A Kinematic Analysis Of The Forehand Technique Of World-class Male Tennis Player Taylor Fritz

This article takes Tyler Fritz as a representative outstanding male tennis player as a research object,uses two JVC high-speed cameras at a shooting frequency of 50 frames per second,and uses the peak frame to collect 3D motion image data on a standard tennis court.And use Xinggao Titanium 3-D Signal Tec video analysis software system for image analysis,using literature data method,image analysis method,mathematical statistics and other research methods,select the inertia parameter index such as the center of gravity,link centroid and the speed and angular velocity Motion parameter indicators such as motion,displacement,etc.,analyze the relevant kinematic parameters of Taylor Fritz's upper and lower limb movements during the forehand stroke.Through the feedback of the time,space parameters of the upper and lower limb links,and the coordination of the lower limb and the trunk,Reflect the problems that occur in the shot,and use this as a matter of attention during training to improve the knee,hip,shoulder,elbow and other links and upper and lower limb coordination and transmission that occur at different stages of the shot.The kinematic data parameters of the lower limbs also provide data references for subsequent improvement and learning of batting techniques.fruit:(1)Back-swing introduction phase: At the end of preparation,Taylor Fritz's left and right knee angles are 129.3 ° and 110.7 °,respectively,and the left and right hip angles are 124.6 ° and 122.5 °.The elbow angles were 77.3 ° and 31.7 °.At the end of the draw,Taylor Fritz's left and right knee angles were 134.5 ° and 114.2 °,and the left and right hip angles were 144.3 ° and 132.6 °,respectively.Ritz's right shoulder speed was 0.78 m / s,right elbow speed was 1.95 m / s,right wrist speed was 4.31 m / s,and center of gravity speed was 1.99 m / s.Large,especially the right wrist.(2)Swing stroke: At the end of the draw,the shoulder and hip angle is-43.4 °,when the racket touches the ball is 16.1 °,and the rotation range is 59.5 °.Taylor Fritz's right shoulder angle at the end of the draw It is 50.2 °,the angle of the right elbow is 121.6 °,the angle of the right shoulder is 46.8 ° when the racket touches the ball,and the angle of the right elbow is 117.2 °.Both are smaller than the angle at the end of the backswing,and show a certain decreasing trend.When the racket touches the ball,the angle of the racket arm changes in the opposite direction to the external force and concentrically contracts.At the end of the shot,Taylor Fritz's The height of the center of gravity is 0.87 m,the moment when the racket touches the ball is 1.12 m,and the height of the center of gravity is different by 0.25 m between the two moments.(3)Swing phase: Taylor Fritz's right shoulder angles at the time the racket touches the ball and the end of the swing phase are 46.8 ° and 104.2 °,respectively,and the right elbow angle is 117.2 ° and 77.5 °,respectively.The right shoulder angle gradually increased during the swing phase,indicating that Taylor Fritz raised his elbow significantly during the swing phase,and the elbow joint was far away from the torso,which complies with the principle of large-scale and long-distance swing during the swing phase.The gradual decrease indicates that Taylor Fritz's movement of the arm forward is more obvious after hitting the ball,moving the body's center of gravity forward,increasing the action time of the racket on the ball,which can make the ball faster and more powerful.At this stage,Taylor Fritz better maintained the balance of the entire body,and the trunk and all links maintained a good rotation speed and cushioning effect.