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Purpose: To summarise measurement properties of translated versions of the Shoulder Pain and Disability Index (SPADI) and to assess their methodological quality. Methods: Relevant studies testing measurement properties of translated versions of the SPADI in non-specific shoulder pain participants were included from 11 databases (August 2020). Two reviewers independently screened articles and assessed individual measurement property risk of bias using the COSMIN checklist as very good, adequate, doubtful or inadequate. For each measurement property results were pooled and rated sufficient, insufficient, or inconsistent. Synthesised evidence was graded as high, moderate, low or very low (GRADE approach). Results: Thirty-four studies (21 languages and 26 different versions) were included from 4402 articles. A total of 141 measurement properties were reported with 60 rated as very good or adequate. These included; internal consistency (19), test-retest reliability (4), construct validity (6), structural validity (10), measurement error (5), responsiveness (9), and cross-cultural validity (2). Comprehensibility was adequate in the Chinese, German, Nepali, Spanish and Urdu versions. Only the Danish, Dutch and Nepali versions confirmed all, or all but one, of their measurement properties with sound methodology. Pooled results of all measurement properties except structural validity were rated as sufficient. Quality of evidence was graded moderate to high with downgrading due to inconsistent results. Conclusion: Overall evidence suggests the SPADI is valid, reliable and responsive in translated form but less than half the measurement properties tested were of adequate quality. Further testing is required in many languages particularly in; test-retest reliability, measurement error and construct validity.

Introduction It is commonly believed that the shoulder external rotation (ER) to internal rotation (IR) strength ratio is decreased in swimmers due to predominant IR loading during the pull-through (propulsive) phase which predisposes to shoulder pain. However, the evidence supporting this hypothesis is inconclusive. Therefore, the aim of this study was to examine shoulder rotation strength parameters in elite swimmers and investigate potential associations with shoulder pain. Methods Sixty-eight (40 men; age, 19.9 ± 3.2 yr) elite swimmers provided demographic and shoulder pain history data before measurement of shoulder rotation strength. Mixed model analyses were used to examine differences in shoulder IR and ER strength normalized to body weight (BW) and the shoulder rotation strength ratio. A multinomial logistic regression model was utilized to examine associations between shoulder rotation strength parameters and shoulder pain. Results Mean shoulder IR strength (BW) was approximately 0.29 for male swimmers and 0.26 for female swimmers. Mean shoulder ER strength (BW) was approximately 0.19 for male swimmers and 0.18 for female swimmer. The shoulder ER/IR strength ratio was approximately 0.70 bilaterally for all swimmers. There were no significant differences between dominant and nondominant shoulders in IR or ER strength normalized to BW (P ≥ 0.547). There were no associations between any shoulder strength parameters and shoulder pain (r = 0.032, P = 0.107). Conclusions Despite the high IR loading, optimal swimming technique does not alter the normal ER/IR strength ratio at the shoulder. Elite swimmers who report current or a history of shoulder pain demonstrate normal shoulder rotation strength ratios. The finding of symmetrical shoulder rotation strength points to side-to-side strength comparisons as a valuable clinical tool in managing swimmers with unilateral shoulder pain.

Background Patient-reported outcome measures (PROMs) are important tools in both clinical practice and research. However, no upper extremity PROM to assess physical disability is available in Nepali. The most commonly used and recommended questionnaire for the shoulder is the Disability of Arm, Shoulder and Hand (DASH). Therefore, the aim of the study was to translate and cross-culturally adapt the DASH into Nepali and determine its measurement properties. Methods The translation and cultural adaptation process followed international standard procedures. The translated Nepali version of the questionnaire (DASH-NP) was completed by 156 patients with shoulder pain from three Nepali hospitals at an initial assessment and by 121 at follow-up. A Nepali version of Global Rating of Change (GROC-NP) was completed at follow-up to dichotomise improved and stable participants. Measurement properties testing included: internal consistency (Cronbach's alpha), test-retest reliability (Intraclass Correlation Coefficient, ICC), Minimal Detectable Change (MDC), construct validity - factor analysis, hypothesis testing with the Shoulder Pain and Disability Index (SPADI) (Pearson Correlation = r) and responsiveness - Area Under the Curve with minimal important change. Results Significant adaptations such as changing measurement units, activities and terminology were incorporated to improve cultural relevance. Internal consistency (α = 0.92) and test-retest reliability (ICC = 0.97, 95% CI: 0.94–0.98, p

Objectives A history of shoulder pain is common in swimmers and may influence scapular position, possibly increasing the risk of shoulder pain recurring. The aim of this study was to establish and compare bilateral static measures of scapular upward rotation in swimmers (14–20 years), some with a history of shoulder pain but all currently pain free, in two different elevated positions of shoulder abduction. Design Cross-sectional, observational study. Participants Eighty-five swimmers without current shoulder pain. Methods Scapular upward rotation position was measured on both shoulders using a digital inclinometer in 90° and 140° shoulder abduction. Descriptive statistics were calculated for degrees of scapular upward rotation in both shoulder positions. Differences between shoulders (dominant, non-dominant, history and no history of pain) were explored using one-way ANOVA and paired t tests. Results A large range of values for scapular upward rotation was found at both positions of shoulder abduction but there were no significant differences between the shoulders: with and without a history of shoulder pain for the dominant and non-dominant sides. Conclusions A history of shoulder pain and arm dominance did not influence scapular upward rotation position when measured in shoulder abduction in swimmers without current shoulder pain.

Objectives Optimal shoulder rotation range of motion (ROM) for swimming is unknown. The primary aim of this study was to examine shoulder rotation ROM in elite swimmers, including the influence of humeral torsion on rotation ROM, in order to establish optimal shoulder rotation parameters for swimming. In addition, we examined the relationship between rotation ROM and shoulder pain. Design Descriptive cohort study. Methods Seventy elite Australian swimmers provided shoulder pain history data prior to measurement of humeral torsion and passive and active shoulder rotation ROM. Repeated measure analyses of variance were used to investigate within and between participant differences for all variables. Associations between humeral torsion and rotation ROM were investigated using Pearson's correlation coefficient. Multiple regression analysis was utilised to examine the associations between rotation ROM and shoulder pain. Results Average humeral torsion angles of 27±10° (dominant side) and 31±10° (non-dominant side) were demonstrated in this elite swimming cohort. In general, increased humeral torsion was positively associated with increased internal rotation (IR) and decreased external rotation (ER) ROM. There were significant differences in both IR and ER ROM measured passively and actively (F 2,136 ≥93.1, p 2 =0.058; p=0.46). Conclusions Humeral torsion angle and passive shoulder IR ROM were similar while passive ER ROM was greater in elite swimmers compared to reported normal population values.

