Several devices are available to measure vertical jump (VJ) height based on flight time, VJ reach height, or ground reaction forces. The purpose of this study was to determine the accuracy of a VJ mat for measuring flight time and VJ height, compared to a VJ tester or a force plate. Seventeen men and 18 women (X+/-SD; age=20.9+/-0.7 yrs, hgt=176.1+/-0.9 cm, wgt=72.6+/-13.5 kg) served as subjects. Subjects performed counter-movement vertical jumps (CMVJ) while standing on both a force plate (1000 Hz), and a VJ mat. A Vertec VJ tester was used to measure jump reach. Compared to the force plate, the VJ mat reported greater VJ height (VJ mat = 0.50+/-0.12 m, force plate = 0.34+/-0.10 m) and flight time (VJ mat = 0.629+/-0.078 s, force plate = 0.524+/-0.077 s). Comparison of VJ heights from the VJ mat and the Vertec revealed no significant differences (Vertec = 0.48+/-0.11 m). Regression analyses indicated strong relationships between testing methods, and suggested high VJ performances may be underestimated with the VJ mat. This particular VJ mat compared favorably with the Vertec but not the force plate. It appears that the different flight times derived from the VJ mat may permit the VJ mat to be in closer agreement with VJ heights from the Vertec. Also, the VJ mat may not be an appropriate tool for assessing high VJ performances (i.e., >= 0.70 m; [almost equal to] 28 in.). Practitioners and researchers using similar VJ mats may not obtain accurate flight times and may underestimate high performers.
Copyright (C) 2014 by the National Strength & Conditioning Association.