The Analysis Of The EMG Characteristics Of The Soccer Goalkeeper's Hook Throwing Technique

Modern goalkeepers are becoming more and more involved in the overall tactics of a team while guarding their own goal.As one of the most common ways of serving by goalkeepers,handball throwing is often used by goalkeepers as one of their passing methods.According to some research data,in the 20 th World Cup in Brazil,the handball throw service accounted for 63% of the total service times of the goalkeeper.Those quick,long hand throws often play a key role in the game.Research purposes:This paper attempts to apply wireless Surface electromyography(SEMG)to the study of goalkeeper hook throwing.Through the processing and analysis of electromyography signals in different movement stages of hook throwing,and the technical movement analysis combined with the knowledge of sports biomechanics,sports training,etc.,the author hopes to find the electromyography characteristics of the movements of the technique and provide theoretical basis for the training guidance of the special technique.Methods:In this study,7 college athletes with professional sports training in football and the required technical level were selected as subjects,and the EMG data of the subjects during the hook throwing technique were collected using the Delsys Trigno wireless surface EMG acquisition system.Using the data processing software of EMG Works Analysis to process the raw data,get muscle activation time and the relevant data such as Integral myoelectricity,in order to study football goalkeeper in the preparation phrase(lead arm),ball throwing phase(handwaving)and each link in the process of the whole muscle activation sequence,the activation time and contribution rate and other characteristics,find out technical movement characteristics,so as to serve the daily training plan and optimization.Results:(1)Preparation phase: During the preparation phase of the action,subjects showed the general characteristics of the trunk muscles(erector spinae,latissimus dorsi,and rectus abdominis)being activated first and for a longer duration.In terms of muscle contribution rate,the muscle contribution rate of deltoid muscle and triceps muscle was significantly higher than that of other muscles,while the muscle contribution rate of erector ridge muscle,latissimus dorsi muscle and rectus abdominis muscle was relatively low.(2)Ball throwing phase: At this stage,almost all the muscles of the subjects were activated at the beginning of the movement.In terms of activation time,most subjects had relatively average muscle activation time at this stage,and the activation time of the middle abdominal rectus,erector spine,pectoralis major and latissimus dorsi muscles was longer than that of other muscles.In terms of muscle contribution rate,in this stage,overall,the subjects showed that the muscle contribution rate of flexor carpi radialis,pectoralis major and deltoid was higher than that of other muscles.(3)The whole stage: Overall,the subjects' trunk muscles activated earlier than the upper limb muscles.From the perspective of muscle activation duration,the activation duration of the erector spinae and latissimus dorsi muscles was longer than that of other muscles in the whole stage,and the activation duration of other muscles was relatively average,while the activation duration of brachioradialis muscle was the shortest.From the perspective of muscle contribution rate,in general,the contribution rate of flexor carpi radialis,brachioradialis,triceps brachii,deltoid and biceps in the whole movement stage is significantly higher than that of other muscles.Conclusions: 1.The trunk muscles(erector spinae,latissimus dorsi,rectus abdominis) are activated first and for the longest time in preparation for the hook throw,and the activation sequence reflected the characteristics of large joints driving small joints.2.The throwing phase(swing arm)of the hook throw is a continuation of the preparation phase(lead arm),and most muscles are pre- activated before the throwing phase.3.The main muscle activity characteristic of hook throw is that the trunk muscles activate earlier and for a longer time,and the muscle contribution rate of each stage is that the upper limb muscles are larger than the trunk.Increasing the contribution rate of trunk muscles within a certain range is conducive to better completing the technical movements.