The Kinematics Analysis To Hook Kick Action Of The Elite Male Karate Athletes In China

Research purposeThe hooking action is one of the most important leg methods in karate sports.The hitting part is on the opponent's head,which is characterized by simplicity,rapidity and concealment.Can be used for both offense and counterattack.The hook-and-kick action is a three-point technical action.It is especially important in competitive games.It can reverse the game situation and widen the score difference.However,the current research on the hooking action is not perfect,so it is imperative to study it.In view of the importance of the technique of karate kicking,the purpose of this study is to compare and analyze the differences between the excellent karate athletes and ordinary karate athletes in the sandbags when hitting the sandbags.In order to better study the technical characteristics of the karate kicking action,Improve the technical level of practitioners to explore the similarities and differences of different levels of karate athletes;provide training basis and theoretical guidance for the scientific training of karate.Research methodExperimental subjects: The excellent group came from the Shanghai Sports Academy Karate Team(n=8),and the sports scores were the top eight active athletes in the national karate competition.The general group came from the top eight active athletes in provincial and municipal karate events and did not win the top eight athletes in the national karate event(n=8).The scientific method is established for the research through the literature method,the expert consultation method,the experimental method and the mathematical statistics method.The experimental instruments used were the VICON motion analysis system,the Kistler three-dimensional force table,and the body weight measuring device.During the test,the selected action is a karate kicking technique.The test leg selects the dominant leg of the subject,and the height is defined according to the height of the chin when the subject is in a realistic posture.This study mainly analyzes the action time,the swing leg joint angle,the swing leg joint angular velocity peak,the swing leg joint line speed peak,the support leg ground reaction force,and the body center of gravity displacement.The experimental data were expressed as mean ± standard deviation(X±SD),analyzed by independent sample T test;P < 0.05(*)was a significant difference,P < 0.01(**)was a highly significant difference.Research result1 The excellent group hook action takes less time than the normal group.Significant differences were observed during the knee lift phase and the hit phase;the reduction phase completion time presented a highly significant difference.2 In terms of the change of the angle of the lower limbs in the kick-kicking action,the hip group angle of the excellent group was smaller than that of the normal group in the knee-lifting stage,and the hip joint angle of the excellent group was significantly larger than that of the normal group.In the excellent group,the knee joint angle of the excellent group from the start-up phase to the knee-lifting stage decreased first and then increased,and the knee joint angle of the excellent group was lower than that of the normal group.The angle of the ankle joint change was greaterin the reduction group than in the normal group,and the start-up phase,the knee-lifting phase,and the striking phase were smaller than the normal group.3 In addition to the peak velocity of the hip,knee and ankle joints in the excellent group at the start-up stage,the peak angular velocity of the hip,knee and ankle joints of the excellent group were higher than that of the normal group.The peak angular velocity of the hip showed a significant difference in three stages,and the peak angular velocity of the knee showed a significant difference in the knee and reduction stages.4 In addition to the peak speed of the hip,knee and ankle joints of the excellent group at the start-up stage,the peak speed of the hip,knee and ankle joints of the excellent group were higher than that of the normal group..Among them,the peak speed of the hip joint line showed significant differences in the knee raising stage,the hitting stage and the reduction stage.During the reduction phase,the knee line velocity peak and the ankle line velocity peak showed a highly significant difference.When the excellent group performs the hooking action,the peak speed of each joint shows an increasing trend,and the hip joint line speed < knee joint line speed < ankle joint line speed.5 In the excellent group,the ground reaction force of the supporting leg in the starting and striking stage is greater than that of the ordinary group,and the ground reaction force of the supporting leg in the knee lifting and reducing stage is smaller than that of the ordinary group.The maximum trend of the ground reaction force of the four-stage support leg of the elite athlete is the knee-lifting stage>the starting stage>the hitting stage>the reduction stage.The maximum trend of the ground reaction force of the four-stage support leg of the ordinary athlete is the knee-lifting stage>starting stage>reduction Stage > Strike stage.6 Excellent group changes in the center of gravity of the four stages are smaller than the ordinary group.In the knee-lifting,hitting,and reducing stages,the two groups of athletes showed significant differences.7 The excellent group's shift in the center of gravity of the four stages is smaller than that of the normal group.In the knee-lifting,hitting,and reducing stages,the two groups of athletes showed significant differences.Research conclusion1 Excellent athletes have short movement time,and excellent athletes are quicker than ordinary athletes.In training,attention should be paid to the training of karate athletes' muscle rapid contraction ability,and the emphasis on speed strength training,including the coordination of movement.Under the premise of ensuring the integrity of the action during the whole process of kicking the hook,it is necessary to pay attention to the completion speed of the restoration phase and shorten the time taken for the kicking action.2 Excellent athletes can actively raise their hips during the hitting stage,use the waist strength to drive the swinging legs,and pass them to the calves to the ankles to reach the sandbags.The knee joint angle of the excellent athletes in the knee-to-hit stage is larger than that of the ordinary athletes.The full-scale clamping of the large and small legs leads to a large change in the angle of the knee joint,and prepares forswinging the legs back to the hook during the striking phase.In order to avoid excessive stretching of the knee joint of the swinging leg during the start-up and reduction phases,the recovery distance can be shortened to reduce the time required for the reduction phase,and the stability of the knee joint can be enhanced to protect the knee joint from sports injuries.3 In addition to the peak velocity of the hip,knee and ankle joints in the excellent group at the start-up stage,the peak angular velocity of the hip,knee and ankle joints of the excellent group were higher than that of the normal group.It shows that the excellent athlete's hip flexion and knee speed are fast,the muscle contraction speed is fast,and the muscle coordination ability is good.4 In the three stages of knee lifting,hitting and reducing,the peak speeds of the hips,knees and ankles of the excellent group were higher than those of the normal group.In daily training,attention should be paid to the practice of movement speed,especially the speed of swinging the legs to improve the ability of the muscles to contract quickly.Factors affecting the speed of movement also include the proficiency of the movement and the ability to coordinate the various aspects of the body.5 The outstanding players' ground reaction force in the starting and striking stages is greater than that of ordinary athletes.The ground reaction force of the supporting legs in the knee lifting and reduction stages is smaller than that of ordinary athletes.The maximum trend of the ground reaction force of the four-stage support leg of the elite athlete is the knee lift phase > reduction phase > hit phase > start phase.In the daily training,we should pay attention to the leg movement and reduce the time spent in the reduction phase.Increase the leg strength training to ensure that the support legs are forced to exert force.The greater the support leg force,the less time it takes,thus improving the completion speed of the hooking action.6 When the excellent athletes do the hooking action,the displacement of the center of gravity and the displacement of the center of gravity are smaller than those of the ordinary athletes,and there are significant differences in the stages of hitting,knee lifting and reduction.When doing the hooking action,try to ensure that the center of gravity sinks,so that the swinging leg can control its own center of gravity when swinging,ensure its own balance,ensure that the kicking action is completed in the fastest speed and the shortest time,and all muscles contract strength and The speed is used for the swinging of the swinging leg.