| Shooting is an event of accurate performance and demands highly on shooter's stability, regularity, consistency, self-control and anti-interference ability. Compared with other events, shooting is special as long time, less changeable gesture, and high concentration. Shooters should keep in excellent condition both mentally and physically. Besides the inner factors, the performance can also be in influence by the outer factors such as outfit, forum situation, weather, gun and bullet. In order to ensure a stable performance, shooters should decrease the influence of inner factors. The first thing is to strengthen the stability, regularity, consistency, decisiveness that is to keep the vibration range, aiming, shooting time choosing and shooting in high consistency during the first and last motion to get a satisfactory performance.The development of modern shooting especially the pistol shooting unceasing improved the accuracy require, which lead to more severe competition and fierce events. China has kept an advantage in shooting for a long time, and shooters have always been proving themselves in Olympic Games. It is well-known that Xu Haifeng won the first gold medal for our China in 1984 Los Angeles Olympic. In 2008 Beijing Olympic, Chinese shooter Pang Weili won a gold medal in Men's 10m air pistol, which proves the leading position in shooting events especially in air pistol. In the air pistol field, it is widely accepted that shooting events especially the air pistol should emphasize on "keeping stability and shooting naturally"----emphasis on stability, consistency and coordination of holding, aiming and shooting. Air pistol is a technical accuracy event combined static with dynamic strength. As the shooters keep a gesture of holding gun with single hand for a long time, the muscles in pistol holding arm is always in long-period isometric contraction, which may lead to short-term hypoxia in heavy load training or even chronic muscle strain cause by over fatigue. The present scientific research has made tremendous achievements. In psychological part, methods to detect, analyze and solve shooters'psychological problems and psychological training methods have made a sound system. Physiological and biochemical index is applied to and proved to be efficient in reflecting the training intensity and volume, and shooters'functional state and health state. However, research on shooting features by SEMG is limited, and research on SEMG of pistol-holding arm has not been found in the previous literature.Limited by the research methods, it used to be difficult to make quantitative research on pistol shooters'muscle strain relationship and its rule. With the development of computer science and materials science, the miniaturized myoelectricity test equipments are easier to carry, which makes it possible to make quantitative research on pistol shooters' muscles in the shooting process. Heavy load training period is significant in improving the physical functions, technical standards, and competition ability of air pistol shooters. Strength caused by muscle strain is the basic of all movements including shooting. The features of shooting are the certain ways of muscle strain, so the stability and consistency of shooters muscle strain is one of the key factors for good performance. SEMG signals can reflect regular discharging pattern of the muscle fiber, and monitor the state of certain muscles in action. It is safe, simple and repeatable. Detailed reports on SEMG variation of Pistol-holding arm of air pistol shooter after heavy load training has not been found.This research is based on wide and long-termed investigation of some municipal and provincial and shooting teams' preparing for the National Games and takes the SEMG as main technique and balance ability test and lizard aiming test as the supplementary means. This research analyzes basic features of pistol shooting events and aims to lay the foundation for scientific training of pistol shooting. The research includes:(1) SEMG features research on the shooting techniques of elite slow fire pistol shooters; (2) biomechanics features research on the pistol holding arm of elite rapid fire air pistol shooters; (3) research on muscle variation after heavy load training of pistol holding arm of elite air pistol shooters; (4) research and produce of monitoring system of shooters' technique training based on statistics.From the perspective of epistemology, this research analyzes the practical situation of shooting teams preparing for the Olympic Games and National Games and technical features of SEMQ combines the research methods of literature study, interview and mathematical statistic study, and gets a conclusion by exploring, testing and deepening the knowledge on SEMG features of elite pistol shooters in practical training. Conclusions are listed as below:1. In the process of elite slow fire pistol shooting, anterior bundle of deltoid, the middle bundle of deltoid, trapezius muscle and radial extensor muscle of wrist are main muscles; bicipital muscle of arm, triceps muscle of arm and are auxiliary muscles. Second-level shooting athletes' have more obvious variation in contribution rate and amplitude of anterior, middle and back bundles of deltoid, which may be the main reason that influences the shooting performance of second-level athletes. For first-level athletes, the contribution rate of radial extensor muscle of wrist has obvious difference in 3 sec and 1 sec before shooting, but has no obvious difference in 2 sec and 1 sec before shooting, which shows that satiability before shooting ensures the stability of shooting performance. The contribution rate of eight muscles used in shooting of national masters of sports and international masters of sports keep stable. The shooting performance may be influenced by shooters' psychological state or instability of other untested muscles. From the perspective of the consistency, anterior bundle of deltoid and trapezius muscle are the main muscles influence the consistency of gun. The variation in amplitude can more effectively reflect the muscle strain consistency.2. In our country, gravity center of elite air pistol shooters vibrate in front-back direction more than in left-right direction, and vibration in both direction in not obvious; Shooters with smaller gravity center vibration make better performance. Chinese female air pistol shooters need to improve their coordination of related muscles in aiming and shooting periods; muscles strained in pistol holding arm are(in maximum to minimum order) anterior bundle of deltoid, trapezius muscle, the middle bundle of deltoid, radial extensor muscle of wrist, triceps muscle of arm, back bundle of deltoid, bicipital muscle of arm, and flexor digitorum superiicialis muscle. In the process of shooting, integrated electromyogram (IEMG) of muscles in pistol holding arm increased gently, and the curve of less functional muscles rise slightly that have small influence on the performance change caused by muscle fatigue in shooting process. Average shooters have more obvious IEMG variation of main strained muscles. In our country, high level female shooters spend less time in aiming and choose the first stable period to shoot; in the aiming phase, the pistol vibrates in up-down direction more than in left-right direction. Shooters with better performance have bigger the scan speed of firearm, and make longer vibration line at 3 sec before shooting. Shooters with better performance have smaller including area of pistol vibration than average shooters; shooters with longer training year and better performance have smaller d-value of impact point in the shooting moment. Body balance ability, muscle coordination of pistol holding arm, and vibration of pistol are three factors influencing one another. When the body balance ability decreases, the muscles in pistol holding arm are strained to keep the pistol stable but decrease the coordination ability of muscles, which will broke the natural vibration pattern of pistol and stability of shooting movement and lead to low ring performance.3. Influence on the muscle contribution rate of air pistol shooters is mainly shown in three parts which are trapezius,the fasciculus anterior of deltoid and musclulus flexor digitorum sublimes. High frequency of pistol raising, small angle of pistol holding arm and body forces the trapezius strain to make force and the contribution rate of musculus flexor digitorum sublimis will raise obviously, but the smooth electromyogram curve and high consistency shows better stability of technical movements. Obvious vibration in musclulus flexor digitorum sublimes may influence the shooting movement and affect the accuracy of ring 10. By analyzing the SEMG index sensation range of predominant shooters in heavy load stage, technique motion situation can be decided in following training and provide object and personal diagnosis.4. When Shanxi, Hebei and other principal and municipal shooting teams are positively preparing for national games, the monitoring system of shooter technique training will be developed to standardize the training index of every event in every training stage and set up a hierarchical data base, and it will be applied in the last training stage in preparation for National Games.
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