The Three-dimensional Kinematics Analysis Of The Last Two Strides Of Run-up And Techniques Of Take-off On Some Elite Women Long Jumpers In China

In the long jump, take-off is the main component and run-up is the key. The last two strides are transitional point that functions as the connecting link between the preceding and the following during the whole process of long jump.The subjects wereélete women long jumpers who participated in"Fei Pu Lai National Athletics Championship Series of 2004", which was held in Nanjing area. The research methods were use of literature, film shooting analysis, statistical analysis and comparison. In addition to the analysis of the last two strides and traditional index, an application of new kinematics index was introduced, including the stretch time index, the conversion of horizontal velocity, and the angle of starting stretch. According to the data analysis, the conclusions were drawn and presented in the following:1. Six athletes thrust the ban by way of the last second stride instead of the last stride, however, the connection of the last two strides of run-up was not adept, the whole length and the difference of the two strides were significantly varied from athletes abroad (P<0.01), and also the speed of the last two strides of run-up was much slower than that of athletes abroad.2. The ratio of T₂ was 30.8% which indicated six athletes'lower limbs were not powerful; the stretch time index and the conversion of horizontal velocity were more suitable to evaluate the effect of take-off.3. It could be found that the angle of thrust was much smaller(57.988±2.856)and the angle of hip was much larger(47.426±4.731); the angle of starting stretch was not widely different from the acknowledged norm (7⁰-15⁰), which was favorable to the stretch of the take-off leg and the take-off angle of body's center of gravity.4. Six athletes attached more importance to the instantaneous upright velocity of...