Schnitzler Christophe, Seifert Ludovic, Button Chris
Laboratory Equipe d'accueil en Sciences Sociales (E3S, UR1342), Faculté des Sciences du Sport, Université de Strasbourg, Strasbourg, France.
Cetaps EA3832, Faculty of Sport Sciences, University of Rouen, Normandie, France.
Front Sports Act Living. 2021 Apr 7;3:618990. doi: 10.3389/fspor.2021.618990. eCollection 2021.
The objectives of this study were to identify how spatiotemporal, kinetic, and kinematic parameters could (i) characterize swimmers' adaptability to different swimming speeds and (ii) discriminate expertise level among swimmers. Twenty male participants, grouped into (a) low-, (b) medium-, and (c) high-expertise levels, swam at four different swim paces of 70, 80, 90% (for 20 s), and 100% (for 10 s) of their maximal speed in a swimming flume. We hypothesized that (i) to swim faster, swimmers increase both propulsion time and the overall force impulse during a swimming cycle; (ii) in the frequency domain, expert swimmers are able to maintain the relative contribution of the main harmonics to the overall force spectrum. We used three underwater video cameras to derive stroking parameters [stroke rate (SR), stroke length (SL), stroke index (SI)]. Force sensors placed on the hands were used to compute kinetic parameters, in conjunction with video data. Parametric statistics examined speed and expertise effects. Results showed that swimmers shared similarities across expertise levels to increase swim speed: SR, the percentage of time devoted to propulsion within a cycle, and the index of coordination (IdC) increased significantly. In contrast, the force impulse ( ) generated by the hand during propulsion remained constant. Only the high-expertise group showed modification in the spectral content of its force distribution at high SR. Examination of stroking parameters showed that only high-expertise swimmers exhibited higher values of both SL and SI and that the low- and high-expertise groups exhibited similar IdC and even higher magnitude in . In conclusion, all swimmers exhibit adaptable behavior to change swim pace when required. However, high-skilled swimming is characterized by broader functional adaptation in force parameters.
本研究的目的是确定时空、动力学和运动学参数如何能够：（i）表征游泳者对不同游泳速度的适应性；（ii）区分游泳者的专业水平。20名男性参与者被分为（a）低、（b）中、（c）高专业水平三组，在游泳水槽中以其最大速度的70%、80%、90%（持续20秒）和100%（持续10秒）这四种不同的游泳速度进行游泳。我们假设：（i）为了游得更快，游泳者在一个游泳周期内会增加推进时间和总力冲量；（ii）在频域中，专业游泳者能够保持主要谐波对总力谱的相对贡献。我们使用三台水下摄像机来获取划水参数[划水频率（SR）、划水长度（SL）、划水指数（SI）]。放置在手上的力传感器与视频数据相结合，用于计算动力学参数。参数统计分析了速度和专业水平的影响。结果表明，不同专业水平的游泳者在提高游泳速度方面有相似之处：SR、一个周期内用于推进的时间百分比以及协调指数（IdC）均显著增加。相比之下，手部在推进过程中产生的力冲量（ ）保持不变。只有高专业水平组在高SR时其力分布的频谱内容有变化。对划水参数的检查表明，只有高专业水平的游泳者SL和SI值更高，且低专业水平组和高专业水平组的IdC相似，并且 中的幅度甚至更高。总之，所有游泳者在需要时都表现出适应改变游泳速度的行为。然而，高水平游泳的特点是在力参数方面有更广泛的功能适应性。
