Electrophysiological Study Of Lumbar Muscle In Patients With Cervical Spondylotic Myelopathy Based On Characteristic Multichannel Surface Electromyography

BackgroundCervical spondylotic myelopathy(CSM)is a neurological disease that damages the spinal cord due to degenerative spinal canal stenosis of the cervical spine compressing the spinal cord and surrounding structures.With the gradual development of an aging society in China,the incidence of cervical spondylotic myelopathy continues to increase and seriously affects the quality of life and work ability of patients,thus bringing a huge burden to the medical and health care industry.The hallmark symptoms of CSM include numbness and weakness of the extremities,decreased hand mobility,balance difficulties,and abnormal gait.Studies have shown that CSM patients can show abnormal psoas muscle function,and may even have obvious non-specific low back pain(NSLBP).However,due to the difficulty in determining the cause of NSLBP,it is difficult to formulate reasonable diagnosis and treatment standards,and there is still widespread use of imaging examinations in clinical diagnosis and treatment,pain medication and even unnecessary surgery.In the past,we usually used electromyography(EMG)to analyze the function and activity state of human motor neurons and muscles,but surface electromyography(sEMG)has the advantages of simple operation,non-invasive and painless,etc.The application of sEMG on kinematics research is becoming more and more extensive.In this study,multi-channel surface electromyography was used to conduct a preliminary study on the spatial distribution of psoas EMG activity in patients with CSM,to observe and quantify the recruitment pattern of lumbar stabilization muscle groups during trunk bending,and to explore the changes in psoas muscle activation patterns.And to explore the correlation between the change of psoas activation pattern and SVA,lower limb muscle strength and JO A score.Multi-channel surface electromyography,as an objective and standardized diagnostic,research and prediction tool,can be used for clinical diagnosis of CSM-related lumbar spine symptoms.It may provide a basis for diagnosis and treatment and prognosis of rehabilitation.ObjectiveMulti-channel surface electromyography(EMG)was used to analyze the spatial distribution characteristics of lumbar muscle electrical activity in CSM patients,observe and quantify the recruitment mode of lumbar muscle activity in CSM patients during dynamic task test,and explore the correlation between characteristic parameters of lumbar muscle activation mode and cervical JOA score.Methods24 patients with cervical spondylosis diagnosed by medical history,symptoms,physical examination and imaging examination(CT or MRI)were selected as the cervical spondylotic myelopathy group,and 13 volunteers who met the inclusion/exclusion criteria of healthy subjects in this study were set as healthy control group;In the rehabilitation department of our hospital,the DELSYS wireless dynamic electromyography tester was used to record sEMG when the subjects performed the specified actions according to the instructions.The commanded action is as follows:the subject takes a natural standing position,with the arms hanging down naturally at the sides of the body,the feet are shoulder-width apart,and the trunk is bent forward for 1 second,so that the angle between the trunk and the horizontal plane is about 30°,The experiment was stopped by maintaining the bent state for 2 seconds and then returning to an upright position for 2 seconds.The surface EMG signal was recorded when the subject was in a natural standing state.After observing the signal baseline for 5 seconds,the subject was instructed to perform a trunk bending motion and simultaneously record the surface EMG signal and motion data until the action was completed.The recorded signals were processed by MATLAB software to obtain relative area(RA),relative width(RW)and relative height(RH).SPSS 26.0 was used for statistical analysis of RA,RW,RH and the ratio of relative width to relative height between groups.Pearson correlation coefficient was used to analyze the correlation between the characteristic parameters of cervical spondylotic myelopathy group and cervical JOA score.Bilateralα=0.05 was set,and P<0.05 was considered to be statistically significant.Results(1)From the overall EMG activity distribution during lumbar flexion and extension,it can be observed that the lumba muscle activity on the left and right sides of the normal subjects is symmetrical,the EMG signal intensity gradually decreases from the caudal to the cephalic side,and the EMG signal in the paravertebral region near the spine The intensity is significantly higher than in areas further away from the spine.During trunk flexion,the most active areas of EMG activity were more concentrated in the L5 paravertebral region.During restoration of uprightness,the active area of EMG activity extended cephalad,and higher EMG signal intensity appeared in the L3-L5 paravertebral regions.10 of the 13 normal subjects in the healthy control group showed similar psoas activation patterns on the sEMG topography.(2)Comparing sEMG topography of CSM patients with sEMG topography of normal subjects revealed that CSM patients had different muscle activation patterns during trunk flexion movements than normal subjects.In CSM patients,the regions with the most active EMG activity during flexion are more widely distributed and disordered,and exhibit multicentricity.In the CSM patient group,the lumbar muscle activation patterns were quite different,but the distribution of EMG activity in most patients was significantly different from that in healthy controls.(3)Statistics show that there are significant differences in the relative width of the active area of myoelectric activity between the healthy control group and CSM patient group during the process of trunk flexion and extension(RW=0.41±0.24 in group C,RW=0.23±0.08 in group H at flexion stage,P<0.05;RW=0.36±0.17 in group C,0.22±0.09 in group H at extension stage,P<0.05).There is a significant difference between CSM patients and healthy controls in the relative height of the active area of trunk flexion(RH=0.86±0.26 in group C and RH=0.52±0.39 in group H at flexion stage,P<0.05).The relative height of CSM patients in the extension stage and the relative area of active areas of electromyography in flexion and extension stages are larger than those in the healthy control group,but there is no statistical difference.The ratio of the relative width to the relative height of the active area of electromyography in CSM patients was smaller than that in the healthy control group,and there was no statistical difference.(4)JOA score of CSM patients was correlated with RW in flexion and extension(P<0.05),but not with RA and RW/RH(P>0.05).Due to the small difference in RH among CSM patients,the correlation analysis of JOA score and RH was not performed.ConclusionThe electromyographic activity of lumbar muscles in CSM patients showed obvious asymmetry and disorder during trunk bending exercise,and the active area of electromyography expanded to both sides of the spine.Motor and sensory dysfunction caused CSM patients to show inefficient lumbar muscle recruitment mode,and lumbar erector spinae showed compensatory activity to maintain body balance.In this study,the abnormal activation pattern of lumbar muscles in CSM patients was analyzed for the first time,which may be related to NSLBP.Multi-channel SEMG topographic map may help to provide standardized objective basis for diagnosis,treatment,prognosis and rehabilitation of lumbar symptoms related to cervical spondylotic myelopathy.