Kinesiology, Vol. 56 No. 2, 2024.
Original scientific paper
https://doi.org/10.26582/k.56.2.2
A reliability and kinetic analysis of the 10/5 repeated jump and drop jump tests to determine the use of a novel teactive strength measure: The reactive quality ratio
Benjamin M. Southey
; School of Human Movements and Nutrition Science, The University of Queensland, St Lucia, Queensland, Australia; Brisbane Lions Australian Football Club, Springfield, Queensland, Australia
Mark J. Connick
; School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
Dirk R. Spits
; Tennis Australia, Tennyson, Queensland, Australia
Damien J. Austin
; Brisbane Lions Australian Football Club, Springfield, Queensland, Australia
Emma M. Beckman
; School of Human Movements and Nutrition Science, The University of Queensland, St Lucia, Queensland, Australia
Abstract
The stretch-shortening cycle (SSC) plays an important role in locomotion, and tests such as the drop jump (DJ) and 10/5 repeated jump (RJ) are commonly used to determine this through the measure of reactive strength index (RSI). With an understanding that these tests emphasize different jump intensities and strategies, a novel measure called the reactive quality ratio (RQR) has been proposed to determine whether an individual is more dominant in RJ or DJ tasks. Furthermore, comparison of kinetic and temporal outputs of both tests were made during the RQR protocol. Therefore, twenty-four professional Australian footballers completed two testing sessions comprising of both the RJ and DJ test. Results indicated that whilst there was no significant difference in RSI output between RJ and DJ tests respectively (2.52±0.43 vs 2.46±0.38), there were several significant differences in underlying kinetic variables: ground contact time (180±25 vs 209±30ms), flight time (444±53 vs 500±39ms), impulse (524±67 vs 721±69 Ns), average force (2924±363 vs 2624±294N), landing RFD (73226±20555 vs 88159±35922N/s) and active stiffness (43852±11549 vs 32309±12006N/m). Additionally, good levels of reliability were found for RQR (ICC=0.76, CV=2.96%) indicating that this novel measure can be used to determine preferred jump strategy for individuals. Overall, this study confirms underlying differences between RJ and DJ tests.
Keywords
reactive strength index; biomechanics; strength profiling; jump profiling
Hrčak ID:
322177
URI
Publication date:
31.12.2024.
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