disease and reverse shoulder arthroplasty implants increases.

The Relationship Between Body Mass Index and Fatty Infiltration in the Shoulder Musculature.

PubMed

Dow, David F; Mehta, Kaushal; Xu, Yuanfang; England, Eric

Fatty infiltration in the rotator cuff muscles has been well studied in the setting of rotator cuff tendon tears to help predict outcomes of surgical repair. Fatty infiltration in the rotator cuff has also been independently correlated to the variables of age and sex. The purpose of our study was to determine if there is a relationship between body mass index and fatty infiltration in patients with no imaging evidence of rotator cuff tendinosis or tear. Radiology reports of all magnetic resonance imaging examinations of the shoulder were searched over a 2-year period. Studies with imaging findings of rotator cuff tendinosis, partial tear, or full thickness tear were excluded from the study, resulting in a total of 143 patients with normal rotator cuffs who were included in the study. These studies were reviewed by consensus by 2 fellowship-trained musculoskeletal radiologists who used the Goutallier 5-stage scoring system to grade the supraspinatus, infraspinatus, subscapularis, teres minor, teres major, and deltoid muscles. Sex was shown not to be significantly associated with fatty infiltration with the exception of the deltoid muscle, which showed a statistically significant increase in fatty infiltration associated with female sex (P = 0.038). Age was shown to be a statistically significant predictor of fatty infiltration for all 6 muscles (P < 0.05). Body mass index was shown to be a statistically significant predictor of fatty infiltration for all of the evaluated shoulder musculature (P < 0.05) with the exception of the teres minor. Our results suggest that increased body mass index is associated with increased fatty infiltration in the supraspinatus, infraspinatus, subscapularis, teres major, and deltoid muscles. This relationship could help guide the decisions of orthopedic surgeons when considering rotator cuff repair.

Quantitative estimation of muscle shear elastic modulus of the upper trapezius with supersonic shear imaging during arm positioning.

PubMed

Leong, Hio-Teng; Ng, Gabriel Yin-Fat; Leung, Vivian Yee-Fong; Fu, Siu Ngor

2013-01-01

Pain and tenderness of the upper trapezius are the major complaints among people with chronic neck and shoulder disorders. Hyper-activation and increased muscle tension of the upper trapezius during arm elevation will cause imbalance of the scapular muscle force and contribute to neck and shoulder disorders. Assessing the elasticity of the upper trapezius in different arm positions is therefore important for identifying people at risk so as to give preventive programmes or for monitoring the effectiveness of the intervention programmes for these disorders. This study aimed to establish the reliability of supersonic shear imaging (SSI) in quantifying upper trapezius elasticity/shear elastic modulus and its ability to measure the modulation of muscle elasticity during arm elevation. Twenty-eight healthy adults (15 males, 13 females; mean age = 29.6 years) were recruited to participate in the study. In each participant, the shear elastic modulus of the upper trapezius while the arm was at rest and at 30° abduction was measured by two operators and twice by operator 1 with a time interval between the measurements. The results showed excellent within- and between-session intra-operator (ICC = 0.87-0.97) and inter-observer (ICC = 0.78-0.83) reliability for the upper trapezius elasticity with the arm at rest and at 30° abduction. An increase of 55.23% of shear elastic modulus from resting to 30° abduction was observed. Our findings demonstrate the possibilities for using SSI to quantify muscle elasticity and its potential role in delineating the modulation of upper trapezius elasticity, which is essential for future studies to compare the differences in shear elastic modulus between normal elasticity and that of individuals with neck and shoulder disorders.

Quantitative Estimation of Muscle Shear Elastic Modulus of the Upper Trapezius with Supersonic Shear Imaging during Arm Positioning

PubMed Central

Leong, Hio-Teng; Ng, Gabriel Yin-fat; Leung, Vivian Yee-fong; Fu, Siu Ngor

2013-01-01

Pain and tenderness of the upper trapezius are the major complaints among people with chronic neck and shoulder disorders. Hyper-activation and increased muscle tension of the upper trapezius during arm elevation will cause imbalance of the scapular muscle force and contribute to neck and shoulder disorders. Assessing the elasticity of the upper trapezius in different arm positions is therefore important for identifying people at risk so as to give preventive programmes or for monitoring the effectiveness of the intervention programmes for these disorders. This study aimed to establish the reliability of supersonic shear imaging (SSI) in quantifying upper trapezius elasticity/shear elastic modulus and its ability to measure the modulation of muscle elasticity during arm elevation. Twenty-eight healthy adults (15 males, 13 females; mean age = 29.6 years) were recruited to participate in the study. In each participant, the shear elastic modulus of the upper trapezius while the arm was at rest and at 30° abduction was measured by two operators and twice by operator 1 with a time interval between the measurements. The results showed excellent within- and between-session intra-operator (ICC = 0.87–0.97) and inter-observer (ICC = 0.78–0.83) reliability for the upper trapezius elasticity with the arm at rest and at 30° abduction. An increase of 55.23% of shear elastic modulus from resting to 30° abduction was observed. Our findings demonstrate the possibilities for using SSI to quantify muscle elasticity and its potential role in delineating the modulation of upper trapezius elasticity, which is essential for future studies to compare the differences in shear elastic modulus between normal elasticity and that of individuals with neck and shoulder disorders. PMID:23825641

Rehabilitation Exercises to Induce Balanced Scapular Muscle Activity in an Anti-gravity Posture

PubMed Central

Ishigaki, Tomonobu; Yamanaka, Masanori; Hirokawa, Motoki; Tai, Keita; Ezawa, Yuya; Samukawa, Mina; Tohyama, Harukazu; Sugawara, Makoto

2014-01-01

[Purpose] The purpose of this study was to compare the intramuscular balance ratios of the upper trapezius muscle (UT) and the lower trapezius muscle (LT), and the intermuscular balance ratios of the UT and the serratus anterior muscle (SA) among prone extension (ProExt), prone horizontal abduction with external rotation (ProHAbd), forward flexion in the side-lying position (SideFlex), side-lying external rotation (SideEr), shoulder flexion with glenohumeral horizontal abduction load (FlexBand), and shoulder flexion with glenohumeral horizontal adduction load (FlexBall) in the standing posture. [Methods] The electromyographic (EMG) activities of the UT, LT and SA were measured during the tasks. The percentage of maximum voluntary isometric contraction (%MVIC) was calculated for each muscle, and the UT/LT ratios and the UT/SA ratios were compared among the tasks. [Results] The UT/LT ratio with the FlexBand was not significantly different from those of the four exercises in the side-lying and prone postures. The UT/SA ratio with the FlexBall demonstrated appropriate balanced activity. [Conclusion] In an anti-gravity posture, we recommend the FlexBand and the FlexBall for inducing balanced UT/LT and UT/SA ratios, respectively. PMID:25540485

Rehabilitation Exercises to Induce Balanced Scapular Muscle Activity in an Anti-gravity Posture.

PubMed

Ishigaki, Tomonobu; Yamanaka, Masanori; Hirokawa, Motoki; Tai, Keita; Ezawa, Yuya; Samukawa, Mina; Tohyama, Harukazu; Sugawara, Makoto

2014-12-01

[Purpose] The purpose of this study was to compare the intramuscular balance ratios of the upper trapezius muscle (UT) and the lower trapezius muscle (LT), and the intermuscular balance ratios of the UT and the serratus anterior muscle (SA) among prone extension (ProExt), prone horizontal abduction with external rotation (ProHAbd), forward flexion in the side-lying position (SideFlex), side-lying external rotation (SideEr), shoulder flexion with glenohumeral horizontal abduction load (FlexBand), and shoulder flexion with glenohumeral horizontal adduction load (FlexBall) in the standing posture. [Methods] The electromyographic (EMG) activities of the UT, LT and SA were measured during the tasks. The percentage of maximum voluntary isometric contraction (%MVIC) was calculated for each muscle, and the UT/LT ratios and the UT/SA ratios were compared among the tasks. [Results] The UT/LT ratio with the FlexBand was not significantly different from those of the four exercises in the side-lying and prone postures. The UT/SA ratio with the FlexBall demonstrated appropriate balanced activity. [Conclusion] In an anti-gravity posture, we recommend the FlexBand and the FlexBall for inducing balanced UT/LT and UT/SA ratios, respectively.

Physiological Strain During Load Carrying: Effects of Mass and Type of Backpack

DTIC Science & Technology

2001-05-01

load did not significantly increase the EMG signal of the trapezius shoulder muscle (pars descenders). While walking, load carrying significantly...descending part of the right trapezius muscle was measured with two surface silver-silver chloride electrodes (PPG, Hellige), positioned on the distal...values using a previously determined RMS versus force relationship. This calibration curve between RMS of the EMG of the trapezius muscle and the force

Exposure-response relationships for work-related neck and shoulder musculoskeletal disorders--Analyses of pooled uniform data sets.

