Features And Application Of Surface Electromyographic Signal In School-age Children With Cerebral Palsy

Now cerebral palsy(CP) is the main disease which results to the children disabilities,and its incidence climbs up yet. Children with cerebral palsy are the main objects who need children rehabilitation.The etiology and clinical manifestion of cerebral palsy is quite complicated and its diagnosis,treatment and rehabilitation relates to clinical medicine, rehabilitation medicine and traditional Chinese medicine.The beginning of studies about cerebral palsy in our country is late and the first rehabilitation stations for disabled children was founded in1987.We have made great advances in the diagnosis, evaluation and treatment of cerebral palsy over20yeas of mutual efforts.But now the research about the objective index on neuromuscular state is still insufficient,and objective criteria for function assessment and effective assessment is deficient.Since it is difficult to optimize the training parameter,it is hard to get the best therapeutic scheme.This study will help to supplement these insufficiency.The surface electromyographic(sEMG) signal is a one-dimensional time series signal of neuromuscular system recorded from skin surface.Its time and frequency domain characters are related to the number and activity patterns of MU and the state of muscle metabolism,,and the sEMG measurement can reflect the states of muscle activity and muscle function accurately and noninvasively.Therefore it is a valuable methods for muscle function evaluation. The sEMG is a noninvasive method which can record and measure the changes of local muscle activities. sEMG is firstly used for sports study to analyze muscular movement time sequence and contribution to movement under different sports and know whether initiation and duration of each muscle during exercise training is normal.Recently,extensive domestic studies on sEMG are focusing on rehabilitation medicine,especially on functional evaluation during muscle strength training exercise. But the research about sEMG on children rehabilitation, especially on cerebral palsy is still insufficient..In this study we measured the values of surface electromyography of the main muscles in school-age children with cerebral palsy, so as to explore the features of sEMG in children with cerebral palsy and evaluate the feasibility of instructing the rehabilitation training and assessment of rehabilitation effect on children with cerebral palsy by electromyography parameters. This study contains three parts. In the first part,100children with cerebral palsy from6to14years[70males and30females;average(11.81±2.05) years old] in Guangzhou Cerebral Palsy Research Center,Guangdong999Brain Hospital,Clifford Hospital from Sep.2009to Jul.2010were recruited.The subjects consist of41spastic diplegia children,27spastic quadriplegia children,9spastic hemiplegia children,12athetoid children,12children mixed with spasticity and athetoisis and49mild children,34moderate children,17severe children.The control group was30age-and sex-matched healthy children.The signals of both biceps brachii,triceps,tibialis anterior and gastrocnemius muscles were recorded.The FexComp EMG machine and Ag/Agcl electrodes were used and the electrodes were applied on the muscle belly and parallelized with muscle fiber.The biceps brachiiand triceps were tested at the position of sitting and the tibialis anterior and gastrocnemius muscles were tested at the position of lying.Testing processes was divided into passive motion and maximum isometric voluntary contraction(MIVC).Integrated electromyography (iEMG),median frequency (MF) and co-contraction ratio(CR) were analyzed.During passive motion,we found that the spasmodic muscles of spastic children, complete muscles of athetoid children and the children of mixed type registered a significantly higher iEMG (P<0.05),but all muscles present no statistically different MF compared with the control group (P>0.05).During MIVC,complete muscles of spastic children present a significantly lower iEMG (P<0.05),while other children registered no statistically different iEMG compared with the control group (P>0.05).The spasmodic muscles of spastic children showed a significantly lower MF (P<0.05),while other children showed a significantly higher MF (P<0.05).The antagonist muscles of spasmodic muscles of spastic children gave a higher co-contraction ratio (P<0.05),but others gave a opposite result (P<0.05).During passive motion,the iEMG from the biceps brachiir and gastrocnemius muscles increased with the worsening of the patient,s condition (P<0.05), but the MF was not different from the patient,s condition (P>0.05).During MIVC,the iEMG and MF from complete muscles decreased with the worsening of the patient,s condition (P<0.05), while the co-contraction ratio from the triceps,tibialis anterior increased with the worsening of the patient,s condition (P<0.05).So it was deemed that the features of sEMG showed great difference between the children with cerebral palsy and the normals.The time,frequency domain characters were different from the clinical types and the motor function levels.In the second part,60children with spastic diplegia aged6to14years[42males and18females;average(11.55±0.21) years old] in Guangzhou Cerebral Palsy Research Center from Mar.2010to Jun.2010were involved..All enrolled subjects received combined rehabilitation therapy:①Bobath methods.