A Research Of Motor Characteristics Of Jump Shot In Basketball

Shooting is the only way of scoring in a basketball game,jump shot is the scoring means which is used most in modern basketball game,and it is a technique of shooting which is quite difficult to master,many high level athletes have excellent hit rate.The research of jump shot can help coaches and athletes deepen understanding of the movement regulation and the movement characteristics of the jump shot,promote the norms and rationality of shooting skill,and improve the ability of use such a skill in game.The research methods used in this paper include:(1)data acquisition methods,including:expert interview,the three-dimensional imaging method in game scene,infrared high-speed three-dimensional imaging method,three-dimensional force,two-dimensional plane shooting.(2)methods for the analysis of data,including:using vector coding method to calculate the values of coordination-variability of elbow-wrist.regression analysis method combining with uncontrolled manifold(UCM),analysis the variation in structure and function of multiple variables(degrees of freedom)related to the results of jump shot.(3)data statistical methods,including:single factor analysis of variance,multiple factor analysis of variance.The main conclusions are as follows:(1)long distance shooting in a game need to be with the help of the upward velocity of the center of gravity,so that it can exert a greater force on the ball,and produce bigger releasing speed.The maximum outspread speed of elbow is almost simultaneous with the releasing moment of the ball.The extension of elbow plays a decisive role in the speed of the ball.(2)A slight elbow outward during the phase of stable and a slight backward lean of trunk in the moment of release,and the rotation of shoulder axis and hip axis,which are adapt to the anatomical structure of human body,in line with the principles of sports biomechanics,conducive to the practical application of match are reasonable postures and actions.(3)These actions such as the rotation a(1)adduction,abduction of the upper arm,the rotation of forearm and adduction of palm etc.are synchronization with the bend and extension of shoulder,elbow and wrist,which will help the player to effectively control and adjust the direction and force to the ball before shooting.(4)Because the defensive intensity is bigger than others in high level group game,in order to maintain the stability and accuracy of the shooting.it must take a faster and higher jump to reduce interference from the defenders to the greatest extent.During the phase of lifting ball,faster flexing shouder joint help to entering the phase of stable and the phase of shooting,so help to release the ball faster.(5)These exterior constraint conditions such as the shooting distance,the connection of action,the experience of practice and with or without defense etc.will lead to change of these factors such as the parameters of release during jump shot,the angle and speed of joint movement,body posture,and the controlling of center of gravity.(6)The release velocity of misses is generally lower than the optimal release velocity which the specific release height and release distance requires,which will make the ball can not get enough power to generate proper motion trajectory and enter angle.The change of the coordination-variabilityof elbow-wrist joint changes the fluency and coherence of controlling force and direction to ball.(7)The coefficient of variation ratio calculated by the uncontrolled manifold method,which is with the release speed of the tip as control variables,were greater than zero under different constraint conditions,which showing coordination characteristic flexibility due to the existence of motion freedom redundancy during jump shot.The flexibility of coordination characteristics shows difference in degree due to the difference of constraint conditions.