Doctor of Physical Therapy Program, College of Health Professions, Trine University, Fort Wayne, Indiana.
Optimum Performance Therapy, Fort Wayne, Indiana.
J Strength Cond Res. 2024 Aug 1;38(8):1428-1432. doi: 10.1519/JSC.0000000000004806. Epub 2024 Apr 25.
Witte, BC, Schouten, TC, Westphal, JA, VanZile, AW, Jones, DD, Widenhoefer, TL, Dobbs, WC, Jagim, AR, Luedke, JA, and Almonroeder, TG. The modified reactive strength index is a valid measure of lower-body explosiveness in male and female high school athletes. J Strength Cond Res 38(8): 1428-1432, 2024-The modified reactive strength index (mRSI) is a commonly used metric to quantify lower-body explosiveness during countermovement jump (CMJ) performance. However, few studies have attempted to examine its validity as a measure of explosiveness, particularly among high school athletes. The purpose of this study was to examine the validity of the mRSI as a measure of lower-body explosiveness among a relatively large sample of male and female high school athletes from various sports. As part of this study, male ( n = 132) and female ( n = 43) high school athletes performed CMJs, while ground reaction forces were recorded using a force platform. The vertical ground reaction force data collected during the CMJs were used to derive the following variables: peak force (PF), peak power, time to PF, time to take-off, peak rate of force development, and the mRSI. Principal component analysis was applied and reduced these variables into 2 components related to "force" and "speed." The mRSI loaded on both the force (loading = 0.82) and speed (loading = -0.46) components, indicating that it incorporates elements of both force and speed, although it loaded more strongly on the force component than the speed component. The observed pattern of cross-loading suggests that the mRSI is generally a valid measure of lower-body explosiveness for male and female high school athletes.
威特，BC，舒滕，TC，韦斯特法尔，JA，范泽尔，AW，琼斯，DD，威登霍弗，TL，多布斯，WC，贾吉姆，AR，卢德克，JA，和阿尔莫罗德，TG。改良反应强度指数是衡量男性和女性高中生运动员下肢爆发力的有效指标。J 力量与调节研究 38（8）：1428-1432，2024-改良反应强度指数（mRSI）是一种常用的指标，用于量化在反跳（CMJ）表现中下肢爆发力。然而，很少有研究试图检验其作为爆发力测量指标的有效性，特别是在高中生运动员中。本研究的目的是检验 mRSI 在各种运动的大量男性和女性高中生运动员中作为衡量下肢爆发力的有效性。作为本研究的一部分，男性（n=132）和女性（n=43）高中生运动员进行了 CMJ，同时使用力台记录地面反作用力。从 CMJ 中收集的垂直地面反作用力数据用于得出以下变量：峰值力（PF）、峰值功率、到达 PF 的时间、离地时间、峰值力发展率和 mRSI。应用主成分分析并将这些变量简化为与“力”和“速度”相关的 2 个分量。mRSI 加载在力（加载=0.82）和速度（加载=-0.46）分量上，表明它包含力和速度两个元素，尽管它在力分量上的加载比速度分量上更强。观察到的交叉加载模式表明，mRSI 通常是衡量男性和女性高中生运动员下肢爆发力的有效指标。
