Comparison of Spinal Alignment, Mobility, Core Endurance, Scapular Dyskinesia, and Upper Extremity Function in Volleyball Players and Asymptomatic Individuals.

OBJECTIVES: Asymmetrical, repetitive, high-impact, fast movements in volleyball can lead to muscle strength imbalances, reducing both strength and endurance due to inefficiencies in shoulder and spinal movement patterns. This study aimed to compare spinal alignment, mobility, trunk endurance, scapular dyskinesis, and upper-extremity function and power between volleyball players and asymptomatic individuals. METHODS: This case-control study included 27 female elite volleyball players (median age: 23 (20-32) years) and 27 asymptomatic women matched for age and body mass index (median age: 24 (21-29) years). Spinal alignment and mobility were assessed with a skin-surface device (Hocoma, Valedo Shape, Idiag GmbH, Switzerland), trunk endurance with the McGill Endurance Test, scapular mobility with the Lateral Scapular Slide Test, upper extremity balance with the Y Balance Test, stability with the Closed Kinetic Chain Upper Extremity Stability Test, and power with the Medicine Ball Throwing Test. RESULTS: Scapular mobility asymmetry, throwing distance at chest level, upper-extremity inferolateral balance, extensor and lateral trunk endurance, and sagittal spinal inclination angles were higher in the athlete group (p < 0.05). Thoracic, lumbar, and sacral angles and spinal mobility were similar between the groups (p > 0.05). CONCLUSION: The athlete group demonstrated greater spinal stability, trunk endurance, and upper extremity balance, a lower risk of scapular dyskinesis, and improved chest-level throwing abilities. Considering the body as a kinetic chain, trunk and scapular stabilization and endurance appear to play a key role in upper-extremity function and performance in volleyball players. Therefore, assessing trunk and scapular stability and endurance, as well as upper-extremity performance, is essential for volleyball players.