The Study On Surface Electromyography (sEMG) Signals In Cerebral Palsy (CP) Children With Knee Hyperextension

Objective To provide an objective and quantitative basis for rehabilitation assessment and treatment of non compensatory knee hyperextension by observing the features of s EMG signals from the muscle around the knees of CP children with non compensatory knee hyperextension.Method The muscle strength of muscles around the knee joint of 26 CP children who meet the inclusion conditions with non compensatory knee hyperextension are measured by the manual muscle testing(MMT).The therapists are trained by a unified training. The level of muscle strength must be recorded. Then all the children’s s EMG signals of both quadriceps femoris and hamstring under maximum isometric voluntary contraction(MIVC) state are tested by the same s EMG instrument. The patient’s root mean square(RMS) and integrated EMG(i EMG) during MIVC are recorded and analyzed by Wilcoxon signed ranks test.Also the correlation between the level of muscle strength and s EMG value is studied by Pearson correlation analysis.Result Under MIVC state, with the knees extended,the RMS and i EMG levels from the severe side of quadriceps femoris are lower than those of mild side,and the difference is significant(p<0.05). With the knees flexed, the RMS and i EMG levels from the severe side of hamstring are lower than those of mild side,and the difference is significant(p<0.05). The study on correlation shows there is correlation between s EMG value and level of muscle strength,and the difference is significant(p<0.05).Conclusion The severity level of non compensatory knee extension in CP children has a relationship with data size of s EMG for muscle strength evaluation in MIVC. The muscle strength lower, the knee extension more serious. SEMG test and MMT also has a correlation. The features of s EMG for muscle strength evaluation in CP children with non compensatory knee hyperextension provide an objective, quantitative and effective reference basis for clinical assessment. SEMG value can makes it more reasonable to perform knee function exercise for CP children with non compensatory knee hyperextension.It is also can evaluate the therapeutic effect of rehabilitation therapy. Especially to adjust the cooperative rate between active muscle and antagonistic muscle around the knee joint.The new ideas can improve the training efficiency and improve the effect of rehabilitation.