The Addition of Glenohumeral Adductor Coactivation to a Rotator Cuff Exercise Program for Rotator Cuff Tendinopathy: A Single-Blind Randomized Controlled Trial

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).