Shoulder strength, scapular displacement, and supraspinatus morphology in male and female competitive water polo players: a cross-sectional study
Year: 2026
Type: article
Study design: Observational Study
Abstract: Background Water polo is an Olympic team sport played by both men and women that combines repetitive throwing and aquatic propulsion, placing unique biomechanical demands on the shoulder. However, sex-related differences in shoulder function and structure remain poorly understood. This study compared the functional and structural shoulder profiles of male and female competitive water polo players. Methods A cross-sectional study included 52 competitive water polo players (26 men and 26 women; 18–30 years). Internal and external rotator strength was assessed using a handheld dynamometer, and the internal-to-external rotation strength ratio (IR/ER ratio) was calculated. Scapular position and displacement were evaluated using a PALM® device, and supraspinatus tendon thickness was measured by ultrasound. Univariate analyses were followed by multiple linear regression adjusted for height and body mass. Results Men showed greater internal rotation strength ( p = 0.011) and a higher IR/ER ratio ( p = 0.004), whereas women exhibited greater scapular displacement ( p = 0.004). No significant sex differences were observed in external rotation strength ( p = 0.052), supraspinatus tendon thickness ( p = 0.384), or arm dominance ( p > 0.05). After adjustment, sex was no longer associated with internal rotation strength or the IR/ER ratio. However, greater scapular displacement in women remained independently associated with sex ( p = 0.005; adjusted p = 0.020). Conclusions Sex differences in shoulder strength were largely explained by anthropometric characteristics. In contrast, greater scapular displacement in female players remained independent of body size, suggesting a sex-specific biomechanical adaptation that may be relevant for shoulder injury prevention. These findings contribute to a better understanding of sex-specific shoulder adaptations in water polo and may support the development of more individualized assessment and injury prevention strategies.
Institution: Universidad Europea de Madrid
Language: English
Subfield: Surgery
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $2,353
OpenAlex ID: W7221782032