Harman E A, Rosenstein M T, Frykman P N, Rosenstein R M
Exercise Physiology Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760-5007.
Med Sci Sports Exerc. 1990 Dec;22(6):825-33. doi: 10.1249/00005768-199012000-00015.
Countermovement and arm-swing characterize most jumping. For determination of their effects and interaction, 18 males jumped for maximal height from a force platform in all four combinations of arm-swing/no-arm-swing and countermovement/no-countermovement. For all jumps, vertical velocity peaked 0.03 s before and dropped 6-7% by takeoff. Peak positive power averaged over 3,000 W, and occurred about 0.07 s before takeoff, shortly after peak vertical ground reaction force (VGRF) and just before peak vertical velocity. Both countermovement and arm-swing significantly (P less than 0.05) improved jump height, but arm-swing's effect was greater, enhancing peak total body center of mass (TBCM) rise both pre and posttakeoff. Countermovement only affected the post-takeoff rise. The arm-swing resulted in higher peak VGRF and peak positive power. During countermovement, the use of arms resulted in less unweighting, slower and less extensive TBCM drop, and less negative power. Countermovement increased pretakeoff jump duration by 71-76%, increased average positive power, and yielded large positive and negative impulses. High test-retest reliability was shown for jump descriptive variables. Body weight together with peak posttakeoff TBCM rise effectively predicted peak power (multiple R2 = 0.89, standard error of estimate = 243 W). The results lend insight into which jumping techniques are most appropriate for given sports situations and indicate that a jump test can effectively be used to estimate peak power output.
反向运动和摆臂是大多数跳跃动作的特征。为了确定它们的作用及相互影响，18名男性在力平台上以摆臂/不摆臂和反向运动/不反向运动的所有四种组合进行了最大高度跳跃。对于所有跳跃，垂直速度在起跳前0.03秒达到峰值，到起跳时下降6 - 7%。平均峰值正功率超过3000瓦，在起跳前约0.07秒出现，就在垂直地面反作用力（VGRF）峰值之后、垂直速度峰值之前不久。反向运动和摆臂均显著（P小于0.05）提高了跳跃高度，但摆臂的效果更大，在起跳前和起跳后均增强了全身质心（TBCM）的峰值上升。反向运动仅影响起跳后的上升。摆臂导致更高的VGRF峰值和峰值正功率。在反向运动过程中，摆臂导致失重更少、TBCM下降更慢且幅度更小以及负功率更小。反向运动使起跳前的跳跃持续时间增加了71 - 76%，增加了平均正功率，并产生了较大的正负冲量。跳跃描述变量显示出较高的重测信度。体重与起跳后TBCM的峰值上升共同有效地预测了峰值功率（复相关系数R2 = 0.89，估计标准误差 = 243瓦）。这些结果有助于深入了解哪种跳跃技术最适合特定的运动场景，并表明跳跃测试可有效地用于估计峰值功率输出。
