Kinematic Analysis Of Block Starting And Accelerating Techniques Of Some Male 100m Athletes Aged 14-17 In China

Research methods: Using literature method,expert interview method,two-dimensional video analysis method,Mathematical statistics method and comparative analysis method;Research content: This paper analyzes the technical video of 4 steps before starting and speeding up the 14-17-year-old part of the young men in China,and understands the present situation of the technical and accelerated running technology of the young men at different levels in our country at the age of 14-17,and the difference between the kinematics parameters of the technology of running and speeding after starting and starting.To find out the shortcomings in the starting technology and accelerated running technology of the 14-17-year-old male hundred meters athletes.Conclusion:(1)The starting attitude: the front and rear leg hip,knee and ankle angle is small,can not make good use of distraction reflex and muscle suitable shrinkage initial length brought about by the best benefits,excessive emphasis on driving down the body torso,there is the use of thoracic spine bending instead of hip-centered torso overall forward tilt phenomenon.(2)Rear pedal removal technology: The torso forward tilt amplitude is large,pedal from the moment swing leg can delay the amplitude of the opening of the knee joint,keep the ankle back curvature,reduce the ground braking power,maintain a certain level of driving force,pedal fit is more appropriate;there is the problem of excessive folding amplitude in knee running and small range of hip pendulum technique;And the pedal distance is slow,the speed increment is small;There are great differences between different groups in pedal technology and poor technical stability,which is manifested in the buckling and variation of hip,knee and ankle joints.(3)The ground technology: the ground distance is far,the ground tibial inclination is small,can maintain the low body posture and slow down the instantaneous horizontal speed loss,but the support leg after the ground rigid support capacity is insufficient,the Flexor force is obvious,and accompanied by the problem of excessive folding amplitude,and the current high-level athletes advocate the low front pendulum requirements;And in the accelerated running technique,the angle of the lower extremity of swinging leg varies greatly.The ability of the lower pressing ground decreases with the acceleration of speed,and the rapid strength is insufficient.(4)Step length,step frequency and support and emptying time: high-grade athletes in the starting stage of the step and frequency ability,especially the step frequency is more prominent,while the lower class athletes tend to be consistent with the higher class athletes,but the step frequency is slow,the support time is long,the rapid burst force ability is insufficient.(5)The technical parameters of accelerated running after starting and starting are not related to age,and are closely related to the level of motion.Recommendation:(1)According to the athlete's body morphological characteristics,strength performance,and comfort degree to carry out the starter debugging,so that the preparation attitude joint angle gradually to the excellent athletes technical model closer,so that the human biological efficiency to maximize.(2)To develop the ability of active muscle and cooperative muscle excitation and inhibition of rapid transition under different force conditions of lower extremity joints,to improve the relaxation ability of knee joint,to improve the flexibility of hip joint,to increase the range of front pendulum amplitude of hip joint,and to develop the ability of pedal pendulum in the starting acceleration stage through the practice under slow stability condition,To ensure the reasonable and stable technology under the premise of transition to fast conditions of practice;(3)The ability to develop rapid force,especially at high speed to extend the hip and stretch the knee muscle group,to ensure that in a relatively short period of time to produce a larger force value,shorten the ground support time,speed up the frequency of action.