The validity and reliability of the my jump 2 app for measuring the reactive strength index and drop jump performance

Haynes, Thomas, Bishop, Chris ORCID: https://orcid.org/0000-0002-1505-1287, Antrobus, Mark and Brazier, Jon (2019) The validity and reliability of the my jump 2 app for measuring the reactive strength index and drop jump performance. The Journal of Sports Medicine and Physical Fitness, 59 (2) . pp. 253-258. ISSN 0022-4707 [Article] (doi:10.23736/S0022-4707.18.08195-1)

[img]
Preview
PDF - Final accepted version (with author's formatting)
Download (331kB) | Preview

Abstract

BACKGROUNDː This is the first study to independently assess the concurrent validity and reliability of the My Jump 2 app for measuring drop jump performance. It is also the first to evaluate the app’s ability to measure the reactive strength index (RSI).

METHODSː Fourteen male sport science students (age: 29.5 ± 9.9 years) performed three drop jumps from 20 cm and 40 cm (totalling 84 jumps), assessed via a force platform and the My Jump 2 app. Reported metrics included reactive strength index, jump height, ground contact time, and mean power. Measurements from both devices were compared using the intraclass correlation coefficient (ICC), Pearson product moment correlation coefficient (r), Cronbach’s alpha (α), coefficient of variation (CV) and Bland-Altman plots.

RESULTSː Near perfect agreement was seen between devices at 20 cm for RSI (ICC = 0.95) and contact time (ICC = 0.99) and at 40 cm for RSI (ICC = 0.98), jump height (ICC = 0.96) and contact time (ICC = 0.92); with very strong agreement seen at 20 cm for jump height (ICC = 0.80). In comparison with the force plate the app showed good validity for RSI (20 cm: r = 0.94; 40 cm; r = 0.97), jump height (20 cm: r = 0.80; 40 cm; r = 0.96) and contact time (20 cm = 0.96; 40 cm; r = 0.98).

CONCLUSIONSː The results of the present study show that the My Jump 2 app is a valid and reliable tool for assessing drop jump performance.

Item Type: Article
Research Areas: A. > School of Science and Technology > London Sport Institute > Strength and Conditioning at the London Sport Institute
Item ID: 23570
Notes on copyright: This is a postprint version of the article published in The Journal of Sports Medicine and Physical Fitness. This version is free to view and download to private research and study only. Not for redistribution or re-use. ©Edizioni Minerva Medica. The final published article is available online on Minerva Medica website at https://doi.org/10.23736/S0022-4707.18.08195-1. Cite this article as Haynes T, Bishop C, Antrobus M, Brazier J. The validity and reliability of the My Jump 2 app for measuring the reactive strength index and drop jump performance. J Sports Med Phys Fitness 2019;59:253-8. DOI: 10.23736/S0022-4707.18.08195-1
Useful Links:
Depositing User: Chris Bishop
Date Deposited: 19 Feb 2018 12:28
Last Modified: 09 Jun 2021 18:49
URI: https://eprints.mdx.ac.uk/id/eprint/23570

Actions (login required)

View Item View Item

Statistics

Downloads
Activity Overview
527Downloads
620Hits

Additional statistics are available via IRStats2.