PubMed

Nordander, Catarina; Hansson, Gert-Åke; Ohlsson, Kerstina; Arvidsson, Inger; Balogh, Istvan; Strömberg, Ulf; Rittner, Ralf; Skerfving, Staffan

2016-07-01

There is a lack of quantitative data regarding exposure-response relationships between occupational risk factors and musculoskeletal disorders in the neck and shoulders. We explored such relationships in pooled data from a series of our cross-sectional studies. We recorded the prevalence of complaints/discomfort (Nordic Questionnaire) and diagnoses (physical examination) in 33 groups (24 female and 9 male) within which the workers had similar work tasks (3141 workers, of which 817 were males). In representative sub-groups, we recorded postures and velocities of the head (N = 299) and right upper arm (inclinometry; N = 306), right wrist postures and velocities (electrogoniometry; N = 499), and muscular activity (electromyography) in the right trapezius muscle (N = 431) and forearm extensors (N = 206). We also assessed the psychosocial work environment (Job Content Questionnaire). Uni- and multivariate linear meta-regression analysis revealed several statistically significant group-wise associations. Neck disorders were associated with head inclination, upper arm elevation, muscle activity of the trapezius and forearm extensors and wrist posture and angular velocity. Right-side shoulder disorders were associated with head and upper arm velocity, activity in the trapezius and forearm extensor muscles and wrist posture and angular velocity. The psychosocial work environment (low job control, job strain and isostrain) was also associated with disorders. Women exhibited a higher prevalence of neck and shoulder complaints and tension neck syndrome than men, when adjusting for postures, velocities, muscular activity or psychosocial exposure. In conclusion, the analyses established quantitative exposure-response relationships between neck and shoulder disorders and objective measures of the physical workload on the arm. Such information can be used for risk assessment in different occupations/work tasks, to establish quantitative exposure limits, and for the evaluation of preventive measures. Copyright © 2016 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Putting the shoulder to the wheel: a new biomechanical model for the shoulder girdle.

PubMed

Levin, S M

1997-01-01

The least successfully modeled joint complex has been the shoulder. In multi-segmented mathematical shoulder models rigid beams (the bones) act as a series of columns or levers to transmit forces or loads to the axial skeleton. Forces passing through the almost frictionless joints must, somehow, always be directed perfectly perpendicular to the joints as only loads directed at right angles to the surfaces could transfer across frictionless joints. Loads transmitted to the axial skeleton would have to pass through the moving ribs or the weak jointed clavicle and then through the ribs. A new model of the shoulder girdle, based on the tension icosahedron described by Buckminster Fuller, is proposed that permits the compression loads passing through the arm and shoulder to be transferred to the axial skeleton through its soft tissues. In this model the scapula 'floats' in the tension network of shoulder girdle muscles just as the hub of the wire wheel is suspended in its tension network of spokes. With this construct inefficient beams and levers are eliminated. A more energy efficient, load distributing, integrated, hierarchical system is created.

A soft wearable robot for the shoulder: Design, characterization, and preliminary testing.

PubMed

O'Neill, Ciaran T; Phipps, Nathan S; Cappello, Leonardo; Paganoni, Sabrina; Walsh, Conor J

2017-07-01

In this paper, we present a soft wearable robot for the shoulder which has the potential to assist individuals suffering from a range of neuromuscular conditions affecting the shoulder to perform activities of daily living. This wearable robot combines two types of soft textile pneumatic actuators which were custom developed for this particular application to support the upper arm through shoulder abduction and horizontal flexion/extension. The advantage of a textile-based approach is that the robot can be lightweight, low-profile, comfortable and non-restrictive to the wearer, and easy to don like an item of clothing. The actuator's ability to fold flat when not in use allows the robot to be almost invisible under clothing, potentially allowing the user to avoid any stigma associated with using assistive devices in public. To abduct the arm, a textilebased pneumatic actuator was developed to fit within the axilla to push the arm upwards, while a pair of smaller actuators pivot the abduction actuator to allow for horizontal extension and flexion. The individual textile actuators were experimentally evaluated before being integrated into a wearable garment. Human subject testing was performed to evaluate the ability of the robot to assist the arm by monitoring changes in biological muscle activity when comparing the robot powered on and off. Preliminary results show large reductions in muscular effort in targeted muscles, demonstrating the feasibility and promise of such a soft wearable robot for the shoulder.

Can exposure variation be promoted in the shoulder girdle muscles by modifying work pace and inserting pauses during simulated assembly work?

PubMed

Januario, Leticia Bergamin; Madeleine, Pascal; Cid, Marina Machado; Samani, Afshin; Oliveira, Ana Beatriz

2018-01-01

This study investigated the acute effects of changing the work pace and implementing two pause types during an assembly task. Eighteen healthy women performed a simulated task in four different conditions: 1) slow or 2) fast work pace with 3) passive or 4) active pauses every two minutes. The root mean square (RMS) and exposure variation analysis (EVA) from the trapezius and serratus anterior muscles, as well as the rate of perceived exertion (RPE) from the neck-shoulder region, were observed. Decreased RMS and RPE as well as more variable muscle activity (EVA) were observed in the slow work pace compared with the fast one. The pause types had a limited effect, but active pauses resulted in increased RMS of the clavicular trapezius. The findings revealed the importance of work pace in the reduction of perceived exertion and promotion of variation in muscle activation during assembly tasks. However, the pause types had no important effect on the evaluated outcomes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Forelimb muscle and joint actions in Archosauria: insights from Crocodylus johnstoni (Pseudosuchia) and Mussaurus patagonicus (Sauropodomorpha)

PubMed Central

Allen, Vivian

2017-01-01

Many of the major locomotor transitions during the evolution of Archosauria, the lineage including crocodiles and birds as well as extinct Dinosauria, were shifts from quadrupedalism to bipedalism (and vice versa). Those occurred within a continuum between more sprawling and erect modes of locomotion and involved drastic changes of limb anatomy and function in several lineages, including sauropodomorph dinosaurs. We present biomechanical computer models of two locomotor extremes within Archosauria in an analysis of joint ranges of motion and the moment arms of the major forelimb muscles in order to quantify biomechanical differences between more sprawling, pseudosuchian (represented the crocodile Crocodylus johnstoni) and more erect, dinosaurian (represented by the sauropodomorph Mussaurus patagonicus) modes of forelimb function. We compare these two locomotor extremes in terms of the reconstructed musculoskeletal anatomy, ranges of motion of the forelimb joints and the moment arm patterns of muscles across those ranges of joint motion. We reconstructed the three-dimensional paths of 30 muscles acting around the shoulder, elbow and wrist joints. We explicitly evaluate how forelimb joint mobility and muscle actions may have changed with postural and anatomical alterations from basal archosaurs to early sauropodomorphs. We thus evaluate in which ways forelimb posture was correlated with muscle leverage, and how such differences fit into a broader evolutionary context (i.e. transition from sprawling quadrupedalism to erect bipedalism and then shifting to graviportal quadrupedalism). Our analysis reveals major differences of muscle actions between the more sprawling and erect models at the shoulder joint. These differences are related not only to the articular surfaces but also to the orientation of the scapula, in which extension/flexion movements in Crocodylus (e.g. protraction of the humerus) correspond to elevation/depression in Mussaurus. Muscle action is highly influenced by limb posture, more so than morphology. Habitual quadrupedalism in Mussaurus is not supported by our analysis of joint range of motion, which indicates that glenohumeral protraction was severely restricted. Additionally, some active pronation of the manus may have been possible in Mussaurus, allowing semi-pronation by a rearranging of the whole antebrachium (not the radius against the ulna, as previously thought) via long-axis rotation at the elbow joint. However, the muscles acting around this joint to actively pronate it may have been too weak to drive or maintain such orientations as opposed to a neutral position in between pronation and supination. Regardless, the origin of quadrupedalism in Sauropoda is not only linked to manus pronation but also to multiple shifts of forelimb morphology, allowing greater flexion movements of the glenohumeral joint and a more columnar forelimb posture. PMID:29188140

A mixed methods study to evaluate the clinical and cost-effectiveness of a self-managed exercise programme versus usual physiotherapy for chronic rotator cuff disorders: protocol for the SELF study.

