Surface Electromyography Study On The Final Force Stage Of Solid Throwing In Situ

Research purpose: According to the <<requirements of the national unified examination of physical education examination in Guangdong>>,by combining the knowledge of sports anatomy,sports training and sports biomechanics for the purpose to analyse the main muscle groups in the stage from final exertion of the solid ball based on parallel and front-back type of Surface electromyography(EMG)characteristics.The standard atlas of the stage of the final exertion of solid ball in the muscle electrical significance is set up to reveal the internal mechanism and the external motion analysis of the final stage of the solid ball throwing and clarify the scientific rationality of the final exertion of the solid ball in a new angle of view in order to better guiding the training and teaching of solid ball throwing and provides a theoretical basis for avoiding sports injuries.Research method:The electroencephalographic signals of the parallel and the final forced motion of the front and back solid ball of 12 athletes were collected synchronously by the DELSY Trig-no Mobil portable remote sensing(16 Guide)and the MotionPro X-4 high speed camera in the United States.The EMGworks 4 Analysis processing system and the Mat lab program are used to process the EMG signal and the internal and external analysis is carried out with the Dwarfish sports mechanics analysis software.The data are analyzed with the software of SPSS 19 and Excel 2007.Research conclusion:(1)From the time of muscle activation(Onset),there was no significant difference in the activation time of muscle between parallel and anterior and posterior muscles.The rectus abdominis,the erector muscle,the ventral oblique muscle,the rectus femoris and the anterior part of the deltoid muscle showed an obvious "pre activation" phenomenon under the control of the central nervous system,indicating that the muscles of parallel and front and back muscles were exerting an obvious force,and the order of muscle force was not "from the bottom".At the same time,the first force of the anterior part of the deltoid muscle in the upper limb muscle group-the last force of the brachialis muscle verified the principle of the biomechanics of the whipping movement,that is,"the big joint is prior to the small joint movement".(2)From the observation of the tendencies of the muscle inactivation time(offset),there were differences in the time sequence of the muscle inactivation in the stage of the finalexertion of the solid ball in parallel and front and back type,but both showed that the inactivation of the lower extremities was relatively early,and the inactivation of the upper limb muscle was relatively later.(3)From the duration of muscle duration,the anterior,triceps and rectus abdominis muscle of the musculus deltoid is relatively long,the shortest is the gluteus maximus and the lateral head of the gastronomic muscle.But on the whole,the time of parallel muscles acting on the solid ball is longer than that of the front and rear,and there is a significant difference.According to S=Vo2Sin2 /g and N=FS/t=maS/t,parallel muscles type is more advantageous than the front and rear type.(4)From the muscle integral electromyography(IEMG),the rectus abdominis,erection muscle,anterior part of deltoid muscle,pectoralis major,triceps brachialis and rectus femoris in parallel and front and back have relatively larger EMG.It shows that these muscles are the main force muscles at the final stage of exertion.The lower integral EMG value is the abdominal and the biceps.These two muscles can not be regarded as the main force muscles.On the whole,there is a significant difference in the integrated electromyography value between the parallel and the front and rear.(5)From the rate of muscle contribution,the contribution rate of the rectus abdominis,the erector muscle and the gluteus maximus in the parallel final force stage is larger than that of the front and back,which shows that the three muscles play a greater role in the parallel type,and the parallel type is more exciting and it show from the side that the parallel type requires higher athletes' waist and abdomen strength and coordination.The latissimus dorsi,triceps brachii and brachial radials were smaller than the anteroposterior ones,and the contribution rate of other muscles was not obvious.(6)From the amplitude of the root mean square of muscle(RMS),the level of the final exertion of the parallel type of solid ball at the final stage of the solid ball is more exciting to the erector,the latissimus dorsi,the gluteus maximus and the rectus abdominis,and the average discharge level of these muscles is higher in the stage of the parallel final force.