Glenohumeral Rotational Deficit and Suprascapular Neuropathy in the Hitting Shoulder in Male Collegiate Volleyball Players

Abstract

Objective: Repetitive overhead movements stress the dominant shoulder of volleyball players, potentially causing glenohumeral internal rotation deficit (GIRD) and suprascapular neuropathy. The aim of this study was to determine the prevalence of pathological GIRD and suprascapular neuropathy in male collegiate volleyball players. Methods: We evaluated 22 male collegiate volleyball players and compared the range of motion, the isometric shoulder strength, the thickness of the infraspinatus (ISP) muscle, and the latency and amplitude of the suprascapular nerve [in a nerve conduction study (NCS)] between the hitting and contralateral shoulders. Correlations between the physical findings and each parameter were also determined. Results: The internal rotation angle of the hitting shoulder (55.1±8.7°) was significantly less than that of the contralateral shoulder (64.5±10.2°) (P<0.001); pathological GIRD (≥20°) was found in four players (18.2%). Three players (13.6%) showed abnormal electrophysiological findings of the suprascapular nerve on the ISP muscle in the hitting shoulder. The external-to-internal rotation (ER/IR) torque ratio in the hitting shoulder (99±18%) was significantly lower than that in the contralateral shoulder (106±12%) (P=0.04); no significant differences were observed in ISP muscle thickness or NCS data between the hitting and contralateral shoulders. Conclusion: The prevalence of pathological GIRD in male collegiate volleyball players was consistent with that of previous studies. Meanwhile, the prevalence of suprascapular neuropathy was less than that previously reported in high-level volleyball players. Preventive posterior rotator cuff strengthening programs are recommended to correct imbalances between ER and IR in the hitting shoulder, thereby decreasing the risk of shoulder injury.