PubMed

Littlewood, Chris; Ashton, Jon; Mawson, Sue; May, Stephen; Walters, Stephen

2012-04-30

Shoulder pain is the third most common reason for consultation with a physiotherapist and up to 26% of the general population might be expected to experience an episode at any one time. Disorders of the shoulder muscles and tendons (rotator cuff) are thought to be the commonest cause of this pain. The long-term outcome is frequently poor despite treatment. This means that many patients are exposed to more invasive treatment, e.g. surgery, and/or long-term pain and disability.Patients with this disorder typically receive a course of physiotherapy which might include a range of treatments. Specifically the value of exercise against gravity or resistance (loaded exercise) in the treatment of tendon disorders is promising but appears to be under-used. Loaded exercise in other areas of the body has been favourably evaluated but further investigation is needed to evaluate the impact of these exercises in the shoulder and particularly the role of home based or supervised exercise versus usual treatment requiring clinic attendance. A single-centre pragmatic unblinded parallel group randomised controlled trial will evaluate the effectiveness of a self-managed loaded exercise programme versus usual clinic based physiotherapy. A total of 210 study participants with a primary complaint of shoulder pain suggestive of a rotator cuff disorder will be recruited from NHS physiotherapy waiting lists and allocated to receive a programme of self-managed exercise or usual physiotherapy using a process of block randomisation with sealed opaque envelopes. Baseline assessment for shoulder pain, function and quality of life will be undertaken with the Shoulder Pain & Disability Index, the Patient Specific Functional Scale and the SF-36. Follow-up evaluations will be completed at 3, 6 and 12 months by postal questionnaire. Both interventions will be delivered by NHS Physiotherapist's.An economic analysis will be conducted from an NHS and Personal Social Services perspective to evaluate cost-effectiveness and a qualitative investigation will be undertaken to develop greater understanding of the experience of undertaking or prescribing exercise as a self-managed therapy. ISRCTN84709751.

Quantification of the Exposure of the Glenohumeral Joint from the Minimally Invasive to More Invasive Subscapularis Approach to the Anterior Shoulder: a Cadaveric Study

DTIC Science & Technology

2014-06-01

dx.doi.org/10.3928/01477447 20101221 14 8. DeFranco MJ, Higgins LD, Warner JJP. Subscapularis management in open shoulder surgery. J Am Acad Orthop Surg...scapular muscle in Latarjet intervention. Rev Chir Orthop Reparatrice Appar Mot 1998;84:217 23. 28. Rokito AS, Gallagher Birdzell M, Cuomo F, Di Paola MJ

At-home resistance tubing strength training increases shoulder strength in the trained and untrained limb.

PubMed

Magnus, C R A; Boychuk, K; Kim, S Y; Farthing, J P

2014-06-01

The purpose was to determine if an at-home resistance tubing strength training program on one shoulder (that is commonly used in rehabilitation settings) would produce increases in strength in the trained and untrained shoulders via cross-education. Twenty-three participants were randomized to TRAIN (strength-trained one shoulder; n = 13) or CONTROL (no intervention; n = 10). Strength training was completed at home using resistance tubing and consisted of maximal shoulder external rotation, internal rotation, scaption, retraction, and flexion 3 days/week for 4 weeks. Strength was measured via handheld dynamometry and muscle size measured via ultrasound. For external rotation strength, the trained (10.9 ± 10.9%) and untrained (12.7 ± 9.6%) arm of TRAIN was significantly different than CONTROL (1.6 ± 13.2%; -2.7 ± 12.3%; pooled across arm; P < 0.05). For internal rotation strength, the trained (14.8 ± 11.3%) and untrained (14.6 ± 10.1%) arm of TRAIN was significantly different than CONTROL (6.4 ± 11.2%; 5.1 ± 8.8%; pooled across arm; P < 0.05). There were no significant differences for scaption strength (P = 0.056). TRAIN significantly increased muscle size in the training arm of the supraspinatus (1.90 ± 0.32 to 1.99 ± 0.31 cm), and the anterior deltoid (1.08 ± 0.37 to 1.21 ± 0.39 cm; P < 0.05). This study suggests that an at-home resistance tubing training program on one limb can produce increases in strength in both limbs, and has implications for rehabilitation after unilateral shoulder injuries. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

[Open-wedge osteotomy of the glenoid for treatment of posterior shoulder instability with increased glenoid retroversion].

PubMed

Pogorzelski, J; Braun, S; Imhoff, A B; Beitzel, K

2016-12-01

Treatment of posterior shoulder instability with increased retroversion of the glenoid using open-wedge osteotomy of the glenoid neck stabilized with an autologous bone block. Symptomatic, atraumatic posterior shoulder instability with increased retroversion (>20°) of the glenoid and previously failed conservative or surgical treatment. General contraindications against surgery. Relative contraindications: osteoporosis, nicotine abuse, or suspected patient noncompliance. Posterior approach with a 7 cm long incision starting medial of the posterolateral corner of the acromion heading to the posterior axillary fold and subsequent preparation of the deltoid muscle and the infraspinatus muscle. The posterior glenohumeral capsule is incised by performing a capsular T‑shift. The osteotomy is performed intracapsulary medial to the genoid rim. The wedge bone graft, harvested from spina scapulae or iliac spine, is placed "press fit" in position. Additional fixation of the graft is not necessary if the anterior cortex is intact. For reinforcing the posterior capsule, a posterior capsule shift should be performed. Insertion of extracapsular wound drainage. Successive wound closure. Postoperative immobilization in a 0° shoulder orthesis for 6 weeks; avoidance of horizontal abduction for 8 weeks. After removing the wound drainage, start of limited active-assisted range of motion. Over-head sports after 6 months. From 2009-2015, 6 posterior open wedge glenoid osteotomies were performed. Postoperative retroversion of the glenoid was 11.2 ± 9.4° compared to 26.0 ± 8.6° before surgery. Of 6 shoulders, 2 showed postoperative signs of persistent posterior instability; the other 4 shoulders were free of complaints. No revision surgery was needed.

Evaluation of regression-based 3-D shoulder rhythms.

PubMed

Xu, Xu; Dickerson, Clark R; Lin, Jia-Hua; McGorry, Raymond W

2016-08-01

The movements of the humerus, the clavicle, and the scapula are not completely independent. The coupled pattern of movement of these bones is called the shoulder rhythm. To date, multiple studies have focused on providing regression-based 3-D shoulder rhythms, in which the orientations of the clavicle and the scapula are estimated by the orientation of the humerus. In this study, six existing regression-based shoulder rhythms were evaluated by an independent dataset in terms of their predictability. The datasets include the measured orientations of the humerus, the clavicle, and the scapula of 14 participants over 118 different upper arm postures. The predicted orientations of the clavicle and the scapula were derived from applying those regression-based shoulder rhythms to the humerus orientation. The results indicated that none of those regression-based shoulder rhythms provides consistently more accurate results than the others. For all the joint angles and all the shoulder rhythms, the RMSE are all greater than 5°. Among those shoulder rhythms, the scapula lateral/medial rotation has the strongest correlation between the predicted and the measured angles, while the other thoracoclavicular and thoracoscapular bone orientation angles only showed a weak to moderate correlation. Since the regression-based shoulder rhythm has been adopted for shoulder biomechanical models to estimate shoulder muscle activities and structure loads, there needs to be further investigation on how the predicted error from the shoulder rhythm affects the output of the biomechanical model. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Targeted Muscle Reinnervation for Transradial Amputation: Description of Operative Technique.

PubMed

Morgan, Emily N; Kyle Potter, Benjamin; Souza, Jason M; Tintle, Scott M; Nanos, George P

2016-12-01

Targeted muscle reinnervation (TMR) is a revolutionary surgical technique that, together with advances in upper extremity prostheses and advanced neuromuscular pattern recognition, allows intuitive and coordinated control in multiple planes of motion for shoulder disarticulation and transhumeral amputees. TMR also may provide improvement in neuroma-related pain and may represent an opportunity for sensory reinnervation as advances in prostheses and haptic feedback progress. Although most commonly utilized following shoulder disarticulation and transhumeral amputations, TMR techniques also represent an exciting opportunity for improvement in integrated prosthesis control and neuroma-related pain improvement in patients with transradial amputations. As there are no detailed descriptions of this technique in the literature to date, we provide our surgical technique for TMR in transradial amputations.

The relationship between physical impairments, quality of life and disability of the neck and upper limb in patients following neck dissection.

