Purpose: Previous studies have demonstrated that asymmetric scapular posture is often associated with abnormalities of the shoulder complex. However, shoulder asymmetries may be related to adaptations to sports practices and may also be different among healthy athletes from different sports. The purpose of this study was to investigate the effects of activities related to sports on scapular resting position and scapulohumeral rhythm ratio. Methods: Seventy-five male subjects (15 volleyball players, 15 table tennis players, 15 swimmers, 15 handball players, and 15 non-athletes) participated in this study. All athletes had at least 2 years’ experience in college teams. Two inclinometers were used to measure humeral abduction and scapular up/downward rotation in resting position, 45°, 90°, and 135° humeral abduction in frontal plane. The scapulohumeral rhythm was calculated from scapular resting position to 45º, 90º, and 135º humeral abduction and from 45º to 90º and 90º to 135º humeral abduction. Results: Findings indicated that there is no asymmetry in up/downward rotation in scapular resting position between dominant and non-dominant shoulders per group (p > 0.05) but handball players’ dominant shoulders had more downward rotation than non-athletes’ dominant shoulders in scapular resting position (p = 0.03). Furthermore, there was a significant difference in scapulohumeral rhythm ratio in different abduction angles among the five groups as table tennis players and non-athletes had more scapulohumeral rhythm ratio than handball players (p < 0.05). Conclusion: Although there may be no asymmetry in up/downward rotation in scapular resting position in some healthy athletes from different sports and non-athletes, activities related to sports may influence the scapulohumeral rhythm ratio.
