The intraday reliability of the reactive strength index calculated from a drop jump in professional men's basketball
Abstract
Purpose: To evaluate the reliability of the Reactive Strength Index (RSI) and jump-height (JH) performance from multiple drop heights in an elite population. Methods: Thirteen professional basketball players (mean ±SD age 25.8 ± 3.5 y, height 1.96 ± 0.07 m, mass 94.8 ± 8.2 kg) completed 3 maximal drop-jump attempts onto a jump mat at 4 randomly assigned box heights and 3 countermovement-jump trials. Results: No statistical difference was observed between 3 trials for both the RSI and JH variable at all the tested drop heights. The RSI for drop-jump heights from 20 cm resulted in a coefficient of variation (CV) = 3.1% and an intraclass correlation (ICC α) = .96, 40 cm resulted in a CV = 3.0% and an ICC α = .95, and 50 cm resulted in a CV = 2.1% and an ICC α = .99. The JH variable at the 40-cm drop-jump height resulted in the highest reliability CV = 2.8% and an ICC α = .98. Conclusion: When assessing the RSI the 20-, 40-, and 50-cm drop heights are recommended with this population. When assessing large groups it appears that only 1 trial is required when assessing the RSI variable from the 20, 40-, and 50-cm drop heights.
Document Type
Journal Article
Date of Publication
2015
Publisher
Human Kinetics Publishers Inc.
School
Centre for Exercise and Sport Science Research
RAS ID
20438
Copyright
subscription content
Comments
Markwick, W.J., Bird, S.P., Tufano, J.J., Seitz, L.B., Haff, G.G. (2015). The intraday reliability of the reactive strength index calculated from a drop jump in professional men's basketball in International Journal of Sports Physiology and Performance, 10(4), 482-488. Available here.