The Shoulders of Professional Beach Volleyball Players High Prevalence of Infraspinatus Muscle Atrophy

Background: Beach volleyball is an Olympic overhead sport. It is not well known which clinical and imaging findings are normal and which are associated with symptoms. Hypothesis: There are typical clinical and imaging findings in the hitting shoulders of fully competitive professional beach volleyball players, as compared with their nonhitting shoulders. Study Design: Cross-sectional study; Level of evidence, 3. Methods: During the Beach Volleyball Grand Slam Tournament in Klagenfurt, Austria, 84 professional players (54 men, 30 women) underwent a questionnaire-based interview and a complete physical examination, including scoring and sonography of both shoulders. Twenty-nine players had shoulder MRIs. Results: The mean age of the athletes was 28 years. Atrophy of the infraspinatus muscle was found in 30% of the hitting shoulders, and it was not typically recognized by the players. The absolute Constant score was significantly lower in the hitting shoulder (87 versus 93 points, P < .0001). Average external rotation strength was decreased in the hitting shoulder (8.2 versus 9.5 kg, P < .0001). There were more abnormalities on the sonography of the hitting shoulder (1.7 versus 0.4, P < .0001) and in the same shoulders on MRI than on sonography (P = .0231). Compression of the suprascapular nerve was not observed. Pain in the hitting shoulder was present in 63% of the players, without clear correlations to the investigated clinical and imaging parameters. Conclusion: The prevalence of infraspinatus muscle atrophy in professional beach volleyball players is 30%. The typical, fully competitive player has subjectively unrecognized decreased strength of external rotation and frequent unspecific shoulder pain. Therefore, abnormal clinical and imaging findings in the beach volleyball player should be interpreted with care.