A Mechanics Analysis And Contrast On Smashing Jump Service Between Jiansu Provincial Women Volleyball Team And High-level Volleyball Players In Suzhou

In present volleyball games, powerful jump serve is an important element, which is as important as the other techniques. Correct and attacked jump serves can not only get scores and destroy the counterparts'attack strategies; but can also ease the team's defense stress, which is to create advantages to fight against counterparts.This thesis is based on a mechanics analysis and contrast on smashing jump service between Jiansu Provincial Women Volleyball Team and high-level volleyball players in Suzhou, by analyzing their differences and similarities, disadvantages of service techniques and thoughts among volleyball players are pointed out, so that some data are available for jump service training on part of Jiangsu Provincial Women Volleyball Team as well as training for public volleyball players and Suzhou volleyball amateurs .Research methods are as follows: data and document research, video analysis, mathematic and physical statistics and compare and contrast. Through the kinematics research on their powerful jump serves and air drives, the conclusions are as follows:1. In the service of volleyball games, most players have adopted two-step running jump, this is helpful to the control of body's speed and gravity, and is used by most volleyball players. While in the adjusting of the distance from baseline, the amateur players have a distinguish disadvantage.2. Players from both groups did not appear much difference in the speed of first step when they perform running jump, but University players'speed of second step and jumping increased much less than that of provincial players. Each step distance is nearly the same between the two groups, but provincial players'jumping distance is prominently longer than that of the university players'. so we can consider that the professional players'break-out force of leg is superior to the amateur players. 3. The transitional rate from level speed to vertical speed can better reflect the jumping effect; provincial players perform better than the university players in this aspect. Their jumping degree shows little divergence individually(37.84°～46.83°), and players from Soochow University appears much divergence(35.63°～51.93°). after training for long time ,the professional players have a better balance understanding for the jumping degree.4. In the jump service, the landing of both right and left feet does not synchronize the taking-off, and the bending of both knees do not synchronize the extending. This is relevant to the purpose of front and upright jump. For a higher and longer distance, you have to bend and extend right knee to get a vertical speed, bend and extend left knee to get a level speed when perform jump service.5. Provincial players'shoulders rotated degree and distance are much bigger than that of players from Soochow University, which proves provincial players'body rotation is distinct, so the professional players have better training methods. Furthermore, there is a distinct difference between both groups'hip rotated degree and distance, this is to say, provincial players'strength of waist and abdominal muscle, along with the relevant muscle of shoulder and back, have a distinguish advantage. Acceleration begins with body movement when jump service players hit the ball, the bigger the distance and degree of movement, the better for the speed of arm swinging in jump service.6. The gravity of university players is quite different with provincial players when hitting the ball, which proves the professional players'hitting time and the ability of staying in the air for long time is a little inferior to provincial players. in addition, the amateurs'hitting speed decreased much more than that of professional players, it's clear that the amateurs'endurance that keep speeding is worse than the professional players.