Agreement Between a Vertec Device and Smartphone Applications for Measuring Vertical Jump Height

Accurate assessment of countermovement jump (CMJ) height is important for evaluating lower-body power and monitoring athletic performance. While force plates are considered the gold standard for jump assessment, their cost often limits accessibility in applied settings. The purpose of this study was to examine the agreement between a Vertec (VT) device, MyJump Lab (MJLAB), and two analytical approaches using MyJump2 standard version (MJ2ST) and the MyJump2 modified version (MJ2MOD) for measuring CMJ height. Twenty healthy adults (19–35 years) completed three maximal countermovement jumps following a standardized warm-up. Jump height were simultaneously assessed using the Vertec, MyJump Lab, MyJump2 Standard and a modified MyJump2 frame-selection procedures. Data was analyzed using repeated-measures analysis of variance (ANOVA), intraclass correlation coefficients (ICC), and Bland–Altman analyses. A significant main effect of measurement method was observed (F(3,57) = 31.61, p < .001, ηp² = .625). MJ2ST produced significantly lower jump heights than the VT, MJLAB, and MJ2MOD (all p < .001). No significant differences were observed between the Vertec and MyJump Lab, the Vertec and Modified MyJump2 or My Jump Lab and Modified MyJump2 (all p = 1.000). Good agreement was observed between the Vertec and MyJump Lab (ICC = 0.801) and between the Vertec and Modifed MyJump2 (ICC = 0.849), whereas only moderate agreement was observed between the Vertec and Myjump2 standard (ICC = 0.608). Bland–Altman analyses demonstrated substantial systematic bias for MyJump 2, which underestimated jump height by 12.93 cm relative to the Vertec. In contrast, MyJump Lab and Modified MyJump2 exhibited minimal bias. These findings indicate that MyJump Lab and the Modified MyJump2 analytical approach provide valid alternatives to the Vertec for assessing CMJ height. (Balsalobre-Fernández et al., 2023). Furthermore, jump-height estimates obtained using MyJump2 were substantially influenced by the operational definitions used to identify take-off and landing events. Practitioners should exercise caution when using standard MyJump2 procedures, as they may underestimate CMJ performance.