著者

湯 海鵬

出版者

バイオメカニズム学会

雑誌

バイオメカニズム

巻号頁・発行日

vol.13, pp.33-40, 1996

被引用文献数

5

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The purpose of this study is to evaluate the jumping smash technique in badminton from the viewpoint of conservation of angular momentum. Angular momentum estimates for the whole body were calculated, and the application of the principle of conservation of angular momentum was discussed for the smash motion. A cinematographic technique was used to determine the angular momentum of the human body about its mass center for general three-dimensional movements. The three orthogonal components of the angular momentum of 15 body segments, composed of a transfer term and a local term, were computed. The total angular momentum of the whole body was considered to be composed of the sum of the angular momenta of all body segments. Three-dimensional coordinates for determining the angular momentum were computed using Direct Linear Transformation method from film data. According to the principle of conservation of angular momentum,the smash motion is supported by the cooperation of all body segments. As the jumping smash movement is initiated, the lower limbs acquire some angular momentum on take-off from the ground, and then transmit it to the smashing arm. The torso and the left arm act as intermediaries in transmission of the initial angular momentum between the lower limbs and the swing arm. During the fore swing phase of the arm, a large angular momentum is generated by rapid arm rotation. The lower limbs and the head react to the arm swing with an equal and opposite angular momentum to keep the angular momentum constant. This kind of counter rotation to the smash arm is useful to keep the body balanced and reinforce the hitting arm. Key points in learning the jumping smash technique are to acquire an initial angular momentum on take-off and to create some counter rotation opposite to the swing arm.