Mechanical mechanism of movements during start in speed skating

通过分析传感器测量的叶片反作用力和三维运动分析测量的运动学参数，研究了速度滑冰运动员起跑时支撑腿的动力学。在这项研究中，我们分析了距离起跑线约5米的第三步（左支撑腿）。启动运动时叶片垂直反力峰值（2.93 N/bw）大于直线滑和曲线滑；这说明在速度滑冰起跑时下肢的外负荷是非常大的。而且，膝关节在下半段的伸展力很大（这个峰值大约是直滑的12倍，曲线滑的4倍）。因此，在速度滑冰的起跑中，膝盖伸展力矩的巨大发挥是一个特点。

We investigated the kinetics of the support leg during the start in speed skating by analyzing blade reaction forces measured by instrumented sensor klapskates and kinematical parameters measured by three-dimensional motion analysis. In this study, the 3rd step(left support leg) at approximately 5 m from the start line was analyzed. The peak value in the vertical blade reaction force during start movement(2.93 N/bw) was greater than those in straight and curve skating. This indicates that the external load at the lower limb during the start in speed skating is extremely large. Moreover, the knee joint exerted a large extension power during the second half of the stroke(this peak value was approximately 12 times that of straight skating and 4 times that of curve skating). Thus, a great exertion of the knee extension torque would be a characteristic of the start in speed skating.