Background The Shoulder Pain and Disability Index (SPADI) is a 13-item shoulder-specific patient-reported outcome measure (PROM). The English version is easy to use and has demonstrated excellent measurement properties for both clinical and research settings. The availability of the SPADI in Nepali would facilitate shoulder research and enhance management of patients with shoulder pain in Nepal. Therefore, the purpose of this study was to translate and cross-culturally adapt the SPADI into Nepali (SPADI-NP) and evaluate its measurement properties. Methods The translation and adaptation process followed international guidelines. Participants completed SPADI-NP on two assessments (N = 150 at initial and 119 at follow-up assessment). A Nepali version of the Global Rating of Change score was completed at follow-up. Assessment of measurement properties included analysis of internal consistency (Cronbach’s α), minimal detectable change (MDC) with standard error of measurement (SEM), test-retest reliability (intraclass correlation coefficient; ICC), validity (factor structure, construct using Pearson’s correlation with the Disability of Arm and Hand [DASH]) and responsiveness (area under the curve; AUC) with minimal important change (MIC). Results Minor changes were integrated in the adaptation process to improve cultural relevance such as dress items. Items were largely loaded under two factors (pain and disability), internal consistencies were good for the pain construct (α = 0.82) and disability (α = 0.88) and test-retest reliability was excellent (pain = 0.89, disability = 0.96). MDC was 5.7 (out of 100) with SEM = 2.1. Strong associations with the DASH (r = 0.63 pain, r = 0.81 disability) demonstrated its construct validity. The AUC was 0.68 and MIC was 12.3 (out of 100). Conclusion The Nepali version of the SPADI demonstrated excellent reliability and validity. It can be used for the assessment of shoulder pain and disability in patients with shoulder pain in Nepal in both clinical practice and research.

Objectives Load is used to increasingly challenge muscle function and has been shown to increase muscle activity levels with no change in activation patterns during shoulder flexion, extension, adduction and rotation. However, the effect of load during shoulder abduction, a movement commonly used in assessment of shoulder dysfunction and to improve shoulder function, has not been comprehensively examined. Therefore, the purpose of this study was to determine if load influences shoulder muscle activation patterns and levels during scapular plane abduction in normal subjects. Design Experimental study. Methods Fourteen volunteers performed shoulder abduction in the scapular plane at 25%, 50% and 75% of maximum load. Eight shoulder muscles were investigated using a combination of indwelling and surface electromyographic recordings: middle deltoid, infraspinatus, subscapularis, supraspinatus, serratus anterior, upper and lower trapezius and rhomboid major. Results All muscles tested showed increasing average muscle activation levels with increasing load and strong correlations in the activation patterns between loads. Conclusions Increasing shoulder abduction load not only increases activity in middle deltoid but also in the rotator cuff (infraspinatus, subscapularis, supraspinatus) and axioscapular (serratus anterior, upper and lower trapezius, rhomboid major) muscles. The functional stabilising role of both the rotator cuff and axioscapular muscles is considered an important contribution to the increased activation levels in these muscle groups as they function to counterbalance potential translation forces produced by other muscles during shoulder abduction. The activation patterns of all shoulder muscle groups during abduction can be trained at low load and progressively challenged with increasing load.

Frozen shoulder (adhesive capsulitis) is a severe chronic pain condition that is not well understood and current treatment is suboptimal. In several other chronic pain conditions motor imagery and tactile acuity deficits are present, which are thought to represent associated neuroplastic changes. The aims of this study were to determine if motor imagery performance assessed by the left/right judgement task, and tactile acuity assessed by two-point discrimination, are altered in people with unilateral frozen shoulder. In this cross-sectional, prospective study eighteen adults diagnosed with frozen shoulder in a physiotherapy clinic setting completed a left/right judgement task, response times (RT) and accuracy for the left/right judgement task were determined. Next, tactile acuity over both shoulders was assessed with a novel, force-standardised two-point discrimination test. Results corresponding to the affected side were compared to the pain free shoulder, Left/right judgement task: mean RT (SD) corresponding to the affected shoulder was significantly slower than RT for the healthy shoulder (p = 0.031). There was no side-to-side difference in accuracy (p &gt, 0.05). Neither RT nor accuracy was related to pain/disability scores or duration of symptoms (p &gt, 0.05). Two-point discrimination: mean two-point discrimination threshold of the affected shoulder was significantly larger than the contralateral healthy shoulder (p &lt, 0.001). Two-point discrimination threshold was not related to pain/disability scores or pain duration (p &gt, 0.05), One explanation for these findings is altered sensorimotor processing and/or disrupted sensorimotor cortex representations of the affected shoulder. A case then exists for the use of treatments aimed at reversing these changes, training the brain to reduce chronic shoulder pain.

Because of its superficial location, surface electrodes are commonly used to record lower trapezius activity. Recent evidence, however, would suggest that surface electromyography is not a valid to record activity from other superficially placed shoulder muscles. Therefore, the aim of this study was to determine the validity of using surface electrodes to record lower trapezius activity. Ten asymptomatic subjects performed ramped isometric (0–100% maximum load) and dynamic (70% maximum load) shoulder tasks. Intramuscular electrodes were inserted into lower trapezius and rhomboid major. Surface electrodes were placed over lower trapezius around the intramuscular electrodes. Differences in the recorded activity of lower trapezius between surface and intramuscular electrodes were tested using a 2 factor repeated measures analysis of variance with factors: test and electrode type. Similarity in the recorded activity patterns between the two electrodes was tested using Pearson’s correlation coefficient (r). Results indicated that there was no difference in lower trapezius activity levels (p = 0.98) or activation patterns (r ≥ 0.74) recorded by the intramuscular and surface electrodes. The results of this study indicate that any potential crosstalk contamination in the surface electrode signal is having little influence on the recorded activity from lower trapezius and therefore, support the common practice of surface electromyography to investigate lower trapezius function.

Objectives To determine the relationship and predictive value of isometric shoulder strength in the development of shoulder pain in young swimmers. Design Prospective, cohort study. Methods Shoulder flexion, extension, external and internal rotation strength tests were performed in elevation on 85 swimmers (14–20 years; 48 females) without current shoulder pain using a hand-held dynamometer. Following testing, swimmers were emailed questionnaires to determine if significant shoulder pain developed within 24 months subsequent to testing. The differences between shoulders that did and did not develop pain and the predictive ability of shoulder strength and strength ratios were investigated using Mann Whitney U tests and receiver operating characteristic curves. Results Thirty-seven swimmers (47%) returned questionnaires and 18 reported shoulder pain. A comparison of individual shoulders (27 with pain reported and 47 without) determined that shoulder extension strength was lower and flexion:extension strength ratio was higher for male swimmers (n = 36 shoulders) who reported shoulder pain compared to those who did not (p = 0.04). The predictive value of extension strength was fair (0.72; p = 0.03) for males with a cut-off value for extension strength calculated at 13.5% body mass. There were no differences between the two groups in shoulder rotation strength, age, training hours or previous pain history. Conclusions Shoulder extension strength, a functional test for swimmers, was associated with and predictive of the development of shoulder pain in male swimmers. Low shoulder extension strength may be a risk factor for the development of shoulder pain in swimmers, proposing a direction for injury prevention and future investigation.

