Research On Neck And Shoulder Muscle Fatigue Characteristics Based On Myoelectric Signal

As time changed,cervical spondylosis presents the low age and pan-socialization tendency.The etiology and pathogenesis of cervical spondylosis are complex,and are closely related to the fatigue of neck and shoulder muscles and the poor contractility.Through the surface EMG signal we can grasp the change in the muscle in real time,determine the fatigue degree,and effectively avoid muscle in long-term fatigue,prevent the occurrence of cervical spondylosis.The evaluation of muscle fatigue degree is widely used in many fields.However,there is no unified standard to the classification of muscle fatigue degree and evaluation methods,and no model corresponding to the muscle fatigue degree of neck and shoulder at the same time.To study the fatigue of the neck and shoulder muscles,this article designs a integral analysis system which uses the trapezius EMG signal.As the main muscle to maintain the balance of the cervix,trapezius muscle produces train easily and affects the health of the cervical spine.When a simple trapezius movement on the beam,ipsilateral or different side will have a neck extension and neck flexion.When the trapezius contract on the beam and the next beam scapular will produce scapular rotation.In this experiment,we collected the trapezius myoelectric signal of scapular rotation during neck and shoulder muscle fatigue deepening.Using the AD8221 and OPA365 sets up a hardware conditioning circuit to complete the original signal amplification filter.Using 32-bit master chip STM32F103RCT6 internal ADC complete the analog-digital conversion of the conditioning circuit output analog voltage signal,the Wi-Fi module complete remote communication between MCU and PC and upload the data to the host computer,through LabVIEW PC,the host computer can complete real-time display and data storage.After preprocessing the EMG signal,the time domain,frequency domain,time-frequency domain parameters are extracted,and the changes are observed and analyzed.The experimental results show that RMS and EMG in neck lateral flexion and scapular rotational movement are all decreased with the muscle fatigue degree Deepening and showing a rising trend,which can be used as the characteristic parameter of fatigue judgment.Because the average power frequency(MPF)and median frequency(MF)are basically balanced and have no phenomenon,that frequency shifts to the left,therefore they are unfit for judging fatigue.Based on BP neural network this paper establishes a model for identifying the degree of neck and shoulder muscles fatigue and uses the first five characteristic parameters as input values,so as to determine the degree of fatigue of neck and shoulder muscles,The results show that the recognition rate of the scapula rotation muscle fatigue degree is 89%,and the recognition rate of neck and shoulder muscle fatigue degree of the neck flexion movement is 83.5%.It can be seen that the EMG characteristic values generated by the rotational movement of the scapula that taken as input Make neck and shoulder muscle fatigue model has a higher recognition rate.The results of this study have important significance for the study of neck muscle fatigue.