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

Research objective: serving technique is one of the most important techniques in the whole tennis technique,and it is the most offensive weapon.China's tennis started late,all kinds of technology is still in the growth stage,technical training and methods are not tend to improve,especially tennis serve is a weak link of our country's players,so improve the service technology to improve the quality of service is the focus of the current development of China's men's tennis.Taylor fritz excellence in men's tennis players in the world,the author of this paper serve kinematics analysis,find out technical characteristics,the young tennis player for the future of the serve technology training and competition to provide theory reference and standard,make our country serve young athletes in daily training to correct mistakes,to make the service standard,comprehensive level,in order to get higher honor in the competition.Research methods: literature review;Expert interview;Three-dimensional video analysis.Research results :(1)in the throwing and racquet lifting stage,the foot position of FB was adopted in the serve technique of Taylor fritz.The advantage was that the player could obtain higher stability and greater horizontal force,which relatively improved the accuracy of the serve.In terms of the height of the ball from the hand,the Ace ball and the successful serve ball have a higher height of the ball from the hand,which can increase the stability of the ball and make the throwing route more stable.By repeatedly watching the video and analyzing the data from the three-dimensional video,it can be seen that the ball drops off the hand at a stable speed,and the ball drops off the hand at a higher height to increase the success rate of the serve.When the ball is out of the hand,Taylor fritz extends the elbow of the ballholder straight,which helps control the direction of the ball and makes the ball rise more steadily.Through repeatedly watched video and 3 d video parsing data found that athletes in the process of ball toss the ball arm shoulder joint Angle,the greater the last effect and on the top of the head position of the ball ball,better to lower energy transfer to the upper body,this moment of knee joint is at his best stretching in power range,reasonable buckling Angle,natural smooth,stretching process for subsequent movements increase pace swing distance and create more favorable conditions.(2)in the backswing stage,the difference between Taylor fritz's Ace ball and the successful first serve in the range of kicking and extension of the supporting leg and knee joint was small and the range of movement was large.At this moment,the knee joint was bent to a relatively reasonable degree of flexion.According to the analysis of the data obtained from the three-dimensional video,the Angle of the elbow joint on the arm side of the racket is larger at the end of the backswing phase,which is conducive to the rapid extension of the force of the elbow joint during the forward swing and the improvement of the whipping speed of the elbow joint.According to the analysis of three-dimensional video data,it was found that the difference between the lowest height of the racket head and the height of the center of gravity of the Ace ball and the successful first serve presented a negative value.After watching the video repeatedly,it was found that the backscratching movement in the backswing stage was the most reasonable,the backbow movement was very sufficient,and the movement structure beyond the apparatus was the most obvious.From the above results and the repeated watching of the video,it can be concluded that Taylor fritz's Ace and successful first serve movements are reasonable in the swing hitting stage.(3)in the swing hitting stage,the ratio of height to height of Taylor fritz's Ace and successful first serve is very close to the ratio of height to height of 1.50 [18] of the world's elite players.It is found that the higher the height of the shot,the higher the serving rate over the net.The difference between the Ace and the highest point of the successful serve and the hitting point is small,which is conducive to the player to judge the position of the ball in the air and improve the accuracy of hitting.The average distance between the throwing point and the hitting point of the Ace was 0.97 m.After watching the video repeatedly,it was found that the Taylor fritz Ace threw the ball more forward and upward,which provided enough space for the subsequent swing force to make the action more open and powerful.When hitting the ball,the potential energy of the ball was stronger forward and downward.During the swing time,the Angle of shoulder joint on the side of the Ace ball and the successful first serve is relatively large,which is conducive to the increase of the rotation radius of the end link around the shoulder joint and the faster swing speed,so as to make the whipping effect more obvious.Through repeatedly watched video and 3 d video parsing data found ACES,successful round knee,hip,shoulder,elbow,wrist and racquet head speed of movement of the incremental quantity grows,reaches the racquet head speed present maximum,shows that action of Taylor fritz upper limbs technology dynamic movement theory,the body each link actions are coordinated.Conclusion :(1)the throwing and racquet action stage: the FB technique is adopted in the serve of Taylor fritz.The advantage is that the player can obtain higher stability and greater horizontal force,which relatively improves the accuracy of the serve.The throwing height of Ace ball and successful first serve reached the maximum height.During the throwing process,the elbow joint was extended straightly from the lowest point of the throwing to the moment when the ball left the hand.The throwing was stable and the ball left the hand at a reasonable speed.(2)the difference between the minimum height of the racket head and the height of the center of gravity of the Ace ball and the successful first serve showed a negative value in the backswing stage.It can be known that the "back-scratching" movement was reasonable,and the back-bow movement structure was the most obvious,which was conducive to more work.The knee joint is bent to reach the best degree of flexion,and the pedal extension is large and powerful.The Angle of elbow joint on one side of racket arm is larger,which is helpful to improve the extension speed of elbow joint during swing.(3)in the swing hitting stage,the high hitting height of Ace and successful first serve is higher,which can improve the net passing rate of the ball in high-speed movement and create more favorable conditions for the successful serving.The increasing speed of the body's knee joint,hip joint,shoulder joint,elbow joint and wrist joint keeps increasing and reaches the maximum value when it reaches the racket head,which indicates that Taylor fritz's upper limb technical movement conforms to the principle of dynamic whipping movement,and the movements of all body parts are very coordinated and smooth.The kinematic analysis of Taylor fritz's serve movement technology is mainly worth learning: the elbow joint is relatively straight and stable when throwing the ball;the ball leaves the hand at a reasonable speed;the flexion Angle of the left and right knee joints reaches the maximum at the end of throwing,forming a good preparation posture;When hitting the ball,the lower limbs quickly kick to turn,the elastic potential energy is fully released,the back arch is full,the movement structure beyond the apparatus is quite obvious,the upper limbs shoulder,elbow,wrist and other joints whip speed to hit the ball is obvious,the whole service process is complete,smooth,natural.