Formosa Daniel P, Toussaint Huub M, Mason Bruce R, Burkett Brendan
Australian Institute of Sport, Canberra, Australia.
J Appl Biomech. 2012 Dec;28(6):746-50. doi: 10.1123/jab.28.6.746. Epub 2012 May 9.
The measurement of active drag in swimming is a biomechanical challenge. This research compared two systems: (i) measuring active drag (MAD) and (ii) assisted towing method (ATM). Nine intermediate-level swimmers (19.7 ± 4.4 years) completed front crawl trials with both systems during one session. The mean (95% confidence interval) active drag for the two systems, at the same maximum speed of 1.68 m/s (1.40-1.87 m/s), was significantly different (p = .002) with a 55% variation in magnitude. The mean active drag was 82.3 N (74.0-90.6 N) for the MAD system and 148.3 N (127.5-169.1 N) for the ATM system. These differences were attributed to variations in swimming style within each measurement system. The inability to measure the early catch phase and kick, along with the fixed length and depth hand place requirement within the MAD system generated a different swimming technique, when compared with the more natural free swimming ATM protocol. A benefit of the MAD system was the measurement of active drag at various speeds. Conversely, the fixed towing speed of the ATM system allowed a natural self-selected arm stroke (plus kick) and the generation of an instantaneous force-time profile.
测量游泳中的主动阻力是一项生物力学挑战。本研究比较了两种系统：（i）主动阻力测量系统（MAD）和（ii）辅助拖曳法（ATM）。九名中级水平游泳者（19.7±4.4岁）在一次训练中使用这两种系统完成了自由泳试验。在相同的最大速度1.68米/秒（1.40 - 1.87米/秒）下，两种系统的平均（95%置信区间）主动阻力显著不同（p = 0.002），大小差异为55%。MAD系统的平均主动阻力为82.3牛（74.0 - 90.6牛），ATM系统为148.3牛（127.5 - 169.1牛）。这些差异归因于每个测量系统内游泳风格的变化。与更自然的自由泳ATM方案相比，MAD系统无法测量早期抓水阶段和踢水动作，以及其固定的手臂入水长度和深度要求，导致了不同的游泳技术。MAD系统的一个优点是能够测量不同速度下的主动阻力。相反，ATM系统的固定拖曳速度允许自然的自选手臂划水（加上踢水）并生成瞬时力-时间曲线。
