A COMPARISON OF SINGLE- AND DOUBLE-LEG RUNNING VERTICAL JUMPS IN VOLLEYBALL

Single- and double-leg vertical jumps are often performed in volleyball games. But the contribution from individual leg in single- and double-leg running vertical jump skills in volleyball has not been revealed. The purpose of this study was to determine the differences between single- and double- leg running vertical jumps (1-LRVJ and 2-LRVJ) on the biomechanical characteristics. Ten male college volleyball players voluntarily participated in this study. Two volleyball running vertical jumps were executed randomly. Three trials of each running vertical jump were recorded for each subject. Data were collected using six infra-red Qualisys motion capture cameras at 180 Hz sampling rate and two AMTI force platforms at 1800 Hz sampling rate, respectively. The jump height of 2-LRVJ was significantly higher than 1-LRVJ (P< .05), In push-off phase, 1-LRVJ had less angle change, but greater moment and higher impact force (P< .05). These results suggested that 1-LRVJ product higher leg stiffness with 2-LRVJ, it also increase higher risk of injury. We suggested using two- leg jumping style to enhance jump high, and avoid lower limbs injury