Analysis On Kinematic Characteristics Of Forehand Hook Technique Of Badminton Players Of Different Grades In Front Of Net

Research purposes : In a series of badminton techniques,the forehand hook technique in front of the net is one of the most commonly used techniques for most athletes.This paper records and analyzes the kinematics of the forehand hook movement of badminton first-level athletes,badminton second-level athletes and badminton special students,and obtains the action time,body center of gravity change and body joint angle of the athletes to complete the forehand hook in front of the net.It reveals the differences in kinematic indicators of badminton first-level athletes,second-level athletes and badminton special students in terms of movement techniques,finds out the internal causes of the differences,helps low-level athletes to efficiently complete the forehand hook technique in front of the badminton net,and provides targeted suggestions for the training of forehand hook technique in front of the net,and provides reference for other badminton enthusiasts who want to master this technique.Research methods: In this study,three groups of subjects were selected,namely,eight badminton level I athletes,eight badminton level II athletes and eight badminton special class students from Xi’an Institute of Sports,who had no history of sports injury in the past two months.Four high-speed cameras were used to record the kinematics of the technical movements of the forehand hook at the net completed by the experimental subjects,and the kinematic parameters such as the angle,speed and center of gravity of each joint during the movement were derived by using SIMI motion analysis software,and the data were organized and statistically analyzed by Excel,SPSS19,Matlab and other software.Research results:(1)In the forehand hook movement in front of the badminton net,the special students spent 0.29 ± 0.08 s in the hitting stage and 0.23 ± 0.01 s in the swinging stage.The time spent in the hitting and swinging stages of the special students was significantly different from that of the first and second level athletes(P<0.01).(2)In the process of completing the forehand hook technique in front of the badminton net,there is a significant difference in the height of the center of gravity between the special students and the first and second level athletes(P<0.05).(3)In the start-up stage: The right elbow angle of the special students in the preparation posture moment was 144.89 ± 2.66 °,which was significantly different from that of the first and second grade athletes(P<0.05).(4)In the stage of moving lead shot : The minimum value of the right knee joint angle of the second-level athletes is 117.57 ± 9.41 °,and the change range is 34.56 ±14.13 °,which is different from the minimum value and change range of the right knee joint angle of the special students(P<0.05).The change range of the right ankle joint of the first-class athletes is 16.41 ± 8.93 °,which is different from that of the second-class athletes and special students(P<0.05).(5)Batting stage : The upper limb joint speed of the forehand hook technique in front of the net of the three groups of athletes increased in turn,and the lower limbs of the athletes gradually stabilized.(6)In the swing stage : The change range of the right shoulder joint angle of the special students is 36.29 ± 21.72 °,which is different from that of the first-class and second-class athletes(P<0.05).There were differences in the right hip angle and right knee angle of the three groups of athletes at the end of the swing(P<0.01).Research conclusions:(1)The first-class athletes have the shortest time to complete the action,and the time of the hitting stage and the swing stage is significantly reduced.The short and efficient movement rhythm of first-class athletes is more conducive to grasping the fighter.(2)Special students have a higher center of gravity in each stage,and the center of gravity fluctuates greatly,which is not conducive to moving and hitting.(3)At the end of the start,the knee joint angle of the special athlete is too large,which is not conducive to the formation of elastic potential energy and ground reaction force.In the early stage of the moving racket stage,the angle of the right shoulder and right elbow of the secondary athletes changed greatly,which caused the phenomenon of premature racket.The excessive distance of the special students affects the quality of the batting in the batting stage.(4)In the batting stage,the ankle-knee-hip joint and shoulder-elbow-wrist joint speed of athletes at all levels increased.The upper limb wrist joint of the first-class athletes has a large abduction in the batting stage,the movement is concealed,and the angle of the hip and knee joints of the lower limbs of the body gradually decreases and tends to be stable.(5)In the swing stage,the angle of the lower limb ankle,knee and hip joint of the special students increases,and the body center of gravity is higher and forward,resulting in a larger swing.