Study On Comparison Between Elite And Beginner Table-tennis Players In Functions Of Elbow Flexion/Extension

Research objectives:This study takes the elite table-tennis players and novice table-tennis players at college as research objects and plans to observe the effects of a long-term training on muscle functions of elite athletes and then learns how sports trainings influence the neuromuscular functions.Research methods:8 elite table-tennis players and 8 novice table-tennis players participated in this study(common college students,1-2 years study and training).Subjects in the ETP and NTP all performed the isokinetic eccentric flexion/extension of the right elbow for 3-5 times at the velocity of 15�/s,90�/s,and 180�/s with a 10 min-rest among different velocities on the Isomed2000.Meanwhile,the surface electromyography(s EMG)signals from biceps brachii muscle and triceps brachii muscle were recorded.The peak torque,the angle of peak torque,peak torque of flexor/extensor,and root mean square(RMS)of s EMG were measured as the observational index.Research results:1.Either the elite table-tennis players or the novice table-tennis players,the peak torque of the elbow decreased with the increase of velocity.And the peak torque and relative peak torque of elite table-tennis players were significant higher than those of the novice table-tennis players.2.The peak torque of flexor/extensor of subjects in the two groups increased with the increase of velocity,of which the peak torque of flexor/extensor of subjects from the NTP was significantly higher at the 180�/s than that at the 15�/s(P < 0.05)and 90�/s(P < 0.05).Although the elbow angle of peak torque showed no significant statistics differences between ETP and NTP,However,the elbow angle of peak torque of the subjects from the ETP were generally smaller than that of the subjects from the NTP.In addition,the peak torque of flexor/extensor of subjects in the ETP was significant lower than that of subjects in the NTP at each velocity.3.At the same velocity,the agonist showed higher RMS of s EMG amplitude of the elite tabletennis players than that of the novice table-tennis players.With the increase of the kinematic velocity of elbow,the s EMG of biceps and triceps muscles demonstrated more �sharply increase� pattern than that of the novice table-tennis players,suggesting that the activation speed of neuromuscular of novice players was slower at a rapid movement.4.The RMS amplitude of antagonists(triceps brachii at the condition of concentric elbow flexion movement and biceps brachii at the condition of concentric elbow extension movement)of the elite table-tennis players was lower than those of the novice table-tennis players at all velocities,especially,at the 180�/s there was a significant difference(P<0.05).Conclusions:1.The elite table-tennis players show stronger flexor or extensor strength of the elbow because of the long-term training,especially for the flexor strength of the elbow.And the flexor strength of the elbow for the novice table-tennis players obviously decreases with the increase of velocity of the elbow.The elbow angle of peak torque of the subjects from the ETP was smaller than that of the subjects from the NTP,indicating that the elbow of the elite table-tennis players can earlier reach the maximal strength,which may be resulted from the long-term training.2.The data in this study demonstrate that the elite table-tennis players have stronger neural activation on the muscles,showing higher EMG amplitude of agonist muscle and faster activation speed of neuromuscular,which may be the neural factor that leads to stronger strength and faster athletic ability of the elbow for the elite table-tennis players.3.The long-term exercise may result in the development of a special neural circuit for the elite table-tennis players,reflecting in the lower activation of antagonistic muscle,compared with novice table-tennis players,which suggests an efficient neuromuscular control for the elite tabletennis players.Suggestions:1.Although the peak torque of the elbow flexor and extensor for the elite table-tennis players were stronger than that of the novice table-tennis players,the strength imbalance of the elbow extensor and flexor for the elite table-tennis players may bring about the instability of the elbow.Therefore,it is suggested that coaches should enhance the training of the strength of elbow flexor for elite table-tennis players.2.The differences of strength between the elite table-tennis players and the novice table-tennis players not only reflect in the absolute strength but also the rapid contraction,which has a negative effect on hitting the ball for novice table-tennis players.Thus,the novice table-tennis players should reinforce the rapid contractions strength of the elbow,especially for the rapid extensor of the elbow so as to improve their technique level or hitting effect.Innovations:1.The innovation of this study mainly reflects in the methodology.By using isokinetic strength testing equipment and electromyography equipment,this research studied the differences of strength of elbow at various velocities between the elite table-tennis players and the novice tabletennis players and the neuromuscular control mechanisms.