Martina Betschart1, Séléna Lauzière1, Carole Miéville1, Bradford J McFadyen2, Sylvie Nadeau3. 1. 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. 2. 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. 3. 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. Electronic address: sylvie.nadeau@umontreal.ca.
Abstract
BACKGROUND: 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. METHODS: 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. RESULTS: 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.
BACKGROUND: 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. METHODS: 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. RESULTS: 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.
Authors: Carolina C Alcântara; Charalambos C Charalambous; Susanne M Morton; Thiago L Russo; Darcy S Reisman Journal: Neurorehabil Neural Repair Date: 2018-11-09 Impact factor: 3.919