高密度表面肌电对青少年特发性脊柱侧凸患者竖脊肌协同活动的评估

Assessment of coordinated activity of the erector spinae muscles based on high-density surface electromyogram in adolescent idiopathic scoliosis patients

目的:基于高密度表面肌电(surface electromyography,sEMG)技术,评估青少年特发性脊柱侧凸(adolescent idiopathic scoliosis,AIS)患者竖脊肌在躯干运动中的协同活动。方法:将高密度sEMG电极阵列沿着脊柱规律分布于AIS患者与健康受试者腰背双侧,记录受试者完成对称动作(挺直站立与躯干前倾)时的sEMG,计算每个通道sEMG的均方根值(root mean square,RMS),经平滑后得到受试者背部sEMG地形图,通过对sEMG均方根值地形图的分析评估受试者竖脊肌的协同活动情况。结果:对称性躯干动作时,健康受试者sEMG均方根值地形图强活动区域左右对称,而AIS患者强活动区域缺乏左右对称性。挺直站立时,AIS患者凸侧地形图强活动区域能量和的平均强度为66.92±12.05μV,高于凹侧的23.77±4.04μV;躯干前倾时,凸侧强活动区域能量和的平均强度为192.25±87.62μV,高于凹侧的95.70±25.93μV。对称性躯干动作时,不同Cobb角的AIS患者凸侧sEMG能量不同,随着Cobb角的增加而提高,与凹侧sEMG能量差值亦随着Cobb角的增加而变大;不同Cobb角AIS患者凸、凹侧对称列sEMG能量比值差异最大的位置均在竖脊肌与腰背部肌群肌腹重叠的区域。结论:AIS患者竖脊肌与腰背部肌群在对称性躯干动作时的sEMG均方根值地形图凸侧强、凹侧弱,凸侧sEMG均方根值随着Cobb角的增大而加强。

Objectives:To assess the coordinated activity erector spinae muscles in AIS patient based on high-density surface electromyography(sEMG).Methods:A high-density sEMG array was symmetrically attached on lumbar back along spine for both AIS and healthy subjects,and sEMG signals were collected when the subjects performed two kinds of torso movements(upright standing and trunk flexion).For each channel,its root mean square(RMS)values were calculated from the sEMG recordings and were smoothened with interpolation method.Then the RMS values of all the channels were used to create a sEMG topography to analyze the muscle coordination activities.Results:Our experimental results demonstrated that during upright standing and trunk flexion tasks,those tense activity regions presented a bilateral symmetry in healthy subjects.For AIS patients,their tense activity regions did not have a bilateral symmetry,which was stronger at convex side than at concave side.In upright standing posture,the average RMS value of the strongest region in AIS patients′convex map was 66.92±12.05μV,greater than 23.77±4.04μV at the concave side.In trunk flexion posture,the average RMS value of the strongest region in AIS patients′convex map was 192.25±87.62μV,greater than 95.70±25.93μV at concave.sEMG energy at convex side became higher and the ratio to concave got bigger as the increase of Cobb angle.For AIS patients with different Cobb angles,the ratio of those sEMG energy in each column at convex to its symmetrical column at concave showed that the most significant difference was presented at the overlapping region of paraspinal and other muscles belly.Conclusions:The RMS maps of the sEMG in AIS patients were significantly different from those in healthy subjects for both tasks of upright standing and trunk flexion,namely,sEMG energy at convex side was higher than that at concave,which became stronger with the increase of Cobb angle.