| Abstrakt: |
In volleyball, the approach run serves as a strategy to execute a spike from an elevated striking position. Nevertheless, the influence of the step number of the approach run on the jumping kinematics in spike jumps is unclear. Therefore, this investigation aims to clarify the impact of varying step numbers within the approach run on jumping kinematics. Seven female volleyball athletes were tasked with executing spike jumps, employing 2 and 3-step approach runs. These trials were recorded using high-speed cameras and digitized, and then the kinematics of the 2 and 3-step trials were compared. The findings of this study unveiled that, in the 3-step trial with higher horizontal velocity, the center of gravity was upheld at an elevated level, thereby curtailing the vertical displacement of the center of gravity from the last step before the takeoff to the takeoff. Within the 2-step trial, a notable deceleration of horizontal velocity in the first half of the takeoff was virtually absent. However, the 3-step trial with higher horizontal velocity entailed more flexion of the dominant knee joint to decelerate the horizontal velocity during the first half. Furthermore, the 3-step trial entails a swifter extension of the hip, knee, and ankle joints of the non-dominant leg. This accelerated extension likely contributes to an augmented vertical velocity at the foot release of the takeoff. [ABSTRACT FROM AUTHOR] |
