Movement Coordination during Forward and Backward Rope Jumping: A Relative Phase Study.

Rope jumping is a popular training method in athletic programs, fitness, and physical education. Forward and backward rope jumping has been used for evaluating athlete's performance. Both of these two jumps require coordination in the upper and lower limbs. However, no study has focused on movement coordination during forward and backward rope jumping. Relative phase (RP) analysis was widely known as an innovative method for evaluating human movement coordination. Thus we aimed to investigate the movement coordination during forward and backward rope jumping by using RP analysis. 78 elementary and junior high school students participated in this study. 30 seconds rope jumping was recorded for both forward and backward by using iPhone video. Pose estimation software was used for jump motion tacking. Movement coordination was analyzed through RP analysis, absolute maximum value, mean absolute RP, and deviation phase were calculated for evaluating movement coordination, the trend of in or out-of-phase, as well as movement stability. As a result, 3994 forward and 3961 backward jumps were analyzed. There was a significant difference in movement coordination between forward and backward rope jumping. Compared to forward, backward jumps showed worse movement coordination, a trend to be out-of-phase, and less stability. It was the first time that movement coordination during rope jumping was studied. We considered that further research on coordination during rope jumping can provide new insight into athlete performance management, fitness guidance, and physical education.