School of Kinesiology, The University of Western Ontario, Thames Hall 2125, 1151 Richmond Street, London, Ontario N6A 3K7, Canada.
Hum Mov Sci. 2014 Feb;33:298-311. doi: 10.1016/j.humov.2013.08.013. Epub 2013 Nov 27.
The purpose of this study was to determine how sagittal kick symmetry in the underwater dolphin kick (UDK) between the downkick and upkick phases is related to UDK performance. Fifteen adult male competitive swimmers ranging from provincial to international level were filmed performing three trials each of maximum effort UDK over 15m using an underwater video camera. Video frames were manually digitized and each subjects' single fastest trial was evaluated for between-subject comparisons. Kinematic variables were calculated for each individual and Pearson product-moment correlations between the average horizontal centre of mass velocity (Vx) and all kinematic variables were calculated. Horizontal velocity during the downkick, horizontal velocity during the upkick, relative time spent in each phase, maximum chest flexion angle, maximum knee and ankle extension angles, the ratio of flexion/extension for chest, knee and ankle angles, and maximum vertical toe velocity during the upkick phase correlated significantly with Vx (p<0.05). The ratio of downkick vertical toe velocity/upkick vertical toe velocity was significantly negatively correlated with Vx (p<0.05). These results indicate the importance of kick symmetry for UDK performance, and indicate that performing the upkick phase well appears to be most important for UDK performance.
本研究旨在确定水下海豚踢（UDK）中下踢和上踢阶段的矢状面踢对称性与 UDK 性能之间的关系。15 名成年男性竞技游泳运动员，从省级到国际水平，使用水下摄像机拍摄了三次最大努力 UDK 试验，每次 15m。视频帧手动数字化，对每个受试者的三个最快试验进行了个体间比较评估。为每个个体计算了运动学变量，并计算了平均水平质心速度（Vx）与所有运动学变量之间的皮尔逊积矩相关。下踢时的水平速度、上踢时的水平速度、每个阶段的相对时间、最大胸部屈曲角度、最大膝关节和踝关节伸展角度、胸部、膝关节和踝关节角度的屈伸比以及上踢阶段的最大垂直脚趾速度与 Vx 显著相关（p<0.05）。下踢垂直脚趾速度/上踢垂直脚趾速度的比值与 Vx 呈显著负相关（p<0.05）。这些结果表明，踢对称性对 UDK 性能很重要，并且表明上踢阶段表现良好似乎对 UDK 性能最重要。
