Effectiveness of Jump Training with Immediate Feedback of Reactive Strength Index Modified

Abstract

Jump training plays an important role in sports training, and RSImod, the ratio of jump height to movement time, is used to evaluate the neuromuscular characteristics of athletes. In a previous study, the influence of feedback was evaluated by training with only the RSImod as feedback, but it has been suggested that this feedback has a negative effect when athleticism is emphasized. In this study, we evaluated the effects of feedback on the subjects by simultaneously providing feedback of RSImod and jump height and setting a standard for jump height. The experiment was conducted on nine subjects, three in the group without feedback and six in the group with feedback on RSImod and jump hight. In the group with no feedback, the subjects changed their posture to a one in which they sank deeper and jumped higher. However, it was difficult to extend RSImod, which is a hidden parameter, and no subject increased RSImod. On the other hand, the subjects with feedback were trained to increase RSImod. The subjects were able to confirm the change in RSImod for each trial in response to their own jumps, and all subjects were able to confirm an increase in RSImod. Previous studies have shown that, it is important to shorten the movement time to increase RSImod even if the jump height is lowered. However, in the present study, the jump height was set as a criterion, and most subjects changed to increase RSImod while also increasing the jump height. This may be due to the feedback given in this study, and it is thought that the effect of highly competitive training was obtained. In the future, we will increase the number of subjects and conduct more quantitative evaluations. In addition, the relationship between posture and jumps will be clarified based on the relationship between the posture data obtained from videos of postures during the pre-test and post-test and the measurement values obtained in this study.