Intersession and Intrasession Reliability and Validity of the My Jump App for Measuring Different Jump Actions in Trained Male and Female Athletes

Abstract

Gallardo-Fuentes, F, Gallardo-Fuentes, J, Ramírez-Campillo, R, Balsalobre-Fernández, C, Martínez, C, Caniuqueo, A, Cañas, R, Banzer, W, Loturco, I, Nakamura, FY, and Izquierdo, M. Intersession and intrasession reliability and validity of the My Jump app for measuring different jump actions in trained male and female athletes. J Strength Cond Res 30(7): 2049-2056, 2016-The purpose of this study was to analyze the concurrent validity and reliability of the iPhone app named My Jump for measuring jump height in 40-cm drop jumps (DJs), countermovement jumps (CMJs), and squat jumps (SJs). To do this, 21 male and female athletes (age, 22.1 ± 3.6 years) completed 5 maximal DJs, CMJs, and SJs on 2 separate days, which were evaluated using a contact platform and the app My Jump, developed to calculate jump height from flight time using the high-speed video recording facility on the iPhone. A total of 630 jumps were compared using the intraclass correlation coefficient (ICC), Bland-Altman plots, Pearson's product moment correlation coefficient (r), Cronbach's alpha (α), and coefficient of variation (CV). There was almost perfect agreement between the measurement instruments for all jump height values (ICC = 0.97-0.99), with no differences between the instruments (p > 0.05; mean difference of 0.2 cm). Almost perfect correlation was observed between the measurement instruments for SJs, CMJs, and DJs (r = 0.96-0.99). My Jump showed very good within-subject reliability (α = 0.94-0.99; CV = 3.8-7.6) and interday reliability (r = 0.86-0.95) for SJs, CMJs, and DJs in all subjects. Therefore, the iPhone app named My Jump provides reliable intersession and intrasession data, as well as valid measurements for maximal jump height during fast (i.e., DJs) and slow (i.e., CMJs) stretch-shortening cycle muscle actions, and during concentric-only explosive muscle actions (i.e., SJs), in both male and female athletes in comparison with a professional contact platform.

Assessing the Validity of the MyJump2 App for Measuring Different Jumps in Professional Cerebral Palsy Football Players: An Experimental Study (Preprint)

“…Our results are in agreement with two other studies that investigated the MyJump TM reproducibility in vertical jumps [14,15]. For example, Balsalobre-Fernandez et al [15] evaluated the app's validity to assess CMJ jump in 20 recreationally active healthy men compared to a force platform.…”

“…A sample size calculation from an earlier investigation indicated that 7 participants would be needed, considering a P = .001 and a power of 90% [14]. Thus, for this study, 40 male athletes (28.1 ± 1.4 y, 72.5 ± 6.2 kg and 176 ± 4.2 cm) without presenting acute or chronic conditions that prevented them from performing the jump protocol were included.…”

“…It is important to note that the reference method used by Balsalobre-Fernandez et al [15] is a more precise method, compared with a contact mat that we have used in this study. The other study on the theme [14] has analysed different jumps (drop jump, SJ and CMJ) in a sample of 21 male and female athletes, and the authors compared the app with a contact platform and a high speed video camera method. In all jumps, there was a strong and significant correlation between the instruments.…”

“…Given the portability and practicality of MyJump2™, smartphones can quickly become a standard method for assessing physical performance in the field with great precision in CP Football. The comparison between MyJump2 TM and other methods, such as force platforms [14][15][16] and the field method (Vertec) [25], is important to consolidate the app. This is justified by the use of few force platforms in field evaluations, which raises the importance of the comparison between MyJump2 TM and other field methods [25].…”

“…In this sense, the MyJump2 TM app becomes a viable option that evaluates the height of the jump. This app provides the data acquisition quickly and immediately, allowing easy monitoring in almost any environment [13], with a high reliability and reproducibility in vertical jumps [14][15][16]. However, it is necessary to validate this app in different populations and sports, which justifies the present study that aims to evaluate the reliability of the measures of the MyJump2™ app to assess vertical jumps in professional CP Football.…”