PubMed

Gane, Elise M; McPhail, Steven M; Hatton, Anna L; Panizza, Benedict J; O'Leary, Shaun P

2018-05-16

The purpose of this study was to examine the relationship between physical impairments, quality of life and disability in patients following neck dissection, with consideration of patient and clinical characteristics. Cross-sectional study of patients < 5 years after neck dissection for head and neck cancer. Quality of life and self-reported disability were measured with the Neck Dissection Impairment Index, Quick Disabilities of the Arm, Shoulder and Hand, and Neck Disability Index. Active neck and shoulder range of motion and isometric muscle strength were also assessed. Generalised linear modelling was used to explore relationships between variables. Eighty-four participants (68% male, median age 61 years) demonstrated reduced quality of life (median (interquartile range) score = 76 (49, 93) from 0 (worst) to 100 (best)), and mild levels of upper limb (14 (2, 32)) and neck disability (14 (6, 28)) (from 0 (best) to 100 (worst)). Bilateral neck dissection was associated with reduced quality of life (coeff (95% CI) = - 12.49 (- 24.69, - 0.29)). Post-operative chemoradiation therapy was associated with reduced quality of life (- 21.46 (- 37.57, - 5.35)) and neck disability (0.71 (0.10, 1.32)). Measures of shoulder flexibility or strength were associated with quality of life and self-reported disability. Quality of life and musculoskeletal disability after neck dissection are associated with factors from multiple domains including physical motor function and treatment modality. Having reduced shoulder flexibility or strength is related to functional deficits and quality of life after neck dissection for head and neck cancer.

Surface EMG of shoulder and back muscles and posture analysis in secretaries typing at visual display units.

PubMed

Kleine, B U; Schumann, N P; Bradl, I; Grieshaber, R; Scholle, H C

1999-09-01

A study was carried out to investigate temporal changes of activation of shoulder and back muscles in workers at visual display units by means of surface EMG. Moreover, postural parameters were recorded to distinguish fatigue-related from posture-related changes of the myoelectrical activity. Nine healthy female office workers typed texts spoken from tape during three 1-h-long sessions. After the first and again after the second hour there was a break of 15 min. Sixteen-channel surface EMG was bipolarly recorded from the erector spinae, trapezius, deltoid and sternocleidomastoid muscles. Root mean square (RMS) and power spectrum median frequency of the EMG were calculated. Sitting posture was assessed using an eight-channel movement analysis system with ultrasound markers. The position of the seventh cervical spinous process and the left and the right acromion were analysed synchronously with the EMG characteristics using regression analysis. The normalised RMS of the left and right trapezius muscle increased, while the median frequency did not change. The increase of the normalised RMS was significantly lower when the linear influence of posture was excluded. On average, the distance between C7 and the left and right acromion decreased within each working an hour. C7 became lower on average by 5.5 mm within an hour, whereas the acromions became lower by only 1.7 mm (left) and 3.3 mm (right). The increase in trapezius muscle activity was partly related to a lifting of the shoulders to compensate a slight slumping of the back. Another part of the EMG activity increase has to be attributed to fatigue, to attention-related activity or to the combination of both. Therefore, training of the back muscles and a varied organisation of work might have a preventive effect with respect to musculoskeletal complaints in VDU workers.

Do magnetic resonance imaging and computed tomography provide equivalent measures of rotator cuff muscle size in glenohumeral osteoarthritis?

PubMed

Chalmers, Peter N; Beck, Lindsay; Stertz, Irene; Aleem, Alexander; Keener, Jay D; Henninger, Heath B; Tashjian, Robert Z

2018-05-10

Rotator cuff muscle volume is associated with outcomes after cuff repair and total shoulder arthroplasty. Muscle area on select magnetic resonance imaging (MRI) slices has been shown to be a surrogate for muscle volume. The purpose of this study was to determine whether computed tomography (CT) provides an equivalent measurement of cuff muscle area to a previously validated MRI measurement. We included 30 patients before they were undergoing total shoulder arthroplasty with both preoperative CT and MRI scans performed within 30 days of one another at 1 institution using a consistent protocol. We reoriented CT sagittal and MRI sagittal T1 series orthogonal to the scapular plane. On both CT and MRI scans, we measured the area of the supraspinatus, infraspinatus-teres minor, and subscapularis on 2 standardized slices as previously described. We calculated intraclass correlation coefficients and mean differences. For the 30 subjects included, when MRI and CT were compared, the mean intraclass correlation coefficients were 0.989 (95% confidence interval [CI], 0.976-0.995) for the supraspinatus, 0.978 (95% CI, 0.954-0.989) for the infraspinatus-teres minor, and 0.977 (95% CI, 0.952-0.989) for the subscapularis. The mean differences were 0.2 cm 2 (95% CI, 0.0-0.4 cm 2 ) for the supraspinatus (P = .052), 0.8 cm 2 (95% CI, 0.1-1.4 cm 2 ) for the infraspinatus-teres minor (P = .029), and -0.3 cm 2 (95% CI, -1.2 to 0.5 cm 2 ) for the subscapularis (P = .407). CT provides nearly equivalent measures of cuff muscle area to an MRI technique with previously validated reliability and accuracy. While CT underestimates the infraspinatus area as compared with MRI, the difference is less than 1 cm 2 and thus likely clinically insignificant. Copyright © 2018 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Quantitative assessment of fat infiltration in the rotator cuff muscles using water-fat MRI.

PubMed

Nardo, Lorenzo; Karampinos, Dimitrios C; Lansdown, Drew A; Carballido-Gamio, Julio; Lee, Sonia; Maroldi, Roberto; Ma, C Benjamin; Link, Thomas M; Krug, Roland

2014-05-01

To evaluate a chemical shift-based fat quantification technique in the rotator cuff muscles in comparison with the semiquantitative Goutallier fat infiltration classification (GC) and to assess their relationship with clinical parameters. The shoulders of 57 patients were imaged using a 3T MR scanner. The rotator cuff muscles were assessed for fat infiltration using GC by two radiologists and an orthopedic surgeon. Sequences included oblique-sagittal T1-, T2-, and proton density-weighted fast spin echo, and six-echo gradient echo. The iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) was used to measure fat fraction. Pain and range of motion of the shoulder were recorded. Fat fraction values were significantly correlated with GC grades (P < 0.0001, κ >0.9) showing consistent increase with GC grades (grade = 0, 0%-5.59%; grade = 1, 1.1%-9.70%; grade = 2, 6.44%-14.86%; grade = 3, 15.25%-17.77%; grade = 4, 19.85%-29.63%). A significant correlation between fat infiltration of the subscapularis muscle quantified with IDEAL versus 1) deficit in internal rotation (Spearman Rank Correlation Coefficient [SRC] = 0.39, 95% confidence interval [CI] 0.13-0.60, P < 0.01) and 2) pain (SRC coefficient = 0.313, 95% CI 0.049-0.536, P = 0.02) was found but was not seen between the clinical parameters and GC grades. Additionally, only quantitative fat infiltration measures of the supraspinatus muscle were significantly correlated with a deficit in abduction (SRC coefficient = 0.45, 95% CI 0.20-0.60, P < 0.01). An accurate and highly reproducible fat quantification in the rotator cuff muscles using water-fat magnetic resonance imaging (MRI) techniques is possible and significantly correlates with shoulder pain and range of motion. Copyright © 2013 Wiley Periodicals, Inc.

Quantitative Assessment of Fat Infiltration in the Rotator Cuff Muscles using water-fat MRI

PubMed Central

Nardo, Lorenzo; Karampinos, Dimitrios C.; Lansdown, Drew A.; Carballido-Gamio, Julio; Lee, Sonia; Maroldi, Roberto; Ma, C. Benjamin; Link, Thomas M.; Krug, Roland

2013-01-01

Purpose To evaluate a chemical shift-based fat quantification technique in the rotator cuff muscles in comparison with the semi-quantitative Goutallier fat infiltration classification (GC) and to assess their relationship with clinical parameters. Materials and Methods The shoulders of 57 patients were imaged using a 3T MR scanner. The rotator cuff muscles were assessed for fat infiltration using GC by two radiologists and an orthopedic surgeon. Sequences included oblique-sagittal T1-, T2- and proton density-weighted fast spin echo, and six-echo gradient echo. The iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) was used to measure fat fraction. Pain and range of motion of the shoulder were recorded. Results Fat fraction values were significantly correlated with GC grades (p< 0.0001, kappa>0.9) showing consistent increase with GC grades (grade=0, 0%–5.59%; grade=1, 1.1%–9.70%; grade=2, 6.44%–14.86%; grade=3, 15.25%–17.77%; grade=4, 19.85%–29.63%). A significant correlation between fat infiltration of the subscapularis muscle quantified with IDEAL versus a) deficit in internal rotation (Spearman Rank Correlation Coefficient=0.39, 95% CI 0.13–0.60, p<0.01) and b) pain (Spearman Rank Correlation coefficient=0.313, 95% CI 0.049–0.536, p=0.02) was found but was not seen between the clinical parameters and GC grades. Additionally, only quantitative fat infiltration measures of the supraspinatus muscle were significantly correlated with a deficit in abduction (Spearman Rank Correlation Coefficient=0.45, 95% CI 0.20–0.60, p<0.01). Conclusion We concluded that an accurate and highly reproducible fat quantification in the rotator cuff muscles using water-fat MRI techniques is possible and significantly correlates with shoulder pain and range of motion. PMID:24115490

