Background: Treatments for rotator cuff tendinopathy include rotator cuff muscle strengthening to promote better muscle recruitment in order to minimize subacromial narrowing during active movement. Glenohumeral adductor recruitment has also been shown to prevent such narrowing in asymptomatic individuals; therefore, adding glenohumeral adductor coactivation during rotator cuff strengthening could enhance the efficacy of rotator cuff strengthening. However, no study has explored its benefits. Objectives: To compare the short-term efficacy of adding glenohumeral adductor coactivation to a rotator cuff–strengthening program to improve function, reduce symptoms, and increase acromiohumeral distance in adults with rotator cuff tendinopathy. Methods: In this single-blind randomized controlled trial, 42 participants with rotator cuff tendinopathy were randomly assigned to 2 groups, one that received strengthening of the scapular and rotator cuff muscles or one that received rotator cuff strengthening plus coactivation with pectoralis major and latissimus dorsi recruitment. The daily programs were performed at home for 6 weeks, with supervised training and follow-up sessions. Functional limitations/symptoms (Disabilities of the Arm, Shoulder and Hand [DASH] questionnaire as the primary outcome, and the Western Ontario Rotator Cuff index), pain (visual analog scale), and acromiohumeral distance were measured at baseline, 3 weeks, and 6 weeks. Data were analyzed using a mixed-model analysis of variance. Results: No significant group-by-time interaction was observed for the Disabilities of the Arm, Shoulder and Hand questionnaire, Western Ontario Rotator Cuff index, visual analog scale, and acromiohumeral distance (P≥.055). Significant time effects were obtained for the Western Ontario Rotator Cuff index and visual analog scale for pain with movement (P<.001). Conclusion: The present findings show that adding glenohumeral adductor coactivation to a rotator cuff–strengthening program does not result in improved short-term efficacy in any of the measured outcomes. This study was registered with ClinicalTrials.gov (NCT02837848). Level of Evidence: Therapy, level 1b. J Orthop Sports Phys Ther 2019;49(3):126–135. Epub 30 Nov 2018. doi:10.2519/jospt.2019.8240

Impaired skeletal muscle stem cell (MuSC) function has long been suspected to contribute to the pathogenesis of muscular dystrophy (MD). Here, we showed that defects in the endothelial cell (EC) compartment of the vascular stem cell niche in mouse models of Duchenne MD, laminin α2–related MD, and collagen VI–related myopathy were associated with inefficient mobilization of MuSCs after tissue damage. Using chemoinformatic analysis, we identified the 13–amino acid form of the peptide hormone apelin (AP-13) as a candidate for systemic stimulation of skeletal muscle ECs. Systemic administration of AP-13 using osmotic pumps generated a pro-proliferative EC-rich niche that supported MuSC function through angiocrine factors and markedly improved tissue regeneration and muscle strength in all three dystrophic mouse models. Moreover, EC-specific knockout of the apelin receptor led to regenerative defects that phenocopied key pathological features of MD, including vascular defects, fibrosis, muscle fiber necrosis, impaired MuSC function, and reduced force generation. Together, these studies provide in vivo proof of concept that enhancing endogenous skeletal muscle repair by targeting the vascular niche is a viable therapeutic avenue for MD and characterized AP-13 as a candidate for further study for the systemic treatment of MuSC dysfunction.

Background: The Fear-Avoidance Components Scale (FACS) is a reliable and valid instrument widely used to assess fear-avoidance beliefs related to pain and disability. However, there is a scarcity of validated translations of the FACS in different cultural and linguistic contexts, including the French population. This study aimed to translate and validate the French version of the FACS (FACS-Fr/CF), examining its psychometric properties among French-speaking individuals. Methods: A cross-cultural translation process–including forward translation, backward translation, expert committee review, and pre-testing–was conducted to develop the FACS-Fr/CF. The translated version was administered to a sample of French-speaking adults (n = 55) with chronic musculoskeletal pain. Internal consistency (including confirmatory analyses of the 2 factors identified in the Serbian version), test-retest reliability and convergent validity were then assessed. Results: The FACS-Fr/CF demonstrated high global internal consistency (α = 0.94, 95% CI: 0.91–0.96) as well as high internal consistency of the 2 factors identified in the Serbian version (α = 0.90, 95% CI: 0.86–0.94 and α = 0.90, 95% CI: 0.85–0.94, respectively). Test-retest analysis revealed a moderate (close to high) reliability (ICC = 0.89; 95% CI: 0.82–0.94 and r = 0.89; p<0.005). Convergent validity was supported by significant correlations between the FACS-Fr/CF scores and the Tampa Scale for Kinesiophobia (r = 0.82; p < 0.005), the Pain Catastrophizing Scale (r = 0.72; p < 0.005) and the Hospital Anxiety and Depression Scale (r = 0.66; p < 0.005). Conclusion: The present study provides evidence for the cross-cultural translation and psychometric validation of the FACS-Fr/CF. The FACS-Fr/CF exhibits a high internal consistency, a moderate (close to high) test-retest reliability, and good construct validity, suggesting its utility in assessing fear-avoidance beliefs in the French-speaking population. This validated tool can enhance the assessment and understanding of fear-avoidance behaviors and facilitate cross-cultural research in pain-related studies.

