Reliability and Validity of Jump Height Measurement using Mobile Applications

Objective:The purpose of this study was to evaluate the concurrent validity and test-retest reliability of the Smart device-based APP "What's My Vertical?" for measuring vertical jump height, using G-Walk as the reference standard.Design: Cross-sectional study.Methods: A total of forty participants were recruited to perform both squat jumps and drop jumps.Their vertical jump height was simultaneously measured using G-Walk and the Smart device-based APP "What's My Vertical?".The concurrent validity between these two measurement methods was analyzed by comparing the recorded values.Additionally, intra-rater and inter-rater reliability of the mobile application's measurements were assessed through repeated evaluations of the recorded data.Results: The findings demonstrated that "What's My Vertical?" had a high level of concurrent validity with G-Walk (ICC 0.951, p 0.001).Moreover, the intra-rater reliability (ICC 0.997) and inter-rater reliability (ICC 0.998) were found to be excellent, indicating consistent measurement performance.However, occasional errors were observed in detecting jump take-off and landing points, which affected measurement accuracy in certain cases.Despite these minor inaccuracies, the overall agreement between the two device-based measurement methods remained strong.Conclusions: "What's My Vertical?"is a reliable and valid tool for measuring vertical jump height and may serve as a cost-effective alternative in clinical and sports settings.However, further research is needed to improve jump phase detection accuracy and validate its broader applicability.