Research On Technical Characteristics Of Elite Athletes In Men’s Rapid-fire Shooting Events During Shooting Phase

Purpose:the purpose of this study is to explore the differences of technical movements of elite athletes in rapid fire pistol under different time conditions by biomechanical measure,so as to provide theoretical basis for the future research and development of this event.Methods:Five rapid-fire pistol athletes were recruited form China national shooting team(both are right-handed),completing six 5-shot series in order of 4 sec.,6 sec.,and 8 sec.Qualisys infrared high-speed motion capture system was used to collect kinematic data with sampling frequency of 200 Hz;DELSYS wireless portable surface electromyography instrument was used to collect EMG signal with sampling frequency of 2000 Hz;Kistler was used to collect displacement data of pressure center with sampling frequency of 1000 Hz.Result:1.Under different time conditions,there are significant differences in the total firing time,time of gun movement,aiming time and aiming time ratio in the single firing process of each athlete during shooting phase.2.Under time conditions,there were significant differences in rotation Angle between different segments and radius length of wrist circle fitting of athletes.3.Under different time conditions,there were significant differences in the peak values of tremor power spectrum in the lateral direction and vertical directions of the upper limb of five athletes.The peak of the tremor power spectrum of the gun barrel in the vertical direction was greater than that in the lateral direction.4.Under different time conditions,there were significant differences in the RMS and iEMG value of surface myoelectricity.Conclusions:1.The athletes adopted the strategy of reducing the rotation of the upper limb relative to the trunk and increasing the twist of the hip joint in the 8 sec shooting,while increasing the rotation of the upper limb to compensate for the decrease of the twist Angle of the hip joint in the 4 sec.shooting.In the future,more attention can be paid to the rotation Angle of the upper limb and hip joint in the process of shooting phase under different time conditions.2.In a 4 sec.shooting,the barrel didn’ stabilize in the vertical direction before firing,which was not conducive to aiming.3.When the shooting time was shortened,the vibration amplitude of the limb ends increased,which affects the stability of the gun.The results of this study showed that the amplitude of tremor in shooting phase was related to sports performance.In the future,more research on the influencing factors of tremor could be carried out to explore the methods to reduce the level of tremor in shooting.4.When the shooting time is shortened,the muscle activation is greater,which was not conducive to shooting performance.