Within-subject consistency of unimodal and bimodal force application during the countermovement jump

Lake, JP and McMahon, JJ ORCID: https://orcid.org/0000-0001-9952-7846 2018, 'Within-subject consistency of unimodal and bimodal force application during the countermovement jump' , Sports, 6 (4) , p. 143.

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Countermovement jump (CMJ) force data are often time-normalized so researchers and practitioners can study the effect that sex, training status, and training intervention have on CMJ strategy: the so-called force⁻time curve shape. Data are often collected on an individual basis and then averaged across interest-groups. However, little is known about the agreement of the CMJ force⁻time curve shape within-subject, and this formed the aim of this study. Fifteen men performed 10 CMJs on in-ground force plates. The resulting force⁻time curves were plotted, with their shape categorized as exhibiting either a single peak (unimodal) or a double peak (bimodal). Percentage-agreement and the kappa-coefficient were used to assess within-subject agreement. Over two and three trials, 13% demonstrated a unimodal shape, 67% exhibited a bimodal shape, and 20% were inconsistent. When five trials were considered, the unimodal shape was not demonstrated consistently; 67% demonstrated a bimodal shape, and 33% were inconsistent. Over 10 trials, none demonstrated a unimodal shape, 60% demonstrated a bimodal shape, and 40% were inconsistent. The results of this study suggest that researchers and practitioners should ensure within-subject consistency before group averaging CMJ force⁻time data, to avoid errors.

Item Type: Article
Schools: Schools > School of Health and Society > Centre for Health Sciences Research
Journal or Publication Title: Sports
Publisher: MDPI
ISSN: 2075-4663
SWORD Depositor: Publications Router
Depositing User: Publications Router
Date Deposited: 26 Nov 2018 10:34
Last Modified: 16 Feb 2022 00:20
URI: http://usir.salford.ac.uk/id/eprint/49044

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