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首页> 外文期刊>Deutsche Zeitschrift fur Sportmedisin >Belastungen des Schlagarmes durch Handgelenk- und Unterarmaktionen im Tennis
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Belastungen des Schlagarmes durch Handgelenk- und Unterarmaktionen im Tennis

机译:网球中手腕和前臂动作产生的紧张手臂负荷

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The precision of the point of impact on the racket determines the amount of rotations of the racket. These have to be managed by the hitting arm and can mean high stress for the wrist, the elbow and the shoulder at the moment of impact depending on the velocity of the racket and the firmness of the grip. We used 2 NAC High Speed Video Cameras (200-400 frames per second) in order to analyse wrist and racket actions of world class and spare time players. Using this method it is possible to get quantitative data about technical aspects and stress of the hitting arm as well. Approx. 150 ms before impact there is a quick stretching of the muscles of the forearm - e.g. in the form of a dorsal flexion of the wrist - that obviously leads to the storage of elastic energy and induces the stretch reflex. This mechanism contributes considerably to high velocities of the racket at impact esp. in world class tennis (over 30 m/s for the gro-undstrokes and the 1st service). Advanced players reach significantly lower values in these situations (approx. 25 m/s), combined with great deviations of the impacts on the racket. The comparable low racket velocities at the return on 1 st serve (approx. 19 m/s) can be attributed to an increased stiffness of the wrist. In contrast to the world class players advanced players often show (approx. 50%) eccentric points of impact on the racket head which lead to rotations and mean stress for the striking arm.
机译:球拍上撞击点的精度决定了球拍的旋转量。这些必须由击打臂来管理,并且在撞击时可能会给腕部,肘部和肩膀带来很大的压力,具体取决于球拍的速度和握力。我们使用2台NAC高速摄像机(每秒200-400帧)来分析世界一流和业余时间运动员的手腕和球拍动作。使用这种方法,还可以获得有关技术方面和击打臂压力的定量数据。大约撞击前150毫秒,前臂的肌肉快速伸展-例如腕背弯曲的形式-显然导致弹性能量的储存并引起伸展反射。这种机制在击球时尤其有助于球拍的高速运动。在世界一流的网球比赛中(突破性击球和第一次比赛的速度超过30 m / s)。在这种情况下,高级选手的球拍值要低得多(约25 m / s),而且对球拍的影响也会有很大的偏差。第一次发球时可比的较低的球拍速度(约19 m / s)可归因于手腕刚度增加。与世界一流的运动员相反,高级运动员经常在球拍头上显示(大约50%)偏心的冲击点,这导致击打臂旋转并产生平均压力。

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