Research On The Joints Angles During Doing The 3^th Radio Gymnastics For Middle-schoolers

As one of China's unique national top-down universal sports,the broadcast gymnastics has obvious advantages in all aspects,for example,the action is consistent with the movement,the rhythm is lively,the space requirement is small,and seldom needing for instrument assistance.The radio gymnastic exercises need to coordinate with each part of the body,as each joint gets exercise by appropriate activities,The exercise effect can be directly influenced by the movement range of the joint angle.In this paper,the joint angle parameters of the head and neck joint,the shoulder joint,the elbow joint,the knee joint,the hip joint and the knee joint were studied when doing the third set of middle school students broadcast gymnastics.The school survey found that Tianjin middle school mainly use the thied set of middle school students broadcasting gymnastics,as "fangfeilixiang" and "wudongqingchun " two sets,each of which includes eight sections:Stretching exercise,chest expansion exercise,kicking movement,body lateral movement,body transferring movement,abdominal movement,jumping movement,finishing movement.This experiment is divided into 16 groups according to the section.Selecting 10 healthy middle school students under the age of 15 to 16(five male and five female)as the experimental samples,using the Xsens MVN inertial motion capture system,and making joint angle measurements in head and neck joint,shoulder joint,elbow joint,intervertebral joint,hip joint,knee joint for each section.According to the experimental results,the accuracy of the joint angle values based on X-sens system is obtained,each of which contains three coordinates based on Euler angle,and then use matlab programming software and SPSS statistical analysis software to analyze the data,such as the value of the data,the mean standard,the difference analysis,and then analyze the differences between the junior and senior high school students,making comparative analysis.Through the acquisition and analysis of the joint angles of the third set of middle school students' broadcast gymnastics,It was found that there is no difference between male and female in joint angle when students doing the third set of middle school students broadcast gymnastics,and the joint angle of famale is bigger than the male's.After comparing the results of the research and analysis of the same movement in different sections,the max angle of joint angle motion range is related to the movement effect.In the comfort range of activities,the greater the angle,the effect of exercise is about good.It's discovered that a larger range of motion is these three sections of body lateral movement,body transferring movement and abdominal movement,followed by the four section of Stretching exercise,chest expansion exercise,kicking movement and jumping movement,the least is finishing movement,it shows that broadcast gymnastics choreography follows the parabola theory,which means the exercise amplitude of the beginning and the ending sections is smaller,intermediate sections is larger,so that getting buffering effect,and it is rationality and safety.There are differences between the two sets of joints in the same section of the same joint,but the whole range of motion is generally consistent,and in the comfort adjustment range,mostly close to the maximum range of comfort,which shows that the design of the action meets the relevant standards,exercise effective and comfortable.Finally,the range of motion of the 3 degree of freedom of the head and neck joint,shoulder joint,hip joint,elbow joint,knee joint and intervertebral joint was obtained by the statistical induction,which provides data support for the design of the angle of the related actions or sports equipment for the youth.