Comparative Kinemics Analysis Of Frontcourt Attack, Backcourt Attack, And Jump Serve

With Wang Lina,Bai Yun and Wang Chen as main subjects,their whole movements of backcourt attacks,forward power attacks and jump serves are researched.With the relative bio-mechanic technical methods,data are obtained.Based on the theories of vertical jumping and the upper limb whiplash,the inside logic among the movement parameters of backcourt attacks,forward power attacks and jump serves is researched with the combination of statistical analysis and case study.Their movements are shot with 3-D camera.The data are obtained by parsing the chosen videos with the method of using Shixun system of parsing videos designed by Sport Bio-mechanics Teaching Office of Beijing Sport University.Statistical data are treated with the method of numeric filtering.The results show that backcourt attacks,forward power attacks and jump serves mainly consist of two phases of cushion and speed kicking.The cushion of forward power attacks is obvious while the horizontal speed loss of body center of gravity is great and the angle of jumping is big compared with backcourt attacks and jump serves.The movements of their right coxae,right knees and right ankles accord with the principles about the movements of joints.While jump serving,they move coxae and knees first.While jumping,the peak angle speeds of their right knees and ankles are in a line while the peak angle speed of coxae is a little earlier.Their movements of pulling arms upward are compound movements with the characteristics of turning the body and bowing the back.Before jumping, they bow their backs backward and upward.While jumping,the angle of right coax influences greatly the degree of bowing the back in the process of attacking.The backward angles of backcourt attacks,forward power attacks and jump serves are different.The biggest backward angle is backcourt attack,the second is jump serve and the smallest is forward attack.However,there are no great differences among them. Based on the above analysis,we suggest that athletes pay attention to the reasonability of structure while jumping and the harmony of joints while training.The speed power quality of athletes' lower limbs,the power of muscles around shoulder joints and flexibility training should be strengthened.