Arthroscopic capsular shift surgery in patients with atraumatic shoulder joint instability: a randomised, placebo-controlled trial.

OBJECTIVES: To determine the effect of arthroscopic capsular shift surgery on pain and functional impairment for people with atraumatic shoulder (glenohumeral) joint instability. METHODS: We conducted a randomised, placebo-controlled clinical trial in a specialist secondary care facility. Patients aged 18 years and over who reported insecurity (apprehension) in their shoulder joint and had evidence of capsulolabral damage on arthroscopic examination were included. Patients were excluded if their shoulder apprehension symptoms were precipitated by a high velocity shoulder injury, they had bony or neural damage, a rotator cuff or labral tear, or previous surgery on the symptomatic shoulder. Sixty-eight participants were randomised and received diagnostic arthroscopy, followed by arthroscopic capsular shift or diagnostic arthroscopy alone. All participants received the same postoperative clinical care. The primary outcome was pain and functional impairment measured with the Western Ontario Shoulder Instability Index. The prespecified minimum clinically important effect was a reduction in pain and disability of 10.4 points. RESULTS: Mean reductions in pain and functional impairment for both groups were similar. Compared with diagnostic arthroscopy, arthroscopic capsular shift increased pain and functional impairment by means of 5 points (95% CI -6 to 16 points) at 6 months, 1 point (95% CI -11 to 13 points) at 12 months and 2 points (95% CI -12 to 17 points) at 24 months. CONCLUSIONS: Compared with diagnostic arthroscopy alone, arthroscopic capsular shift confers, at best, only minimal clinically important benefit in the medium term. TRIAL REGISTRATION NUMBER: NCT01751490.

A comparison between measurement properties of four shoulder-related outcome measures in Nepalese patients with shoulder pain.

PURPOSE: The Patient-Specific Functional Scale (PSFS), Disability of the Arm, Shoulder and Hand (DASH), Quick-DASH, and Shoulder Pain and Disability Index (SPADI) are frequently used instruments in shoulder functional assessment. They are available in Nepali and all but the PSFS has been validated for shoulder assessment. Therefore, the aim of this study was to validate the Nepali PSFS in shoulder pain patients and to compare validity, reliability, and responsiveness of all four instruments to provide a recommendation for their use. METHOD: Patients attending physiotherapy completed the Nepali PSFS at baseline and follow-up (1-3 weeks). It was tested for reliability using internal consistency (Cronbach's α), intraclass correlation coefficient (ICC), construct validity by hypothesis testing and responsiveness by anchor-based method using Area Under the Curve (AUC). The instruments were compared based on reported measurement properties and patients' preference. RESULTS: 156 patients enrolled at baseline and 121 at follow-up. The PSFS showed sufficient reliability (α = 0.70, ICC = 0.82), construct validity (all three hypotheses met) and responsiveness (AUC = 0.83). Measurement property comparison demonstrated adequate reliability and validity, while PSFS was the most responsive instrument. Patients favoured the verbal rating scale of the DASH/Quick-DASH. The DASH had a lower completion rate for 'culturally sensitive' and 'uncommon' activities. CONCLUSION: The Nepali PSFS is a reliable, valid, and responsive instrument in shoulder functional assessment. The combined use of the Quick-DASH or SPADI with the PSFS is recommended for a comprehensive assessment of Nepali shoulder pain patients in clinical and research settings. They are shorter, more appropriate to the Nepali context and provide balanced self-evaluation.

Effectiveness of workshops to teach a home-based exercise program (BEST at Home) for preventing falls in community-dwelling people aged 65 years and over: a pragmatic randomised controlled trial.