②Conductive education.③Massage.④Acupuncture.⑤Orthosis.⑥Games.⑦Music therapy.⑧Physical therapy.The treatment was performed for5successive days with an interval of2days for3months.All patients were evaluated by the gross motor function measure scale(GMFM) and the sEMG before and after the rehabilitation training.The GMFM included5parts:lying (A),sitting (B),climbing and kneeling(C),standing(D),walking and jumping(E) evaluation.The children would get100if they could complete all items and would get0if they could complete nothing at all.The FexComp EMG machine and Ag/Agcl electrodes were used and the electrodes were applied on the muscle belly and parallelized with muscle fiber.The signals of both quadriceps and gastrocnemius muscles were recorded.The quadriceps were tested at the position of sitting and the gastrocnemius muscles were tested at the position of lying.Testing processes included passive motion and MIVC.The iEMG,root mean square (RMS),mean power frequency (MPF),MF and average electromyography (AEMG) were analyzed.After3months exercise,the score of section of A,B,C(GMFM) got no statistically different change (P>0.05), while the total and the section of D,E increased significantly (P<0.05).The sEMG evaluation showed that the iEMG of quadriceps and gastrocnemius muscles decreased significantly during passive motion (P<0.05), while the iEMG、RMS、AEMG of quadriceps and gastrocnemius muscles increased significantly during MIVC (P<0.05).Multinomial linear regression analysis showed that factors influencing the section of D,E included the iEMG of quadriceps and gastrocnemius muscles during passive motion and the iEMG and RMS of quadriceps and gastrocnemius muscles during MIVC,the iEMG had the most influence and the AEMG had no influence.Since the clinical results was correlate with the sEMG data,we acquired that sEMG was feasible to assess the rehabilitation effect in children with cerebral palsy.In the last part.,60children with spastic diplegia aged6to9years[32males and28females;average(7.68±0.36) years old] in Clifford Hospital from Jun.2010to Oct.2010were involved.All patients were randomly divided into treatment group(n=30,16males and14females) and control group(n=30,17males and13females). No statistically significant differences of age,height,weight and gender was found between2groups (P>0.05).The treatment was performed for5successive days with an interval of2days for3months.The evaluation of GMFM was performed before and after the rehabilitation training. All patients received combined therapy(Bobath methods,conductive education,massage,acupuncture,orthosis therapy,games and recreation therapy,music therapy,physical therapy).While the treatment group was evaluated by the sEMG apparatus before training and were trained with the program instructed by its result.The signals of both gastrocnemius,tibialis anterior, adductor,quadriceps and hamstring muscles were recorded.The FexComp EMG machine and Ag/Agcl electrodes were used and the electrodes were applied on the muscle belly and parallelized with muscle fiber.The quadriceps and hamstring muscles were tested at the position of sitting and the gastrocnemius, tibialis anterior and adductor muscles were tested at the position of lying.Testing processes included passive motion and maximum isometric voluntary contraction.The iEMG.,RMS,AEMG and CR were analyzed.The treatment group was trained with the program instructed by the sEMG:①Decreasing the muscular tone.Decrease the tension of the muscle which iEMG is higher during passive motion.②Strength training.Trained the muscle which had lower time domain indexes.③Coordination training.Not only decreased the tension of the contracting muscle,but also trained the strength of the antagonist muscles during MIVC.④Balance training.Focused on the weaker side if both sides had significant differences in the time domain indexes.It was found that the section of A,B,C(GMFM) got no statistically different change (P>0.05), while the total and the section of D,E increased significantly after3months exercise in both groups (P<0.05).There was no statistical differences in the section of A,B,C (P>0.05) between2groups, while the differences in the section of D,E and total points were statistically significant after the exercise (P<0.05).The results indicated that the gross motor function was much better in the training group than that in the control group,especially with regard to standing,walking and running. The conclusion was drown that the sEMG might be useful to the rehabilitation training in children with cerebral palsy.This paper verified that the features of sEMG of the children with cerebral palsy was different from that of the normals and the features of sEMG were different from the clinical types and the motor function levels.We acquired that sEMG was feasible to assess the rehabilitation effect in children with cerebral palsy.It was also proved that sEMG was workable to assess the rehabilitation effect in children with cerebral palsy and might be helpful to the rehabilitation training in children with cerebral palsy.In a word,sEMG might be a useful electrophysiological index in the auxiliary diagnosis,evaluation and rehabilitation training of cerebral palsy,it is of practical value in the evaluation of neuromuscular state in children with cerebral palsy.