| Research purposes: On the basis of pole vault,this paper studies the characteristics of the kinematics indexes of the key techniques in the last two steps of run-up and take-off of Niu Chunge,reveals the obvious characteristics and laws of Niu Chunge in the process of pole vault,and deeply analyses the pole vault techniques used in this process,and points out the shortcomings of Niu Chunge.It also systematically summarizes and summarizes the influencing factors related to the final results,which lays a good theoretical and practical support for the further study of pole vault in China,and also provides a good reference for other pole vaulters.Research object:Taking Niu Chunge-lai as the main research objective,this paper makes a comprehensive and detailed data analysis of the pole vault process.Research methods: Three main research methods are introduced,namely,literature method,mathematical statistics and experimental method.Results:Eight conclusions are drawn from the above research.1.Niu Chunge's approach speed shows an increasing trend.The approach speed of successful crossing the pole increases from the penultimate step 7.15 m/s,7.26 m/s and 7.33 m/s to the penultimate step 7.17 m/s,7.28 m/s and 7.38 m/s,respectively.The increments are0.02 m/s,0.02 m/s and 0.05 m/s,which indicate that Niu Chunge's approach ability to hold the pole has a certain degree with the increase of training time.Enhance.2.Niu Chunge has the problem that the step length of backward step is longer than that of backward step.3.Niu Chunge's elbow angle and shoulder angle are not large in the process of lifting off the ground,which represents that Niu Chunge's chest phenomenon exists in the process of take-off,which leads to faster leg throwing than pole throwing,thus reducing the quality of pole vault;this also shows that his pole lifting is not enough,and the pole lifting is not positive enough in the instant of landing.4.The distance between the landing pole chord angle and the takeoff pole chord angle of Niu Chunge's takeoff action shows an increasing trend.The analysis from the point of view of kinematics and physics shows that the speed of the transformation between kinetic energy and elastic potential energy increases sharply in this process.5.The trunk angle of Niu Chunge's take-off and landing is generally over 90 degrees.This is because she has the problem of body backward in the process of take-off,which leads to the trunk unable to keep upright.Therefore,when the pole head contacts the bucket wall,the trunk superiority can not maintain good balance due to the influence of the resistance of the pit fight.6.The knee bends too much at the moment of landing.It can be seen that the relative strength of the take-off leg isinsufficient.7.The lifting angle of the center of gravity tends to decrease.The lifting angle of the center of gravity at the time of successful crossing the pole on August 18,2018 is 19.4 degrees,which is close to the lifting angle of the center of gravity of the world's elite pole vaulters.8.The speed of the trunk is faster than that of the shoulder,which indicates that the body is backward,but the run-up technique is better and achieves a higher speed.It is also possible that Niu Chunge does not raise his hands fast enough when he leaves the ground.Conclusion:1.Niu Chunge's pole-holding run-up ability has been enhanced.The last step increased slightly.2.From the point of view of the stride length,her last step is smaller than the previous one,which makes the run-up speed increase.In the last two steps,the run-up technology has obviously improved and improved.She runs more actively,and also enhances the sense of attack.3.After a period of training,Niu Chunge enlarged the lower elbow angle to make the arm support to the limbs more stable.4.Compared with the previous training,Niu Chunge's run-up movement is more and more active,and the take-off pole chord angle has gradually become rationalized. |
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