Introduction Falling when older is a major public health issue. There is compelling evidence to show that specific exercise programs can reduce the risk and rate of falls in community-dwelling older people. Another major health issue for older people living in the community is upper limb dysfunction, including shoulder pain. Home-based exercise programs appeal to some older people, due to their convenience. Research questions This trial aims to determine the effectiveness and cost-effectiveness of a home-based lower limb exercise program compared with a home-based upper limb exercise program to prevent falls and upper limb dysfunction among community-dwelling people aged 65+ years. Design Randomised, controlled trial. Participants and setting A total of 576 community-dwelling people will be recruited from the Illawarra and Shoalhaven regions of New South Wales, Australia. Intervention Participants will be randomised to either a home-based lower limb exercise intervention or a home-based upper limb exercise intervention. The lower limb program is designed to improve balance and strength in the lower limbs. The upper limb program is designed to improve upper limb strength and mobility. Participants will attend three group-based instruction sessions to learn and progress the exercises, and will be instructed to perform the exercises three times per week at home for 12 months. Outcome measures The two primary outcomes will be fall rates, recorded with monthly calendars for a 12-month period, and upper limb dysfunction, measured with the Disability of the Arm, Shoulder and Hand questionnaire. Secondary outcomes will include: lower limb strength and balance; shoulder strength and mobility; physical activity; quality of life; attitudes to exercise; proportion of fallers; fear of falling; and health and community service use. The cost-effectiveness of both exercise programs from a health and community service provider perspective will be evaluated. Analysis Negative binomial regression models will be used to estimate the between-group difference in fall rates. Modified Poisson regression models will be used to compare groups on dichotomous outcome measures. Linear regression models will be used to assess the effect of group allocation on the continuously scored measures, after adjusting for baseline scores. Two economic evaluations will be conducted: the first will assess cost-effectiveness of the lower limb program compared with the upper limb program; and the second will assess cost-effectiveness of the upper limb program compared with the lower limb program. Discussion If effective, the trial will provide a model for both upper limb and lower limb exercise programs that can be performed at home and implemented at scale to community-dwelling older adults.

Study Design Observational: cross-sectional study. Background Idiopathic frozen shoulder is a common cause of severe and prolonged disability characterised by spontaneous onset of pain with progressive shoulder movement restriction. Although spontaneous recovery can be expected the average length of symptoms is 30 months. Chronic inflammation and various patterns of fibrosis and contracture of capsuloligamentous structures around the glenohumeral joint are considered to be responsible for the signs and symptoms associated with frozen shoulder, however, the pathoanatomy of this debilitating condition is not fully understood. Objectives To investigate the feasibility of a muscle guarding component to movement restriction in patients with idiopathic frozen shoulder. Methods Passive shoulder abduction and external rotation range of motion (ROM) were measured in patients scheduled for capsular release surgery for frozen shoulder before and after the administration of general anaesthesia. Results Five patients with painful, global restriction of passive shoulder movement volunteered for this study. Passive abduction ROM increased following anaesthesia in all participants, with increases ranging from approximately 55°–110° of pre-anaesthetic ROM. Three of these participants also demonstrated substantial increases in passive external rotation ROM following anaesthesia ranging from approximately 15°–40° of pre-anaesthetic ROM. Conclusion This case series of five patients with frozen shoulder demonstrates that active muscle guarding, and not capsular contracture, may be a major contributing factor to movement restriction in some patients who exhibit the classical clinical features of idiopathic frozen shoulder. These findings highlight the need to reconsider our understanding of the pathoanatomy of frozen shoulder. Level of evidence Level 4.

Because of its superficial location surface electrodes are commonly used to record latissimus dorsi (LD) activity. Despite the fact that the recommended electrode placement is over the belly where LD is quite thin no studies have investigated the possibility of signal contamination from muscles lying deep to LD. Therefore, the aim of this study was to determine the validity of using surface electrodes to record activity from LD. Eight asymptomatic subjects performed ramped isometric (0-100% maximum load) and dynamic (70% maximum load) shoulder tasks. Intramuscular electrodes were inserted into LD and the adjacent erector spinae. Surface electrodes were placed over LD around the intramuscular electrodes. Results indicated that while there was no difference in activity level or activation pattern (ICC0.94) recorded by the two electrode types during shoulder tasks in which LD would be expected to be active (extension and adduction), significantly lower (p0.05) LD activity was recorded via intramuscular electrodes during the shoulder flexion and abduction tasks. Therefore, recordings of LD activity by surface electrodes overestimate LD activity during shoulder tasks when this muscle would be expected to be activated at minimum levels. Erector spinae immediately deep to LD was confirmed as a source of crosstalk contamination.

Static optimization is commonly employed in musculoskeletal modeling to estimate muscle and joint loading; however, the ability of this approach to predict antagonist muscle activity at the shoulder is poorly understood. Antagonist muscles, which contribute negatively to a net joint moment, are known to be important for maintaining glenohumeral joint stability. This study aimed to compare muscle and joint force predictions from a subject-specific neuromusculoskeletal model of the shoulder driven entirely by measured muscle electromyography (EMG) data with those from a musculoskeletal model employing static optimization. Four healthy adults performed six sub-maximal upper-limb contractions including shoulder abduction, adduction, flexion, extension, internal rotation and external rotation. EMG data were simultaneously measured from 16 shoulder muscles using surface and intramuscular electrodes, and joint motion evaluated using video motion analysis. Muscle and joint forces were calculated using both a calibrated EMG-driven neuromusculoskeletal modeling framework, and musculoskeletal model simulations that employed static optimization. The EMG-driven model predicted antagonistic muscle function for pectoralis major, latissimus dorsi and teres major during abduction and flexion; supraspinatus during adduction; middle deltoid during extension; and subscapularis, pectoralis major and latissimus dorsi during external rotation. In contrast, static optimization neural solutions showed little or no recruitment of these muscles, and preferentially activated agonistic prime movers with large moment arms. As a consequence, glenohumeral joint force calculations varied substantially between models. The findings suggest that static optimization may under-estimate the activity of muscle antagonists, and therefore, their contribution to glenohumeral joint stability.

