Research On Evaluation System Of Cross-event Material Selection Of Freestyle Skiing Aerials Based On Event-group Training Theory

China's Freestyle Skiing Aerials(hereinafter referred to as Aerials)has a strong competitiveness in the world,but the development of its reserve talent is still far behind the advanced level in the world.According to the event-group training theory,gymnastics,trampoline,skills project and aerials all belong to the event-group of difficult and beautiful category which is dominated by skills(hereinafter referred to as difficult and beautiful event-group).Gymnastics and other sports have a strong talent reserve and mature training system,if the high-quality talent foundation of gymnastics and other sports can be absorbed to drive the development of reserve talent of the relatively weak aerials and other snow sports,it will be the key to solving the shortage of snow sports reserve talent in China.It is concluded through the consultation of a large number of literature that previous studies are lacking in the theoretical support for cross-event material selection of aerials,which may lead to the deviation in material selection results.The purpose of this study is to improve the theoretical support for cross-event material selection of aerials in China,as well as to scientifically and effectively select reserve talents for aerials by combining the rich experience of a large number of coaches.The test objects of this paper are 26 male and female members of the national youth team of freestyle skiing aerials program in China.The main research methods are mathematical statistics methods such as documentary data method,questionnaire survey method,index measurement method,factor analysis method,principal component analysis method and so on.The research results are as follows:(1)Through the analysis of expert questionnaire,84 items meeting the requirements of cross-event material selection of aerials are selected,including 17 body shape index,6 physiology index,6 sports quality index,10 skills index and 10 female trampoline,male trampoline,female gymnastics and male gymnastics technical movement index each,2 background index,3 health condition index.(2)The weight formula is used to calculate the weight of each index,and the index model is established.(3)Based on the measurement data of the athletes,the scoring standard and grade evaluation standard for cross-event material selection of aerials are established,and the established evaluation standard is tested strictly.Research conclusions:(1)The cross-event material selection of aerials is focused on the ability to measure the non-innate,relatively variable and controllable indexes of the athletes.(2)Health condition index and technical action index are the key factors to determine the results of cross-event material selection;the psychological quality index is relatively less important for athletes of this age,which is not used as evaluation index in this study.(3)Among the physical fitness indexes,the length ratio of athletes' lower limbs and body girth are important in terms of the body form;the cardiopulmonary ability and sensitivity and endurance of the athletes are important in terms of the physiological function;the lower limbs strength,explosive power and core strength of the athletes are important in terms of sports quality.(4)The grade evaluation standard and scoring standard constructed in the end can accurately reflect the true level of athletes and play a good role in predicting whether cross-event athletes are suitable for aerials and whether they can achieve excellent results.