Gray V L, Pollock C L, Wakeling J M, Ivanova T D, Garland S J
Department of Physical Therapy and Rehabilitation Science, University of Maryland, Baltimore, MD 21201, USA.
Dept Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada.
J Electromyogr Kinesiol. 2015 Dec;25(6):959-65. doi: 10.1016/j.jelekin.2015.09.003. Epub 2015 Oct 8.
This study compared self-induced stepping reactions of seventeen participants after stroke and seventeen controls. Surface electromyographic (EMG) signals were recorded bilaterally from the soleus (SOL), tibialis anterior (TA), biceps femoris (BF) and rectus femoris (RF) muscles. Principal component analysis (PCA) was used to reduce the data into muscle activation patterns and examine group differences (paretic, non-paretic, control leg). The first principal component (PC1) explained 46.7% of the EMG signal of the stepping leg. Two PCs revealed distinct activation features for the stepping paretic leg: earlier TA onset at step initiation and earlier BF and SOL onset at mid-step. For the stance leg, PC1 explained 44.4% of the EMG signal and significant differences were found in the non-paretic leg compared to paretic (p < 0.001) and control (p < 0.001). In PC1, at step onset the BF and SOL EMG and the RF and TA EMG were increased over the latter half of the step. No PC loadings were distinct for the paretic leg during stance, however differences were found in the non-paretic leg: earlier TA burst and increased BF and SOL EMG at step initiation. The results suggest impairments in the paretic leg when stepping and compensatory strategies in the non-paretic stance leg.
本研究比较了17名中风患者和17名对照者的自我诱发踏步反应。从双侧比目鱼肌（SOL）、胫骨前肌（TA）、股二头肌（BF）和股直肌（RF）记录表面肌电图（EMG）信号。主成分分析（PCA）用于将数据简化为肌肉激活模式，并检查组间差异（患侧、非患侧、对照侧）。第一个主成分（PC1）解释了踏步侧EMG信号的46.7%。两个主成分揭示了患侧踏步腿不同的激活特征：踏步开始时TA起始较早，步中时BF和SOL起始较早。对于支撑腿，PC1解释了EMG信号的44.4%，与患侧（p < 0.001）和对照侧（p < 0.001）相比，非患侧存在显著差异。在PC1中，在步开始时，BF和SOL的EMG以及RF和TA的EMG在步的后半段增加。在支撑期，患侧腿的主成分负荷没有明显差异，然而在非患侧腿发现了差异：步开始时TA爆发较早，BF和SOL的EMG增加。结果表明患侧腿在踏步时有损伤，非患侧支撑腿有代偿策略。
