Analysis On Kinematics Characteristics Of Women’s 400m-m Hurdle Athletes’ Bend And Straight Hurdle Steps

Objective: as one of the track and field events with potential advantages in China,the women’s 400 m hurdles once won the fifth place in the world track and Field Championships and has been leading the development of Asian hurdles.Some scholars have studied the inter hurdle rhythm,running ability of Chinese women400 m hurdlers and the advantages and disadvantages of other world-class athletes,which has further promoted the development of Chinese women 400 m hurdles.However,after reading the literature and summarizing the results of women’s 400 m hurdles,it is found that the hurdle step technology of curved and straight track hurdles is one of the key factors affecting the performance of women’s 400 m hurdles.In order to improve the special performance of women’s 400 m hurdles,it is necessary to continuously improve the 400 m hurdle technology,and continuously improve the combination of hurdle technology and running.Methods: This study took 2 elite athletes,4 first-class athletes and 2 second-class athletes as the research objects,and used the methods of literature,expert interview,testing,mathematical statistics and so on.Four high-speed cameras were used to take on-site photos of female 400 m hurdle athletes participating in the experiment.The high-speed cameras were used to take fixed-point photos of the hurdle movement of the athletes’ curved and straight hurdles,so as to obtain the kinematic data of the complete hurdle step technology from starting the hurdle to attacking the hurdle to running down the hurdle.The obtained data were used to analyze the technical parameters of the athletes,so as to provide a theoretical basis for the athletes’ specific conditions to adopt different training methods,So as to achieve the goal of hurdle technology diagnosis.The research results are as follows:1.straight hurdle technique: the instant landing angle of athletes of different levels on the straight hurdle is 62.01 °,60.33 ° and 57.91 ° respectively;The average value of the starting angle is 63.14 °,66.31 ° and 68.21 ° respectively;The average value of the horizontal speed at the time when the toe of the starting leg is off the ground is 7.60m/s for the master,7.11m/s for the first level and 6.43m/s for the second level.2.curve hurdle technique: the minimum knee angle of the swinging leg of the hurdler when crossing the hurdle on the curve is 31.01 °,31.22 ° and 33.92 °respectively;The knee joint angle of vertical support in the lower column is 177.12 °,176.38 ° in the first level and 173.85 ° in the second level.3.comparative analysis of curved and straight barrier technologies: the knee angle curved barrier is 152.61 ° and the straight barrier is 157.17 ° when the toe of the starting leg is off the ground;The average value of horizontal speed on curve bar and straight bar is 6.65m/s and 7.41m/s respectively at the time when the toe of the starting leg is off the ground;When crossing the hurdles on the curve,the average value of the maximum angle between the two legs of athletes at all levels is 125.62 °,123.73 ° at the first level and 120.45 ° at the second level.When crossing the hurdles on the straight track,the average value of the maximum angle between the two legs of athletes at all levels is 128.62 °,125.94 ° at the first level and 123.85 ° at the second level.Research conclusions:1.straight hurdle hurdle technology: the landing angle of the second-class athletes at the moment of the toe landing of the starting leg is too small,the minimum knee angle of the swinging leg is too large,and the starting angle is too large;The knee angle of the second-class athlete is small when the toe of the take-off leg is off the ground,the horizontal speed of the take-off is small,and the center of gravity has a large lift range;The vertical support knee joint angle of athletes at different levels is too small,the swing leg support time of athletes at level one and level two is longer,and the range of motion of ankle and knee joint is too large.2.curve hurdle hurdle technology: there is no obvious difference in the landing angle at the moment when the toe of the starting leg touches the ground of athletes of different levels.The minimum knee angle of the swinging leg meets the modern technical requirements（28-34 °）.The starting angle of class I and class II athletes is large,and the knee angle of the starting leg is small at the moment when the toe of the starting leg touches the ground.The starting time of class II athletes is too long to attack the hurdle,and the lifting angle of the body center of gravity is large;The lower hurdle landing angle of level 2 athletes is too small,the vertical support knee joint angle is too small,and the swing leg support time is too long.3.comparison of hurdle techniques in curved and straight lanes: when crossing the curved hurdle,the landing angle of the athlete’s starting leg at the time of toe landing is small,the horizontal speed is small,the vertical angle of starting is large,the buffer range of the starting leg is small,and the maximum included angle of the two legs is smaller when flying over the hurdle;The minimum knee angle of the swinging leg is larger when crossing the straight barrier,the landing of the jumping leg is more sufficient,and the thigh angular speed of the swinging leg is greater.4.the influence of curving and straight track hurdle technology on Performance:too long starting stage will directly affect the whole hurdle time,increase the hurdle time,and the forward inclination of the trunk is not active enough when flying over the hurdle;When landing on the lower hurdle,the landing angle of the starting leg is too small,the angle of the knee joint vertically supported by the swinging leg is too small,and the knee joint is not fully extended.The lower the center of gravity of the lower hurdle body,the smaller the power obtained horizontally.Technical problems in the landing stage of the lower hurdle will lead to the long support time of the swinging leg.