Research On The Technique And Propulsion Of High-level Male Swinmmers' In The 50-meter Butterfly Tour

Purpose of the research: The kinematic evaluation of the butterfly midway tour is mainly based on the evaluation of the propulsion and the impulse.At present,the study of swimmer with butterfly stroke midway swimming skill is generally only at the level of stroke frequency and stroke range,and the dynamics study of athletes' propulsion are rare.This study mainly uses the biomechanics experimental method,measuring the speed,zoning,frequency and propulsion of 8 high-level male swimmers in the 50-meter butterfly and analyze results.The purpose is to find out the problems existing in the middle reaches of the tour.It reveals the main changes of the speed and the main factors influencing the speed of the tour.It will offer reference to 50 meters butterfly technical training and the improvement of the performance.Methods: Eight subjects of high level male swimmers were selected as experimental subjects.The subjects' images and related kinematic parameters were obtained by means of land and underwater high-speed imaging.The subjects were obtained by pulling the sensor to measure propulsion.The results of the test data were processed and the results of the test data were analyzed by mathematical statistics.The results of the study: In the men's 50 meters butterfly tour on the way to test the following results:(1)the overall decline in the trend,which last from the second stage(20 meters to 30 meters)to the third stage(30 meters to 40 meters(P <0.01);(3)due to the frequency drop,the decline of the plan,the overall decline in the rate of travel is the most significant decline in the final stage(P <0.01)(4)There was no significant difference between the single-cycle chronograph and the frequency of the athletes in the propulsion test(5)The reliability of the experimental data was very high;(6)In single cycle in the butterfly stroke,out catch and in sweep propulsion as time increases,upper stage propulsion to achieve maximum recovery period does not produce thrust in the air;(7)longer the time is during upper stage,the larger propulsion is,the better performance the athlete will have;(8)in the 50-meter butterfly,Designated site and tour speed of related coefficient r for 0.304,P value for 0.045<0.05,has explicit with sex related,designated frequency and tour speed of related coefficient r for 0.861,P value for 0.006<0.01,has very explicit with sex related,advance force and tour speed of related coefficient r for 0.959,P value for 0.000<0.01,has very explicit with sex related,which,designated frequency and designated site is negative related,related coefficient r for-0.823,P value for 0.012<0.05,correlation explicit with,designated frequency and advance force is are related,related coefficient r for 0.877,P value for 0.004<0.01,phase Turn off verysignificantly.Through research and analysis leads to the following conclusions:(1)The way travel stroke frequency and stroke length,accelerate the overall downward trend.Improve the 50-meter Butterfly swim stroke frequency should raise the level of the way,increased stroke length and enhance the viability of way swim stroke rate and stroke effects.Increased swim speed is an important factor to improve athlete performance.Middle speed the process of ensuring that the swim smooth at the same time to improve explosive force and prolong the Sprint distance.(2)The propulsion as a whole declined in the middle way.To improve and maintain the 50-meter Butterfly swim speed should promote power and propulsion of viability.(3)Druing the butterfly stroke in four phases,phase out and drive less,on the biggest part of the propulsion stage,arms in the air are almost without propulsion.The longer the time is during upper stage is,the larger propulsion.To increase the speed of butterfly,one must improve cross-stage propellant force,time,reducing the air arm time,and find their own rhythm of the stroke.(4)in the 50 m butterfly,speed change is caused by changes in propulsion,propulsion directly has impact on athletes ' body.Propulsion speed and stroke frequency plays a decisive role.