Study On Kinematic Features Of Man's 100m Starting And Accelerating Running After Starting

As one of the core projects of track and field,the basic task of the 100 meters sprint is to make the human body quickly detached from the still state,and enable the speed up advantage after starting.With the early stage of the accelerated run,followed by the continuous acceleration run,this will cause the human body to run as fast as possible in achieving the maximum speed.Therefore,the early pickup speed and continuous acceleration speed are undoubtedly will affect the final result.With the knowledge of biomechanics,this research is done on level-2 100 meters athletes from Xi An physical education university.This paper explores the status and characteristics of the current technical issues.Comparison is carried out on the relevant parameters of elite athletes.This data will be useful as reference in the future teaching and training.With the application of high definition video camera and analysis software,biomechanical methodology is done on 10 athletes,in studying the early pickup speed and continuous acceleration speed.In the later stage,Dartfish is applied in analyzing the data collected from these pickup speed and continuous acceleration speed.The result is as follow:1.Starting stage:(1)The distance from the point of projection between the two arms in the preparatory position is 0.056 ±0.02 m,and the proportion of height is3.13 ±3.54%.(2)The overall change in the angle of the trunk lift at the acceleration run is gradually increasing,with the elevation angle of the torso at the landing moment increasing the most between the first step and the second step,while the angle of the trunk lift angle at the moment off the ground fluctuates the most between the second and the third steps.2.Accelerated running phase:(1)In the technique of swinging arm of upper limb in accelerated running stage,the elbow angle of front arm decreases from the first step to the fourth step in turn,and the elbow angle of the rear arm swing has no obvious change regularity.(2)The overall change in the angle of the trunk lift at the acceleration run is gradually increasing,with the elevation angle of the torso at the landing moment increasing the most between the first step and the second step,while the angle of the trunk lift angle at the moment off the ground fluctuates the most between the second and the third steps.(3)The first four steps gradually increased with the decrease of step size,and the first step accounted for the largest proportion of totalachievement.3.The comparisons with elite athletes are as follows:(1)The first four steps are larger than the domestic elite athletes,and the first step and the fourth step have significant difference(p < 0.05).Secondly,the proportion of the first step is about10% higher than that of the domestic outstanding athletes in the ratio of step length to height.(2)The two level athletes speed up the hip joint angle to the world level hip joint angle more than the domestic elite athletes.(3)Compared with the top athletes in China,there is a significant difference between the two athletes in the acceleration stage and the domestic elite athletes.That is,when the athletes in the stage of p<0.01 accelerate,the supporting angle is larger when the supporting feet are off the ground.Based on the results,the following conclusions are concluded:1.Starting stage:(1)The greater the distance from the starting line between the projection points of the two arms,the larger the ratio of height to height,and the shorter the distance required for moving the center of gravity.(2)When pedal off the starter,the same side is smaller than the other side on the maximum swing.Height affects the size of an athlete's pedal swing.2.Accelerated running phase:(1)The overall change in the angle of lift of the torso that accelerates the running is gradually increasing,but the rhythm of the landing and the moment off the ground is not consistent.(2)The first four steps gradually increased with the decrease of step by step,and the proportion of total achievement was the largest in the first step.(3)The angle of hip joint is larger than the moment of landing,and the overall trend is upward.(4)The first four steps of acceleration after starting are not proportional to results3.Compared with the outstanding athletes:The second level athlete is in the step,the torso lift angle,the hip joint angle is far bigger than the outstanding athlete.4.The second level athletes still need to strengthen special training,pay attention to shoulder strength,flexibility of hip joint,torso strength training and coordination exercises of upper and lower limbs,accelerate running rhythm practice,form a good pace rhythm.