Faculty of Science and Technology, London Sport Institute, Middlesex University , London, UK.
Department of Sport Science and Research, Nucleus of High Performance in Sport , Sao Paulo, Brazil.
J Sports Sci. 2020 Jun-Jun;38(11-12):1296-1303. doi: 10.1080/02640414.2019.1649525. Epub 2019 Jul 29.
The aims of the present study were to provide an in-depth comparison of inter-limb asymmetry and determine how consistently asymmetry favours the same limb during different vertical jump tests. Eighteen elite female under-17 soccer players conducted unilateral squat jumps (SJ), countermovement jumps (CMJ) and drop jumps (DJ) on a portable force platform, with jump height, peak force, concentric impulse and peak power as common metrics across tests. For the magnitude of asymmetry, concentric impulse was significantly greater during the SJ test compared to CMJ ( = 0.019) and DJ ( = 0.003). No other significant differences in magnitude were present. For the direction of asymmetry, Kappa coefficients revealed fair to substantial levels of agreement between the SJ and CMJ (Kappa = 0.35 to 0.61) tests, but only slight to fair levels of agreement between the SJ and DJ (Kappa = -0.26 to 0.18) and CMJ and DJ (Kappa = -0.13 to 0.26) tests. These results highlight that the mean asymmetry value may be a poor indicator of true variability of between-limb differences in healthy athletes. The direction of asymmetry may provide a useful monitoring tool for practitioners in healthy athletes, when no obvious between-limb deficit exists.
本研究的目的是深入比较四肢不对称，并确定在不同的垂直跳跃测试中，不对称性如何一致地有利于同一肢体。18 名优秀的 17 岁以下女子足球运动员在便携式力量平台上进行了单侧深蹲跳（SJ）、反向跳跃（CMJ）和跳落（DJ），以跳高技术、峰值力、向心冲量和峰值功率作为各测试的常用指标。对于不对称的幅度，SJ 测试中的向心冲量明显大于 CMJ（=0.019）和 DJ（=0.003）。没有其他显著的幅度差异。对于不对称的方向，SJ 和 CMJ 测试之间的 Kappa 系数显示出相当程度的一致性（Kappa=0.35 至 0.61），但 SJ 和 DJ 测试之间的一致性只有轻微到相当程度（Kappa=-0.26 至 0.18），CMJ 和 DJ 测试之间的一致性也是如此（Kappa=-0.13 至 0.26）。这些结果表明，平均不对称值可能是健康运动员四肢间差异真实变异性的不良指标。当不存在明显的肢体缺陷时，不对称的方向可能为健康运动员的从业者提供有用的监测工具。
