1998 Volume 11 Issue 1 Pages 203-210
It is the purpose of this study to analyze the take-off motion of Drop jump biomechanically applying a method of normalization and standardization. The subjects were 29 male athletes of track and field. Each subject was required to make the jump with arms' motion from 40cm-high-stand. All the trials were taped by a high speed camera. The biomechanic variables including jumping-height, contact time, drop jump index were computed to characterize their jumps. Their jumps analyzed and then a method of narmalization and standerdization was applied to them. The main results were as follows;
1. A large standard deviation was obtained large about lower limb motion on the take-off phase in the subjects that performed the higher jump.
2. The ankle showed the large standard deviation in the subjects with shortest contact time and highest drop jump index, and then the second was the hip, the third was the knee. The results suggested that the most important factor was the knee joint motion on the take-off phase.
3. The ankle showed the largest standard deviation on the early half of take-off phase in the subjects with the shortest contact time. The results suggested that temporal and spatial anticipation from short before of contact to the early half of take-off phase were the important factors to shorten the contact time in drop jump.
