Synthetic Study On Jump In Spike And Its Specific Strength Of Volleyball Players

With the fast development of the world volleyball athletic level, it has become an important topic to be settled about training the outstanding volleyball athletes and rapidly enhancing volleyball athlete's level on the net in our country. In this paper, I chose the take-off in spike at the fourth position as my research object, using advanced biological mechanic measuring instruments, the photograph, footscan insole system and the electromyography test system in order to obtain the volleyball athletes'kinematics, dynamics and the biology parameter accurately in the jump process. By using the theories of kinematics and biology theory, this paper intends to explore the features of take-off and its related factors which may affect the effect of take-off. Moreover, on such basis, this research relates the existing concrete questions and provides a theory and method instruction for athlete's special strength training through the training experiment. Also, this research obtains a lot of complete data of kinematics, dynamics and the electromyography which can promulgate skills of the features of take-off and its special strength and thus it provides a scientific basis for a volleyball coach to direct his training.Concrete conclusions as follows:1. Volleyball athletes'step spike can be divided into three phase: the cushion phase, the brake phase and the extend stage. As it is an essential factor that total time proportion occupied by take- off in various stages can influence its take-off structure, it should be pay to be rational when we are training. On the other hand, the changed characteristics of the athletes'hip, knee and ankle joint in the jump process show what the lower limb stretch muscle group completes is "Stretch–shortening cycle", therefore we must strengthen the quality of the lower limb stretch muscle group in our training.2. In the jump process, it shows a double peaky curve for the changes of plantar pressure of volleyball athletes with its related time which is an important influence factor for take-off action. Therefore, we should pay attention to strengthen the ability of fast take-off by volleyball player in training. At the same time, the order appeared in right foot-bottom volleyball athletes explains their plantar pressure has a transmission feature, so we should choose similar methods and means matched with above features in special strength training3. In the jump process, the stretch muscle groups of volleyball athletes, such as gluteus maximus, quadriceps and triceps surae are playing a vital role in the jump process, therefore we must pay attention to take-off training of the lower limb stretch group. In addition, we should also pay enough attention to function of the muscle group after the cushion stage, so training should be pointed at enhancing strength level of the muscle group. Besides, in the jump process, it is regular for time order when the lower limb group acts, among this, the lower limb muscle makes an effort through the coordination to have the biggest effect.4. Features of volleyball athletes'knee joint constant speed muscle strength conform to the Hill equation and the strength-velocity curve relations. And electromyography signals of quadriceps gained in the period of test movement may objectively evaluate relationship between the IEMG and the muscle strength, instructing the specific strength training .5. Test result of lower limbs deep squat at constant speed indicates that muscle working characteristics of lower limb have the similarity with extend stage when jumping, which prompts us to use the advanced constant speed test and training system to apply special strength training for the volleyball players'lower limb.6. Through the experiment, the strength practice such as the triple jump, multistage jump by single foot, deep jump by vaulting–box and high-jump bar, proved to be extremely effective to develop special strength in the volleyball athletes'step spike. Although the barbell exercise has its shortcomings, the barbell practice still takes an important position in the take-off strength practice for volleyball players as long as it can show the special technical characteristics in arrangement and application methods.7. In the training practice, it is an important way to carry on the feature research of volleyball athletes'take-off strength systematically, and seek the scientific special strength training methods, which will enhance the movement effect and change backward condition of volleyball athletes'special ability in our country. In addition, the volleyball coaches should make clear that the"concession- contraction"ability of the lower limb is a leading factor to decide the volleyball athletes'take-off effect. So we should understand there are not only some relations but distinctive ways of muscle work between"concession" and "the restraint" in the jump process, then choose a training method accurately to raise our training level in a scientific way.8. On the research foundation, my suggestions is to expand sample quantity, use the more advanced high speed photograph system together with the 16 electromyography tests system and plantar system to study the muscles of volleyball players'left and right leg. Thus it can promulgate more thorough for kinematics features of the jump. Another suggest is to test the training methods of the volleyball specific strength and analysis them deeply, so as to enhance scientific training level and better instruct the training practice.