Objectives: Open and closed-chain abduction of the shoulder are commonly used in rehabilitation and exercise programs to assess and/or improve shoulder muscle function. However, it is not known if shoulder muscle activation patterns differ between these two exercises. Therefore the purpose of this study was to compare muscle activation patterns during closed-chain shoulder abduction performed using a shoulder press machine with open-chain abduction using free weights. Design: Experimental study. Methods: Open and closed-chain abduction were performed by 15 and 14 subjects respectively at low (25%), medium (50%) and high (75%) load. Surface and indwelling electrodes were used to record the activation pattern of seven shoulder muscles during the concentric phase of each exercise. Data were normalised to maximum voluntary contractions (MVC), time normalised and compared over the common range of motion (40°–140° abduction). Results: Only the activation pattern of middle deltoid had a strong positive correlation between exercises (r ≥ 0.65, p < 0.05) with similar activation levels at all loads (35%, 50% and 60% MVC, p = 1.0). All other muscles tested had inconsistent, low or negative correlations between exercises. Significantly lower average activation levels were recorded during closed-chain abduction for subscapularis at all loads, upper trapezius at medium and high loads and infraspinatus and lower trapezius at high load (p < 0.05). Conclusions: Open-chain abduction is required to facilitate the stabilising role of the rotator cuff and axioscapular muscles, in response to middle deltoid activity. Closed-chain exercises may enable full range shoulder abduction earlier in rehabilitation programs, with an inherent stability and less demand on the rotator cuff.

The prevalence of shoulder pain in young swimmers is high. Shoulder rotation strength and the ratio of internal to external rotation strength have been reported as potential modifiable risk factors associated with shoulder pain. However, relative strength measures in elevated positions, which include flexion and extension, have not been established for the young swimmer. The aim of this study was to establish clinically useful, normative shoulder strength measures and ratios for swimmers (14-20 years) without shoulder pain.Cross-sectional, observational study.Swimmers (N=85) without a recent history of shoulder pain underwent strength testing of shoulder flexion and extension (in 140° abduction); and internal and external rotation (in 90° abduction). Strength tests were performed in supine using a hand-held dynamometer and values normalised to body weight. Descriptive statistics were calculated for strength and strength ratios (flexion:extension and internal:external rotation). Differences between groups (based on gender, history of pain, test and arm dominance) were explored using independent and paired t tests.Normative shoulder strength values and ratios were established for young swimmers. There was a significant difference (p0.002) in relative strength between males and females for all tests with no differences in strength ratios. Relative strength of the dominant and non-dominant shoulders (except for extension); and for swimmers with and without a history of shoulder pain was not significantly different.A normal shoulder strength profile for the young swimmer has been established which provides a valuable reference for the clinician assessing shoulder strength in this population.

Background: Disruption of cortically-held working body schema has been associated with a variety of pain conditions. A motor imagery technique - the left right judgement task (LRJT) - has been used as an indirect assessment of the integrity of the working body schema. To date there is no LRJT specifically designed to investigate the body schema of persons with shoulder pain. Objectives: To develop a shoulder specific LRJT and assess its validity and reliability. Design: Cross-sectional repeated measures. Methods: Shoulder images were developed representing the shoulder in a variety of postures of graded complexity/awkwardness and degree of rotation. These images were digitally mirrored to represent both left and right shoulders. Participants viewed the images on a computer and determined whether images were of a left or right shoulder. Results: 1413 participants were recruited worldwide and performed the shoulder LRJT (laterality judgement). Mean response time (SD) for the task was 1738(741) ms. Mean accuracy (SD) was 93.5(9.2)%. Chronbach's Alpha for shoulder image response times was 0.95. Participants were fastest responding to images of simple postures and slowest to images corresponding to the more awkward postures (mean difference 520 ms, 95%CI 469–570 ms). Participants were fastest responding to the least rotated images and slowest responding to inverted images, (mean difference 981 ms, 95%CI 919–1043 ms). Conclusions: The shoulder specific LRJT proved to be highly reliable. Response times increased with complexity and rotation of images, implying a motor imagery strategy was used to complete the task, validating the task as a measure of shoulder joint implicit motor imagery. Abnormal performance cut-offs for age were reported. This result will enable further research examining the relationship between shoulder pain and body schema. Refereed/Peer-reviewed

Objectives 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. Design Original research. Methods 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. Results 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 Conclusions 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.

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.

The four "Shoulder Normalization Tests" were found previously to be a parsimonious set of isometric tests that produce maximal voluntary isometric contractions (MVIC) in the supraspinatus, infraspinatus, subscapularis, trapezius, serratus anterior, deltoid, latissimus dorsi, and pectoralis major [Boettcher et al. (2008). J Orthop Res 26:1591-1597]. However, these tests have not been validated for rhomboid major and teres major. In the current study, these Shoulder Normalization Tests were evaluated and compared to three other tests that could possibly elicit maximum activity in rhomboid major and teres major: abduction/extension in 90° abduction; adduction at 90° abduction; and extension in 30° abduction. No statistical difference was found in the mean activation of rhomboid major and teres major in these additional MVIC tests compared to the Shoulder Normalization Tests. However, the extension MVIC test produced maxima for at least 50% of subjects in rhomboid major, teres major, and latissimus dorsi. We concluded that the original Shoulder Normalization Tests should be expanded to include the extension MVIC test. The EMG normalization reference value for any of the above muscles would be the maximum EMG level generated across these Revised Shoulder Normalization Tests.

Background: Passive mobilization of shoulder region joints, often in conjunction with other treatment modalities, is used for the treatment of people with shoulder pain and minimal movement restriction. However, there is only limited evidence supporting the efficacy of this treatment modality. Objective: The purpose of this study was to determine whether passive mobilization of shoulder region joints adds treatment benefit over exercise and advice alone for people with shoulder pain and minimal movement restriction. Design: This was a randomized controlled clinical trial with short-, medium- and longer-term follow-up. Setting: The study was conducted in a metropolitan teaching hospital. Patients: Ninety-eight patients with shoulder pain of local mechanical origin and minimal shoulder movement restriction were randomly allocated to either a control group (n=51) or an experimental group (n=47). Intervention: Participants in both groups received advice and exercises designed to restore neuromuscular control at the shoulder. In addition, participants in the experimental group received passive mobilization specifically applied to shoulder region joints. Measurements: Outcome measurements of shoulder pain and functional impairment, self-rated change in symptoms, and painful shoulder range of motion were obtained at 1, 3, and 6 months after entry into the trial. All data were analyzed using the intention-to-treat principle by repeated-measures analyses of covariance. Results: No statistically significant differences were detected in any of the outcome measurements between the control and experimental groups at short-, medium-, or longer-term follow-up. Limitations: Therapists and participants were not blinded to the treatment allocation. Conclusion: This randomized controlled clinical trial does not provide evidence that the addition of passive mobilization, applied to shoulder region joints, to exercise and advice is more effective than exercise and advice alone in the treatment of people with shoulder pain and minimal movement restriction.

