Structural and Functional Asymmetries in Male Basketball Players: A Cross-Sectional Analysis of Body Composition, Bone Status, and Performance.

Background: Basketball is a high-intensity, multidirectional sport involving frequent jumping, sprinting, and rapid changes of direction, which may expose the musculoskeletal system to varying and potentially asymmetric mechanical demands. The mechanical loading associated with basketball-specific movements may also serve as a consistent osteogenic stimulus, potentially leading to side-specific adaptations in body composition and bone characteristics. Long-term participation in basketball may lead to functional and structural asymmetries between the lower and upper limbs, potentially increasing the risk of injury and impacting performance. This study aimed to investigate structural and functional asymmetries in male basketball players using body composition, health, and performance-related measures. Methods: Thirty-eight right-handed basketball players (age: 21.1 ± 2.8 years; body mass: 86.2 ± 9.2 kg; height: 1.91 ± 8.3 cm) were assessed in a single testing session. The evaluation included bioelectrical impedance analysis (BIA), dual-energy X-ray absorptiometry (DXA), single-leg countermovement rebound jumps (CMRJs), and handgrip strength testing. Results: Significant interlimb differences were observed in lean mass and the phase angle for both the arms and legs. Performance differences favored the left leg in terms of maximum jump height (12.0 ± 17.5%, p = 0.001) and reactive strength index (RSI), whereas the right arm exhibited greater grip strength than the left (6.4 ± 5.9%, p = 0.001). DXA analysis revealed significant asymmetries in bone parameters, including bone mineral density (BMD) of the trochanter (1.81 ± 5.51%, p = 0.031, dz = 0.37), total hip (1.41 ± 4.11%, p = 0.033, dz = 0.36), and total arms (-1.21 ± 2.71%, p = 0.010, dz = 0.43), as well as bone mineral content (BMC) in total arms (-2.16 ± 5.09%, p = 0.012) and total legs (1.71 ± 3.36%, p = 0.002, 0.54). Conclusions: These findings suggest that basketball may induce both functional and structural adaptations, likely due to repetitive unilateral loading and sport-specific movement patterns. However, individual variability and the use of diverse assessment methods may complicate the detection and interpretation of asymmetries. Coaches and practitioners should monitor and address such asymmetries to reduce injury risk and optimize performance.