Abstract
The vertical jump test is one of the simplest and most prevalent physical tests used in practice and research. This study investigated the validity and reliability of a new mobile application (Jumpo) for measuring jump performance on Android devices.
University-aged students (n = 10; 20 +- 3 years; 176 +- 6 cm; 68 +- 9 kg) reported to the laboratory on three occasions (2-7 days apart): to be familiarized with the jump performance measurements and then for test-retest reliability assessments. Participants performed countermovement jumps (CMJ), squat jumps (SJ), and right and left single-legged jumps in random order on a force platform while being recorded by a smartphone's slow-motion camera.
Flight time was selected as the criterion variable. Strong positive correlations between the Jumpo and force platform were observed for each jump type tested (r >= 0.93), although the flight times obtained with the Jumpo App were systematically shorter than those provided by the force platform by 3-6% (p = 0.94, CV = 0.25).
With respect to jump type, data from double-legged jumps (CMJ and SJ) were more accurately measured than data from single-legged jumps. The Jumpo App provides a valid and reliable measurement of jump performance, but the following equation should be used to calibrate its flight time results, allowing comparisons to be made to force platform data: Force platformflight time = 0.948 x Jumpoflight time + 41.515.
Future studies should cross-validate the calibration equation in a different sample of individuals.