Kinematics Analysis Of The Difficulty Triple Connection Of Aerobics (C466?C288?A207)

The three-connection combination action is proposed for the first time in the2017 version of the rule,and reaching the minimum completion standard will get an additional 0.2 points.In this paper,the difficulty combination(C466,C288A207)is studied by means of literature,expert interview,experiment and mathematical statistics,in order to find the technical model and error-prone point of the selected three-connection action.In this paper,Qualisys infrared spot high speed motion capture system is used to collect the data of the movements completed by four athletes,from which one highest score action and one minimum score action are selected,and the highest score action is split and analyzed.Select the correct technical characteristics,and compare the lowest score action with the highest,find the error-prone link and the easy-to-fan error,and provide a reference for the training and teaching of the difficulty action combination.The research conclusions are as follows:1.The elastic potential energy of the former difficult C466 take-off buffer stage of the four athletes is more,and the average total time of the take-off stage is 0.24 s,which belongs to the rapid stretch and contraction cycle.At the time of landing of the take-off legs,the athletes' torso is tilted back 20 °,and the center of gravity is backward.The horizontal initial velocity is more optimized to convert the horizontal initial velocity into upward kinetic energy.When the maximum angle of difficulty is vacated,the torso of the athlete tilts forward from 10 °to 20 °,and the center of gravity moves forward slightly,which is beneficial to maintain the control attitude and kick into a longitudinal fork.2.The first connection stage has a strong centrifugal power rate,and the knee joint extension force is the dominant force in the pedal and extension stage,which prepares for the pedal off the ground.The average time of the athletes in the connection stage is 0.22 s,which belongs to the rapid stretch and contraction cycle.In the connection stage,it is necessary to make an active rotation and form a certain torsional amplitude of the shoulder.In order to store the core anti-rotation energy and increase the initial speed of the rotation at the moment of departure,the flexion angleof C288 is less than 60 °,which meets the requirements of the rules.The quality of the whole action is high,the hip should be extended and rotated actively in the stage of take-off and fall,and 180 °before touching the ground,so as to make sufficient accuracy for landing buffer.Ready.3.During the buffering process of the second connection stage,the elbows are mainly buffered by the elbow joint,and the angle of the elbow joint is between 60 °and 80 ° at the maximum buffering time.All the pedal extensor groups are fully centrifugal and shrink,and the elastic potential energy is stored in the stage of pushing the hand off the ground.In order to prepare for pushing off the ground,the success rate of difficulty A207 after completion is not high,only one person reaches the standard at the moment of flexion,the angle of flexion is slightly worse,and Cheng Wensen has a good posture.4.The trajectory of the center of gravity of the four athletes is basically the same,the displacement of the center of gravity of the body moves up and down in waves,the displacement of the center of gravity changes greatly in the take-off stage,and the core control ability is strong.The higher altitude is the premise of completing the difficult movement and increasing the stability of the action.The displacement of the center of gravity of the body before and after the displacement is large,and the displacement of the difficulty in the middle and back is small,and almost rise and fall in place.5.Through the analysis of easy to make mistakes,it is found that the stage in which athletes are prone to problems is the second connection stage and the post-difficult emptout stage,and the easy to make mistakes is as follows:(1)the horizontal speed of the first connection stage has not been overcome.As a result,the horizontal displacement of the medium difficulty is large.2 the first connection stage and the middle difficulty take-off and decline stage do not actively turn.3 the second connection stage cushions passively,the pedal extension is not enough,and the difficulty is not enough.