Examination of Poststroke Alteration in Motor Unit Firing Behavior Using High-Density Surface EMG Decomposition.
Examination of Poststroke Alteration in Motor Unit Firing Behavior Using High-Density Surface EMG Decomposition.
复制标题
使用高密度表面肌电图分解检查运动单元放电行为的中风后改变。
DOI：
10.1109/tbme.2014.2368514
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发表时间：
2015-05
期刊：
影响因子：
--
通讯作者：
Zhou P
中科院分区：
文献类型：
--
作者：
Li X;Holobar A;Gazzoni M;Merletti R;Rymer WZ;Zhou P
高密度表面肌电（EMG）分解的最新进展使得从表面肌电干扰模式中区分单个运动单元活动成为一项可行的任务，从而为检查运动单元控制特性提供了一种非侵入性方法。在本研究中，我们应用高密度表面肌电图记录和分解技术来评估中风后运动单位放电行为的改变。使用64通道二维电极阵列从9名偏瘫卒中受试者的麻痹和对侧第一背侧骨间肌（FDI）收集表面EMG信号，在不同的等长离散收缩水平（2 N至10 N，增量为2 N）。通过对高密度表面肌电信号进行分解，提取运动单位放电频率，并比较麻痹侧和对侧肌肉的放电频率。在九个测试对象中，在不同的收缩水平下，与对侧肌肉相比，麻痹的FDI肌肉显示出运动单位放电率降低。回归分析表明，麻痹侧和对侧肌肉的平均运动单位放电率与肌肉收缩水平之间存在线性关系（p < 0.001），前者的增量率（0.32 pps/N）低于后者（0.67 pps/N）。麻痹肌肉运动单位放电频率的变异系数（CoV，收缩水平上的平均值）（0.21 ± 0.012）显著高于对侧肌肉（0.17 ± 0.014）（p < 0.05）。这项研究提供了直接的证据，运动单位放电行为改变中风后使用表面肌电图，这可能是一个重要的因素，有助于偏瘫肌无力。
Recent advances in high density surface electromyogram (EMG) decomposition have made it a feasible task to discriminate single motor unit activity from surface EMG interference patterns, thus providing a noninvasive approach for examination of motor unit control properties. In the current study we applied high density surface EMG recording and decomposition techniques to assess motor unit firing behavior alterations post-stroke. Surface EMG signals were collected using a 64-channel 2-dimensional electrode array from the paretic and contralateral first dorsal interosseous (FDI) muscles of nine hemiparetic stroke subjects at different isometric discrete contraction levels between 2 N to 10 N with a 2 N increment step. Motor unit firing rates were extracted through decomposition of the high density surface EMG signals, and compared between paretic and contralateral muscles. Across the nine tested subjects, paretic FDI muscles showed decreased motor unit firing rates compared with contralateral muscles at different contraction levels. Regression analysis indicated a linear relation between the mean motor unit firing rate and the muscle contraction level for both paretic and contralateral muscles (p < 0.001), with the former demonstrating a lower increment rate (0.32 pulses per second (pps)/N) compared with the latter (0.67 pps/N). The coefficient of variation (CoV, averaged over the contraction levels) of the motor unit firing rates for the paretic muscles (0.21 ± 0.012) was significantly higher than for the contralateral muscles (0.17 ± 0.014) (p < 0.05). This study provides direct evidence of motor unit firing behavior alterations post-stroke using surface EMG, which can be an important factor contributing to hemiparetic muscle weakness.