The Modified Reactive Strength Index Is a Valid Measure of Lower-Body Explosiveness in Male and Female High School Athletes.

Autor:	Witte BC; Doctor of Physical Therapy Program, College of Health Professions, Trine University, Fort Wayne, Indiana., Schouten TC; Doctor of Physical Therapy Program, College of Health Professions, Trine University, Fort Wayne, Indiana., Westphal JA; Doctor of Physical Therapy Program, College of Health Professions, Trine University, Fort Wayne, Indiana., VanZile AW; Optimum Performance Therapy, Fort Wayne, Indiana., Jones DD; Carroll High School, Fort Wayne, Indiana., Widenhoefer TL; Doctor of Physical Therapy Program, College of Health Professions, Trine University, Fort Wayne, Indiana., Dobbs WC; Exercise & Sport Science Program, College of Science and Health, University of Wisconsin-La Crosse, La Crosse, Wisconsin; and., Jagim AR; Sports Medicine, Mayo Clinic Health System, La Crosse, Wisconsin., Luedke JA; Sports Medicine, Mayo Clinic Health System, La Crosse, Wisconsin., Almonroeder TG; Doctor of Physical Therapy Program, College of Health Professions, Trine University, Fort Wayne, Indiana.
Jazyk:	angličtina
Zdroj:	Journal of strength and conditioning research [J Strength Cond Res] 2024 Aug 01; Vol. 38 (8), pp. 1428-1432. Date of Electronic Publication: 2024 Apr 25.
DOI:	10.1519/JSC.0000000000004806
Abstrakt:	Abstract: 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. (Copyright © 2024 National Strength and Conditioning Association.)
Databáze:	MEDLINE
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