Department of Sports Disciplines, Northern (Arctic) Federal University Named After M.V. Lomonosov, 163002, Severnaya Dvina embankment, 17, Arkhangelsk, Russia.
J Biomech. 2023 Mar;149:111486. doi: 10.1016/j.jbiomech.2023.111486. Epub 2023 Feb 10.
The research aimed at further improvement of the technology of measuring swimmers' active drag by the small perturbation method (SPM) at the average maximal swimming velocity (v). For better reliability and accuracy of measurements, a standard variant of SPM was developed to measure automatically active drag (F), dimensionless coefficient of hydrodynamic force (C) and total external mechanical power P in different competitive swimming techniques during a single 50 m trial. The study involved twelve elite swimmers who specialized in front crawl at the distances of 100 and 200 m (780-850 FINA Points). From our measurements, in front crawl the results are following: v = 1.909 ± 0.017 m·s, F = 106.892 ± 7.276 N, C = 0.311 ± 0.028 and P = 204.033 ± 13.221 W. For objective estimation of the results, a verification variant of SPM was applied: v = 1.911 ± 0.018 m·s, F = 107.033 ± 7.232 N, C = 0.311 ± 0.030 and P = 204.467 ± 12.982 W. The correlation analysis of the results obtained by the standard and verification variants of SPM confirms high accuracy and reliability of the method used (r = 0.988 for v; r = 0.979 for F; r = 0.988 for C; r = 0.979 for P). The measurement error, including the method error and the devices error, does not exceed 2.4 %. This method has also a systematic error that reduces the measured data in the same direction from the actual values (min = -2.1 %; max = -2.9 %). This error should be taken into account when analyzing and evaluating the measured hydrodynamic characteristics of swimmers.
本研究旨在通过小扰动量法（SPM）进一步改进测量游泳者在平均最大游泳速度（v）下主动阻力的技术。为了提高测量的可靠性和准确性，开发了一种标准的 SPM 变体，以在单次 50 米试验中测量不同竞技游泳技术的主动阻力（F）、流体动力力的无因次系数（C）和总外部机械功率 P。该研究涉及 12 名专门从事 100 米和 200 米（780-850 FINA 点）自由泳的精英游泳运动员。从我们的测量结果来看，在自由泳中，结果如下：v=1.909±0.017 m·s，F=106.892±7.276 N，C=0.311±0.028，P=204.033±13.221 W。为了客观评估结果，应用了 SPM 的验证变体：v=1.911±0.018 m·s，F=107.033±7.232 N，C=0.311±0.030，P=204.467±12.982 W。标准 SPM 变体和验证变体的结果相关性分析证实了所使用方法的高度准确性和可靠性（v 为 r=0.988；F 为 r=0.979；C 为 r=0.988；P 为 r=0.979）。测量误差包括方法误差和设备误差，不超过 2.4%。该方法还有系统误差，会导致测量数据向实际值的同一方向减小（最小值为-2.1%；最大值为-2.9%）。在分析和评估游泳者的测量流体动力特性时，应考虑到这一误差。