Question: During isometric shoulder adduction in normal subjects, do the rotator cuff muscles activate more than other shoulder muscles? Are the activation patterns influenced by shoulder abduction angle or load? Design : A within-participant, repeated measures experimental study. Participants: 15 healthy adults. Intervention: Participants performed an isometric adduction exercise at 30°, 60°, and 90° abduction in the scapular plane and at 25%, 50%, 75%, and 100% load. Outcome measures: During the exercises, a combination of indwelling and surface electromyographic recordings were taken from 11 shoulder muscles: supraspinatus, infraspinatus, subscapularis, pectoralis major, teres major, latissimus dorsi, rhomboid major, serratus anterior, lower trapezius, upper trapezius, and deltoid. Results: At 100% load, mean rotator cuff activation levels were low (supraspinatus at 3% of its maximum voluntary contraction, infraspinatus 27%, and subscapularis 27%) and significantly less than the activation levels of rhomboid major (81%), latissimus dorsi (103%), and teres major (76%) (F 10,140 = 15.5, p 0.89). Among the muscles activated above minimum levels (> 10% of maximum voluntary contraction), mean activation levels increased as load increased (F 3,42 = 72.0, p < 0.01) Conclusion: Since isometric adduction in normal subjects does not produce moderate to high activation levels in any of the rotator cuff muscles tested, these results do not support the use of shoulder adduction to identify rotator cuff muscle dysfunction or strengthen the rotator cuff muscles. [Reed D, Halaki M, Ginn K (2010) The rotator cuff muscles are activated at low levels during shoulder adduction: an experimental study. Journal of Physiotherapy 56: 259–264]

Based on previous electromyographic studies the 'empty can' (EC) and 'full can' (FC) tests have been promoted as being able to isolate activity to supraspinatus and are therefore diagnostic of supraspinatus dysfunction. However, there is evidence to suggest that these positions do not selectively activate supraspinatus, and that they may have poor diagnostic accuracy, bringing into question the validity of these tests. Due to limitations in the original EMG papers describing the EC and FC tests the current study aimed to further examine shoulder muscle activity during these tests to determine their ability to selectively activate supraspinatus. EMG activity was recorded from 13 muscles in 15 normal subjects while performing these two tests. Results showed that during the EC and FC muscle tests nine and eight other shoulder muscles, respectively, were equally highly activated as supraspinatus. It was concluded from these results that the EC and FC tests do not primarily activate supraspinatus with minimal activation from other shoulder muscles and therefore, do not satisfy basic criteria to be valid diagnostic tools for supraspinatus pathology. Therefore, these tests should not be interpreted as definitive tests for the clinical diagnosis of supraspinatus pathology. They may, however, be beneficial during shoulder muscle strengthening programs.

Objectives To determine the relationship between the amount of humeral torsion and a measure of active proprioception in adolescent male throwing athletes. Design Cross-sectional laboratory study with uninjured subjects. Setting University of Sydney and NSW Institute of Sport. Participants Participants were 16 adolescent male baseball players (15.0–18.1 years old, SD=16.3) holding baseball scholarships at the NSW Institute of Sport. Main outcome measures The main outcome measures, active proprioception (shoulder rotation, in 90° of arm abduction moving towards external rotation, using the Active Movement Extent Discriminating Apparatus) and humeral torsion (using an ultrasound-assisted method), were measured bilaterally. Results A strong ( r =0.88) and significant ( p =0.001) correlation was found between increasing humeral retrotorsion and better active proprioceptive acuity in the non-dominant arm, while the relation was weaker ( r =0.41) and did not reach statistical significance ( p =0.120) for the dominant arm. Conclusions A cognitive processing capacity model, which suggests that greater humeral retrotorsion reduces neural processing requirements, has been proposed to explain the direct relationship between proprioceptive acuity and humeral retrotorsion.

Objectives To determine the career history of low back pain (LBP) in current elite female cricket fast bowlers and then compare measures of lumbar spine and hip range of motion (ROM) and trunk extensor endurance between those bowlers with and without a history of LBP. Measures for the female bowlers were also compared to a small sample of male fast bowlers. Participants Twenty-six elite female fast bowlers and eight male fast bowlers of similar age and bowling experience. Main outcome measures The career history of LBP was determined by a self-administered questionnaire and by accessing medical records. Range of motion measures for the lumbar spine and hips were obtained using inclinometry or goniometry. Trunk extensor endurance was assessed using a modified Sorensen test. Results Fourteen female fast bowlers had a history of LBP. There was a significant difference in lumbar lateral flexion ROM to the bowling arm side between those female fast bowlers with and without a history of LBP ( p ⩽0.05). The female fast bowlers had significantly more bilateral hip extension ROM ( p ⩽0.05) compared to the male fast bowlers. Conclusions This information should be useful for practitioners involved in the conditioning and rehabilitation of cricketers. Future prospective studies should investigate potential predictors of LBP in female fast bowlers.

Study design Observational laboratory study. Background Abduction is a movement commonly used in the assessment of shoulder dysfunction and prescription of exercises to improve shoulder function. Abduction in the scapular and coronal planes are used interchangeably. It is not known if the activation of individual shoulder muscles differ between abduction performed in these planes and therefore, if they represent different tests/exercises. Objective To quantify and compare the muscle activation patterns and levels for each shoulder muscle during abduction performed in the scapular plane with that performed in the coronal (scapular −30°) and scapular +30° planes. Methods Electromyographic recordings were taken from eight shoulder muscles of fourteen healthy volunteers during shoulder abduction in the scapular and coronal planes and in a plane 30° anterior to the scapular plane (scapular +30°) at 50% of maximum load. Results Similar average muscle activation levels were demonstrated during abduction in the scapular plane and within a 30° arc of this plane for all muscles except: middle deltoid (5% MVC higher activation in the coronal and 4% MVC lower activation in the scapular +30° plane) and upper trapezius (6% MVC lower activation in the scapular +30° plane). Activation patterns between planes for all muscles were similar (ICC (3,1) ≥ 0.87). Conclusions Abduction can be performed within a 30° arc of the scapular plane with no change in shoulder muscle activation patterns. Only middle deltoid activation levels change between the scapular and coronal planes and middle deltoid and upper trapezius between the scapular and scapular +30° planes.

Background and Purpose Graduated rotation exercises performed with the arm by the side are commonly used to improve rotator cuff (RC) muscle function. The aim of this study was to compare the pattern of recruitment of the RC muscles with that of other shoulder muscles that rotate the shoulder joint during these exercises. Subjects The nondominant shoulders of 15 subjects who were healthy were tested. Methods Activity in the infraspinatus, supraspinatus, subscapularis, latissimus dorsi, pectoralis major, and posterior deltoid muscles was recorded. Low-, medium-, and high-intensity rotation exercises were performed with a pulley system. Results As the intensity of both internal and external rotation exercises increased, activity increased in a systematic manner in all muscles capable of producing rotation torque during concentric and eccentric contractions. Discussion and Conclusion The results indicate that, in people who are healthy, the motor strategy used to deal with increasing rotation resistance with the arm in a pendant position is to gradually increase activity in all shoulder rotation torque-generating muscles.

