Kinetic Analysis Of The Last Two Steps Of The Throwing Step And The Final Attempt From The Left Support By Excellent Men Javelin Throwers In China

Kinetic Analysis of the Uses of the Explosion Force and its Key Factors. Javelin throwing is an event with light sports equipment with the nature of multi-axis. The whole process is to hold the javelin, accelerate the speed, obtain energy, focus the explosion force on the vertical axis and let go the javelin from over the shoulder successively. In the whole process, the explosion force is the key step to accelerating the javelin. The braking, buffering, and stepping of the left leg, as well as the braking of the left arm play an important role in the outburst and acceleration of the javelin. The close connection of the last two steps and the outburst of the focused force is the key technique in the whole throwing process. This essay is based on the research on the 8 javelin throwers in the National Track and Field Championships 2008, Shijiazhuang. The last two steps and the explosion force from the left support by the javelin throwers were filmed with a high-speed camera at a speed of 50fp/s. The following technical data was obtained by means of related information, image analysis, and image measurement for future training reference so that javelin throwers can improve their techniques and make greater progress. The conclusions of the kinetic analysis are as follows.1 With the outburst of the explosion force comes a speed increase of the javelin in the javelin gravity centre before the left foot touches the ground. If the throwers use the force with the right elbow and wrist before they get stable support, the throwing will be badly affected.2 The essay deals with the cross-steps, the final step length and the lasting time.3 The essay deals with the tilting degree of the body, the greater speed of the right shoulder than the right hip speed after the cross-step, the trend of the advanced outburst of the force from the right shoulder, the advanced opening of the left shoulder after the cross-step, the tilting angle , the space and the step length. All the above affects the javelin speed.4 The essay deals with the braking of the left shoulder and hip after the outburst of the force and at the same time braking for no apparent regulation of the braking order. According to the horizontal braking features, braking is classified as fast braking, stable braking, and curve braking, of which fast braking is the most effective.5 Great difference will be shown on the left hip corner during the last throwing process as soon as the player lands on his left foot and throws the javelin.6 The essay deals with the comparison of the differences in the buffering angles between the excellent javelin throwers in the world.Suggestions are as follows.1 The cross-step is the key to the connection of acceleration and the explosion force. The javelin throwers should try their best to avoid the loss of speed and keep a good body position. They are demanded to keep a reasonable angle, lower the height of the cross-step, control the left shoulders and hips, avoid the advanced opening of the left shoulders, accelerate the swaying of the right legs, touch the ground in a reasonable way and at a reasonable angle, and reduce the loss of the horizontal speed at most.2 The final step should focus on the regulation of the lower part of the body, shorten the step length and time, keep tilting backward in a good position, increase the force space to obtain a good effect, keep practicing the order of movement from right shoulder to elbow to wrist to avoid the advanced outburst of the force and reduce the throwing bad effect and the throwing speed.3 The moving steps of the left shoulder should be seriously analyzed to obtain fast braking of the left shoulder, provide greater energy for the acceleration of the right side, and lay emphasis on the braking of the left hip. These are the breaking points.4 According to the final angles of the body, the trainers should make use of any effective ways or methods to improve the drawing-back technology of the left hip and at the same time raise the stretched power of the knee joint.