Tanaka Takahiro, Hashizume Satoru, Sato Takahiko, Isaka Tadao
Graduate School of Sport and Health Science, Ritsumeikan University, Kusatsu 525-8577, Japan.
Faculty of Sport and Health Science, Ritsumeikan University, Kusatsu 525-8577, Japan.
Int J Environ Res Public Health. 2022 Mar 28;19(7):3998. doi: 10.3390/ijerph19073998.
The foot and trunk kinematics could be associated with horizontal velocity during underwater undulatory swimming (UUS). This study aimed to compare the foot and trunk kinematic parameters during UUS between faster and slower swimmers. The three-dimensional coordinates of the markers were collected during 15 m UUS for 13 swimmers. Participants were divided into two groups based on their horizontal UUS velocity. The range of motion of the lower waist was greater for the faster swimmers than for the slower swimmers; however, no group differences were found for the foot orientation angle. Both the maximum flexion and extension angular velocities of the lower waist and maximum extension angular velocity of the chest were greater for faster swimmers than for slower swimmers. The toe vertical velocity during upward and downward kicks and horizontal displacement per kick were greater for the faster swimmers than for the slower swimmers, whereas no group difference was found for kick frequency. The increase in the long horizontal displacement per kick could be explained by the increase in vertical velocity of the great toes due to the increased trunk angular velocity. These results indicate that faster swimmers performed the UUS with greater trunk angular velocity.
在水下波动式游泳（UUS）过程中，足部和躯干的运动学特征可能与水平速度相关。本研究旨在比较快速游泳者和慢速游泳者在UUS过程中的足部和躯干运动学参数。在13名游泳者进行15米UUS时收集了标记点的三维坐标。根据水平UUS速度将参与者分为两组。快速游泳者下腰部的运动范围比慢速游泳者更大；然而，两组在足部定向角度上没有差异。快速游泳者下腰部的最大屈伸角速度和胸部的最大伸展角速度均高于慢速游泳者。快速游泳者在向上和向下踢水时的脚趾垂直速度以及每次踢水的水平位移均大于慢速游泳者，而两组在踢水频率上没有差异。每次踢水时较长水平位移的增加可以通过由于躯干角速度增加导致的大脚趾垂直速度增加来解释。这些结果表明，快速游泳者在进行UUS时具有更大的躯干角速度。
