全身選択応答時間に及ぼす事前のジャンプの効果

抄録

The present study attempted to investigate the effect of preliminary jump action on the total body choice response time. The preliminary jump action is frequently observed in ball games. In a tennis game, for example, the jump action may be seen in the movement of the receiver prior to the server's hitting a ball or just before returning a ball. The current study provided two experimental conditions. Firstly, each subject was asked to jump voluntarily during the moment of preparatory period (JUMP). Secondly, each subject attempted to maintain his posture without jump action during the period (NO-JUMP). In both experimental conditions, each subject was asked to step out either right or left side indicated by the reaction signal as quickly as possible. Twenty healthy males volunteered as subjects for this study. Three interval times were analysed in the following manner. First, the choice response time (RESPONSE TIME), defined as the interval time from the reaction signal to the moment of step out, was recorded. Second, the choice reaction time (REACTION TIME), defined as the interval time from the reaction signal to the moment of lifting a leg for stepping Out, was measured. Then, the movement time (MOVEMENT TIME), defined as the interval time subtracted RESPONSE TIME from REACTION TIME was taken. Moreover, this study investigated the effect of the timing of performing perliminary jump action during the preparatory period on RESPONSE TIME and the practice effect of performing the two conditions OUMP and NO-JUMP) on RESPONSE TIME for 16 days. Statistical analysis of variance for comparison of various experimental conditions was proceeded. The results are summarized as follows: 1. Both RESPONSE TIME and REACTION TIME under JUMP condition were shorter than these under N0-JUMP condition. But MOVEMENT TIME under JUMP condition was not necessarily shorter than that under JUMP condition. 2. As the landing time (interval time between the warning signal and landing after a free preliminary jump during the preparatory period) resulted in wide range within subject and between subjects. No significant relationships between RESPONSE TIME and the landing time were found. 3. The practice effect of both JUMP and NO-JUMP conditions over 16 days resulted in shorter RESPONSE TIME. RESPONSE TIME under JUMP condition was shorter than that under NO-JUMP condition. But no differences Were found on the practice effect between the given conditions of JUMP and NO-JUMP. 4. The study suggested that shortened RESPONSE TIME with preliminary jump action resulted from both increased muscle activity and higher arousal level.