Kinematic Characteristics Analysis Of High-level Badminton Players' Backcourt Forehand Hitting Techniqu

By using QUALISYS infrared system to shoot and capture the three technical movements of eight high-level badminton players in Tianjin Institute of Physical Education,namely forehand high shot,drop shot and kill shot,complete the kinematics data collection of related movements,and use Visual 3D to analyze the joint angle,speed and angular velocity data,so as to understand the time Explore the characteristics and patterns of three types of hitting techniques in the form and amplitude of movement in space,and summarize the technical movement characteristics of high-level badminton athletes.The kinematics characteristics of three kinds of backcourt forehand hitting techniques completed by athletes were analyzed by means of testing and data analysis.The research conclusion is as follows:(1)In the process of executing a forehand stroke in the backcourt,the time taken for each stage is as follows: movement and positioning stage > returning to position stage > racket preparation stage > swing and hit stage.Additionally,the time taken to execute a forehand lob is greater than the time taken to execute a high clear or a smash stroke.(2)The footwork used for movement and positioning during the execution of a forehand high clear,lob or smash stroke involves a three-step backward movement with a parallel footwork pattern.During this movement,the hip joints twist backwards to form a posture with the left hip raised in front and the right hip lowered at the back,while the shoulder joint is extended outward and the forearm is lifted.Furthermore,the time required for movement and positioning during the three types of strokes is similar,as are the joint angles at the end of the movement and positioning phase.(3)During the racket preparation stage,the elbow joint moves forward and upward,while the forearm is tilted backward to form a "backswing" posture that conforms to the principle of "surpassing the equipment".The degree to which the racket is properly prepared will directly affect the power and speed of the swing and hit phase.(4)During the execution of a forehand high clear,lob or smash stroke,the elbow,shoulder,and wrist joints reach their maximum speed in sequence,with the wrist joint accelerating after the elbow and shoulder joints and reaching its maximum speed at the moment of impact.This indicates that the wrist joint is the final force generation link to complete the three stroke techniques.For a forehand high clear,the elbow and shoulder joints reach their maximum speed during the swing and hit phase,while for a lob or a smash stroke,the elbow and shoulder joints reach their maximum speed at the end of the racket preparation phase,and the speed of the elbow and shoulder joints begins to decline during the swing and hit phase.(5)During the execution of a forehand high clear,lob or smash stroke,the power generated through pushing off the ground,extending the knees,and twisting the hips is transmitted through the trunk to the shoulder,elbow,wrist,racket,and ball,forming a complete "power chain".The knee and hip joints act as the starting links of the power chain,with small angle changes and mainly serving to support and adjust the body position during the stroke.