BACKGROUND: Falls are a significant public health issue. There is strong evidence that exercise can prevent falls and the most effective programs are those that primarily involve balance and functional exercises, however uptake of such programs is low. Exercise prescribed during home visits by health professionals can prevent falls however this strategy would be costly to deliver at scale. We developed a new approach to teach home exercise through group-based workshops delivered by physiotherapists. The primary aim was to determine the effect of this approach on the rate of falls among older community-dwelling people over 12 months. Secondary outcomes included the proportion of people falling, fear of falling, physical activity, lower limb strength, balance and quality of life. METHODS: A randomised controlled trial was conducted among community-dwelling people aged ≥65 in New South Wales, Australia. Participants were randomised to either the intervention group (exercise targeting balance and lower limb strength) or control group (exercise targeting upper limb strength). RESULTS: A total of 617 participants (mean age 73 years, +SD 6, 64% female) were randomly assigned to the intervention group (n = 307) or control group (n = 310). There was no significant between-group difference in the rate of falls (IRR 0.91, 95% CI 0.64 to 1.29, n = 579, p = 0.604) or the number of participants reporting one or more falls (IRR 0.99, 95% CI 0.76 to 1.29, n = 579, p = 0.946) during 12 month follow-up. A significant improvement in the intervention group compared to control group was found for fear of falling at 3, 6 and 12 months (mean difference 0.50, 95% CI 0.2 to 0.8, p = 0.004; 0.39, 95% CI 0.001 to 0.8, p = 0.049; 0.46, 95% CI 0.006 to 0.9, p = 0.047, respectively), and gait speed at 3 months (mean difference 0.09 s, 95% CI 0.003 to 0.19, p = 0.043). No statistically significant between-group differences were detected for the other secondary outcomes. CONCLUSIONS: There was no significant intervention impact on the rate of falls, but the program significantly reduced fear of falling and improved gait speed. Other exercise delivery approaches are needed to ensure an adequate intensity of balance and strength challenge and dose of exercise to prevent falls.

Measurement properties of translated versions of the Shoulder Pain and Disability Index: A systematic review.

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.

The effectiveness of ergonomics interventions in reducing upper limb work-related musculoskeletal pain and dysfunction in sonographers, surgeons and dentists: a systematic review.

The aim of this systematic review was to summarise the effects of ergonomics interventions on work-related upper limb musculoskeletal pain and dysfunction, and on productivity in sonographers, surgeons and dentists. A total of 31 studies were included. All studies reported effects on upper limb pain. Nine studies reported effects on dysfunction and only two studies reported effects on productivity. Moderately strong evidence in reducing upper limb pain was found for instigation of microbreaks into long duration surgical procedures, and the use of wider, lighter handles in dental instruments. Moderate evidence was also found for use of prismatic glasses and favourable positioning in reducing upper limb pain. Weak, inconsistent or no evidence was found for all other ergonomics interventions in reducing upper limb pain and dysfunction and increasing productivity. The lack of high quality research, particularly in sonographers and in the outcome of productivity, should be addressed. Practitioner summary: This systematic review investigates the effectiveness of ergonomics interventions on upper limb pain, dysfunction and productivity in sonographers, dentists and surgeons. Instigation of microbreaks during long duration procedures and the use of wider, lighter instrument handles were most effective in reducing upper limb work-related pain. Abbreviations: ANOVA: analysis of variance; CLS: conventional laparoscopic surgery; DMAIC: define, measure, analyze, improve and control; GRADE: grading of recommendations, assessment, development and evaluations; HD: high definition; PRISMA: preferred reporting items for systematic reviews and meta-analyses; PROSPERO: The International Prospective Register of Systematic Reviews; RCT: randomised control trial; SILS: single incision laparoscopic surgery; VITOM: video telescopic operative microscope; WNSWLHD: Western New South Wales Local Health District; WMSD: work related musculoskeletal disorder.

