High Reliability Of Jump Performance Assessed With A Linear Transducer In Elite Track And Field Athletes

Abstract

Although the countermovement vertical jump (CMJ) has been extensively used, data about reliability parameters on a large subject sample (∼50) of elite athletes are limited. PURPOSE: To determine the reliability of CMJ performance in a large sample of track and field top athletes using a linear transducer. METHODS: A group of 48 elite male sprinters and long-jumpers volunteered to participate in this study. Subjects performed three trials with 3 minutes of rest between each CMJ. This was accomplished by measuring jump performance using a linear transducer and a force platform simultaneously. The relationships between force-time dependent variables and CMJ performance were examined during the concentric phase using a Smith machine. RESULTS: The present study demonstrated high intraclass correlations (ICC) values for maximum rate of force development (RFDmax) accessed with linear transducer, however, the coefficient of variation (CV) was somewhat high (15-17%). Nevertheless, ICC of peak force (PF) and the maximum power measured with force platform were very high. The maximum negative velocity presents a somewhat smaller but likewise high degree of stability, although the CV is slightly high (9.9%). The trial-to-trial reliability of the CMJ measured by the force platform gave an ICC of 0.87-0.97 for PF, maximum power and maximum negative velocity. Similar ICCs of 0.93-0.98 for RFDmax, PF, and for rate of force development at PF were observed by the linear transducer. The CVs were 3.6-17% and 5.8-9.9% with force platform and with linear transducer, respectively. CONCLUSIONS: The present findings showed that the calculations derived from the linear transducer synchronized with a force platform were very similar and hence provided evidence of the reliability of this method in elite track and field athletes. Moreover, this method suggests that the linear position transducer offers a cost-effective, versatile, and valid means for the measurement of force in track and field top athletes.