Swimmer's Shoulder: Ultrasound Anatomical Description of Shoulder Tendons in Elite Swimmers and Water Polo Players

Objectives: This study aimed to examine the differences in shoulder ultrasonographic parameters between overhead aquatic athletes and their relationship with shoulder pain. Methods: Sixty-four healthy junior subjects (n = 128 shoulders) participated in the study, including 17 healthy controls, 25 elite junior swimmers, and 22 elite junior water polo players. An ultrasonographic study of the shoulder was carried out to measure the thickness of the rotator cuff structures in sex- and age-paired groups. Results: Compared to controls, female and male swimmers and water polo players had thicker values in the rotator cuff tendons, including the subscapularis (SSB) (p < 0.001), supraspinatus (p < 0.001), infraspinatus (p < 0.001) and teres minor (Tm) (p < 0.025). The female swimmers had thicker values than the water polo players in the SSB (p < 0.001) and Tm (p < 0.011). In the comparison by sexes, the female controls had a thinner LHBB, SSB and Tm (p < 0.019), the female swimmers had a thinner ISP (p = 0.001), and the female water polo players had a thinner LHBB, SSB, ISP and acromiohumeral distance than their group-paired counterparts (p < 0.018). Finally, the females had a lower incidence of positive Jobe test results compared to the males (p = 0.018), which was associated with lower pain scores at rest (p < 0.034) and during training (p < 0.036). Conclusions: The rotator cuff tendon structures were larger in the healthy overhead aquatic athletes compared to the age- and sex-paired controls. The females had smaller values in the shoulder ultrasonographic tendon parameters compared to the age- and sport-paired males, except for the supraspinatus tendon.