Study On The Technical Characteristics Of Chinese Elite Female Hammer Athletes "Late Fall Early Lift"

Objective: The women's hammer is a traditional track and field track project of our country.Although it started late,it has developed rapidly,and its performance has grown rapidly.The level of sports ranks among the front ranks of the world and has won our honor in the international competition.This article selects the results that are close to the research object,and uses the knowledge of kinematics,biomechanics,and other disciplines to analyze the characteristics of Chinese women's excellent hammer throwing techniques in three aspects: rhythm,speed,and trajectory,and discovers the advantages and existence of Chinese players.The main issues are to seek the right direction of development;provide basis for training methods,means,content,and training plans;and provide assistance for athletes to further improve and perfect the throwing technology.Method: Two Casio high-speed cameras with model EX-FH25 were used to perform fixed-focus three-dimensional photography.The first machine was placed directly behind the throwing direction.The second machine was placed on the right side perpendicular to the throwing direction.The two cameras shot at the same frequency.For 120 frames/S,the angle between the main optical axis is approximately90° and the height of the two cameras is approximately 1.2 meters from the ground.Recorded the entire process of the athlete's game;selected the American ARIEL company's APAS motion analysis system to analyze the captured images and calculate the data required by the research institute.Conclusions:(1)On the rotation time,the athletes of our country are declining each lap time,and the time of single and double support is shortened with the shortening of each lap time,which is in line with the technical requirements of chain sprocket;the duration of single support is common in the third and fourth laps.The situation of double support time shows that the allocation time between single and double supports is unreasonable;(2)The Chinese athletes' utilization rate of pre-swing is not high,and the pre-swing speed is not maximized.In the change of the ball speed,the overall trend is upward.The increment decreases as the number of laps increases.In the phase of rotation,the increase in the speed of Chinese sports mobilization is mainly in the double-support stage.The speed of single-support stage is more obvious and accelerates in the single-support stage.(3)The Chinese athletes have higher angles of slope and higher center of gravity during the rotation stage.In the moment of right foot landing,the upper body lifted slightly higher,which is not conducive to the acceleration of the double-support stage hammer.Compared with thefirst two circles of the third and fourth laps,the trajectory length is shortened,and the trajectory length of the single-support stage also appears greater than The length of the double support stage trajectory,the upper limb stretchability in the double support stage is poor,affecting the length of the rotation radius,there is an unreasonable existence in the rotating technology.