Continuous change in spring-mass characteristics during a 400 m sprint
Continuous change in spring-mass characteristics during a 400 m sprint
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DOI：
10.1016/j.jsams.2009.02.002
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发表时间：
2010-03-01
影响因子：
4
通讯作者：
Kanosue, Kazuyuki
中科院分区：
文献类型：
--
作者：
Hobara, Hiroaki;Inoue, Koh;Kanosue, Kazuyuki
本研究的目的是利用弹簧-质量模型，（1）连续测量整个400 W短跑过程中的垂直刚度（K（vert））和腿部刚度（K（leg）），（2）研究腿部弹簧刚度（K（vert）和K（vert））与平均前跑速度性能特征的关系（V（向前））、平均步幅频率（f（步幅））和平均步幅长度（L（步幅））。八名训练有素的男运动员在室外田径场上进行了400瓦的短跑。根据受试者的体重、地面接触时间和每一步的飞行时间计算得出。从视频图像确定V（forwad）、f（stride）和L（stride）。K（vert）和V（forward）在50-100 m间隔达到峰值，并从短跑的中期到后期持续下降。K（腿），在第一个50米间隔达到峰值，并保持不变，从下一个50米间隔完成。与峰值相比，最后50 m的K（vert）和V（forward）分别下降约40%和25%。K（vert）与V（forward）之间存在显著的正线性关系。K（vert）与f（stride）显著相关，而与L（stride）无相关性。此外，在K（腿）与V（向前）、f（步幅）或L（步幅）之间没有发现显著的正线性关系。这一结果表明，为了在400 W短跑的后期保持V（向前），通过保持较高的K（垂直）来保持较高的f（步幅）是必要的。(C)2009年澳大利亚运动医学。由爱思唯尔有限公司出版。保留所有权利。
The purpose of the present study was to utilise a spring-mass model to (1) continuously measure vertical stiffness (K(vert)) and leg stiffness (K(leg)) over an entire 400w sprint, and (2) investigate the relationship between leg spring stiffness (K(vert) and K(vert)) and the performance characteristics of mean forward running velocity (V(forward)), mean stride frequency (f(stride)), and mean stride length (L(stride)). Eight well-trained male athletes performed a 400w sprint with maximal effort on an outdoor field track. was calculated from the subjects' body mass, ground contact time and flight time at each step. V(forwad), f(stride) and L(stride) were determined from video images. K(vert) and V(forward) peaked at the 50-100 m interval, and consistently decreased from the middle to the later part of the sprint. K(leg), peaked at first 50m interval, and remained constant from next 50 m interval to finish. As compared with peak values, K(vert) and V(forward) in the last 50 m decreased by about 40% and 25%, respectively. A significant positive linear relationship existed between the K(vert) and V(forward). While K(vert) was significantly correlated with f(stride), it had no correlation with L(stride). Further, no significant positive linear relationship was found between K(leg), and V(forward), f(stride), or L(stride). This result indicates that in order to keep V(forward) at later stage of a 400w sprint, maintaining the higher f(stride) through retaining a higher K(vert) would be necessary. (C) 2009 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.