Mr John McMahon J.J.McMahon@salford.ac.uk
Comparison of countermovement jump–derived reactive strength index modified and underpinning force-time variables between super league and championship rugby league players
McMahon, JJ; Jones, PA; Comfort, P
Authors
Mr Paul Jones P.A.Jones@salford.ac.uk
Associate Professor/Reader
Prof Paul Comfort P.Comfort@salford.ac.uk
Professor of Strength & Conditioning
Abstract
The countermovement jump (CMJ) is regularly tested in rugby league (RL), with recent work reporting reactive strength index modified (RSImod) to distinguish between levels of play. Differences in CMJ-derived RSImod and underpinning force-time variables between English Super League (SL) and RL Championship (RLC) players are, however, unknown. As SL and RLC teams compete against each other, this study addressed this knowledge gap. Sixty RL players from the English SL (n = 30) and RLC (n = 30) performed 3 CMJs on a force platform at the start of the preseason training. The RSImod was calculated by dividing jump height (JH) by time to take-off (TTT), and several other variables were also extracted from the force-time record. The SL players achieved a significantly higher (large effect) RSImod by performing the CMJ with a significantly shorter (large effect) TTT but a similar (small effect) JH. The SL players achieved the shorter TTT through a significantly reduced (large effects) relative displacement during both the countermovement (combined unweighting and braking displacement) and propulsion phases but a significantly higher (moderate effects) propulsion peak force and power. The relationships between TTT and relative countermovement (r = 0.719, p < 0.001) and propulsion (r = 0.771, p < 0.001) displacement for combined group data were very large. Practitioners working in RL should, therefore, consider reporting RSImod and TTT, alongside JH, after CMJ force-time testing. We also suggest that RL players who produce lower RSImod scores would benefit from being trained to produce larger CMJ propulsion forces over a shallower range of hip, knee, and ankle extension.
Citation
McMahon, J., Jones, P., & Comfort, P. (2019). Comparison of countermovement jump–derived reactive strength index modified and underpinning force-time variables between super league and championship rugby league players. Journal of Strength and Conditioning Research, https://doi.org/10.1519/JSC.0000000000003380
Journal Article Type | Article |
---|---|
Acceptance Date | Aug 3, 2019 |
Online Publication Date | Nov 7, 2019 |
Publication Date | Nov 7, 2019 |
Deposit Date | Dec 3, 2019 |
Publicly Available Date | Nov 7, 2020 |
Journal | Journal of Strength and Conditioning research |
Print ISSN | 1064-8011 |
Electronic ISSN | 1533-4287 |
Publisher | Lippincott, Williams & Wilkins |
DOI | https://doi.org/10.1519/JSC.0000000000003380 |
Publisher URL | https://doi.org/10.1519/JSC.0000000000003380 |
Related Public URLs | https://journals.lww.com/nsca-jscr/pages/default.aspx |
Files
ACCEPTED MANUSCRIPT.pdf
(415 Kb)
PDF
Licence
http://creativecommons.org/licenses/by-nc/4.0/
Publisher Licence URL
http://creativecommons.org/licenses/by-nc/4.0/
You might also like
Downloadable Citations
About USIR
Administrator e-mail: library-research@salford.ac.uk
This application uses the following open-source libraries:
SheetJS Community Edition
Apache License Version 2.0 (http://www.apache.org/licenses/)
PDF.js
Apache License Version 2.0 (http://www.apache.org/licenses/)
Font Awesome
SIL OFL 1.1 (http://scripts.sil.org/OFL)
MIT License (http://opensource.org/licenses/mit-license.html)
CC BY 3.0 ( http://creativecommons.org/licenses/by/3.0/)
Powered by Worktribe © 2024
Advanced Search