Cross-cultural adaptation and measurement properties of the Nepali version of the DASH (disability of arm, shoulder and hand) in patients with 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 < 0.001) were excellent. The MDC was 11 out of 100 points. There were moderate-high positive correlations with the SPADI pain and disability items (rs = 0.63 and 0.81, P < 0.001). Four factor solution was retrieved for the DASH-NP. The Area Under the Curve was 0.69 (95% CI: 0.57 - 0.81, p < 0.001) with minimal important change of 11.2/100 points. CONCLUSIONS: The Nepali translation of the DASH is comprehensible, easy to administer via self-report or interview. It is found to be a reliable, valid, and responsive measure in patients with shoulder pain in Nepal. The DASH-NP can be used to assess shoulder pain related disability in Nepal for clinical practice or research.

The Reliability of Strength Tests Performed In Elevated Shoulder Positions Using a Handheld Dynamometer.

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 <16% for every test and ≤11% for tests performed in supine. 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.

Consensus for physiotherapy for shoulder pain.

PURPOSE: Shoulder pain is a common disorder. Despite growing evidence of the importance of physiotherapy, in particular active exercise therapy, little data is available to guide treatment. The aim of this project was to contribute to the development of an internationally accepted assessment and treatment algorithm for patients with shoulder pain. METHODS: Nine physiotherapists with expertise in the treatment of shoulder dysfunction met in Sweden 2012 to begin the process of developing a treatment algorithm. A questionnaire was completed prior to the meeting to guide discussions. Virtual conferences were thereafter the platform to reach consensus. RESULTS: Consensus was achieved on a clinical reasoning algorithm to guide the assessment and treatment for patients presenting with local shoulder pain, without significant passive range of motion deficits and no symptoms or signs of instability. The algorithm emphasises that physiotherapy treatment decisions should be based on physical assessment findings and not structural pathology, that active exercises should be the primary treatment approach, and that regular re-assessment is performed to ensure that all clinical features contributing to the presenting shoulder pain are addressed. Consensus was also achieved on a set of guiding principles for implementing exercise therapy for shoulder pain, namely, a limited number of exercises, performed with appropriate scapulo-humeral coordination and humeral head alignment, in a graduated manner without provoking the presenting shoulder pain. CONCLUSION: The assessment and treatment algorithm presented could contribute to a more formal, extensive process aimed at achieving international agreement on an algorithm to guide physiotherapy treatment for shoulder pain.

Does surgery followed by physiotherapy improve short and long term outcome for patients with atraumatic shoulder instability compared with physiotherapy alone? - protocol for a randomized controlled clinical trial.

BACKGROUND: Shoulder instability is a common problem affecting young adults. Stabilization surgery followed by physiotherapy rehabilitation has been shown to reduce the chance of further episodes of shoulder dislocation and to improve quality of life in patients who sustain a shoulder dislocation as a result of a high collision trauma, but it is unclear if surgical intervention is beneficial for patients with atraumatic shoulder instability who have structural damage at the shoulder. The aim of this randomized controlled clinical trial is to determine if the addition of surgical intervention to physiotherapy rehabilitation improves outcomes for patients with atraumatic shoulder instability who have sustained soft tissue damage at their joint. METHODS/DESIGN: 140 participants will be recruited. Patients with feelings of insecurity (apprehension) at their shoulder joint, which is not the result of a collision injury, with physical signs of shoulder joint instability will be invited to participate. Consenting participants will undergo arthroscopic investigation of the shoulder joint. Patients with capsulolabral damage will be randomly allocated using a concealed allocation procedure to either stabilization surgery immediately following the arthroscopic examination or no additional surgical procedure. All participants will then receive the same postoperative physiotherapy protocol for up to 6 months. Outcomes (pain, functional impairment and number of shoulder dislocations sustained) will be evaluated prior to surgery and, together with participant-reported improvement, again at 6, 12 and 24 months after randomization. The primary endpoint will be pain and functional impairment at 2 years. Participants, clinical staff (but not surgeons) and assessors will be blind to whether stabilization surgery was performed. Data analysis will be conducted on an intention-to-treat basis with the focus on estimation of the effect. DISCUSSION: This trial will have a direct and immediate impact on clinical decision making by establishing if patients presenting with soft tissue shoulder damage associated with atraumatic shoulder instability should be referred for stabilization surgery before commencing physiotherapy rehabilitation in order to ensure optimal outcome. This in turn will ensure effective, efficient use of scarce health resources to manage this common often disabling musculoskeletal condition. TRIAL REGISTRATION: Study was registered with National Institutes of Health Clinical Trials Protocol Registration System in December 2012.ClinicalTrials.gov Identifier: NCT01751490.

