| In this study,infrared human motion capture and surface electromyography(SEMG)test were used to collect and sort out the kinematics data and electromyography signals of the male 100 m second-class athletes’ mid-way running techniques,and to analyze and study the joint movement characteristics and muscle exertion characteristics,so as to clarify the kinematics and surface electromyography characteristics of the mid-way running techniques and the optimization path,and to provide reference for the basic coaches(teachers)in the process of teaching and training the 100 m running techniques.Research methods:(1)Literature review;(2)Expert interview;(3)experimental method;(4)Mathematical statistics.The athletes in this experiment are all 100 m second-class male athletes majoring in sports training in Shanxi University.The instruments used in the experiment are Vicon infrared human motion capture system in Britain and Noraxon wireless surface electromyography tester in the United States.Research conclusions:(1)The ratio of the flying time to the supporting time is unreasonable and the step length is short.At the moment of maximum buffering,the knee joint angle of swinging leg is larger,which will increase the extra radius of rotation and moment of inertia.The landing angle is small at the moment of landing,which leads to the long front support distance.In the whole supporting stage,the cushioning amplitude of ankle joint and knee joint is small,the cushioning posture of knee joint is too high,and the back pedal angle is too large at the moment of back pedal off the ground,which will lead to unnecessary vertical component and directly affect the horizontal displacement speed of athletes.(2)In the process of running and swinging during the sprint,the sequence of peak activity of EMG amplitude of the measured muscles is: tensor fascia lata → rectus femoris→ medial femoris → tibialis anterior → biceps femoris → gluteus maximus →gastrocnemius.During the sprint,the peak activity sequence of EMG amplitude of the measured muscles is gluteus maximus → rectus femoris → medial femoris → gastrocnemius →biceps femoris → tensor fascia lata → tibialis anterior.The muscles that exert the main force will exert different degrees of force in different action phases and different joint angles.In the folding forward swing stage,tensor fascia lata,gastrocnemius and rectus femoris are the main exertion muscles;Biceps femoris and gluteus maximus are the main muscles in the stage of pressing down and preparing for landing.In the landing buffer stage,biceps femoris and gluteus maximus are the main exertion muscles;In the back pedal stage,biceps femoris,gluteus maximus and gastrocnemius are the main exertion muscles.(3)Biceps femoris is a bicuspid muscle,which makes the greatest contribution in the whole running process,and is prone to the phenomenon of "lack of initiative".The rectus femoris is a double-jointed muscle,which has the mechanism of rapid contraction and relaxation during running.Gastrocnemius is also a double joint muscle,and its flexibility and strength play an important role in cushioning and pushing back. |
