Domire Zachary J, Challis John H
Department of Kinesiology, East Carolina University, 332A Ward Sports Medicine Building, Greenville NC 27858 USA.
Biomechanics Laboratory, 29 Recreation Building, The Pennsylvania State University, University Park, PA 16802-3408, USA.
J Biomech. 2015 Aug 20;48(11):2865-70. doi: 10.1016/j.jbiomech.2015.04.021. Epub 2015 Apr 22.
The performance criterion in maximum vertical jumping has typically been assumed to simply raise the center of mass as high as possible. In many sporting activities minimizing movement time during the jump is likely also critical to successful performance. The purpose of this study was to examine maximum height jumps performed while minimizing jump time. A direct dynamics model was used to examine squat jump performance, with dual performance criteria: maximize jump height and minimize jump time. The muscle model had activation dynamics, force-length, force-velocity properties, and a series of elastic component representing the tendon. The simulations were run in two modes. In Mode 1 the model was placed in a fixed initial position. In Mode 2 the simulation model selected the initial squat configuration as well as the sequence of muscle activations. The inclusion of time as a factor in Mode 1 simulations resulted in a small decrease in jump height and moderate time savings. The improvement in time was mostly accomplished by taking off from a less extended position. In Mode 2 simulations, more substantial time savings could be achieved by beginning the jump in a more upright posture. However, when time was weighted more heavily in these simulations, there was a more substantial reduction in jump height. Future work is needed to examine the implications for countermovement jumping and to examine the possibility of minimizing movement time as part of the control scheme even when the task is to jump maximally.
在最大垂直跳跃中，通常认为表现标准仅仅是将质心尽可能地抬高。在许多体育活动中，尽量缩短跳跃过程中的运动时间对于成功表现可能也至关重要。本研究的目的是研究在尽量缩短跳跃时间的同时进行的最大高度跳跃。使用直接动力学模型来研究深蹲跳的表现，有两个表现标准：最大化跳跃高度和最小化跳跃时间。肌肉模型具有激活动力学、力-长度、力-速度特性，以及一系列代表肌腱的弹性成分。模拟以两种模式运行。在模式1中，模型被置于固定的初始位置。在模式2中，模拟模型选择初始深蹲配置以及肌肉激活顺序。在模式1模拟中加入时间因素导致跳跃高度略有下降，时间节省适中。时间的改善主要是通过从伸展程度较小的位置起跳来实现的。在模式2模拟中，通过以更直立的姿势开始跳跃可以实现更多的时间节省。然而，当在这些模拟中更看重时间时，跳跃高度会有更显著的降低。需要未来的工作来研究对反向跳跃的影响，并研究即使任务是最大程度跳跃时，将尽量缩短运动时间作为控制方案一部分的可能性。
