Exell T, Irwin G, Gittoes M, Kerwin D
Department of Sport and Exercise Science, University of Portsmouth, Portsmouth, UK.
Cardiff School of Sport, Cardiff Metropolitan University, Cardiff, UK.
Scand J Med Sci Sports. 2017 Nov;27(11):1273-1282. doi: 10.1111/sms.12759. Epub 2016 Sep 27.
The aim of this study was to empirically examine the interaction of athlete-specific kinematic kinetic and strength asymmetry in sprint running. Bilateral ground reaction force and kinematic data were collected during maximal velocity (mean = 9.05 m/s) sprinting for eight athletes. Bilateral ground reaction force data were also collected while the same athletes performed maximal effort squat jumps. Using novel composite asymmetry scores, interactions between kinematic and kinetic asymmetry were compared for the group of sprinters. Asymmetry was greater for kinematic variables than step characteristics, with largest respective values of 6.68% and 1.68%. Kinetic variables contained the largest asymmetry values, peaking at >90%. Asymmetry was present in all kinematic and kinetic variables analyzed during sprint trials. However, individual athlete asymmetry profiles were reported for sprint and jump trials. Athletes' sprint performance was not related to their overall asymmetry. Positive relationships were found between asymmetry in ankle work during sprint running and peak vertical force (r = 0.895) and power (r = 0.761) during jump trials, suggesting that the ankle joint may be key in regulating asymmetry in sprinting and highlighting the individual nature of asymmetry. The individual athlete asymmetry profiles and lack of relationship between asymmetry of limb strength and sprint performance suggest that athletes are not "limb dominant" and that strength imbalances are joint and task specific. Compensatory kinetic mechanisms may serve to reduce the effects of strength or biological asymmetry on the performance outcome of step velocity.
本研究的目的是通过实证研究短跑过程中运动员特定的运动学、动力学和力量不对称性之间的相互作用。在8名运动员以最大速度(平均 = 9.05米/秒)冲刺时收集双侧地面反作用力和运动学数据。在同组运动员进行最大强度深蹲跳时也收集双侧地面反作用力数据。使用新颖的综合不对称分数,比较短跑运动员组运动学和动力学不对称之间的相互作用。运动学变量的不对称性大于步幅特征,其各自的最大值分别为6.68%和1.68%。动力学变量的不对称值最大,峰值超过90%。在冲刺试验期间分析的所有运动学和动力学变量中均存在不对称性。然而,报告了短跑和跳跃试验中个体运动员的不对称情况。运动员的短跑成绩与他们的整体不对称性无关。在短跑过程中踝关节做功的不对称性与跳跃试验中的垂直力峰值(r = 0.895)和功率(r = 0.761)之间发现了正相关关系,这表明踝关节可能是调节短跑不对称性的关键,并突出了不对称性的个体特性。个体运动员的不对称情况以及肢体力量不对称与短跑成绩之间缺乏相关性表明,运动员并非“肢体主导型”,力量不平衡是关节和任务特异性的。代偿性动力学机制可能有助于减少力量或生物不对称性对步速表现结果的影响。