Electromyography Analysis Of Different Patterns Of Exercise In The Early Stage Of Biceps Femoris Strain

Objective: To analyze the changes of surface electromyography(s EMG)signals under different movement modes in the early stage of biceps femoris muscle strain,and to select a more suitable movement mode for the rehabilitation training of the muscle after strain.Methods:The subjects of the study were 16 male students with biceps femoris muscle strain within two weeks who attended the Rehabilitation Center of the First Affiliated Hospital of Harbin Medical University from October 2019 to October 2020.They were performed isotonic,isometric and centrifugal movements on biceps femoris of both lower limbs under muscle strength testing system.The application of EMG signal acquisition instrument to collect EMG time domain indexes: the maximum value of original EMG,root mean square EMG(RMS);i EMG value,frequency domain index: median frequency(MF)value;reaction time indexes: preaction time(PMT)and electromechanical delay(EMD),and statistical analysis was conducted for each index.Results:1.The biceps femoris of the subject's strained side under different modes of movements,the maximum value of original EMG and the i EMG values of the isometric were significantly higher than those of isotonic and centrifugal movements,the difference was statistically significant(P<0.05);the MF value and the RMS value of the isometric and isotonic movements were higher than those of centrifugal movements,the differences were statistically significant(P<0.05);the PMT value was no significant difference under different modes of movements(P>0.05);the EMD value in centrifugal movements was significantly higher than that in isometric and isotonic movements,and the difference was statistically significant(P<0.05).2.Compared with the healthy side,the EMG signal of the strained side of the biceps femoris muscle of the subjects during movements was weakened,the exercise force was decreased,and the response time was increased.Conclusion:In the condition of biceps femoris strain,by comparing the EMG signals of different movement modes,it is concluded that isometric movements is the first choice in early rehabilitation training,followed by isotonic movements,and centrifugal movements is not recommended.