Precise muscle co-ordination is required to maintain normal shoulder function and alterations in synchrony between shoulder muscles can result in loss of full range of movement and pain. Although shoulder pain in kayakers is high with 53% of elite international paddlers reporting shoulder injuries, little information is available regarding the pattern of shoulder muscle recruitment during paddling. The aim of this study was to investigate the normal recruitment pattern of shoulder muscles during the kayak stroke. Nine recreational paddlers without shoulder pain were examined. EMG data from eight shoulder muscles of the dominant arm were collected simultaneously with video data during simulated paddling on an ergometer. EMG data was normalized to time and peak amplitude. Intersubject consistency was evaluated using Pearson correlation analysis. The results of this study indicated a fair to high correlation in at least one phase of the kayak stroke in five of the muscles examined: upper trapezius, supraspinatus, latissimus dorsi, serratus anterior and rhomboid major. This normative data will enable comparisons with the shoulder muscle recruitment patterns in kayakers with shoulder pain in order to determine the role of altered motor control in the painful kayaking shoulder.

Context: The reliable measurement of shoulder strength is important when assessing athletes involved in overhead activities. Swimmers' shoulders are subject to repetitive humeral elevation and consequently have a high risk of developing movement-control issues and pain. Shoulder-strength tests performed in positions of elevation assist with the detection of strength deficits that may affect injury and performance. The reliability of isometric strength tests performed in positions of humeral elevation without manual stabilization, which is a typical clinical scenario, has not been established. Objective: To establish the relative and absolute intrarater reliability of shoulder-strength tests functional to swimming in 3 body positions commonly used in the clinical setting. Design: Repeated-measures reliability study. Setting: Research laboratory. Subjects: 15 university students and staff (mean ± SD age 24 ± 8.2 y).Intervention: Isometric shoulder-strength tests were performed in positions of humeral elevation (flexion and extension in 140° abduction in the scapular plane, internal and external rotation in 90° abduction) on subjects without shoulder pain in supine, prone, and sitting. Subjects were tested by 1 examiner with a handheld dynamometer and retested after 48 h. Main Outcome Measures: Relative reliability (ICC3,1) values with 95% CI. Absolute reliability was reported by minimal detectable change (MDC). Results: Good to excellent intrarater reliability was found for all shoulder-strength tests (ICC .87-.99). Intrarater reliability was not affected by body position. MDC% was Conclusions: Shoulder flexion, extension, and internal- and external-rotation strength tests performed in humeral elevation demonstrated excellent to good intrarater reliability regardless of body position. A strength change of more than 15% in any position can be considered meaningful.

Accurate clinical interpretation of shoulder rotation range requires knowledge of the contribution of humeral torsion. This study compares the reliability of indirectly measuring humeral torsion using ultrasound visualisation with direct palpation and compares the degree of humeral torsion in a non-throwing adult population with a population of elite adolescent baseballers. The reliability of a novel method of indirectly measuring humeral torsion using palpation and ultrasound was established prior to using the ultrasound method to determine the amount of humeral torsion in both humeri of a group of 16 non-throwing subjects and 36 elite adolescent baseball players. Excellent inter-tester reliability was found for the ultrasound method of measuring humeral torsion in each arm (ICC 2,1: 0.98 and 0.94) but poor reliability for the direct palpation method (ICC 2,1: 0.51 and 0.49). Using the ultrasound method, side-to-side differences in humeral torsion ranged from 0 to 13 degrees for the non-throwing group and 0 to 29 degrees for the baseball players. This side-to-side difference was significant in the baseball players (p

Purpose 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. Methods 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. Results 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. Conclusions 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.

The aim of this study was to compare activity in shoulder muscles during an external rotation task under conditions of increasing arm support to investigate whether changing support requirements would influence muscle recruitment levels, particularly in the rotator cuff (RC) muscles. Electromyographic recordings were collected from seven shoulder muscles using surface and indwelling electrodes. The dominant shoulder of 14 healthy participants were examined during dynamic shoulder external rotation performed at 90° abduction with the arm fully supported, partially supported, and unsupported. Linear regressions between arm support load and the averaged muscle activity across participants for each muscle showed infraspinatus predominantly contributing to rotating the shoulder whilst supraspinatus, deltoid, upper trapezius, and serratus anterior were predominantly functioning in support/stabilization roles. During dynamic shoulder external rotation in mid-range abduction, the RC muscles perform different functional roles. Infraspinatus is responsible for producing external rotation torque, supraspinatus is playing a larger joint stabilizer role, and subscapularis is contributing minimally to joint stability. The results also indicate that increasing support load requirements during an external rotation task may be a functionally specific way to retrain the stabilization function of axioscapular muscles. Manipulating joint stabilization requirements while maintaining constant rotational load is a novel method of investigating the differential contribution of muscles to joint movement and stabilization during a given task.

Purpose It is commonly stated that supraspinatus initiates abduction; however, there is no direct evidence to support this claim. Therefore, the aims of the present study were to determine whether supraspinatus initiates shoulder abduction by activating prior to movement and significantly earlier than other shoulder muscles and to determine if load or plane of movement influenced the recruitment timing of supraspinatus. Methods Electromyographic recordings were taken from seven shoulder muscles of fourteen volunteers during shoulder abduction in the coronal and scapular planes and a plane 30° anterior to the scapular plane, at 25%, 50% and 75% of maximum load. Initial activation timing of a muscle was determined as the time at which the average activation (over a 25 ms moving window) was greater than three standard deviations above baseline measures. Results All muscles tested were activated prior to movement onset. Subscapularis was activated significantly later than supraspinatus, infraspinatus, deltoid and upper trapezius, while supraspinatus, infraspinatus, upper trapezius, lower trapezius, serratus anterior and deltoid all had similar initial activation times. The effects of load or plane of movement were not significant. Conclusions Supraspinatus is recruited prior to movement of the humerus into abduction but not earlier than many other shoulder muscles, including infraspinatus, deltoid and axioscapular muscles. The common statement that supraspinatus initiates abduction is therefore, misleading.

