The Impact of Glenohumeral Rotational Asymmetries on the Risk of Shoulder Pain in Volleyball Players: A Cross-Sectional Study

Abstract

Background: Shoulder rotational imbalances are common adaptations in volleyball players due to repetitive overhead movements. This study investigates the relationship between shoulder rotational asymmetries and the risk of shoulder pain in professional and semi-professional volleyball players. Methods: A cross-sectional study was conducted on 84 volleyball players, divided into groups with and without history of shoulder pain (n=29 and n=55, respectively). Shoulder internal rotation (IR) and external rotation (ER) were measured using a goniometer. Glenohumeral internal rotation deficit (GIRD), external rotation gain (ERG), total range of motion (TROM) and TROM asymmetry were calculated. Multivariable logistic regression was used to determine independent risk factors, and receiver operating characteristic (ROC) curve analysis was performed to define pathological thresholds. Results: The pain group exhibited significantly higher GIRD (median: 18° vs. 10°, p<0.001) and greater TROM asymmetry (median: 8° vs. 4°, p=0.033) compared to the no pain group. No significant differences were observed in ERG. Logistic regression identified GIRD (OR=1.100, p=0.011) and playing position (attackers: OR=11.101, p=0.005) as independent risk factors for shoulder pain. ROC analysis determined cutoff values of 17° for pathological GIRD and 5° for pathological TROM asymmetry. Conclusion: Increased GIRD and TROM asymmetry are associated with a higher risk of shoulder pain in volleyball players. Attackers are at greater risk due to repetitive high-intensity movements. These findings highlight the importance of monitoring shoulder rotational imbalances and implementing preventive strategies, including targeted mobility and strengthening exercises, to mitigate injury risk and optimize performance.