Validation of an electronic jump mat to assess stretch-shortening cycle function
journal contributionposted on 24.05.2012, 10:40 by Ian C. Kenny, Ainle Ó Cairealláin, Thomas M. Comyns
The purpose of this investigation was to determine the concurrent validity of a commonly used Electronic Switch Mat (ESM), or jump mat, compared to force plate data. Efficiency of collection and accuracy of data is paramount to athlete and player field testing for the strength and conditioning coach who often has access only to a jump mat. Ten subjects from five different sporting backgrounds completed three Squat Jumps (SJ), three Countermovement (CMJ) jumps and three Drop Jumps (DJ). The jumps were performed on an AMTI force plate (FP) operating at 1000 Hz with an ESM positioned on top of the platform. All subjects were experienced with the protocols involved with jump testing. The resulting absolute error between force plate and ESM data were 0.01 m, 0.02 m and 0.01 m for CMJ, SJ and DJ jump height respectively. However, coefficient of variation for DJ contact time was 57.25 %, CMJ (r=0.996) and SJ (r=0.958) jump heights correlated very strongly with force platform data, and drop jump data was not as strong (r=0.683). Confidence interval tests revealed bias towards CMJ and SJ (p < 0.05). The jump mat can accurately calculate CMJ height, and SJ height, as well as Reactive Strength Index (RSI) for all three jump protocols. However, the faster contact times, and rapid movements involved in a DJ may limit its reliability when giving measures of contact time, flight time, and height jumped for DJs. Strength and conditioning coaches can use such a jump mat device with the confidence that it is accurately producing valid measurements of their athlete’s performance for CMJ and SJ slow SSC protocols.