Temporal Co-Variation between Eye Lens Accommodation and Trapezius Muscle Activity during a Dynamic Near-Far Visual Task

PubMed Central

Zetterberg, Camilla; Richter, Hans O.; Forsman, Mikael

2015-01-01

Near work is associated with increased activity in the neck and shoulder muscles, but the underlying mechanism is still unknown. This study was designed to determine whether a dynamic change in focus, alternating between a nearby and a more distant visual target, produces a direct parallel change in trapezius muscle activity. Fourteen healthy controls and 12 patients with a history of visual and neck/shoulder symptoms performed a Near-Far visual task under three different viewing conditions; one neutral condition with no trial lenses, one condition with negative trial lenses to create increased accommodation, and one condition with positive trial lenses to create decreased accommodation. Eye lens accommodation and trapezius muscle activity were continuously recorded. The trapezius muscle activity was significantly higher during Near than during Far focusing periods for both groups within the neutral viewing condition, and there was a significant co-variation in time between accommodation and trapezius muscle activity within the neutral and positive viewing conditions for the control group. In conclusion, these results reveal a connection between Near focusing and increased muscle activity during dynamic changes in focus between a nearby and a far target. A direct link, from the accommodation/vergence system to the trapezius muscles cannot be ruled out, but the connection may also be explained by an increased need for eye-neck (head) stabilization when focusing on a nearby target as compared to a more distant target. PMID:25961299

Shoulder Muscle Activation Levels During the Push-Up-Plus Exercise on Stable and Unstable Surfaces.

PubMed

Torres, Rafaela J B; Pirauá, André L T; Nascimento, Vinícius Y S; Dos Santos, Priscila S; Beltrão, Natália B; de Oliveira, Valéria M A; Pitangui, Ana Carolina R; de Araújo, Rodrigo C

2017-07-01

The aim of this study was to evaluate the acute effect of the use of stable and unstable surfaces on electromyography (EMG) activity and coactivation of the scapular and upper-limb muscles during the push-up plus (with full protraction of the scapula). Muscle activation of anterior deltoid (AD), posterior deltoid (PD), pectoralis major, biceps brachii (BB), triceps brachii (TB), upper trapezius (UT), middle trapezius (MT), lower trapezius (LT), and serratus anterior (SA) levels and coactivation index were determined by surface EMG in 20 young men during push-up plus performed on a stable and unstable condition (2 unstable devices applied to hands and feet). The paired t test and Cohen d were used for statistical analysis. The results showed that during the execution of the push-up plus on the unstable surface an increased EMG activity of the scapular stabilizing muscles (SA, MT, and LT) was observed, while AD and PD muscles showed a decrease. During exercise execution on the unstable surface there was a higher index of coactivation of the scapular muscles (SA-MT and UT-LT pairs). No significant differences were observed in TB-BB and AD-PD pairs. These results suggest that the push-up-plus exercise associated with unstable surfaces produced greater EMG activity levels and coactivation index of the scapular stabilizing muscle. On the other hand, the use of an unstable surface does not promote the same effect for the shoulder muscles.

Assessing the validity of surface electromyography for recording muscle activation patterns from serratus anterior.

PubMed

Hackett, Lucien; Reed, Darren; Halaki, Mark; Ginn, Karen A

2014-04-01

No direct evidence exists to support the validity of using surface electrodes to record muscle activity from serratus anterior, an important and commonly investigated shoulder muscle. The aims of this study were to determine the validity of examining muscle activation patterns in serratus anterior using surface electromyography and to determine whether intramuscular electromyography is representative of serratus anterior muscle activity. Seven asymptomatic subjects performed dynamic and isometric shoulder flexion, extension, abduction, adduction and dynamic bench press plus tests. Surface electrodes were placed over serratus anterior and around intramuscular electrodes in serratus anterior. Load was ramped during isometric tests from 0% to 100% maximum load and dynamic tests were performed at 70% maximum load. EMG signals were normalised using five standard maximum voluntary contraction tests. Surface electrodes significantly underestimated serratus anterior muscle activity compared with the intramuscular electrodes during dynamic flexion, dynamic abduction, isometric flexion, isometric abduction and bench press plus tests. All other test conditions showed no significant differences including the flexion normalisation test where maximum activation was recorded from both electrode types. Low correlation between signals was recorded using surface and intramuscular electrodes during concentric phases of dynamic abduction and flexion. It is not valid to use surface electromyography to assess muscle activation levels in serratus anterior during isometric exercises where the electrodes are not placed at the angle of testing and dynamic exercises. Intramuscular electrodes are as representative of the serratus anterior muscle activity as surface electrodes. Copyright © 2014 Elsevier Ltd. All rights reserved.

Temporal Co-Variation between Eye Lens Accommodation and Trapezius Muscle Activity during a Dynamic Near-Far Visual Task.

PubMed

Zetterberg, Camilla; Richter, Hans O; Forsman, Mikael

2015-01-01

Near work is associated with increased activity in the neck and shoulder muscles, but the underlying mechanism is still unknown. This study was designed to determine whether a dynamic change in focus, alternating between a nearby and a more distant visual target, produces a direct parallel change in trapezius muscle activity. Fourteen healthy controls and 12 patients with a history of visual and neck/shoulder symptoms performed a Near-Far visual task under three different viewing conditions; one neutral condition with no trial lenses, one condition with negative trial lenses to create increased accommodation, and one condition with positive trial lenses to create decreased accommodation. Eye lens accommodation and trapezius muscle activity were continuously recorded. The trapezius muscle activity was significantly higher during Near than during Far focusing periods for both groups within the neutral viewing condition, and there was a significant co-variation in time between accommodation and trapezius muscle activity within the neutral and positive viewing conditions for the control group. In conclusion, these results reveal a connection between Near focusing and increased muscle activity during dynamic changes in focus between a nearby and a far target. A direct link, from the accommodation/vergence system to the trapezius muscles cannot be ruled out, but the connection may also be explained by an increased need for eye-neck (head) stabilization when focusing on a nearby target as compared to a more distant target.

Extrapulmonary features of bronchiectasis: muscle function, exercise capacity, fatigue, and health status.

PubMed

Ozalp, Ozge; Inal-Ince, Deniz; Calik, Ebru; Vardar-Yagli, Naciye; Saglam, Melda; Savci, Sema; Arikan, Hulya; Bosnak-Guclu, Meral; Coplu, Lutfi

2012-06-11

There are limited number of studies investigating extrapulmonary manifestations of bronchiectasis. The purpose of this study was to compare peripheral muscle function, exercise capacity, fatigue, and health status between patients with bronchiectasis and healthy subjects in order to provide documented differences in these characteristics for individuals with and without bronchiectasis. Twenty patients with bronchiectasis (43.5 ± 14.1 years) and 20 healthy subjects (43.0 ± 10.9 years) participated in the study. Pulmonary function, respiratory muscle strength (maximal expiratory pressure - MIP - and maximal expiratory pressure - MEP), and dyspnea perception using the Modified Medical Research Council Dyspnea Scale (MMRC) were determined. A six-minute walk test (6MWT) was performed. Quadriceps muscle, shoulder abductor, and hand grip strength (QMS, SAS, and HGS, respectively) using a hand held dynamometer and peripheral muscle endurance by a squat test were measured. Fatigue perception and health status were determined using the Fatigue Severity Scale (FSS) and the Leicester Cough Questionnaire (LCQ), respectively. Number of squats, 6MWT distance, and LCQ scores as well as lung function testing values and respiratory muscle strength were significantly lower and MMRC and FSS scores were significantly higher in patients with bronchiectasis than those of healthy subjects (p < 0.05). In bronchiectasis patients, QMS was significantly associated with HGS, MIP and MEP (p < 0.05). The 6MWT distance was significantly correlated to LCQ psychological score (p < 0.05). The FSS score was significantly associated with LCQ physical and total and MMRC scores (p < 0.05). The LCQ psychological score was significantly associated with MEP and 6MWT distance (p < 0.05). Peripheral muscle endurance, exercise capacity, fatigue and health status were adversely affected by the presence of bronchiectasis. Fatigue was associated with dyspnea and health status. Respiratory muscle strength was related to peripheral muscle strength and health status, but not to fatigue, peripheral muscle endurance or exercise capacity. These findings may provide insight for outcome measures for pulmonary rehabilitation programs for patients with bronchiectasis.

Kinetic chain abnormalities in the athletic shoulder.

