Biomechanical analysis of badminton forehand and backhand net smash strokes in Taiwan badminton players

[[abstract]]The purpose of this study was to analyze the kinematical variables of the badminton players when they were performing forehand and backhand net smashes. Eight collegiate elite male badminton players in Taiwan (age 20yrs, high 176cm, weight 71kg) were served as the subjects. In this study, we were interested in analyzing the motions from the phase of preparation while the center of gravity (COG) went down to the lowest position to the point of making contact with the shuttlecock. Ten Vicon MX-13+ cameras (Vicon, Oxford, UK, 250Hz) were used to record the 3D kinematics data and calculated by Vicon Nexus 1.1 system. The nonparametric statistical test of the Wilcoxon matched-paired signed-rank test between forehand and backhand net smashes for the differences in kinematics at a .05 significant level. The results showed that there were no significant differences between forehand and backhand net smashes in the initial shuttle velocity, the initial shuttle angle, the contact height and the movement duration time. The distance from the contact point to COG, the forehand net smash was greater than the distance of backhand in the lateral orientation, but the forehand net smash was less than backhand in saggital distance. The COG lateral moving velocity of the forehand net smash was greater than the velocity of backhand net smash. The dominate upper limb joint angle at the contact point, the forehand net smash was greater than the backhand’s in the extension and abduction shoulder angle. The forehand net smash was greater than the wrist adduction angle of backhand net smash. The player raised their upper arms to perform the forehand net smashes. From the results of the upper limb joint angular velocity, the subjects manipulate the shoulder rotation to perform the forehand net smash, but they exert the wrist joint to perform the backhand net smash. The backhand net smash seemed more relate with the kinetics chain rule. The movement performance effect was very similar between forehand and backhand net smashes, but the strategy of the forehand and backhand net smash movement was different. Key words：Biomechanics, Badminton, Forehand, Backhand, Net Smash