Effect of imposing changes in kick frequency on kinematics during undulatory underwater swimming at maximal effort in male swimmers
Effect of imposing changes in kick frequency on kinematics during undulatory underwater swimming at maximal effort in male swimmers
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DOI：
10.1016/j.humov.2014.09.001
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发表时间：
2014-12-01
影响因子：
2.1
通讯作者：
Takagi, Hideki
中科院分区：
文献类型：
--
作者：
Shimojo, Hirofumi;Sengoku, Yasuo;Takagi, Hideki
波浪水下游泳（UUS）是一项重要的起跳后和转身后游泳技术。我们认为，较高的蹬腿频率(f)会导致较高的游泳速度(U)，而较低的f则会导致较高的推进效率，即Strouhal数（St）和frode效率（eta(f)）。本研究的目的是研究f的变化是否会影响U和St、撕裂以及UUS的其他运动学。10名国家级男子游泳运动员参与了这项研究。首先，游泳者完成最大UUS （Pre；这个f被定义为100% f）。其次，游泳者与节拍器的声音同步，并随机呈现六种频率（85% f, 90% f, 95% f, 105% f， 110% f和115% f）。在高f阶段，踢腿幅度(A)较前阶段显著降低（115% f: -10.8%, p < 0.05）；然而，U不变。相比之下，在较低的f时段，St和eta(f)没有变化，但每体长波长（lambda(BL)）显著降低（90% f: -1.3%, p < 0.05），这表明UUS模式。总之，这些结果表明，增加UUS的f不会影响U，但减少f可能适合人体波动训练。(C) 2014 Elsevier B.V.版权所有
Undulatory underwater swimming (UUS) is an important swimming technique after a start and after turns. It was considered that a higher swimming velocity (U) resulted from a higher kick frequency (f), and greater propelling efficiency, i.e., Strouhal number (St) and Froude efficiency (eta(F)), resulted from a lower f. The aim of this study was to investigate whether changing f affected U and St, rip plus other kinematics of UUS. Ten national-level male swimmers participated in the study. First, the swimmers performed maximal UUS (Pre; this f was defined as 100% F). Second, the swimmers synchronized their f with the sound of a metronome and with six frequencies (85% F, 90% F, 95% F, 105% F, 110% F, and 115% F) randomly presented. During the higher f sessions, kick amplitude (A) significantly decreased from Pre (115% F: -10.8%, p < .05); however, U was unchanged. In contrast, in lower f sessions, St and eta(F) were unchanged, but the wavelength per body length (lambda(BL)), which indicates UUS mode, significantly decreased (90% F: -1.3%, p < .05). In conclusion, these results suggest that increasing f for UUS would not affect U, but a decrease in f may be suitable for human undulation training. (C) 2014 Elsevier B.V. All rights reserved.