Electromyography Exposes Heterogeneity in Muscle Co-Contraction following Stroke.
Electromyography Exposes Heterogeneity in Muscle Co-Contraction following Stroke.
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DOI：
10.3389/fneur.2017.00699
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发表时间：
2017
影响因子：
3.4
通讯作者：
Patten C
中科院分区：
文献类型：
--
作者：
Banks CL;Huang HJ;Little VL;Patten C
中风后行走通常被描述为需要过度的肌肉共同收缩，然而，共同收缩是这一人群普遍存在的运动控制策略的证据仍然没有定论。共同收缩，同时激活的激动剂和拮抗剂肌肉，可以评估与肌电图（EMG），但往往是定性描述。在这里，我们的目标是确定共同收缩是否与中风后的步态障碍有关。15名慢性中风患者和9名健康对照者以自选速度在装有仪器的跑步机上行走。从每条腿的内侧腓肠肌（MG）、比目鱼肌（SOL）和胫骨前肌（TA）收集表面肌电图。EMG包络振幅以三种方式评估：（1）未归一化，（2）归一化至整个步态周期的最大值，或（3）归一化至最大M波。计算每个激动剂/拮抗剂肌肉对（MG/TA和SOL/TA）的三个共收缩指数，以评估使用各种指标量化共收缩的效果。双因素方差分析用于比较各组和标准化对每个指标的影响。无论用于量化共同收缩的指标如何，健康对照组和中风后个体的麻痹腿之间在步态的终端站立（TSt）阶段的共同收缩没有差异。有趣的是，M-max和非标准化EMG之间的共同收缩相似;然而，标准化并不影响解决组差异的能力。虽然TSt共收缩量与步行速度之间存在适度的相关性，但这种关系不足以激发进一步探索卒中后共收缩与步行功能之间的因果关系。共同收缩似乎不是中风后个体采用的常见策略。我们建议探索替代的肌电图分析方法，努力了解更多关于中风后步态障碍的因果机制。
Walking after stroke is often described as requiring excessive muscle co-contraction, yet, evidence that co-contraction is a ubiquitous motor control strategy for this population remains inconclusive. Co-contraction, the simultaneous activation of agonist and antagonist muscles, can be assessed with electromyography (EMG) but is often described qualitatively. Here, our goal is to determine if co-contraction is associated with gait impairments following stroke. Fifteen individuals with chronic stroke and nine healthy controls walked on an instrumented treadmill at self-selected speed. Surface EMGs were collected from the medial gastrocnemius (MG), soleus (SOL), and tibialis anterior (TA) of each leg. EMG envelope amplitudes were assessed in three ways: (1) no normalization, (2) normalization to the maximum value across the gait cycle, or (3) normalization to maximal M-wave. Three co-contraction indices were calculated across each agonist/antagonist muscle pair (MG/TA and SOL/TA) to assess the effect of using various metrics to quantify co-contraction. Two factor ANOVAs were used to compare effects of group and normalization for each metric. Co-contraction during the terminal stance (TSt) phase of gait is not different between healthy controls and the paretic leg of individuals post-stroke, regardless of the metric used to quantify co-contraction. Interestingly, co-contraction was similar between M-max and non-normalized EMG; however, normalization does not impact the ability to resolve group differences. While a modest correlation is revealed between the amount of TSt co-contraction and walking speed, the relationship is not sufficiently strong to motivate further exploration of a causal link between co-contraction and walking function after stroke. Co-contraction does not appear to be a common strategy employed by individuals after stroke. We recommend exploration of alternative EMG analysis approaches in an effort to learn more about the causal mechanisms of gait impairment following stroke.
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影响因子：
14.5
作者：
CORCOS, DM;GOTTLIEB, GL;AGARWAL, GC
通讯作者：
AGARWAL, GC
影响因子：
2.5
作者：
Hermens, HJ;Freriks, B;Rau, G
通讯作者：
Rau, G
影响因子：
2.4
作者：
Amarantini, D;Martin, L
通讯作者：
Martin, L
影响因子：
3.2
作者：
Banks, Caitlin L.;Pai, Mihir M.;Patten, Carolynn
通讯作者：
Patten, Carolynn
影响因子：
2.5
作者：
CORCOS, DM;AGARWAL, GC;GOTTLIEB, GL
通讯作者：
GOTTLIEB, GL