羽球正拍網前擊球動作之生物力學分析

Abstract

羽球網前球是所有的羽球技巧中最細膩也是失誤率最高的動作，而網前的基本擊球動作是以輕彈球、搓球及勾球為主。本研究的主要目的是比較八位大專男子甲組羽球選手網前正拍的輕彈球、搓球及勾球動作在運動學及肌電訊號的差異。運動學是利用Vicon動作系統(250Hz)擷取受試者身上反光球的資料，並經由Visual 3D算出運動學參數；肌電訊號是由Biovision生物訊號擷取系統(1000Hz)來擷取，並經由Dasy Lab 6.0的軟體來分析；所有參數均透過SPSS 13.0版統計套裝軟體計算，以無母數弗里曼二因子變異數分析來檢定，並使用Excel計算軟體進行三種動作的事後比較，顯著水準定為α= .05。其結果發現：擊輕彈球時，拍面與水平面的夾角較小(約30度)、肢段伸展較慢及擊球前上肢肌群有共同收縮的現象。搓球則有較快的重心位移、遠端肢段的伸展及肌群由近端到遠端依序發力的現象，造成較快的拍頭速度以削擊球頭，使球有偏轉的效果。勾球則有較明顯的身體偏轉、右上臂的內轉、前臂的內旋動作及較為傾斜的拍面現象，以提供較大的側向力來擊球。因此，在擊輕彈球時，為了要減緩拍面對球的反作用力，所以擊球的肢段動作要放慢；擊搓球時，為了要提供球較大的偏心力，所以要靠遠端肢段的伸展及身體重心的移動；擊勾球時，上肢動作要以能提供球側向力的上臂內轉、前臂內旋的動作為要。

Net shot is the finest skill in the badminton game. The dab shot, the stab shot and the cross court net shot are the main techniques of this skill. The purpose of this study was to compare the kinematics and electromyography variables of forehand dab shot, stab shot and cross court shot of badminton. The subjects were eight elite collegiate male badminton players (ages: 21 ± 2 years; height: 176 ± 8cm; weight: 68 ± 6 kg). The mark trajectories were collected by VICON system (250Hz) and the kinematic variables were computed by Visual 3D software. The electromyography variables were recorded by the Biovision system (1000Hz) and analyzed by the DasyLab 6.0 software. All the variables were tested by Friedman two-way analysis of variance nonparametric statistical test which was calculated by SPSS 13.0, and the post-hoc comparison were calculated by the Excel software, the significant levels as α= .05. The results were: There was a less angle between the racket surface and the horizontal plane in the dab net shot, the players would slower the upper limbs stretch movement and co-contract the upper limb muscle groups before the contact point. The players performed the stab net shot with a faster COG displacement, stretched distal segments and a sequence burst in muscle groups of dominate limbs in order to make a faster racket velocity to stab the shuttle. The players performed cross court net shot with an obvious trunk rotation, upper arm interotation, forearm pronation and greater angle in racket surface with horizontal plane to hit the shuttle. We should slow down the movements in the dab shot to reduce the reaction force between the racket and the shuttle. The players should performed a faster stretch of distal segments and COG in stab net in order to create a greater eccentric force to hit the shuttle. The players increased the upper arm interotation and the forearm pronation to hit the shuttle by inward racket swing.