Concurrent validity of a portable force plate using vertical jump force-time characteristics

Lake, J, Mundy, P, Comfort, P ORCID:, McMahon, JJ ORCID:, Suchomel, TJ and Carden, P 2018, 'Concurrent validity of a portable force plate using vertical jump force-time characteristics' , Journal of Applied Biomechanics, 34 (5) , pp. 410-413.

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This study examined concurrent validity of countermovement vertical jump (CMJ) reactive strength index modified and force-time characteristics recorded using a one dimensional portable and laboratory force plate system. Twenty-eight men performed bilateral CMJs on two portable force plates placed on top of two in-ground force plates, both recording vertical ground reaction force at 1000 Hz. Time to take-off, jump height, reactive strength index modified, braking and propulsion impulse, mean net force, and duration were calculated from the vertical force from both force plate systems. Results from both systems were highly correlated (r≥.99). There were small (d<.12) but significant differences between their respective braking impulse, braking mean net force, propulsion impulse, and propulsion mean net force (p<.001). However, limits of agreement yielded a mean value of 1.7% relative to the laboratory force plate system (95% CL: .9% to 2.5%), indicating very good agreement across all of the dependent variables. The largest limits of agreement belonged to jump height (2.1%), time to take-off (3.4%), and reactive strength index modified (3.8%). The portable force plate system provides a valid method of obtaining reactive strength measures, and several underpinning force-time variables, from unloaded CMJ and practitioners can use both force plates interchangeably.

Item Type: Article
Schools: Schools > School of Health and Society > Centre for Health Sciences Research
Journal or Publication Title: Journal of Applied Biomechanics
Publisher: Human Kinetics
ISSN: 1543-2688
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SWORD Depositor: Publications Router
Depositing User: Publications Router
Date Deposited: 24 Aug 2018 09:42
Last Modified: 27 Aug 2021 21:10

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