Betschart Martina, Lauzière Séléna, Miéville Carole, McFadyen Bradford J, Nadeau Sylvie
Centre de recherche interdisciplinaire en réadaptation (CRIR), Institut de réadaptation Gingras-Lindsay de Montréal (IRGLM) du CIUSSS Centre-Sud-de-l'île-de-Montréal, Québec, Canada; École de réadaptation, Université de Montréal, Québec, Canada.
Centre interdisciplinaire de recherche en réadaptation et intégration sociale (CIRRIS), CIUSSS de la Capitale-Nationale, Québec, Canada; Département de réadaptation, Faculté de médecine, Université Laval, Québec, Canada.
J Electromyogr Kinesiol. 2017 Feb;32:93-100. doi: 10.1016/j.jelekin.2016.12.007. Epub 2017 Jan 3.
There is growing evidence that stroke survivors can adapt and improve step length symmetry in the context of split-belt treadmill (SBT) walking. However, less knowledge exists about the strategies involved for such adaptations. This study analyzed lower limb muscle activity in individuals post-stroke related to SBT-induced changes in step length.
Step length and surface EMG activity of six lower limb muscles were evaluated in individuals post-stroke (n=16) during (adaptation) and after (after-effects) walking at unequal belt speeds.
During adaptation, significant increases in EMG activity were mainly found in proximal muscles (p⩽0.023), whereas after-effects were observed particularly in the distal muscles. The plantarflexor EMG increased after walking on the slow belt (p⩽0.023) and the dorsiflexors predominantly after walking on the fast belt (p⩽0.017) for both, non-paretic and paretic-fast conditions. Correlation analysis revealed that after-effects in step length were mainly associated with changes in distal paretic muscle activity (0.522⩽r⩽0.663) but not with functional deficits. Based on our results, SBT walking could be relevant for training individuals post-stroke who present shorter paretic step length combined with dorsiflexor weakness, or individuals with shorter nonparetic step length and plantarflexor weakness.
越来越多的证据表明，中风幸存者在分带跑步机（SBT）行走过程中能够适应并改善步长对称性。然而，对于这种适应所涉及的策略了解较少。本研究分析了中风后个体与SBT诱导的步长变化相关的下肢肌肉活动。
在中风后个体（n = 16）以不等带速行走期间（适应阶段）和之后（后效应阶段），评估了六条下肢肌肉的步长和表面肌电图活动。
在适应过程中，肌电图活动的显著增加主要出现在近端肌肉（p⩽0.023），而后效应尤其在远端肌肉中观察到。在非瘫痪侧和瘫痪侧快速行走条件下，在慢带行走后跖屈肌肌电图增加（p⩽0.023），在快带行走后背屈肌肌电图主要增加（p⩽0.017）。相关性分析表明，步长的后效应主要与远端瘫痪肌肉活动的变化相关（0.522⩽r⩽0.663），而与功能缺陷无关。基于我们的结果，SBT行走可能与训练中风后出现瘫痪侧步长较短且伴有背屈肌无力的个体，或非瘫痪侧步长较短且伴有跖屈肌无力的个体相关。
