The Study Of The Features Of Force Breaking Of Muscles In Backwards Sliding Shot Put

Purpose:Through adopt the surface electromyography technique and Three-dimensional shoot,this study attempts to conclude the relationships between the movement characteristics of shot put and the principle of muscles works in the whole process.Then,in order to seek for a new method which can evaluate the technique of shot put.Methods:This study takes 7 second grade shot putters as the objects and makes use of 3D technique for shooting image and surface electromyography technique,and collect the parameters of 3D kinematics and surface electromyography during the process of backwards sliding shot put,then make sure that the begin and end time is corresponding through the video information between the results of surface electromyography and three-dimensional kinematics.Change the results into numbers,and use the Bivariate Correlationsâ†'Correlation Coefficientsâ†'Spearman in the Spss program to analysis the relationships between the results of surface electromyography for example iEMG,the percentage of iEMG and strength and the velocity of shot put and the body center of gravity.Results:1.At sliding stage,the main factor which leads to speed difference is the difference of the power,namely the difference of strength level of right quadriceps femoris and right gastrocnemius,but in the meantime the increase of strength of right erector spinae and the descend of acentric contract of right gluteus maximus results that the trunk lift early.The right rectus femoris is one of the main factors that influence shot put speed at the jumping stage.The sequence of muscle works can nicely reflect that the characteristic of technique of shot put,which can diagnose the technique.2.At transitional phase,the work ability of right quadriceps femoris, and the strength of the erector spinae is the main factor that influences the loss of shot put speed.3.In the last phase,the weak strength of the left gastrocnemius can’t brake the movement of the left body well,and right quadriceps femoris stretch not enough in time,which is the factor that influences the prepare process of the last phase.The coordination during difference muscles is the key that develops the biggest effect in the last phase.4.According to the rule of strength transfer in the movement chain,the increase of shot put result needs the use of the coordination of each muscle of whole body,to develop the biggest effect.5.The combine of surface electromyography and 3D shoot can nicely come out the regulation of shot put,which can aim at technique problem,and provide in brief a reference data.