双杠向后大回环转体类动作的生物力学分析

双杠向后大回环转体类动作,是近几年来在向后大回环基础上发展起来的高难杠下动作。本文从生物力学角度,对我国优秀体操运动员所完成的向后大回环转体180°和360°两组动作做了定性、定量分析,得出向后大回环转体动作的技术可分为两种类型。一种是“跳转”技术,即两手同时放手,身体在有较明显的腾空中转体;另一种是“撑转”技术,即身体没有明显的腾空,两手依次换握转体。前者动作高飘、优美,可高质量完成向后大回环转体180°成手倒立,但绕身体纵轴转体的动力小;后者绕身体纵轴转体的动力大,可以发展180°以上的高难转体动作,但长时间维持身体的动态平衡较难。两种技术各有特点,只要不断改进、提高,都可以高质量完成向后大回环转体类动作。

A BIOMECHANICAL ANALYSIS FOR THE GIANT CIRCLE BACKWARD WITH TURN CLASSIFICATION ON THE PARALLEL BARS

The giant circle backward with turn classification on the parallel bars is a superior difficult part under the bars developed besed on giant circle backward in recent years. This paper makes a qualitative and quantitative analysis in terms of biomechanism for the two series movements of giant circle backward with 1/2 turn and 1/1 turn completed by the excellent gymnasts of our country It has been obtained that the technology of giant circle backward with surn classification can be divided into two kinds: One is "Jump-turn" technology, i.e, the two hands loose at the same time and the body turns in the obvious flight phase. The other is "Support-turn" technology, i.e, the two hands change grip in turn, and the body turns without any obviouse flight phase. The former movement is performed in a high-fling way and gracefully. It can help complete the giant circle backward with 1/2 turn to handstand of high quality. Howerer, the turning dynamic round the long axis is weaker; the latter is stronger, and in this case, it can develop the superior difficult movement with overl/2turn. But it is difficult to keep the dynamic eguilibrium of body for a long time. Either of the two technologies has its own characteristic, As long as the two technologies can be improved and raised continuously, both of them can help complete the giant circle backward with turn classification of high quality.