Elbow joint loading and spatiotemporal performance under different hand positions during the forward handspring

This study examined how different hand positions influence key biomechanical characteristics of elbow joint loading and performance during the forward handspring. Nine adolescent male gymnasts performed five trials using parallel (PHP) and outward (OHP) hand positions. Kinematic and kinetic data were collected using eight infrared cameras (250 Hz) and two force plates (1,000 Hz), with analysis conducted on the arm in contact with the force plate. The OHP produced greater maximum vertical and resultant ground reaction forces and net vertical impulse than the PHP, while exhibiting a shorter contact time. As a result, vertical velocity at take-off, change in centre of mass height, and flight time increased, indicating mechanical characteristics favourable for forward handspring performance. Meanwhile, the OHP exhibited greater elbow adduction moments, suggesting higher elbow joint loading. In contrast, the PHP attenuated elbow joint loading through greater flexion and internal rotation, facilitating shock absorption and propulsion over a longer contact time. This was reflected in greater negative and positive elbow joint work in the PHP than in the OHP, despite similar net joint work. These findings suggest that hand position selection may involve a balance between performance and elbow joint loading, highlighting its importance during the forward handspring.