Biomechanical improvements in performance and injury prevention in volleyball spikes: effects of a 4-week training...

This study aimed to develop a 4-week volleyball-specific training program for the unique movement requirements of volleyball to enhance performance and reduce injury risk among adult players. Sixteen male participants were college players with at least 10 years of volleyball experience (ages: 18-22 years). Participants performed spikes in pre- and post-test, starting with a 5 m run-up from the left side of the net to a force platform. They underwent a four-week training program aimed at improving spike performance. The analyzed variables included the center of mass (COM), joint angles, angular velocities, moments, ground reaction forces (GRF), and forces in the three planes of the knee joint. For statistical analysis, paired t-tests and statistical parametric mapping (SPM) were employed to evaluate pre- and post-test differences in the measured variables (α = .05). During the jumping phase, knee extension angular velocity and peak vertical GRF increased after training (p < .05), and SPM analysis revealed a higher knee flexion moment between 40 and 80% of the phase post-test (p < .001). In the airborne phase, the center of mass (COM) reached a greater height after the training program (p < .05). During the landing phase, the minimum COM height decreased post-test (p < .05), while flexion angular velocity increased (p < .05). In addition, the extension moment and vertical joint forces of the knee were reduced (p < .05), and vertical GRF remained consistently high at 35% of the landing phase (p < .001). The four-week specific training program effectively enhanced jump performance and reduced knee joint load, promoting both improved performance and safer landing mechanics.