Study On The Synergistic Characteristics Of Lower Limb Muscles In The 50m Sprint Run Of Male Sprint College Athletes

Objectives: With the continuous improvement of training level,it is difficult to distinguish the factors restricting sprint ability through intuitive kinematic differences,so studying the muscle synergy characteristics under neural control in the body has gradually become a new direction to further understand the influencing factors of athletes’ sprint technology development.In this study,by collecting the lower limb muscle s EMG data of the male sprint college athlete 50 m sprint run,this study analyzed and compared the muscle synergy status of the lower limb muscle activation intensity,joint co-activation level,muscle synergy element combination and other muscle synergy conditions of the college athlete sprint running,revealed the synergistic characteristics of the lower limb muscles of the college athlete sprint run,and provided a scientific theoretical basis for improving the sprint ability of college athletes.Methods: In this study,the test method and mathematical statistics method were mainly used,and 14 male sprint college athletes of the athletics team of Wuhan Institute of Physical Education were used as the test objects,with the help of video motion capture system and portable surface myoelectric system,the kinematic and s EMG data of college athletes when they sprinted at full strength on the plastic track were synchronously collected,and Simi motion and EMGwords Analysis analysis software were used to post-process the collected raw data.The muscle synergy indexes such as the activation intensity,joint co-activation level,and muscle synergy combination of lower limbs during the sprint of college athletes were refined.SPSS statistical software was used to statistically analyze the data and reveal the synergistic characteristics of lower limb muscles in college athletes’ sprint running.According to the median of the maximum sprint running speed of college athletes,they were divided into high-speed group and general group,and the independent sample T test was used to compare the differences in muscle activation intensity,joint coactivation level and muscle synergistic combination of lower limbs in the high-speed group and general group of college athletes,and the similarity of muscle synergistic vector was evaluated based on Pearson’s correlation coefficient.Results:(1)In terms of the activation intensity of each muscle of the lower limb,the rectus femoris,gastrocnemius,soleus muscle and tibial anterior muscle of the male sprint college athletes as a whole reached the peak activation peak in the braking stage;The gluteus maximus reaches its peak activation during the propulsion phase;The lateral femoral muscle,biceps femoris and semitendon muscle reach their peak activation in the preactivation stage;The s EMG amplitude of the lateral femoral muscle in the high-speed group was significantly higher than that in the general group(P<0.05),and there was no significant difference between the other stages(P>0.05).(2)In terms of the level of joint co-activation,the co-activation level of the knee joint muscles of the upper and lower limbs of the male sprint college athletes was generally higher than that of the ankle joint;The knee coactivation coefficient in the immobilization stage of the high-speed group was significantly higher than that in the general group(P<0.05),but there was no significant difference in the ankle coactivation coefficient(P<0.05).(3)In terms of muscle synergy combination,male sprint college athletes extracted two kinds of muscle synergistic elements as a whole,and the muscles involved in the first muscle synergy element in turn included gluteus maximus,medial head of gastrocnemius,anterior tibial muscle,soleus muscle and rectus femoral muscle;The second type of muscle synergy is mainly involved in the muscles of hemitendons,biceps femoris,lateral femoral muscles,and rectus femoris muscles;The number and composition of lower limb synergists in the high-speed group and the general group were similar(r=0.943,r=0.903).Conclusions:(1)In terms of the activation intensity of each muscle of the lower limb,the cycle change of the activation intensity of the lower limb muscle of college athletes in sprint running was generally similar;The sprint ability of college athletes is affected by the change of individual muscle electromyoactive intensity,and the high-speed group athletes in the braking stage have significantly stronger lateral femoral muscle activation intensity than the general group,and the training should focus on the mobilization ability of key muscles in specific action cycle stages,and improve their personal maximum sprint speed by making adaptive adjustments to the participating muscle activation intensity to cope with their own neuromuscular control.(2)In terms of joint co-activation level,the ankle coactivation level of college athletes sprint running is relatively stable;The sprint ability of college athletes is affected by the level of co-activation of their knee joints,and the level of knee co-activation of athletes in the braking stage of high-speed group athletes is high,and the co-activation level of knee joints can be adjusted by adding strength training to enhance the stiffness of the knee joint,which can improve the sprint ability of athletes.(3)In terms of muscle synergy combination,college athletes all present similar muscle synergistic combinations,and their entire action cycle activities are mainly controlled by the calf and hip muscles participating in the muscle synergy element I and the posterior femoral muscles participating in the muscle synergy element II,which clarifies the muscle groups leading the different cycle stages of the sprint and their respective weights,and can design special movements that are more in line with the characteristics of sprint muscle synergy contraction according to the research results,so as to improve the pertinence and effectiveness of sprint training.