Although flexion is a common component of the routine clinical assessment of the shoulder the muscle recruitment patterns during this movement are not clearly understood making valid interpretation of potential muscle dysfunction problematic. The purpose of this study was to comprehensively examine shoulder muscle activity during flexion in order to compare the activity levels and recruitment patterns of shoulder flexor, scapular lateral rotator and rotator cuff muscles. Electromyographic (EMG) data were recorded from 12 shoulder muscles sites in 15 volunteers. Flexion was performed in standing in the sagittal plane at no load, 20%, and 60% of each subject's maximum load. EMG data were normalized to maximum values obtained during maximum voluntary contractions. Results indicated that anterior deltoid, pectoralis major, supraspinatus, infraspinatus, serratus anterior, upper, and lower trapezius were activated at similar moderate levels. However, subscapularis was activated at low levels and significantly lower than supraspinatus and infraspinatus. Similar activity patterns across time were demonstrated in the muscles that produce flexion torque, laterally rotate the scapula, as well as supraspinatus and infraspinatus, and did not change as flexion load increased. The onset of activity in supraspinatus and anterior deltoid occurred at the same time and prior to movement of the limb at all loads with infraspinatus activity also occurring prior to movement onset at the medium and high load conditions only. Posterior rotator cuff muscles appear to be counterbalancing anterior translational forces produced during flexion and it would appear that supraspinatus is one of the muscles that consistently “initiates” flexion. Clin. Anat. 24:619–626, 2011. © 2011 Wiley-Liss, Inc.

A recent study has shown that posterior rotator cuff (RC) muscles are recruited at significantly higher levels than the anterior RC during shoulder flexion. It was proposed that the mechanism whereby the posterior RC muscles were providing shoulder stability during flexion was to counterbalance potential anterior humeral head translation caused by flexion torque producing muscles. This hypothesis implies that anterior RC activity should be higher than posterior RC activity during extension to prevent posterior humeral head translation. As the normal recruitment pattern of the RC during extension has not been established, the purpose of this study was to examine this hypothesis by comparing shoulder muscle activation levels and recruitment patterns during flexion and extension exercises. Electromyographic (EMG) activity was recorded from 9 shoulder muscles in 15 volunteers. Flexion and extension exercises were performed in prone at 20%, 50%, and 70% of each participant's maximal load. A repeated measures ANOVA was used to determine differences between exercises, muscles and loads, while Pearson's correlation analysis was used to relate mean EMG patterns. During extension subscapularis and latissimus dorsi were activated at higher levels than during flexion; during flexion, supraspinatus, infraspinatus, deltoid, trapezius, and serratus anterior were more highly activated than during extension. In addition, the pattern of activity in each muscle did not vary with load. These results support the hypothesis that during flexion and extension the RC muscles are recruited in a direction specific manner to prevent potential antero-posterior humeral head translation caused by torque producing muscles.

Humeral torsion is thought to be beneficial for throwing. To examine this hypothesis, the throwing and non-throwing arms of 84 Masters baseball players over 35 years of age were measured for humeral torsion, and the highest playing level they achieved and their playing history were recorded. Regression analyses were used to obtain predictors of the highest playing level achieved, throwing arm humeral torsion, and side-to-side difference in humeral torsion. Equations accounting for 36%, 46%, and 12% of the variance respectively were produced. Achieving representative level playing status was associated with the number of seasons played under 16 years of age and having greater throwing arm humeral retrotorsion. Throwing arm humeral retrotorsion was associated with non-throwing arm humeral retrotorsion and an increased number of seasons played before the age of 16 years. A model in which repeated throwing develops an adaptive unilateral bone torsion along with growth in baseball expertise is proposed. Thus dominant arm humeral retrotorsion is a predictor of highest baseball playing level achieved, which in turn is influenced by genetic endowment (as seen in the torsion of the non-throwing arm) and amount of throwing activity, particularly prior to the age of 16.

Limited information is available to support the validity of using surface electrodes to record activity from infraspinatus. The aims of this study were to compare infraspinatus activity recorded using surface and intramuscular electrodes during several shoulder isometric and dynamic tasks and to establish if infraspinatus activity recorded using intramuscular electrodes is representative of whole muscle activity. Surface and intramuscular electrodes were placed over infraspinatus in nine subjects without shoulder pain. Isometric shoulder external rotation, at 0° and 90° abduction, and extension were performed at six loads. Dynamic shoulder flexion and abduction were performed at 70% maximum load. Results indicated that while surface and intramuscular electrodes record similar activation patterns when infraspinatus is moderately to highly activated (r and slope ∼ 1), only intramuscular electrodes accurately reflected low (10%MVC) infraspinatus activity (r=0.95 ± 0.04, slope=15.6 ± 16.3). The linear relationship between the activity recorded with surface and intramuscular electrodes when infraspinatus is moderately to highly active also indicated that intramuscular recordings from infraspinatus are representative of activity in the whole muscle. To ensure validity in reporting infraspinatus activation patterns when studying functional shoulder tasks in which infraspinatus may be relatively active and inactive at different phases of these tasks, intramuscular electrodes should be used to record infraspinatus activity.

Purpose: Supraspinatus strengthening is an important part of shoulder rehabilitation programs. Because of the force-couple relationship between supraspinatus and deltoid during shoulder abduction, it has been proposed that the optimal exercise to strengthen supraspinatus is one that would maximize supraspinatus activity while minimizing surrounding muscle activity, particularly deltoid. The aim of this study was to simultaneously examine all exercises known to recruit supraspinatus at high levels and to compare the level of recruitment in supraspinatus, deltoid, and infraspinatus. Methods: Using a combination of surface and intramuscular electrodes, EMG recordings were taken from supraspinatus, infraspinatus, and the three parts of deltoid of 15 subjects with normal dominant shoulder function during maximal isometric contractions in "empty can," "full can," prone elevation, pendant external rotation, and prone external rotation exercise positions. Results: There was no significant difference in the level of supraspinatus activation for all exercise positions examined. No significant difference was found in activation levels across all muscles during the "can" exercise positions. The exercise positions using external rotation were found to activate parts of deltoid significantly less than the "can" and prone elevation positions. Infraspinatus was activated at greater levels than supraspinatus during the external rotation exercises. Conclusions: Using the criteria that the optimal exercise to strengthen supraspinatus should maximize supraspinatus activity while particularly minimizing deltoid activity, this study has shown that the pendant external rotation and prone external rotation exercises are more valid than the "can" and prone elevation exercises for supraspinatus strengthening in subjects with normal dominant shoulder function

Cross-sectional study.To examine differences between arms in humeral torsion in adult and adolescent throwing and nonthrowing athletes, and nonathletic adults.It is hypothesized that humeral retrotorsion develops by, and is beneficial for, throwing. Thus throwers should demonstrate greater retrotorsion in their dominant arm relative to their nondominant arm and have more side-to-side retrotorsion difference than nonthrowing groups. In addition, adult throwers should have a greater side-to-side retrotorsion difference than adolescent throwers, and swimmers should not demonstrate a retrotorsion difference.Using ultrasound to standardize the location of the bicipital groove, the amount of humeral torsion was measured in both arms of male baseball players (85 adult, 35 adolescent), female softball players (16 adult, 37 adolescent), 29 elite adolescent swimmers (19 female), and 16 nonathletic adults (8 female).More retrotorsion was found in the dominant arm of almost all throwing athletes, irrespective of their gender or whether they were adults or adolescents (mean+/-SD side-to-side difference, 11.9 degrees+/-10.5 degrees). This difference was less for swimmers (6.4 degrees+/-9.9 degrees) and nonathletic adults (1.3 degrees+/-8.9 degrees).Greater dominant armhumeral retrotorsion is observed contingent with participation in throwing sports.

