Chollet Didier, Seifert Ludovic M, Carter Melwyn
Faculty of Sports Sciences, University of Rouen, Mont Saint Aignan, France.
J Sports Sci. 2008 May;26(7):675-82. doi: 10.1080/02640410701787791.
In this study, we assessed arm coordination in the backstroke over increasing speeds by adapting the index of coordination originally used in the front crawl. Fourteen elite male backstroke swimmers swam four trials of 25 m at the speeds corresponding to the 400-m, 200-m, 100-m, and 50-m events. The six phases of the arm stroke were identified by video analysis and then used to calculate the index of coordination, which corresponded to the time between the propulsive phases of the two arms. With increases in speed, the elite swimmers increased the stroke rate, the relative duration of their arm pull, and their index of coordination, and decreased the distance per stroke (P < 0.05). Arm coordination was always in catch-up (index of coordination of -12.9%) because the alternating body-roll and the small shoulder flexibility did not allow the opposition or superposition coordination seen in the front crawl. This new method also quantified the relative duration of the hand's lag time at the thigh, which did not change ( approximately 2%) with increasing speed for the elite swimmers. The index of coordination enables coaches to assess mistakes in backstroke coordination, particularly in the hand's lag time at the thigh.
在本研究中，我们通过采用最初用于自由泳的协调性指标，评估了仰泳在不同速度下的手臂协调性。14名精英男子仰泳运动员以对应400米、200米、100米和50米项目的速度进行了4次25米的试游。通过视频分析确定划水的六个阶段，然后用于计算协调性指标，该指标对应于两臂推进阶段之间的时间。随着速度增加，精英游泳运动员提高了划水频率、手臂划水的相对持续时间以及协调性指标，并减小了每划水的距离（P<0.05）。手臂协调性始终处于追赶状态（协调性指标为-12.9%），因为交替的身体转动和较小的肩部灵活性不允许出现自由泳中可见的对抗或叠加协调性。这种新方法还量化了手部在大腿处滞后时间的相对持续时间，对于精英游泳运动员来说，该时间不会随着速度增加而改变（约2%）。协调性指标使教练能够评估仰泳协调性方面的失误，尤其是手部在大腿处的滞后时间。