Rotator cuff muscles perform different functional roles during shoulder external rotation exercises.

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.

Ultrasound assessment of the inferior glenohumeral capsule in normal shoulders-a study of measurement variables and reliability.

OBJECTIVES: To establish the reliability of a standardised ultrasound protocol to measure normal inferior glenohumeral capsule (IGHC) thickness and to investigate the effects of age, sex, hand dominance and angles of abduction on the thickness. METHODS: IGHC images were obtained at 60o, 90o and 180o abduction angles of 151 asymptomatic shoulders in supine position. Following the proposed guidelines, three sonographers blindly measured the IGHC thicknesses for intra- and interrater reliability assessments. RESULTS: The intrarater reliability was excellent (intraclass correlation coefficient value = 0.95; 95% CI = 0.92-0.97). The interrater reliability was moderate (intraclass correlation coefficient value = 0.74; 95% CI = 0.60-0.83). The mean IGHC thickness values in mm ± SD at 60o, 90o and 180o abduction angles for males were 3.3 ± 0.93, 3.0 ± 0.80 and 2.6 ± 0.55 and those for females were 2.7 ± 0.86, 2.4 ± 0.7 and 2.0 ± 0.56 respectively. Although males had thicker IGHC, the rate at which the thickness reduced with increased abduction was same in both males and females. Age and hand dominance had no effect. CONCLUSION: The normal IGHC thickness varies with sex and the abduction angle of the arm at which it is measured. A large variation of IGHC thickness exists in the normal population. ADVANCES IN KNOWLEDGE: The results of this study discourage the use of a single value of IGHC thickness and emphasise the importance of comparing the thickness of the symptomatic side to that of the asymptomatic side of the same subject at the same abduction level. The guidelines provided in this study can be used in clinical practice and in future research studies.

Analysis of phase detects altered timing of muscle activation in subjects with chronic shoulder pain.

Optimal exercise therapy for shoulder pain is unknown due to limited information regarding specific changes in muscle function associated with pain. Timing of muscle activity with respect to movement (phase) can provide information about muscle activation patterns without requiring electromyography data normalization which is problematic in the presence of pain. The aim of this study was to determine if a phase measure is able to detect differences in the timing of shoulder muscle activation in subjects with chronic shoulder pain. Fourteen subjects with pain and 14 without pain were recruited. Electromyography from eight shoulder muscles was recorded. Approximately 20 cycles of small amplitude (∼30°) rapid shoulder flexion/extension was performed. A cross-correlation and spectrographic analysis provided a measure of phase. Welch's t-tests were used to compare mean phase angles between groups. Subjects with chronic shoulder pain had greater variability in the relative timing of muscle activation with significant differences found in the phase angles for pectoralis major, infraspinatus, supraspinatus, upper and lower trapezius and serratus anterior. This preliminary study indicates that the examination of the timing of muscle activation using a phase measure can identify significant differences in muscle function between normal subjects and those with chronic shoulder pain.

Ultrasound Features for the Diagnosis of Adhesive Capsulitis/Frozen Shoulder: A Systematic Review.