A comparison of electromyographic (EMG) activity of muscles between and within subjects, and during separate occasions of testing, requires normalization. The most common way for generating the reference level used for normalizing shoulder EMG data is with a maximum isometric voluntary contraction (MVIC). The purpose of this study was to develop a parsimonious set of standardized tests that generate an MVIC in all the major muscle groups of the shoulder. Twelve muscles of the dominant shoulder of 15 subjects were examined using a combination of surface and intramuscular electrodes during 15 tests. The results indicated that many tests maximally activated more than one muscle simultaneously. Four tests were identified as being sufficient for generating an MVIC in the 12 muscles examined and are recommended as the standard set for normalizing shoulder muscle EMG: abduction 90 degrees with internal rotation ("empty can"), internal rotation in 90 degrees abduction ("internal rotation 90 degrees"), flexion at 125 degrees with scapula resistance ("flexion 125 degrees"), and horizontal adduction at 90 degrees flexion ("palm press"). The use of these shoulder normalization tests will make comparisons between shoulder EMG studies more reliable.

Shoulder internal rotation (IR) is commonly assessed by an indirect method where the hand is placed behind the back and the distance reached by the tip of the extended thumb is recorded. The aim of this study was to assess the validity of measuring active IR range of motion (ROM) by use of the indirect hand-behind-back (HBB) ROM method in subjects with shoulder pain of mechanical origin. We recruited 137 subjects with unilateral shoulder pain. HBB ROM was determined by measuring the distance between the T1 spinous process and the radial styloid process. Active shoulder IR was measured in the supine position in 45 degrees or 90 degrees abduction. Correlation coefficients adjusted for measurement error were calculated. HBB ROM demonstrated only a low to moderate correlation with active shoulder IR. Active HBB ROM is not an accurate method of measuring active shoulder IR in patients with shoulder pain.

To compare the effectiveness of exercise therapy aimed at restoring neuromuscular control mechanisms at the shoulder with other conservative interventions for the treatment of chronic shoulder pain with and without accompanying stiffness.Randomized control trial.A total of 138 volunteers with unilateral shoulder pain of local mechanical origin.Subjects were randomly allocated to receive exercise therapy aimed at restoring dynamic stabilizing mechanisms and muscle co-ordination at the shoulder; or subacromial corticosteroid injection; or a combination of physical modalities and range of motion exercises. Outcome measurements of pain intensity, functional impairment, active range of motion, isometric muscle force and self-assessed improvement were taken at baseline and after 5 weeks of treatment.The mean/median changes in all outcome measurements at 5 weeks indicated that subjects in each treatment group, improved significantly with no difference between the treatment groups. Comparison with an earlier no-treatment trial would suggest that this improvement is greater than that which could be expected by natural recovery.Exercise therapy aimed at restoring neuromuscular control, corticosteroid injection and multiple physical modalities and range of motion exercises are equally effective in the short-term treatment of shoulder pain, with exercise therapy and corticosteroid injection being less costly to administer.

The optimal form of rehabilitation after rotator cuff repair has yet to be determined. A randomised clinical trial was undertaken to compare outcomes for two forms of rehabilitation for this condition: individualised supervised physiotherapy treatment, and a standardised unsupervised home exercise regime. Fifty-eight volunteers with all sizes of operatively repaired rotator cuff tears were allocated randomly to one of the two treatment groups. All subjects received a standardised home exercise regime. Subjects who were randomised to the physiotherapy group received additional individualised treatment. Independent, blinded assessments of range of motion, muscle force and functional outcome measures were performed pre-operatively, and at six, 12 and 24 weeks post-operation. At six, 12 and 24 weeks post-operation, comparable outcomes were demonstrated for both rehabilitation groups. By 24 weeks post-operation, most subjects demonstrated outcomes that were consistent with a favourable recovery, regardless of rehabilitation mode. On the basis of these results, outcomes for subjects allocated to individualised physiotherapy treatment after rotator cuff repair are no better than for subjects allocated to a standardised home exercise regime.

Question: Is the addition of passive mobilisation of shoulder region joints to advice and exercise for patients with shoulder pain and stiffness more effective than advice and exercise alone? Design: Randomised trial with concealed allocation, assessor blinding, and intention-to-treat analysis. Participants: 90 people who had shoulder pain and stiffness for more than one month. Intervention: All participants received advice and exercise. The experimental group also received passive joint mobilisation of shoulder region joints. Outcome measures: Primary outcome measures included pain and disability measured with the 13-point Shoulder Pain and Disability Index. Secondary outcome measures were self-perceived global improvement measured on a 6-point scale and active ranges of motion. Subjects received a maximum of 10 sessions of therapy. Outcome measurements were taken at baseline, one month, and six months. Results: The experimental group had 3% (95% CI –5 to 11) less pain and disability than the control group at one month and 1% (95% CI –13 to 16) less pain at six months, which are statistically non-significant. Their global perceived effect was 0.1 out of 5 (95% CI –0.2 to 0.4) worse than the control group at one month and 0.1 (95% CI –0.5 to 0.7) better at 6 months, which are also statistically non-significant. Differences between groups in all range of motion measures were small and statistically non-significant. Conclusion: The addition of passive joint mobilisation of shoulder region joints is not more effective than advice and exercise alone for shoulder pain and stiffness. Trial registration: ACTRN 12605000080628. [Chen JF, Ginn KA, Herbert RD (2009) Passive mobilisation of shoulder region joints plus advice and exercise does not reduce pain and disability more than advice and exercise alone: a randomised trial. Australian Journal of Physiotherapy 55: 17–23]

Background and Purpose. The aim of this study was to evaluate the efficacy of a physical therapy approach to the treatment of shoulder pain. Subjects. Sixty-six volunteers with shoulder pain believed to be of local mechanical origin were randomly allocated to either a treatment group or a control group. Methods. Subjects in the treatment group received 1 month of physical therapy aimed at restoring function of their shoulder muscles. Subjects in the control group received no treatment. Outcome measurements of pain intensity, range of motion (ROM), isometric muscle force, functional impairment, and self-perception of improvement were obtained by blinded assessment. Results. Subjects in the treatment group showed improvement in pain-free abduction and flexion ROM, functional impairment, and self-perception of improvement. The control group deteriorated slightly over the experimental period in ROM and functional impairment measures. Conclusion and Discussion. These results suggest that the physical therapy approach used in this study is effective in improving shoulder function in subjects experiencing pain of mechanical origin. The results also provide little evidence of spontaneous recovery over a 1-month period.