Analysis Of Lower Extremity Surface Electromyography Characteristics Of Healthy Male Runners Based On Gait Cycle

Research objectives: By analyzing the kinematic parameters and surface electromyography parameters of running movements of healthy males collected,the purpose is to explore the movement structure and power generation characteristics of this technology,and to understand and master the kinematic characteristics of lower limbs and surface electromyography activities of main power generation muscle groups of healthy adult males during running.In order to provide scientific and reasonable reference significance for running from the perspective of gait cycle and surface electromyography,it can enhance the effect of running training and fitness while reducing the occurrence of sports injuries.Research methods: In this study,the data of 7 pairs of lower limb muscles of 12 healthy males in running state were collected by Noraxon electromyography testing instrument.Meanwhile,the kinematic data of running gait was collected by Vicon threedimensional dynamic capture system,and the collected electromyography parameters were analyzed by MATLAB.Research results:(1)In the brace phase,the flexion and extension angles of the knee joint and ankle joint increase first and then decrease,and the angular velocity decreases first and then increases and then decreases;In the swing phase,the Angle of the knee joint first increases and then decreases,the angular velocity first increases and then increases,and the Angle of the ankle joint first decreases and then increases,and the angular velocity first increases and then decreases,and then slightly increases and then decreases.(2)The maximum angular velocity of extension and flexion of the knee joint appeared in the swing phase,the maximum angular velocity of plantar flexion of the ankle joint appeared in the support phase,and the maximum angular velocity of dorsiflexion appeared in the swing phase.(3)In the landing buffer period,the integrated EMG value of muscles was in the order of medial head of gastrocnemius → lateral head of gastrocnemius → rectus femoris → semitendinosus → long head of biceps femoris → external muscle →internal muscle.On the whole,there was little difference in the discharge amount of each muscle at this stage.(4)In the postpedal period,the lateral head and medial head of the gastrocnemius muscle had the largest discharge capacity,contributing 57.01%,which were the main muscles of exertion at this stage.(5)Compared with the previous two stages,the electromyography integral value of the flexural stage before folding decreased significantly.The lateral head of the gastrocnemius muscle had the highest electromyography value,followed by the semitendinosus muscle,and the external femoris muscle and rectus femoris muscle had the lowest electromyography value.(6)The integrated electromyoelectric value of the muscle in the pressing preparation period was in the order of semitendinosus → long head of biceps femoris → internal muscle → medial head of gastrocnemius → lateral head of gastrocnemius → external muscle of femoris → rectus femoris.Semitendinosus and long head of biceps femoris were the main generating muscles,and the combined contribution rate of muscles reached46.22%.(7)From the point of view of the critical force phase of the measured muscles,the critical force phase of the rectus femoris muscle occurred in the early stage of the back push,the middle stage of the swing before folding and the stage of the push down to prepare for landing;The femoris external muscle occurs in the back push phase,the swing phase before folding and the press preparation phase,the femoris internal muscle occurs in the initial landing phase,the front and middle of the back push phase and the press preparation phase,the back push phase,the swing phase before folding and the press preparation phase corresponding to the semitendinosus,the long head of the biceps femoris corresponds to the back push phase,the swing phase before folding and the press preparation phase.The lateral head of the gastrocnemius muscle corresponds to the later stage of landing buffering and the swing stage before folding,while the medial head of the gastrocnemius muscle corresponds to the later stage of landing buffering and the push period.Research conclusion:(1)During the landing buffer period,the knee joint is the main buffer site with a large buffer range.At the moment of landing,the Angle of the knee joint changes greatly and the angular velocity is high,which makes it easy to be injured.At this stage,the lateral head of the gastrocnemius,the medial head of the gastrocnemius,the rectus femoris and the semitendinosus had high em G integrals,which played an important role in landing cushioning.(2)In the early stage of the push back,the Angle and angular velocity of the ankle joint changed the most,which was the main push extension joint.In this stage,the medial head of the gastrocnemius muscle and the lateral head of the gastrocnemius muscle were the main force groups,accounting for more than 50% of the contribution rate,indicating that the ankle joint had a large force at this stage,and the related muscles were more prone to injury.(3)Knee flexion is the main manifestation of the swing period before folding.In this stage,the ankle joint first flexes the plantars and the back flexes.In this stage,the contribution rates of the front thigh muscle group,the back thigh muscle group and the calf muscle group are not different,approximately reaching 1:1:1.(4)Knee extension and ankle dorsiflexion are the main manifestations in the stage of preparation for landing under pressure.The maximum knee angular velocity in the whole gait cycle occurs at this stage,which is more prone to injury.Attention should be paid to preventing knee joint related muscle strain.(5)According to the time series curve analysis,in order to distinguish different types of running movements,the force performance of the medial femoris muscle and the lateral head of the gastrocnemius muscle can be used as the main identification parameter during the landing buffer period,and the force performance of the rectus femoris muscle,the external femoris muscle,the medial femoris muscle,the semitendinosus muscle and the lateral head of the gastrocnemius muscle can be used as the identification parameter during the back push period.During the swing period before folding,the rectus femoris,the externus femoris and the semitendinosus were used as the main force performance identification parameters.During the press preparation period,the main force performance of the rectus femoris and the semitendinosus muscles were used as the identification parameters to distinguish different movement types.