In Take-off Movement "Critical Speed" Phenomenon Experimental Study

Research goal: In jumps in the deep practice, along with jumps deep high increase, the bounce upsprings highly also increases, But when jumps deep rises highly to certain altitude, the human will instead feel that cannot jump. Similarly, in long jump, high jump, triple jump, when athlete's approach speed increases to some threshold value time, its take-off effect instead reduces Therefore, we call this threshold value it"the critical speed". This article is for the purpose of through the experimental verification critical speed this phenomenon existence, promulgates mechanism which and influencing factor this phenomenon produces, the athlete controls the good approach speed for the caper class project, to produce the best take-off results accurately to provide the effective theory basis.Research technique: The present paper uses the literature material law, the cut-and-try method, the expert interview law and the mathematical method of average, chooses the athlete 20 artificial objects of study specially by the Wuhan Sports Institute sports education specialized track and field, Selects five kinds jump deep highly (H1=40cm, H2=60cm, H3=80cm, H4=100cm, H5=120cm) and three kind of spacings (L1=50cm, L2=100cm, L3=150 cm) the combination to jump the deep practice, the survey jumps the deep long jump result. Uses measured the strength Taiwan instrument obtains the dependence test parameter has the take-off time, the take-off most vigorously value, the take-off impulse. According to throws the movement evenly the principle, calculates differently highly, time the spacing combination whereabouts take-off speed. Uses SPSS 11.5 to count the software to obtain the data to carry on statistics processing.Conclusion: (1) 5 kinds jumped, 3 kind of spacing combinations to jump deeply the deep long jump experiment to prove highly in the take-off movement"the critical speed"the phenomenon existence, namely had a best take-off speed correspondence to jump the deep long jump result to be best; (2) the take-off time with jumps the deep long jump result relations to indicate: In certain scope, the take-off time is shorter, the take-off effect is better, between both assumes highly the inverse correlation; The regression equation error analysis indicated: Using the take-off time may forecast effectively jumps the deep long jump result; (3) along with the take-off strength, impulse enlargement, jumps the deep long jump result is the enhancement; The take-off strength, the impulse become the consistent change tendency with the take-off speed, namely take-off speed the take-off strength, the impulse are greatly big; The take-off strength, the impulse and the take-off time become the opposite change tendency, namely the take-off time is longer, then the take-off strength, the impulse are smaller; (4) selects 30 meters on the move to run, the standing broad jump, in-situ vertical to jump traces high, squats 4 targets to have the high potency deeply regarding the lower limb strength quality diagnosis, the research indicated: Lower limb's strength quality is the influence jumps the deep long jump result important attribute;Suggested: (1) in the caper class project take-off process, the athlete lower limb myo- contraction process essence is a complete high grade length contraction process, both's critical speed phenomenon produces the mechanism is the same. But, because the caper class project's critical speed is also at present unable to measure actually, it between the critical speed which studies with this article definitely has some kind of connection, needs us to further launch more thorough research. (2) looked from tentative data's statistical process that has the individual athlete its target data change is not and the sample overall target data change is consistent, explained the different spacing combination practice has the different influence highly to individual, must consider the individual in the training the difference, the differential treatment.