Effect Of Different Parts Of Muscle Force On Distance Of Standing Long Jump In Teenagers Based On Surface Electromyography

Research objective: To quantify the contribution of muscle strength of different parts of the body to the distance of standing jump,reveal the muscle strength characteristics of different parts,establish the key force phase of different parts of the muscle strength,and improve the recognition of the whole movement specification.Methods: The VICON infrared 3D motion capture acquisition and analysis system and Noraxon Ultium surface electromyography acquisition and analysis system were used to complete the surface electromyography acquisition and analysis of 18 randomly selected subjects during standing long jump.Noraxon’s built-in MR3.16 software was used to process and analyze the collected EMG signals and obtain the integrated EMG value.Then data processing and mapping were carried out through EXCEL2017,SPSS21.0 and Origin2022.Research results:(1)In the pre-pendulum stage of take-off,the muscle with the largest integr ated EMG value was the posterior deltoid tract.From this stage,the contributio n ratio of upper limb,trunk and lower limb muscles was basically maintained i n the range of 1:1:1;In the stage of take-off,push and stretch,the contribution rate of lower limbs is the largest,and the contribution rate of trunk muscle is not much different from that of upper limb muscle.The integrated EMG value of muscles is shown in the order from large to small: Anterior deltoid tract→r ectus femoris→posterior deltoid tract→medial gastrocnemius→upper trapezius→bi ceps femoris→erector spinus→lateral gastrocnemius→semitendinosus→pectoralis major→latissimus dorsi→gluteus maximus→external oblique abdominal muscle→r ectus abdominis;Contribution rate of lower limb muscle>contribution rate of up per limb muscle>contribution rate of trunk muscle.From the perspective of low er limb muscle,the semitendinosus muscle had the highest integrated EMG valu e and contribution rate;from the perspective of upper limb muscle,the deltoid tract had the highest integrated EMG value and contribution rate;from the pers pective of trunk muscle,the upper trapezius muscle had the largest integrated E MG value and contribution rate.The integrated EMG value of the deltoid poste rior bundle was the highest in the descending stage,and the contribution rate o f the upper limb muscles was the largest.The contribution rate of trunk muscle was the least.In the landing stage,the integrated EMG value and contribution rate were in descending order as follows: anterior deltoid bundle→upper trapez ius→medial gastrocnemius→posterior deltoid bundle→erector spinus→latissimus dorsi→semitendinosus→pectoralis major→gluteus major→biceps femoris→lateral gastrocnemius→triceps eps femoris→rectus abdominis→external oblique abdomin al muscle,contribution rate of trunk muscle>contribution rate of lower limb mu scle>contribution rate of upper limb muscle.(2)In terms of the influence of different muscle forces at different stages on the distance,the posterior tract of deltoid muscle,biceps femoris,triceps humerus and other muscle groups have significant influence on the distance at the pre-swing stage of take-off;Semitendinosus muscle,trapezius muscle,pectoralis major muscle and other muscle groups have a significant effect on the distance of push off extension stage;Triceps,external oblique,rectus femoris and other muscle groups have a significant effect on the distance of the ascent stage.The upper part of trapezius muscle,biceps femoris muscle and anterior tract of deltoid muscle had significant influence on the distance of the descending stage.Latissimus dorsi,gluteus maximus,external oblique abdominal muscle and other muscle groups significantly affect the distance of landing stage.Triceps,deltoid tract,latissimus dorsi,semitendinosus,rectus femoris,trapezius upper,pectoralis major and biceps femoris had significant influence on the total distance of standing long jump.(3)From the time phase analysis of the key force that the distance of the standing jump mainly affects the muscle group;The main exertion phase of semitendinosus muscle occurred from the ascending stage to the descending stage of the ascending stage.The biceps femoris occurred in the ascending stage of aeration;The latissimus dorsi muscle occurs in the ascending stage of flight.The anterior tract of deltoid muscle occurs in the transition stage from ascending to descending.The pectoralis major muscle is the take-off,push and extend stage,the ascent stage and the descent stage.The rectus femoris occurs in the ascending stage.Triceps occurred in the ascent stage;The trapezius muscle occurs during the transition phase from pre-swing to push.Research conclusion:(1)The contribution rate of upper limb muscle group was basically the same in different stages,indicating the importance of synergistic exertion of upper limb muscle group in completing the whole movement;The trunk muscle group was better than the upper and lower limb muscle group in the landing stage,showing the strength characteristics of first rising,then falling and then rising.The contribution rate of lower extremity muscle group was the most obvious in the ascent stage,showing the power sequence characteristic of first ascending,then descending and then ascending.(2)From the regression analysis of measured muscles to the distance of each stage of the standing long jump,biceps femoris is the main accumulator muscle in the pre-swing stage of take-off;The force of semitendinosus muscle and trapezius muscle is beneficial to the increase of the distance in the take-off and push stage.The force of the external oblique muscle of the abdomen is beneficial to the elevation of the distance in the ascending stage.The anterior deltoid binding force is beneficial to the elevation of the distance in the descending stage and landing stage.Deltoid muscle strength is beneficial to the improvement of the total distance of the standing long jump,which further indicates the importance of upper limb deltoid muscle strength.At the same time,it also shows the importance of the order of major muscle strength in different stages.(3)Through time series analysis,it was found that the semitendinosus muscle changed from the ascending stage to the descending stage;Biceps femoris,rectus femoris,latissimus dorsi and triceps humeris in the ascent stage;The anterior tract of deltoid muscle is in the transition stage of ascending to descending in the air;Pectoralis major muscle in the stage of take-off,push and stretch,airborne ascent and airborne descent;The force performance of the trapezius muscle in the transition stage from preswing to push and extend can be used as the main identification parameters of the standing long jump,which can effectively distinguish different types of movements.