While ultrasound has become a preferred tool for musculoskeletal imaging, differing ultrasound findings that have been reported in patients with adhesive capsulitis can create confusion and misconceptions. This systematic review was aimed at summarizing all the ultrasound features currently described in the literature and providing a critical analysis of the sources to allow the readers to make a well-informed decision on the reliability of these features in the diagnosis of this condition. Databases were searched for original studies up to August 2021. Twenty-three studies were included. The QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies 2) tool was used to assess the quality of each selected article. Fourteen ultrasound features were identified. A quality analysis of all ultrasound features was performed using the GRADE (Grading of Recommendations, Assessment, Development and Evaluations) framework. All studies exhibited considerable heterogeneity in investigated ultrasound features and methodologies employed; therefore, meta-analysis was not considered to be appropriate. Hence, narrative synthesis was performed. The overall quality of each ultrasound outcome was found to be of "low" to "very low" level, and the generalisability of the results was also thought to be limited. Cautious interpretation and clinical correlation are recommended while applying these ultrasound features in clinical practice.

Does participatory ergonomics reduce musculoskeletal pain in sonographers? A mixed methods study.

Introduction: Sonographers in the Western New South Wales Local Health District (WNSWLHD) reported a musculoskeletal pain prevalence rate of 95%. Participatory ergonomics, where workers are consulted about improving work conditions, was utilised to identify work-related musculoskeletal disorder (WMSD) risks and potential solutions. The aim of this study was to compare the prevalence of WMSD in a cohort of sonographers before and after implementation of ergonomic changes that were driven by recommendations from a participatory ergonomics approach. Methods: This observational mixed methods study analysed the impact of participatory ergonomic-driven interventions on changes on musculoskeletal pain in a cohort of sonographers employed within the WNSWLHD. A retrospective analysis of 10 sonographer WMSD pain surveys over five sites was completed, along with semi-structured interviews regarding which interventions were perceived as useful, which interventions were not implemented and any barriers to implementation. Results: Installation of patient monitors, use of ergonomic scanning techniques and job rotation were perceived as responsible for decreased musculoskeletal pain. Taking lunch breaks and microbreaks, use of antifatigue mats and having two sonographers perform mobile exams were not fully implemented. No interventions were perceived as responsible for increased pain. Conclusion: This small study provides preliminary evidence that a participatory ergonomics approach facilitated identification of occupation and site-specific risks for WMSD in the WNSWLHD, allowing implementation of ergonomic changes to be tailored to the workplace, resulting in a safer work environment for sonographers.

A comprehensive analysis of muscle recruitment patterns during shoulder flexion: an electromyographic study.

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.

Measurement properties of the Nepali version of the Quick-DASH in patients with shoulder pain.

PURPOSE: To examine the measurement properties of the Nepali version of the Quick-Disabilities of the Arm, Shoulder and Hand (QuickDASH-NP). MATERIALS AND METHODS: The Nepali DASH and Shoulder Pain and Disability Index (SPADI) were completed at baseline assessment, and again at follow-up with the Nepali Global Rating of Change (GROC-NP) score. The 11 items of the QuickDASH-NP were extracted from the DASH and tested for confirmatory factory analysis (CFA), exploratory factor analysis (EFA), internal consistency (α), item-total correlation (ITC), test-retest reliability (ICC), measurement errors, hypothesis testing (correlation with DASH and SPADI) and responsiveness (effect size-ES, standardised response mean-SRM). RESULTS: A total of 156 participants completed questionnaires at baseline and 121 at follow-up with all questionnaires valid (no participant leaving more than one question blank). CFA suggested a poor fit for the single-factor model. The EFA demonstrated two factors with acceptable internal consistency (α = 0.79 and 0.75) for each factor. The test-retest reliability was excellent (ICC = 0.94; 95%CI:0.92-0.98), correlation was positive and very strong with the DASH-NP (r = 0.96) and strong with the SPADI-NP (r = 0.81). The Standard Error of Measurement was 2.83 and Smallest Detectable Change 7.84/100. The ES and SRM were moderate to high. CONCLUSIONS: The QuickDASH-NP is reliable, valid, and able to detect change in shoulder symptoms among Nepali participants. It offers a short, easy to complete self-reporting tool for clinical use and research.

Acute experimentally-induced pain replicates the distribution but not the quality or behaviour of clinical appendicular musculoskeletal pain. A systematic review.

