The relationship between common ability to perform the ballistic stretch-shortening cycle movement in unilateral horizontal jump events and performance of various jump events

Abstract

The purpose of this study was to develop a new method for measuring the common ability to perform the ballistic stretch-shortening cycle movement in unilateral horizontal jump events and to in- vestigate the relationship between the performances of various jump events. Ten male college track and ˆeld athletes performed the rebound long jump test (RLJ test). The participants jumped from a 0.1-m- high step to the ground after an approach run (falling jump), followed by jumping without interruption for as far as possible (propulsive jump). The fallingjumpdistance was setat1, 2,or 3 m, andtouchdown velocity, jumping distance, contact time, ground reaction force and leg joint torque weremeasured for all three falling jump distances. To evaluate RLJ test performance, the RLJ index was calculated by divid- ing jumping distance by contact time. Simultaneously, the rebound jump test (RJ test) method for meas- uring the common ability to perform the ballistic stretch-shortening cycle movement in lateral vertical jump events and the ˆve steps of bounding (5SB) method for measuring the common ability to perform unilateral horizontal jump events were conducted. We found that there were no signiˆcant correlations between the jumping height, contact time, and RJ power [RJ power (W/kg)＝jumping height (m)/ (contact time (sec)/2)] of the RJ test and the jumping distance, contact time, and RLJ index of the RLJ test, or any of the three falling jump distances. Thus, it was concluded that abilities to perform those two tests diŠered. On the other hand, there was a strong correlation (r＝0.859) between the RLJ index meas- ured for a falling jump distance of 3 m (RLJ index3) andthe IAAF score oftrack andˆeldathletes.In addition, the pattern and magnitude for the ground reaction force and leg joint torque measured during the RLJ for a falling jump distance of 3 m had similar characteristics to takeoŠ in the long jump or triple jump during a competition. Furthermore, 5SB was correlated (r＝0.790) with the IAAF score, but the correlation coe‹cient was less than that of the RLJ index3. The RJ index was not correlated with the IAAF score. These results demonstrate the signiˆcance of using the RLJ test and RLJ index from a 0.1- m-high step for measuring the common ability to perform the ballistic stretch-shortening cycle move- ment in unilateral horizontal jump events.