PubMed

Sciascia, Aaron; Thigpen, Charles; Namdari, Surena; Baldwin, Keith

2012-03-01

Overhead activities require the shoulder to be exposed to and sustain repetitive loads. The segmental activation of the body's links, known as the kinetic chain, allows this to occur effectively. Proper muscle activation is achieved through generation of energy from the central segment or core, which then transfers the energy to the terminal links of the shoulder, elbow, and hand. The kinetic chain is best characterized by 3 components: optimized anatomy, reproducible efficient motor patterns, and the sequential generation of forces. However, tissue injury and anatomic deficits such as weakness and/or tightness in the leg, pelvic core, or scapular musculature can lead to overuse shoulder injuries. These injuries can be prevented and maladaptations can be detected with a thorough understanding of biomechanics of the kinetic chain as it relates to overhead activity.

Negative Influence of Motor Impairments on Upper Limb Movement Patterns in Children with Unilateral Cerebral Palsy. A Statistical Parametric Mapping Study

PubMed Central

Simon-Martinez, Cristina; Jaspers, Ellen; Mailleux, Lisa; Desloovere, Kaat; Vanrenterghem, Jos; Ortibus, Els; Molenaers, Guy; Feys, Hilde; Klingels, Katrijn

2017-01-01

Upper limb three-dimensional movement analysis (UL-3DMA) offers a reliable and valid tool to evaluate movement patterns in children with unilateral cerebral palsy (uCP). However, it remains unknown to what extent the underlying motor impairments explain deviant movement patterns. Such understanding is key to develop efficient rehabilitation programs. Although UL-3DMA has been shown to be a useful tool to assess movement patterns, it results in a multitude of data, challenging the clinical interpretation and consequently its implementation. UL-3DMA reports are often reduced to summary metrics, such as average or peak values per joint. However, these metrics do not take into account the continuous nature of the data or the interdependency between UL joints, and do not provide phase-specific information of the movement pattern. Moreover, summary metrics may not be sensitive enough to estimate the impact of motor impairments. Recently, Statistical Parametric Mapping (SPM) was proposed to overcome these problems. We collected UL-3DMA of 60 children with uCP and 60 typically developing children during eight functional tasks and evaluated the impact of spasticity and muscle weakness on UL movement patterns. SPM vector field analysis was used to analyze movement patterns at the level of five joints (wrist, elbow, shoulder, scapula, and trunk). Children with uCP showed deviant movement patterns in all joints during a large percentage of the movement cycle. Spasticity and muscle weakness negatively impacted on UL movement patterns during all tasks, which resulted in increased wrist flexion, elbow pronation and flexion, increased shoulder external rotation, decreased shoulder elevation with a preference for movement in the frontal plane and increased trunk internal rotation. Scapular position was altered during movement initiation, although scapular movements were not affected by muscle weakness or spasticity. In conclusion, we identified pathological movement patterns in children with uCP and additionally mapped the negative impact of spasticity and muscle weakness on these movement patterns, providing useful insights that will contribute to treatment planning. Last, we also identified a subset of the most relevant tasks for studying UL movements in children with uCP, which will facilitate the interpretation of UL-3DMA data and undoubtedly contribute to its clinical implementation. PMID:29051729

Fibromyalgia

MedlinePlus

Fibromyalgia is a disorder that causes muscle pain and fatigue. People with fibromyalgia have "tender points" on the body. Tender points are specific places on the neck, shoulders, back, hips, arms, and ...

Corticospinal control of antagonistic muscles in the cat.

PubMed

Ethier, Christian; Brizzi, Laurent; Giguère, Dominic; Capaday, Charles

2007-09-01

We recently suggested that movement-related inter-joint muscle synergies are recruited by selected excitation and selected release from inhibition of cortical points. Here we asked whether a similar cortical mechanism operates in the functional linking of antagonistic muscles. To this end experiments were done on ketamine-anesthetized cats. Intracortical microstimulation (ICMS) and intramuscular electromyographic recordings were used to find and characterize wrist, elbow and shoulder antagonistic motor cortical points. Simultaneous ICMS applied at two cortical points, each evoking activity in one of a pair of antagonistic muscles, produced co-contraction of antagonistic muscle pairs. However, we found an obvious asymmetry in the strength of reciprocal inhibition; it was always significantly stronger on physiological extensors than flexors. Following intravenous injection of a single bolus of strychnine, a cortical point at which only a physiological flexor was previously activated also elicited simultaneous activation of its antagonist. This demonstrates that antagonistic corticospinal neurons are closely grouped, or intermingled. To test whether releasing a cortical point from inhibition allows it to be functionally linked with an antagonistic cortical point, one of three GABA(A) receptor antagonists, bicuculline, gabazine or picrotoxin, was injected iontophoretically at one cortical point while stimulation was applied to an antagonistic cortical point. This coupling always resulted in co-contraction of the represented antagonistic muscles. Thus, antagonistic motor cortical points are linked by excitatory intracortical connections held in check by local GABAergic inhibition, with reciprocal inhibition occurring at the spinal level. Importantly, the asymmetry of cortically mediated reciprocal inhibition would appear significantly to bias muscle maps obtained by ICMS in favor of physiological flexors.

Activation of the serratus anterior and upper trapezius in a population with winged and tipped scapulae during push-up-plus and diagonal shoulder-elevation.

PubMed

Park, Se-Yeon; Yoo, Won-Gyu

2015-01-01

Scapular winging and tipping are types of abnormal scapular kinematics, which is caused by not only the entrapment of peripheral nerve, but also imbalance of the scapulothoracic musculatures. The purpose of this study was to investigate the presence of muscular imbalance in the middle and lower parts of the serratus anterior and upper trapezius in people with scapular winging and tipping. Twenty male participants (age, 23.0 ± 1.92 y) were placed into symptomatic group (n = 10) and control group (n = 10). Participants completed two individual trials of a push-up plus, and a diagonal shoulder elevation, while electromyography (EMG) recorded muscle activity of the low and middle serratus anterior and upper trapezius. The root mean squared EMG values for three muscles were normalized using maximum voluntary isometric contractions (%MVIC). The value was calculated using modified isolation equation for comparing activation of middle and lower serratus anterior (%isolation). During a diagonal shoulder elevation, the % maximal voluntary isometric contraction (%MVIC) data showed that the symptomatic participants had significantly greater activation of the middle serratus anterior compared to the control group (P = 0.01). During a diagonal shoulder elevation, the symptomatic participants had not only significantly increased %isolation of the middle serratus anterior, but also significantly decreased for the lower serratus anterior compare with the control group (p = 0.00). Present result indicated that different muscle activation between middle and lower serratus anterior could represent in group with scapular dyskinesis, and need for selective activation of the lower serratus anterior in patients with scapular winging and tipping.

The Impact of Ergonomically Designed Workstations on Shoulder EMG Activity during Carpet Weaving

PubMed Central

Motamedzade, Majid; Afshari, Davood; Soltanian, Alireza

2014-01-01

Background: The present study aimed to evaluate the biomechanical exposure to the trapezius muscle activity in female weavers for a prolonged period in the workstation A (suggested by previous studies) and workstation B (proposed by the present study). Methods: Electromyography data were collected from nine females during four hours for each ergonomically designed workstation at the Ergonomics Laboratory, Hamadan, Iran. The design criteria for ergonomically designed workstations were: 1) weaving height (20 and 3 cm above elbow height for workstations A and B, respectively), and 2) seat type (10° and 0° forwardsloping seat for workstations A and B, respectively). Results: The amplitude probability distribution function (APDF) analysis showed that the left and right upper trapezius muscle activity was almost similar at each workstation. Trapezius muscle activity in the workstation A was signifi­cantly greater than workstations B (P<0.001). Conclusion: In general, use of workstation B leads to significantly reduced muscle activity levels in the upper trapezius as compared to workstation A in weavers. Despite the positive impact of workstation B in reducing trapezius muscle activity, it seems that constrained postures of the upper arm during weaving may be associated with musculoskeletal symptoms. PMID:25650180

The Impact of Ergonomically Designed Workstations on Shoulder EMG Activity during Carpet Weaving.

