The effect on human body at the impact of tennis racket and balls from the viewpoints of mechanical characteristics of the grip

从握把力学特性看网球拍与球撞击时对人体的影响

• 批准号: 16500415
• 负责人: MAEDA Hiroshi
• 金额: $ 2.05万
• 依托单位: Oita University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16500415/
• 关键词: tennis racket; grip; impulse; vibration; link model; visco-elasticity model; simulation; リンク機械モデル

Experiments reveal clearly that when the vibration occurred at the impact of a ball and a racket, there are two kinds of frequency, one is high frequency around 130 Hz and another one is low frequency around 10 to 50 Hz. These results lead us to the conclusion that the racket acts as one is a vibration body and another one is a rigid object at the impact. This high frequency vibration disappeared when a ball impacts only just on the center of racket face, and low frequency remains on the racket. This law frequency vibration transmits to a hand and a forearm though. At the off center impact, when changing the rigidity of the grip from tight to loose, it was found that the high frequency was hard to transmit to a hand, but low frequency passed through the grip. Yoneyama, S. (2003) and other studies reported that the vibration after the impact may causes the "tennis elbow". The results of this experiment reveal that not only the vibration of high frequency but also the low frequency origi … More nates in the tennis elbow, when the racket is regarded as a rigid body.Findings from the experimental results show that the racket acts as a body with two types of properties, one is a vibration body and another one is a rigid object at the impact. From this point of view, we made a model of impact as a rigid body, and the racket links to a hand through a grip that has the characteristics of visco-elasticity. By means of this model, the characteristics of grip are investigated. The model was identified by comparing the experiment data such as the duration time of contact with the ball and racket, the coefficient of restitution of ball, the characteristics of damping of vibration, the frequency and the peak value of vibration. From the simulation of the model, it is inferred that the coefficient of viscosity of grip changes 1.0 to 5.5 N/m/s and the coefficient of elasticity changes from 50 to 500 N/m, according to the tightness of grip. As the tightness of the grip changes, the visco-elasticity coefficients of wrist joint are also influenced. Less

实验清楚地表明，当球和球拍撞击时发生振动时，有两种频率，一种是130 Hz左右的高频，另一种是10至50 Hz左右的低频。结论是，球拍在撞击时，一个是振动体，另一个是刚性体，当球仅撞击到球拍面的中心时，这种高频振动消失，而低频则保留在球拍上。频率振动然而，在偏心冲击时，当将握把的刚度从紧变为松时，发现高频很难传递到手，但低频会通过握把。 Yoneyama, S. (2003)等研究报道，撞击后的振动可能会导致“网球肘”。该实验结果表明，不仅高频振动，低频振动也起源于撞击。网球肘，当球拍被视为刚体。实验结果表明，球拍作为一个物体具有两种属性，一种是振动体，另一种是撞击时的刚体。制作了一个刚体击球模型，球拍通过具有粘弹性特性的握把与手相连，通过该模型研究了握把的特性，并通过实验进行了识别。数据，例如接触的持续时间球和球拍、球的恢复系数、振动的阻尼特性、振动的频率和峰值，从模型的模拟推断握把的粘性系数变化1.0到5.5N。 /m/s，弹性系数根据握力的松紧程度从 50 到 500 N/m 变化。随着握力的松紧变化，腕关节的粘弹性系数为影响也较小。

项目成果

Mechanical Characteristics of Tennis Grip

网球握拍的机械特性

• 发表时间: 2005
• 期刊: Proceedings of 18^<th> Symposium of Japanese Biomechanics Society
• 作者: Yasuharu Oishi;Tomonori Ogata;Hiroshi Maeda
• 通讯作者: Hiroshi Maeda

テニスにおけるグリップの粘弾性特性

网球握把的粘弹性特性

• 发表时间: 2005
• 期刊: トレーニングを科学するバイオメカニクス 第18回大会論集
• 作者: 杉浦春雄;杉浦浩子 他;前田 寛
• 通讯作者: 前田 寛

テニスラケットにおける低周波衝撃の振動伝播

网球拍中低频冲击的振动传播

• 发表时间: 2005
• 期刊: 日本体育学会第56回大会予稿集
• 作者: Hashimoto M.;Yamamoto N.;Sugawara M.;前田 寛
• 通讯作者: 前田 寛

The transmission of low frequencies vibration from tennis racket to hand

低频振动从网球拍传递到手

• 发表时间: 2005
• 期刊: Proceedings of 56^<th> Symposium of Japan Society of Physical Education, Health and Sport Science 260
• 作者: L-J.Guo;Y.Oshida et al.;Sugawara M.Hashimoto M.;Hiroshi Maeda
• 通讯作者: Hiroshi Maeda