Koyama Hiroyuki, Muraki Yuya, Ae Michiyoshi
Graduate School of Comprehensive Human Sciences, University of Tsukuba, Japan.
Sports Biomech. 2006 Jul;5(2):139-53. doi: 10.1080/14763140608522870.
We investigated the immediate effects of the combined use of inclined and raised flat boards on the take-off motion of the long jump. Eight male long jumpers were videotaped with two high-speed video cameras (250 Hz) set perpendicular to the runway. The athletes jumped with three modified take-off boards: upward-inclined boards of two different inclinations (2.5 and 5.0 degrees), and a raised flat board (50 mm high). The jumpers performed pre- and post-jumps using their own techniques before and after use of the boards to test their effects. The post- jump revealed significantly less reduction in the horizontal velocity during the take-off than the pre-jump, and the effectiveness of converting the velocity from horizontal to vertical increased significantly in the post-jump. The post-jump demonstrated significantly less knee flexion of the take-off leg during take-off. The reduced knee flexion and slower extension velocity of the take-off leg in the second phase of the post-jump contributed to increasing the knee extension torque in the second phase and resulted in the increases in vertical ground reaction force and vertical velocity. These results suggest that the combined use of the inclined and raised flat boards induced immediate effective changes in the kinematics and kinetics of the take-off motion and represent appropriate training tools for take-off techniques of the long jump.
我们研究了倾斜板和升高平板组合使用对跳远起跳动作的即时影响。使用两台垂直于跑道设置的高速摄像机（250赫兹）对八名男性跳远运动员进行了录像。运动员使用三种改良的起跳板进行跳跃：两种不同倾斜度（2.5度和5.0度）的向上倾斜板，以及一块升高平板（50毫米高）。在使用这些板子前后，运动员先用自己的技术进行预跳和后跳，以测试其效果。后跳显示，起跳时水平速度的降低明显少于预跳，并且起跳时将水平速度转换为垂直速度的效率显著提高。后跳表明起跳腿在起跳时的屈膝程度明显减小。后跳第二阶段起跳腿屈膝程度减小以及伸展速度变慢，有助于增加第二阶段的伸膝扭矩，并导致垂直地面反作用力和垂直速度增加。这些结果表明，倾斜板和升高平板的组合使用能在起跳动作的运动学和动力学方面引发即时有效的变化，是跳远起跳技术的合适训练工具。
