A Kinematic And Myoelectric Analysis Of Continuous Effective Jump Smash In Badminton

Research purpose: Smash is a very important backcourt offensive technique,especially jump smash is the most important backcourt scoring method used by men athletes.However,the most mistakes in backcourt technology are also smash.Changes in physical fitness have an important impact on muscle working characteristics and human kinematics indicators.Their changes will cause the batting effect to move and jump.This research uses the electromyography test technology and three-dimensional image analysis to complete the experiment,and analyzes the batting effect,the working characteristics of the main exerting muscles,and the characteristics of each kinematic index in the process of the two-point continuous moving jump smash in different heart rate intervals.This study can more accurately determine the characteristics of electromyography and kinematics of backfield continuous effective jump kills at different heart rate intervals,as well as their relationship with the effect of jump kills to guide scientific strength and technical training.Research method: The experimental method uses 11 outstanding athletes of Shandong provincial team(5 national master level and 6 national first-class)as experimental objects.Athletes are required to move continuously to kill and hit the 40* 40,20 * 20 concentric targets arranged on the sidelines,and the killing line is a straight line;there are 4 groups of 20 shuttles each,and each of the left and right courts has 10 shuttles,and with a 1 minute break between groups.Use high-speed camera to capture the whole experimental process and use the ALTAIR 8-channel surface wireless electromyograph to collect the surface electromyographic signals of the main muscles of the jumping samsh,record the drop point,and use the heart rate belt to record the real-time heart rate at each jump smash,And divide the heart rate interval after the experiment.Finally,using mathematical statistics method,SPSS software was used to analysis the one way ANOVA of EMG indicators,kinematic indicators and killing effects in different heart rate intervals.Research results: 1.The heart rate range is between 130-150 beats / min,the fastest kill speed,and the heart rate is 170-190 beats / min,the highest hit rate.2.The highest point of the center of gravity and the change in the center of gravity are the smallest in the heart rate 170-190 interval;the linear velocity of each link of the upper limbs has increased slightly in the 130-150 interval,and the 130-150,150-170,170-190 intervals have a downward trend;When shooting,the maximum shoulder angle increased to the range of 150-170 to reach a maximum of 132 °,and then decreased.The knee flexion angle was the smallest in the heart rate 130-150 interval,and the knee flexion amplitude was the largest in this interval.3.The integral myoelectric value of each muscle has an increasing trend from the 110-130 interval to the 130-150 interval,and it has a decreasing trend from the 150-190 interval.Among them,the integral muscles of the upper trapezius,pectoralis major,and latissimus dorsi.There are statistically significant differences in electrical value(IEMG)in the four heart rate intervals.There are very significant differences in the deltoid and biceps brachii muscles.The median frequency(MF)of each muscle is within the high heart rate interval(150-170).(170-190),showing a downward trend,and an increase trend from 110-130 to 130-150.There is a very significant difference between the upper trapezius,pectoralis major,and triceps,and a significant difference between the ulnar carpi flexor muscles..Research conclusions: esearch conclusions: 1.Under the load of 20 balls in each group,1 minute interval,a total of 4 groups,the shuttel speed and hit rate of continuous back-kicks are not linear;the heart rate range is 130-150 beats / min.And the inflection point of the effect,after this interval,the speed showed a downward trend and the hit rate showed an upward trend.2.After the heart rate exceeds 150 beats per minute,the speed of the upper limbs decreases,the flexion angle and abduction angle of the shoulder joints decrease;the flexion amplitude of the knees in the lower limbs during squat take-off and stagnation decreases.3.In the range of 130-150 beats per minute,the activation level of the muscle and nerve working level is the highest,and the shuttle speed is the fastest.As the heart rate rises,the trapezius upper bundle,pectoralis major muscle,and deltoid muscle are among the main force muscles.The changes in the median bundle and triceps are significant,the integral myoelectricity decreases,and the muscle strength decreases;the median frequency decreases,and the slow muscle fiber mobilization increases,resulting in a decrease in the ball speed;the common muscle contraction rate increases,and the stability is enhanced to a certain extent.Improved hit rate.