PubMed

Motamedzade, Majid; Afshari, Davood; Soltanian, Alireza

2014-01-01

The present study aimed to evaluate the biomechanical exposure to the trapezius muscle activity in female weavers for a prolonged period in the workstation A (suggested by previous studies) and workstation B (proposed by the present study). Electromyography data were collected from nine females during four hours for each ergonomically designed workstation at the Ergonomics Laboratory, Hamadan, Iran. The design criteria for ergonomically designed workstations were: 1) weaving height (20 and 3 cm above elbow height for workstations A and B, respectively), and 2) seat type (10° and 0° forwardsloping seat for workstations A and B, respectively). The amplitude probability distribution function (APDF) analysis showed that the left and right upper trapezius muscle activity was almost similar at each workstation. Trapezius muscle activity in the workstation A was signifi-cantly greater than workstations B (P<0.001). In general, use of workstation B leads to significantly reduced muscle activity levels in the upper trapezius as compared to workstation A in weavers. Despite the positive impact of workstation B in reducing trapezius muscle activity, it seems that constrained postures of the upper arm during weaving may be associated with musculoskeletal symptoms.

Comparison of isometric exercises for activating latissimus dorsi against the upper body weight.

PubMed

Park, Se-yeon; Yoo, Won-gyu; An, Duk-hyun; Oh, Jae-seop; Lee, Jung-hoon; Choi, Bo-ram

2015-02-01

Because there is little agreement as to which exercise is the most effective for activating the latissimus dorsi, and its intramuscular components are rarely compared, we investigated the intramuscular components of the latissimus dorsi during both trunk and shoulder exercises. Sixteen male subjects performed four isometric exercises: inverted row, body lifting, trunk extension, and trunk lateral bending. Surface electromyography (sEMG) was used to collect data from the medial and lateral components of the latissimus dorsi, lower trapezius, and the erector spinae at the 12th thoracic level during the isometric exercises. Two-way repeated analysis of variance with two within-subject factors (muscles and exercise conditions) was used to determine the significance of differences between the muscles and differences between exercise variations. The inverted row showed the highest values for the medial latissimus dorsi, which were significantly higher than those of the body lifting or trunk extension exercises. For the lateral latissimus dorsi, lateral bending showed significantly higher muscle activity than the inverted row or trunk extension. During body lifting, the % maximum voluntary isometric contraction (MVIC) of the erector spinae showed the lowest value, significantly lower than those of the other isometric exercises. The inverted row exercise was effective for activating the medial latissimus dorsi versus the shoulder depression and trunk exertion exercises. The lateral bending and body lifting exercises were favorable for activating the lateral component of the latissimus dorsi. Evaluating trunk lateral bending is essential for examining the function of the latissimus dorsi. Copyright © 2014 Elsevier Ltd. All rights reserved.

Exoskeletal meal assistance system (EMAS II) for progressive muscle dystrophy patient.

PubMed

Hasegawa, Yasuhisa; Oura, Saori

2011-01-01

This paper introduces a 4-DOFs exoskeletal meal assistance system (EMAS II) for progressive muscle dystrophy patient. It is generally better for the patient to use his/her hands by himself in daily life because active works maintain level of residual functions, health and initiative of him/her. The EMAS II that has a new joystick-type user interface device and three-DOFs on a shoulder part is enhanced for an easier operation and more comfortable support on eating, as the succeeding model of the previous system that has two-DOFs on a shoulder. In order to control the 4-DOFs system by the simple user interface device, the EMAS II simulates upper limb motion patterns of a healthy person. The motion patterns are modeled by extracting correlations between the height of a user's wrist joint and that of the user's elbow joint at the table. Moreover, the EMAS II automatically brings user's hand up to his/her mouth or back to a table when he/she pushes a preset switch on the interface device. Therefore a user has only to control a position of his/her wrist to pick or scoop foods and then flip the switch to start automatic mode, while a height of the elbow joint is automatically controlled by the EMAS II itself. The results of experiments, where a healthy subject regarded as a muscle dystrophy patient eats a meal with EMAS II, show that the subject finished her meal in a natural way in 18 minutes 40 seconds which was within a recommended time of 30 minutes. © 2011 IEEE

A Unique Case of Melorheostosis Presenting with Two Radiologically Distinct Lesions in the Shoulder.

PubMed

Elsheikh, Ahmed A; Pinto, Rohan S; Mistry, Alpesh; Frostick, Simon P

2017-01-01

Melorheostosis is a rare, nonhereditary, benign, mesenchymal condition of unknown aetiology affecting the bones and surrounding tissues. A male patient complaining of left shoulder pain, swelling, and mildly limited range of motion has an exclusive combination of the classic dripping wax lesion in the scapula and the myositis ossificans-like lesion in the deltoid muscle; this combination is the first to be reported in the shoulder. Both lesions showed typical findings of melorheostosis in radiographs, CT, MRI, and bone scan. This case has a stationary course over the follow-up period, and no specific treatment is needed in due course.

A Unique Case of Melorheostosis Presenting with Two Radiologically Distinct Lesions in the Shoulder

PubMed Central

Pinto, Rohan S.; Mistry, Alpesh; Frostick, Simon P.

2017-01-01

Melorheostosis is a rare, nonhereditary, benign, mesenchymal condition of unknown aetiology affecting the bones and surrounding tissues. A male patient complaining of left shoulder pain, swelling, and mildly limited range of motion has an exclusive combination of the classic dripping wax lesion in the scapula and the myositis ossificans-like lesion in the deltoid muscle; this combination is the first to be reported in the shoulder. Both lesions showed typical findings of melorheostosis in radiographs, CT, MRI, and bone scan. This case has a stationary course over the follow-up period, and no specific treatment is needed in due course. PMID:29234550

Effects of concurrent physical and cognitive demands on muscle activity and heart rate variability in a repetitive upper-extremity precision task.

PubMed

Srinivasan, Divya; Mathiassen, Svend Erik; Hallman, David M; Samani, Afshin; Madeleine, Pascal; Lyskov, Eugene

2016-01-01

Most previous studies of concurrent physical and cognitive demands have addressed tasks of limited relevance to occupational work, and with dissociated physical and cognitive task components. This study investigated effects on muscle activity and heart rate variability of executing a repetitive occupational task with an added cognitive demand integral to correct task performance. Thirty-five healthy females performed 7.5 min of standardized repetitive pipetting work in a baseline condition and a concurrent cognitive condition involving a complex instruction for correct performance. Average levels and variabilities of electromyographic activities in the upper trapezius and extensor carpi radialis (ECR) muscles were compared between these two conditions. Heart rate and heart rate variability were also assessed to measure autonomic nervous system activation. Subjects also rated perceived fatigue in the neck-shoulder region, as well as exertion. Concurrent cognitive demands increased trapezius muscle activity from 8.2% of maximum voluntary exertion (MVE) in baseline to 9.0% MVE (p = 0.0005), but did not significantly affect ECR muscle activity, heart rate, heart rate variability, perceived fatigue or exertion. Trapezius muscle activity increased by about 10%, without any accompanying cardiovascular response to indicate increased sympathetic activation. We suggest this slight increase in trapezius muscle activity to be due to changed muscle activation patterns within or among shoulder muscles. The results suggest that it may be possible to introduce modest cognitive demands necessary for correct performance in repetitive precision work without any major physiological effects, at least in the short term.

Normal isometric strength of rotatorcuff muscles in adults.

PubMed

Chezar, A; Berkovitch, Y; Haddad, M; Keren, Y; Soudry, M; Rosenberg, N

2013-01-01

The most prevalent disorders of the shoulder are related to the muscles of rotator cuff. In order to develop a mechanical method for the evaluation of the rotator cuff muscles, we created a database of isometric force generation by the rotator cuff muscles in normal adult population. We hypothesised the existence of variations according to age, gender and dominancy of limb. A total of 400 healthy adult volunteers were tested, classified into groups of 50 men and women for each decade of life. Maximal isometric force was measured at standardised positions for supraspinatus, infraspinatus and subscapularis muscles in both shoulders in every person. Torque of the force was calculated and normalised to lean body mass. The profiles of mean torque-time curves for each age and gender group were compared. Our data showed that men gradually gained maximal strength in the fifth decade, and showed decreased strength in the sixth. In women the maximal strength was gained in the fourth decade with gradual decline to the sixth decade of life. The dominant arm was stronger in most of the tested groups. The torque profiles of the rotator cuff muscles in men at all ages were significantly higher than that in women. We found previously unrecognised variations of rotator cuff muscles' isometric strength according to age, gender and dominancy in a normal population. The presented data may serve as a basis for the future studies for identification of the abnormal patterns of muscle isometric strength in patients with pathology of the rotator cuff muscles. Cite this article: Bone Joint Res 2013;2:214-19.

