The present study aimed to elucidate the characteristics of lower limb movement in the “split leap” motion technique of rhythmic gymnastics using three-dimensional motion analysis. Six rhythmic gymnasts were examined during the jump motion and in two static anteroposterior leg-opening positions, one with pelvic rotation suppression（1）and the other without（2）. The angle of the hip joint and dynamics of the swinging leg during the jump were compared based on the skill level of the subjects. Furthermore, the evaluation of the movement of the jump attempt by the international judge qualification holder was compared with the motion index obtained through measurement and analysis.
The results showed that the angle of the hip joint with pelvic rotation was the largest among the split conditions. In terms of pelvic rotation, the rotation angle of the upper portion（anterior superior iliac spine line）was smaller than that of the greater lower portion（trochanteric line）. Advanced subjects were able to maintain a larger angle, approximately 90% of the maximum split angle, for a longer period during the jump motion. Notably, the angular velocity of the swinging leg exhibited a movement pattern that aided the maintenance of the split angle. These movement characteristics were deemed to meet some of the high evaluation criteria set by judges.

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