Purpose: Graft diameter in anterior cruciate ligament reconstructions has been shown to influence the risk of failure. It is therefore important to be able to adjust the graft configuration to modify the diameter. To measure the impact of a 6-strand (6S) hamstring autograft configuration on graft diameter compared to the standard 4-strand (4S) configuration. Methods: Cadaveric study on 33 knees, using the usual hamstring graft harvesting technique. Semitendinosus and gracilis tendons were harvested and their length, width, and diameter were measured in 4S and 6S configurations separately by three evaluators. Results: 6S configuration leads to a median increase of 1.5 (range: 0.0–2.0) mm in diameter compared to 4S (p < 0.001). A graft diameter of more than 8 mm is attained in less than a third of 4S grafts within this population in comparison to 84% when the 6S configuration is used. Discussion: The 6S hamstring graft configuration increases the graft diameter by a median of 1.5 millimeters compared to the traditional 4S configuration. It can reliably be used to obtain an 8.5 mm graft diameter or more in cases where the semitendinosus measures at least 270.5 mm and the 4S configuration has a diameter of 7.5 mm or 8 mm. This information helps to better delineate the impact of a 6S configuration in a pre-operative or intra-operative setting to optimize the decisional process and surgical flow and to easily adapt the graft diameter. Level of evidence: V (cadaveric study)

Background: Shoulder pain secondary to rotator cuff tendinopathy affects a large proportion of patients in orthopedic surgery practices. Corticosteroid injections are a common intervention proposed for these patients. The clinical evaluation of a response to corticosteroid injections is usually based only on the patient’s self-evaluation of his function, activity, and pain by multiple questionnaires with varying metrological qualities. Objective measures of upper extremity functions are lacking, but wearable sensors are emerging as potential tools to assess upper extremity function and activity. Objective: This study aimed (1) to evaluate and compare test-retest reliability and sensitivity to change of known clinical assessments of shoulder function to wrist-based accelerometer measures and visual analog scales (VAS) of shoulder activity during daily living in patients with rotator cuff tendinopathy convergent validity and (2) to determine the acceptability and compliance of using wrist-based wearable sensors. Methods: A total of 38 patients affected by rotator cuff tendinopathy wore wrist accelerometers on the affected side for a total of 5 weeks. Western Ontario Rotator Cuff (WORC) index; Short version of the Disability of the Arm, Shoulder, and Hand questionnaire (QuickDASH); and clinical examination (range of motion and strength) were performed the week before the corticosteroid injections, the day of the corticosteroid injections, and 2 and 4 weeks after the corticosteroid injections. Daily Single Assessment Numeric Evaluation (SANE) and VAS were filled by participants to record shoulder pain and activity. Accelerometer data were processed to extract daily upper extremity activity in the form of active time; activity counts; and ratio of low-intensity activities, medium-intensity activities, and high-intensity activities. Results: Daily pain measured using VAS and SANE correlated well with the WORC and QuickDASH questionnaires (r=0.564-0.815) but not with accelerometry measures, amplitude, and strength. Daily activity measured with VAS had good correlation with active time (r=0.484, P=.02). All questionnaires had excellent test-retest reliability at 1 week before corticosteroid injections (intraclass correlation coefficient [ICC]=0.883-0.950). Acceptable reliability was observed with accelerometry (ICC=0.621-0.724), apart from low-intensity activities (ICC=0.104). Sensitivity to change was excellent at 2 and 4 weeks for all questionnaires (standardized response mean=1.039-2.094) except for activity VAS (standardized response mean=0.50). Accelerometry measures had low sensitivity to change at 2 weeks, but excellent sensitivity at 4 weeks (standardized response mean=0.803-1.032). Conclusions: Daily pain VAS and SANE had good correlation with the validated questionnaires, excellent reliability at 1 week, and excellent sensitivity to change at 2 and 4 weeks. Daily activity VAS and accelerometry-derived active time correlated well together. Activity VAS had excellent reliability, but moderate sensitivity to change. Accelerometry measures had moderate reliability and acceptable sensitivity to change at 4 weeks.