The Study Of Cross-step Technology Of Excellent Man's Volleyball Players

The volleyball sport,as an important part of athletic sports,is one of Olympic items.Chinese athletes have not gained too much achievements on it.and there is still a great gap in research between research China and the developed countries.To provide scientific foundation for improving Chinese volleyball sport,this thesis tries to do research on lateral movement,technique of chinese excellent volleyball men athletesPurposes:Using and analyzing the characteristics of the ralatated indexes in the different lateral movement velocity by biomechanics and myoelectric technology,we try to find the factors that affect the movement velocity,to provide scientific foundation for routine training,and achieve the goal of improving movement performance.Subjects:Five second spiker of national men volleyball team,which were selected from excellent athletes of provincial team.They were engaged in preparing the 29th Olympic games.Using Surface ElectroMyography test and the QUALISYS-MCUSO0 far infrared test system,we observed the characteristics of indicators of multiple lateral movement of athlete individual.The multiple lateral movement is considered as research variable.The athletes did the movement as they were in completely imitating competitions.The sEMG activity was recorded from the gluteus maximus,gluteus medius,vastus medialis,biceps femoris,adductor magnus,tibialis anterior, gastrocnemius and external oblique in both sides of body.The far infrared test was also finished at the same time.Results:1.ln completely imitating competitions during athletes move right,the velocity of swing leg is higher,the prepairing time of swing leg and the time moving in air is shorter when they do rapid movement compared with slow movement.The prepairing time of swing leg is the most important factor which influences the movement velocity.During athletes move left,the velocity of swing leg is higher when they move fast compared with slow.In order to improve moving velocity we should training the implosive power of swing leg,and make its movements reasonable.2.A comparison of the electromyographic integration in one unit of time between fast movement and slow movement:the electromyographic integration of gluteus medius during setup phase when moving left,the electromyographic integration of gluteus maximus during swing phase when move right,and the electromyographic integration of adductor during taking off on the ground pbase when move right,which are all lower in fast movement than slow movement,this phenomena show that proper relax can improve contracting power of primary motorial muscle3.A comparison of muscle contribution rate between fast movement and slow movement show that the muscle contribution rate of tibialis anterior during the setup time phase when moving left is higher in fast movement than slow movement;adductor's during the taking off on the ground phase when move right is lower in fast movement than slow movement;these indicates that tibialis anterior and adductor are the important primary motorial muscle4.The muscle mobilization sequence shows great individual difference because of different training background and individual motor technology, That means using different training methods to improve diferent athletes to make it scientific reasonable.