On-the-Field Resistance-Tubing Exercises for Throwers: An Electromyographic Analysis

PubMed Central

Myers, Joseph B; Pasquale, Maria R; Laudner, Kevin G; Sell, Timothy C; Bradley, James P; Lephart, Scott M

2005-01-01

Context: Athletes who throw commonly use rubber-tubing resistance exercises in the field setting to assist with warm-up before throwing. Yet no researchers have described which muscles are being activated or which exercises are most effective during rubber-tubing exercises used by throwers for warm-up. Objective: To describe the effectiveness of 12 rubber-tubing resistance exercises commonly used by throwers in activating the shoulder muscles important for throwing. Design: Descriptive research design. Setting: An applied biomechanics research laboratory. Patients or Other Participants: Fifteen physically active male subjects with no history of shoulder injury. Main Outcome Measure(s): Subjects randomly performed 12 rubber-tubing resistance exercises while we assessed muscle activation of the subscapularis, supraspinatus, teres minor, and rhomboid major by indwelling electromyography. Activation of the sternal portion of the pectoralis major, anterior deltoid, middle deltoid, latissimus dorsi, serratus anterior, biceps brachii, triceps brachii, lower trapezius, and infraspinatus muscles was assessed by surface electromyography. Results: Performance of 7 exercises (external rotation at 90° of abduction, throwing deceleration, humeral flexion, humeral extension, low scapular rows, throwing acceleration, and scapular punch) resulted in the highest level of muscle activation of all muscles tested. Conclusions: These 7 exercises exhibited moderate activation (>20% maximal voluntary isometric contraction) in each muscle of the rotator cuff, the primary humeral movers, and the scapular stabilizer muscles. The results suggest that these exercises are most effective in activating the muscles important to the throwing motion and may be beneficial for throwers during their prethrowing warm-up routine. PMID:15902319

The Position and Mobility of the Shoulder, Spinal Column and Pelvis in Seated Subjects.

DTIC Science & Technology

1985-02-01

Wright-Patterson AFB acted as contract monitor; and Ints Kaleps, * Ph.D., Chief, Modeling and Analysis Branch, Biodynamics and Bioengineering Division...lumbar flexion and luibar extension motion series. Fewer motion segments are available for shoulder abduction motion analysis . These data are reported in...the measurements of this cadaver, samples of muscle and tendon were examined histologically to 12 attachments to trolley and arm cuff so that it

Shoulder pain among high-level volleyball players and preseason features.

PubMed

Forthomme, Benedicte; Wieczorek, Valerie; Frisch, Anne; Crielaard, Jean-Michel; Croisier, Jean-Louis

2013-10-01

The main goal of this prospective study was to identify the most significant intrinsic risk factors for shoulder pain by measuring strength developed by shoulder rotators and by carrying out various morphostatic assessments. Sixty-six players (mean ± SD age = 24 ± 5 yr) were recruited from nine volleyball teams from the first and second divisions (34 men and 32 women) to participate in the study. Before the start of the volleyball season, all the participants completed a preseason questionnaire and underwent both a bilateral isokinetic evaluation of the shoulders and morphostatic measurements. During the subsequent 6 months of the competition period, the players reported through a weekly questionnaire any shoulder pain experienced. During the ongoing season, 23% (15 of 66 players) of the volleyball players experienced dominant shoulder pain. Interestingly, participants who reported a history of dominant shoulder pain were found to have nine times higher risk of suffering further pain in their dominant shoulder. The eccentric maximal strength developed by the internal and external rotators was found to represent a protective factor in the volleyball players (respective odds ratios = 0.946, P = 0.01 and 0.94, P = 0.05). No risk factors were found among the shoulder morphostatic measurements. In our study, the evaluation of shoulder rotator muscle strength through isokinetic assessment, especially eccentric mode, appeared to be the most contributing parameter to identify risk factors for shoulder pain. This evaluation should allow to better identify players at risk.

Serratus anterior and trapezius muscle activity during knee push-up plus and knee-plus exercises performed on a stable, an unstable surface and during sling-suspension.

PubMed

Horsak, Brian; Kiener, Marion; Pötzelsberger, Andreas; Siragy, Tarique

2017-01-01

Push-up plus variations are commonly prescribed to clients during shoulder rehabilitation. The purpose of this study was to compare electromyographic (EMG) activities of the serratus anterior (SA), upper (UT), and lower trapezius (LT) during a knee push-up plus and knee-plus exercise performed on various surfaces. Within-subjects Repeated-Measure Design. 19 healthy, young female participants performed both exercises on a stable and unstable surface and during sling-suspension. Surface EMG activities were recorded and average amplitudes were presented as a percentage of the maximal voluntary contraction. A two-way repeated-measures ANOVA was performed to determine differences in activity for each muscle. SA showed no significant differences between exercises and was independent of the base of support (p > 0.05). Muscle activity of UT (95% CI [1.2, 1.4]) and LT (95% CI [2.4, 3.5]) showed slightly greater values when performing the knee push-up plus compared to the knee-plus exercise. The isolated protraction of the shoulder girdle in a kneeling position is as sufficient as the push-up plus in activating the SA selectively. Therefore, we recommended this exercise for clients who are unable to perform an entire push-up or should avoid detrimental stress on the shoulder joint. Copyright © 2016 Elsevier Ltd. All rights reserved.

Obesity Has Minimal Impact on Short-Term Functional Scores After Reverse Shoulder Arthroplasty for Rotator Cuff Tear Arthropathy.

PubMed

Morris, Brent J; Haigler, Richard E; Cochran, John M; Laughlin, Mitzi S; Elkousy, Hussein A; Gartsman, Gary M; Edwards, T Bradley

2016-01-01

The potential adverse effect of body mass index (BMI) on shoulder function scores after reverse shoulder arthroplasty (RSA) has not been investigated. We conducted a study to examine outcomes of RSA performed for rotator cuff tear arthropathy (RCTA) across BMI categories (normal weight, overweight, obese). We hypothesized that, compared with normal-weight patients, obese patients would have worse shoulder function scores, worse mobility, and more complications. Using a prospective shoulder arthroplasty registry, we identified 77 primary RSAs performed for RCTA with minimum 2-year follow-up. Thirty-four patients had normal weight (BMI <25 kg/m2), 21 were overweight (BMI 25-30 kg/m2), and 22 were obese (BMI >30 kg/m2). Shoulder function scores, mobility, and satisfaction were evaluated before surgery and at final follow-up. The 3 BMI groups were not significantly different on demographic factors, preoperative shoulder function scores, or preoperative mobility (P > .05). For each group, shoulder function scores and mobility significantly improved between the preoperative and final follow-up assessments (P < .001). Patient satisfaction was similar between groups (P = .967). Improved shoulder function scores, mobility, and patient satisfaction can be expected after RSA for RCTA in patients regardless of BMI.

Effects of physical and mental stressors on muscle pain.

PubMed

Westgaard, R H

1999-01-01

Physical and mental stressors as risk factors for pain development are discussed. These multifaceted stressor terms are narrowed down so that physical stressors are represented by muscle activity recorded by electromyography (EMG), while mental stress is considered synonymous with psychosocial stress in vocational studies; in experimental studies cognitive stress is used as a model. Pain in the shoulder and neck are focused and related to EMG recordings of activity in the trapezius muscle. Major challenges in this field include proper risk assessment at low physical work loads and criteria for evaluating stress as a risk factor. A 3-factor conceptual model is presented in which the independent dimensions physical work load, mental stress, and individual sensitivity determine the risk of shoulder and neck complaints. It is pointed out that a predominant reduction in physical work load for many jobs and an increasing interaction between work conditions and the general life situation of workers pose particular challenges for risk assessment.

Proximal and distal muscle fatigue differentially affect movement coordination

PubMed Central

Cowley, Jeffrey C.

2017-01-01

Muscle fatigue can cause people to change their movement patterns and these changes could contribute to acute or overuse injuries. However, these effects depend on which muscles are fatigued. The purpose of this study was to determine the differential effects of proximal and distal upper extremity muscle fatigue on repetitive movements. Fourteen subjects completed a repetitive ratcheting task before and after a fatigue protocol on separate days. The fatigue protocol either fatigued the proximal (shoulder flexor) or distal (finger flexor) muscles. Pre/Post changes in trunk, shoulder, elbow, and wrist kinematics were compared to determine how proximal and distal fatigue affected multi-joint movement patterns and variability. Proximal fatigue caused a significant increase (7°, p < 0.005) in trunk lean and velocity, reduced humeral elevation (11°, p < 0.005), and increased elbow flexion (4°, p < 0.01). In contrast, distal fatigue caused small but significant changes in trunk angles (2°, p < 0.05), increased velocity of wrench movement relative to the hand (17°/s, p < 0.001), and earlier wrist extension (4%, p < 0.005). Movement variability increased at proximal joints but not distal joints after both fatigue protocols (p < 0.05). Varying movements at proximal joints may help people adapt to fatigue at either proximal or distal joints. The identified differences between proximal and distal muscle fatigue adaptations could facilitate risk assessment of occupational tasks. PMID:28235005