Countermovement jump phase characteristics of senior and academy rugby league players

McMahon, JJ; Murphy, S; Rej, SJE; Comfort, P

Abstract

Purpose:

Gross measures of countermovement jump (CMJ) performance are commonly used to track maturational changes in neuromuscular function within rugby league (RL). The purpose of this study was to conduct both a gross and a more detailed temporal phase analysis of the CMJ performances of senior and academy RL players, to provide greater insight into how neuromuscular function differs between these groups.


Methods:

Twenty senior and fourteen academy (under-19) male RL players performed three maximal effort CMJs on a force platform with forward dynamics subsequently employed to allow gross performance measures and entire kinetic and kinematic-time curves to be compared between groups.


Results:

Jump height (JH), reactive strength index modified, concentric displacement, and relative concentric impulse (C-IMP) were the only gross measures that were greater for senior players (d = 0.58-0.91) compared to academy RL players. The relative force- and displacement-time curves were similar between groups, but the relative power- and velocity-time curves were greater (d = 0.59-0.97) for the senior players at 94-96% and 89-100% of the total movement time, respectively.


Conclusions:

The CMJ distinguished between senior and academy RL players, with seniors demonstrating greater JH through applying a larger C-IMP and thus achieving greater velocity throughout the majority of the concentric phase and at take-off. Therefore, academy RL players should train to improve triple (i.e. ankle, knee and hip) extension velocity during the CMJ in order to bring their jump height scores in line with those attained by senior players.

Citation

McMahon, J., Murphy, S., Rej, S., & Comfort, P. (2017). Countermovement jump phase characteristics of senior and academy rugby league players. International Journal of Sports Physiology and Performance, 12(6), 803-811. https://doi.org/10.1123/ijspp.2016-0467

• Journal Article Type: Article
• Acceptance Date: Oct 17, 2016
• Publication Date: Jul 1, 2017
• Deposit Date: Jan 12, 2017
• Publicly Available Date: Jan 12, 2017
• Journal: International Journal of Sports Physiology and Performance
• Print ISSN: 1555-0265
• Electronic ISSN: 1555-0273
• Publisher: Human Kinetics
• Volume: 12
• Issue: 6
• Pages: 803-811
• DOI: https://doi.org/10.1123/ijspp.2016-0467
• Publisher URL: http://dx.doi.org/10.1123/ijspp.2016-0467
• Related Public URLs: http://journals.humankinetics.com/journal/ijspp