Comparative Kinemics Analysis Arm Swing Of Jump Serve, Backcourt Attack And Frontcourt Attack In Step Of Jump And Off

Spiking and serving is the certainty in Volleyball, swing is the certainty too. Make a distinction between them has big realistic significance in teaching and training. In reviewing of the literature we can discover that there are many relevant researches in Jump Serve,Backcourt Attack and Frontcourt Attack, but there is few researches synthesizes the three. Use data to explain the differences is much less. The three actions have important meanings in volleyball, so make a distinction between them has big realistic significance in teaching and training.The article selected eight sportsmen (two grades) as the objectives of the test in Soochow University. Uses the method of documentary, picture shooting, statistics method, analyzing video material to research arm swing of Jump Serve, Backcourt Attack and Frontcourt Attack, conclusions as follows:1The angle of lumbar is the biggest in jump serve, and then is Backcourt Attack and Frontcourt Attack. The angle of rear protraction is the biggest in jump serve, and then is Frontcourt Attack and Backcourt Attack.2The Range of abdomen in body is the biggest in backcourt attack, the range of twist is smaller. The Range of abdomen in body is smaller in jump serve , the range of twist is the smallest. The range of twist in Frontcourt attack is the biggest in backcourt attack and jump serve.3The moment of take off backcourt attack the ball is between the midcourt line and three meter attack line, the team member should enhance the height of the take off, so the height of the take off is the highest than frontcourt and jump serve.4 The maximum to arm draw away in backcourt attack, the height of center of gravity is the highest. Then is frontcourt attack and jump serve. Backcourt attack is farther than frontcourt attack from the net. So the height in taking off is higher. The height of center of gravity is the lowest in Jump serve.5 From unstuck to the maximum to arm draw away, the speed of shoulder joint, elbow joint,wrist joint are increasing. But jump serve and backcourt attack is decreasing by 0.02m/s.This maybe because the three meter attack line impeded the speed increasing.6 The angle of arm rotate is the biggest in frontcourt attack, 31.82°, this explained that the range of twist in frontcourt attack is the biggest. Then is the moment of hitting in jump serve, 30.22°.The body faced the net when hitting in jump serve, so the angle of arm rotate is smaller.7 The moment of hitting in jump serve, the range of right shoulder overtop the left shoulder is the biggest, because farther from the net, the sportsman shoulder raise the right shoulder to increase the height. Because the three meter attack line in backcourt attack, the differences between the shoulders is smaller.8 The moment of hitting–taking off, displacement of center of gravity from high to low is: backcourt attack 0.56m, frontcourt attack 0.53m,jump serve 0.39m. Because the three meter attack line in backcourt attack, the height of center of gravity should higher. Because the long distance running in jump serve, the height of center of gravity should be the lowest.