Mechanical mechanism of movements during start in speed skating

通过对仪表式传感器溜冰鞋测量的叶片反作用力和三维运动分析测量的运动学参数的分析，研究了速度滑冰起跑过程中支撑腿的动力学。在这项研究中，分析了距离起跑线大约5米处的第三步(左支撑腿)。起跑时垂直叶片反作用力峰值(2.93N/BW)大于直滑和弯滑。由此可见，速滑起跑过程中，下肢的外载荷极大。膝关节在下半程伸展力量较大(这一峰值约为直滑的12倍，弯滑的4倍)。因此，最大限度地发挥伸膝扭矩将是速滑起跑的一个特点。

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.