Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan.
Institute for Sport, Physical Education & Health Sciences, The University of Edinburgh, Edinburgh, Scotland, UK.
Eur J Appl Physiol. 2018 Jun;118(6):1107-1118. doi: 10.1007/s00421-018-3841-z. Epub 2018 Mar 19.
The purpose of this study was to determine kinematic and energetic differences between front crawl and backstroke performed at the same aerobic speeds.
Ten male competitive swimmers performed front crawl and backstroke at a pre-determined sub-anaerobic threshold speed to assess energy cost (through oxygen uptake measurement) and kinematics (using three-dimensional videography to determine stroke frequency and length, intra-cycle velocity fluctuation, three-dimensional wrist and ankle speeds, and vertical and lateral ankle range of motion). For detailed kinematic analysis, resultant displacement, the duration, and three-dimensional speed of the wrist during the entry, pull, push, and release phases were also investigated.
There were no differences in stroke frequency/length and intra-cycle velocity fluctuation between the swimming techniques, however, swimmers had lower energy cost in front crawl than in backstroke (0.77 ± 0.08 vs 0.91 ± 0.12 kJ m, p < 0.01). Slower three-dimensional wrist and ankle speeds under the water (1.29 ± 0.10 vs 1.55 ± 0.10 and 0.80 ± 0.16 vs 0.97 ± 0.13 m s, both p < 0.01) and smaller ankle vertical range of motion (0.36 ± 0.06 vs 0.47 ± 0.07 m, p < 0.01) in front crawl than in backstroke were also observed, which indirectly suggested higher propulsive efficiency in front crawl.
Front crawl is less costly than backstroke, and limbs motion in front crawl is more effective than in backstroke.
本研究旨在确定以相同有氧速度进行的自由泳和仰泳的运动学和能量差异。
10 名男性竞技游泳运动员以预定的亚无氧阈速度进行自由泳和仰泳，以评估能量消耗（通过耗氧量测量）和运动学（使用三维录像确定划频和划长、周期内速度波动、三维腕关节和踝关节速度以及垂直和侧向踝关节活动范围）。为了进行详细的运动学分析，还研究了入水、划水、推水和出水阶段的手腕总位移、持续时间和三维速度。
两种泳姿的划频/划长和周期内速度波动没有差异，但自由泳的能量消耗低于仰泳（0.77±0.08 比 0.91±0.12 kJ·m，p<0.01）。水下的三维腕关节和踝关节速度较慢（1.29±0.10 比 1.55±0.10 和 0.80±0.16 比 0.97±0.13 m·s，均 p<0.01），踝关节垂直活动范围较小（0.36±0.06 比 0.47±0.07 m，p<0.01），这间接表明自由泳的推进效率更高。
自由泳比仰泳成本更低，而且自由泳的肢体动作比仰泳更有效。
