The Efficacy of Higher Versus Lower Dose Exercise in Rotator Cuff Tendinopathy: A Systematic Review of Randomized Controlled Trials.

OBJECTIVES: To compare the effectiveness and harms of higher exercise dose, including higher exercise load or higher volume, with lower exercise dose (lower load or lower volume) in individuals with rotator cuff tendinopathy. DESIGN: Systematic review. DATA SOURCES: Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, and CINAHL from inception to March 2019. STUDY SELECTION: Randomized controlled trials comparing higher versus lower dose exercise that investigated function and pain (overall, activity, night) and adverse event outcomes were independently determined by 2 reviewers. DATA EXTRACTION: Two authors independently extracted data and assessed risk of bias using the Cochrane tool. The primary endpoint was at least 6 weeks to 3 months (other endpoints included up to 6 weeks and beyond 3 months) and the Grades of Recommendation, Assessment, Development and Evaluation was used to assess evidence certainty. DATA SYNTHESIS: Three trials (N=283), none at low risk of bias for all domains, were included. Low-certainty evidence (1 trial, N=102) indicated improved function (20 points [95% confidence interval, 12-28] on a 0-100 point scale) with higher load and volume exercise at 3 months, but little or no clinically important between-group difference in activity or night pain (overall pain not reported). Very low-certainty evidence (1 trial, N=120) indicated higher load exercise conferred no function benefits over lower load exercise at 6 weeks. Very low-certainty evidence (1 trial, N=61) indicated benefit of uncertain clinical importance in function with higher versus lower volume exercise at 3 months and clinically important benefit at more than 3 months (pain outcomes not reported). The risk of adverse events was uncertain. CONCLUSIONS: There are few studies that have investigated higher dose exercise for rotator cuff tendinopathy. There was low to very low certainty and conflicting evidence regarding the value of higher exercise dose in individuals with rotator cuff tendinopathy.