Altered Scapulothoracic Muscle Activity in Overhead Athletes with Rotator Cuff-Related Shoulder Pain: A Systematic Review and Meta-Analysis.

Abstract

The systematic review and meta-analysis aimed to compare the electromyographic (EMG) activity of the scapulothoracic muscles in overhead athletes with and without rotator cuff-related shoulder pain (RCRSP). PubMed, Web of Science, Scopus and SPORTDiscus databases were searched from inceptions to May 2025. Methodological quality was evaluated using the Joanna Briggs Institute Appraisal Tool. Meta-analyses using random-effects models were conducted. The level of evidence was assessed using the GRADE approach. Eleven studies (237 athletes with RCRSP and 205 healthy controls) were included. Very low-certainty evidence showed that athletes with RCRSP demonstrated increased upper trapezius (UT) activity (SMD=0.52; 95% CI: 0.07-0.96), decreased lower trapezius (LT) activity (SMD=-0.52; 95% CI: -0.94 to -0.11), and increased UT/LT ratios (SMD=1.20; 95% CI: -0.03-2.43) compared to healthy athletes. Delayed serratus anterior (SA) activation was also observed (SMD=1.01; 95% CI: 0.42-1.59). There is very low-certainty evidence that overhead athletes with RCRSP demonstrate altered scapular muscle activity. These findings may indicate an association rather than a causal relationship. Further high-quality, prospective studies are needed to confirm causal relationships and determine the clinical implications of altered scapular muscle activity in overhead athletes with RCRSP.