高难度直体旋翻动作的研究——为创新“1440°旋”所作的实验

A Study of Difficult Fliffises in Sports Acrobatics

本研究设计了高难度的空翻加转体动作“1440°直旋”。通过高速摄影、影片解析,定量分析了实验对象在技巧男子单人项目中的360°、1080°、1440°直旋的起跳、腾空、空翻、转体、落地等数据,论述了纵轴转体的机理和横轴动量矩向纵轴两次转移的时机、条件和方法,发现了腾空中转体和空翻角速度变化的规律和符合这一规律的适宜的空中动作,提出了完成1440°直旋的条件和指标,并在实验中得到了证实。

'Double back saltos with four twists stretched,' a new value part in sports acrobatics, has been designedand performed successfully. By means of a high-speed camera, quantitative kinetic analyses have been made of the take-offs, flights,sal-tos, twists and landings exhibited by male subjects performing fliffises with 360°, 1080°and 1440°twists withbody in straight position. With the data thus obtained, the authors of this paper discussed the mechanism of thetwists around the vertical axis of the body and put forward suggestions about the time, conditions and methods of shifting the angular momentum twice from the lateral to the vertical axis. Having discovered the aerial move-tnent patterns that can be best adapted to the changes of rotational speeds during a flight, they set forth thenorms and requirements to be fulfilled in performing the new stunt of double back saltos with four twistsstretched. Their proposition has proved to be sound in actual practice.