Reliability of bilateral and shear components in a two-legged counter-movement jump
Reliability of bilateral and shear components in a two-legged counter-movement jump
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DOI：
10.1177/1754337121995967
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发表时间：
2021-02-21
影响因子：
1.5
通讯作者：
West, Andrew
中科院分区：
文献类型：
--
作者：
Gordon, David;Hayward, Steven;West, Andrew
力量不对称可能对运动员的表现不利，并可能导致受伤。反向运动跳跃（CMJ）可用于通过剪切力产生来测量强度不对称性。以15名大学生短跑和跳高运动员（m = 11，f = 4）为研究对象，分析了参数的可靠性以及不对称性和剪切力对CMJ垂直运动性能的影响。运动员在两个场合进行了三次CMJ，间隔一周。三轴地面反作用力（GRF）记录使用两个力平台嵌入在定制的重量训练区。实时计算关键性能指标，描述总CMJ性能、不对称性和剪切力产生。平均值和变异系数（CV）的变化用于表示可靠性。来自总分析的26个参数和21个不对称分析参数显示CV低于10%。描述不对称分析的时间和动力学变量与来自总分析的等效参数相比突出显示了较低的CV。与全分析和不对称分析相比，剪切参数显示出高水平的CV。使用本工作中描述的方法计算的不对称性的措施被证明是可靠的监测CMJ性能。在CMJ中，不对称性或剪切力的测量与传统的性能指标（例如跳跃高度、特定峰值功率和峰值力）之间没有发现显著的负相关关系。需要进一步的工作，以确定潜在的减少不对称CMJ性能。
Strength asymmetry can be detrimental to athlete performance and may lead to injury. The countermovement jump (CMJ) can be used to measure strength asymmetry via shear force production. The reliability of parameters and effects of asymmetry and shear force production on vertical CMJ performance were evaluated in a study with 15 university-level sprint and high jump athletes (m = 11, f = 4). The athletes performed three CMJs on two occasions, separated by 1 week. Tri-axial ground reaction force (GRF) was recorded using two force platforms embedded within a bespoke weight training area. Key performance metrics were calculated in real-time describing total CMJ performance, asymmetry and shear force production. Changes in the means and coefficients of variation (CV) were used to express reliability. Twenty-six parameters from the Total analysis and 21 Asymmetry analysis parameters showed a CV lower than 10%. Temporal and kinetic variables describing Asymmetry analysis highlight a lower CV compared with equivalent parameters derived from Total analysis. Shear parameters show high levels of CV compared with Total analysis and Asymmetry analysis. The measures of asymmetry calculated using methods described in this work were shown to be reliable for monitoring CMJ performance. No significant negative relationships were found between measures of asymmetry or shear force and traditional performance metrics in the CMJ (e.g. jump height, specific peak power and peak force). Further work is required to identify the potential of reducing asymmetry on CMJ performance.