Relationship of Infraspinatus Muscle Atrophy with Shoulder Joint Function in Volleyball Players

Abstract

Objective: This study clarified the relationship between ultrasonography results for infraspinatus muscle atrophy and shoulder joint function in high school volleyball players.
Methods: Subjects included male volleyball players from eight high schools. Muscle atrophy was assessed using ultrasonography and infraspinatus muscle atrophy was determined using criteria from previous studies. Statistical analyses were performed on basic information and physical function between atrophic and normal groups. A stepwise method was used for binary logistic regression analysis. The significance level was set at 5%.
Results: A total of 68 subjects were analyzed, with 19 (27.5%) showing infraspinatus muscle atrophy. Between-group comparisons found more individuals with shoulder pain history and positive dominant-hand HFT (Horizontal Flexion Test) results in the atrophy group. Binary logistic regression analysis identified dominant-hand HFT as a significant factor (odds ratio: 4.19).
Conclusion: Positive dominant-hand HFTs are associated with infraspinatus muscle atrophy.