OBJECTIVES: Experimental pain is a commonly used method to draw conclusions about the motor response to clinical musculoskeletal pain. A systematic review was performed to determine if current models of acute experimental pain validly replicate the clinical experience of appendicular musculoskeletal pain with respect to the distribution and quality of pain and the pain response to provocation testing. METHODS: A structured search of Medline, Scopus and Embase databases was conducted from database inception to August 2020 using the following key terms: "experimental muscle pain" OR "experimental pain" OR "pain induced" OR "induced pain" OR "muscle hyperalgesia" OR ("Pain model" AND "muscle"). Studies in English were included if investigators induced experimental musculoskeletal pain into a limb (including the sacroiliac joint) in humans, and if they measured and reported the distribution of pain, quality of pain or response to a provocation manoeuvre performed passively or actively. Studies were excluded if they involved prolonged or delayed experimental pain, if temporomandibular, orofacial, lumbar, thoracic or cervical spine pain were investigated, if a full text of the study was not available or if they were systematic reviews. Two investigators independently screened each title and abstract and each full text paper to determine inclusion in the review. Disagreements were resolved by consensus with a third investigator. RESULTS: Data from 57 experimental pain studies were included in this review. Forty-six of these studies reported pain distribution, 41 reported pain quality and six detailed the pain response to provocation testing. Hypertonic saline injection was the most common mechanism used to induce pain with 43 studies employing this method. The next most common methods were capsaicin injection (5 studies) and electrical stimulation, injection of acidic solution and ischaemia with three studies each. The distribution of experimental pain was similar to the area of pain reported in clinical appendicular musculoskeletal conditions. The quality of appendicular musculoskeletal pain was not replicated with the affective component of the McGill Pain Questionnaire consistently lower than that typically reported by musculoskeletal pain patients. The response to provocation testing was rarely investigated following experimental pain induction. Based on the limited available data, the increase in pain experienced in clinical populations during provocative maneuvers was not consistently replicated. CONCLUSIONS: Current acute experimental pain models replicate the distribution but not the quality of chronic clinical appendicular musculoskeletal pain. Limited evidence also indicates that experimentally induced acute pain does not consistently increase with tests known to provoke pain in patients with appendicular musculoskeletal pain. The results of this review question the validity of conclusions drawn from acute experimental pain studies regarding changes in muscle behaviour in response to pain in the clinical setting.

The effectiveness of EMG-driven neuromusculoskeletal model calibration is task dependent.

Calibration of neuromusculoskeletal models using functional tasks is performed to calculate subject-specific musculotendon parameters, as well as coefficients describing the shape of muscle excitation and activation functions. The objective of the present study was to employ a neuromusculoskeletal model of the shoulder driven entirely from muscle electromyography (EMG) to quantify the influence of different model calibration strategies on muscle and joint force predictions. Three healthy adults performed dynamic shoulder abduction and flexion, followed by calibration tasks that included reaching, head touching as well as active and passive abduction, flexion and axial rotation, and submaximal isometric abduction, flexion and axial rotation contractions. 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 subject-specific EMG-driven neuromusculoskeletal models that were uncalibrated and calibrated using (i) all calibration tasks (ii) sagittal plane calibration tasks, and (iii) scapular plane calibration tasks. Joint forces were compared to published instrumented implant data. Calibrating models across all tasks resulted in glenohumeral joint force magnitudes that were more similar to instrumented implant data than those derived from any other model calibration strategy. Muscles that generated greater torque were more sensitive to calibration than those that contributed less. This study demonstrates that extensive model calibration over a broad range of contrasting tasks produces the most accurate and physiologically relevant musculotendon and EMG-to-activation parameters. This study will assist in development and deployment of subject-specific neuromusculoskeletal models.

Playing level achieved, throwing history, and humeral torsion in Masters baseball players.

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.

Do surface electrodes validly represent lower trapezius activation patterns during shoulder tasks?

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.