Jacqueline A Palmer1, HaoYuan Hsiao2, Louis N Awad3, Stuart A Binder-Macleod4. 1. Department of Physical Therapy, University of Delaware, Newark, DE 19713, USA; Graduate Program in Biomechanics and Movement Science, University of Delaware, Newark, DE 19713, USA. Electronic address: palmerja@udel.edu. 2. Graduate Program in Biomechanics and Movement Science, University of Delaware, Newark, DE 19713, USA. 3. Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA; Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA 02138, USA. 4. Department of Physical Therapy, University of Delaware, Newark, DE 19713, USA; Graduate Program in Biomechanics and Movement Science, University of Delaware, Newark, DE 19713, USA.
Abstract
OBJECTIVE: A deficit in paretic limb propulsion has been identified as a major biomechanical factor limiting walking speed after stroke. The purpose of this study was to determine the influence of corticomotor symmetry between paretic and nonparetic plantarflexors on the propulsive strategy used to increase walking speed. METHODS: Twenty-three participants with post-stroke hemiparesis underwent transcranial magnetic stimulation and biomechanical testing at their self-selected and fastest walking speeds. Plantarflexor corticomotor symmetry (CS(PF)) was calculated as a ratio of the average paretic versus nonparetic soleus motor evoked potential amplitude. The ratio of the paretic and nonparetic peak ankle plantarflexion moments (PF(sym)) was calculated at each speed. RESULTS: CS(PF) predicted the ΔPF(sym) from self-selected and fastest speeds (R(2)=.629, F(1,21)=35.56, p<.001). An interaction between CS(PF) and ΔPF(sym) (β=.596, p=.04) was observed when predicting Δspeed ((adj)R(2)=.772, F(3,19)=20.48, p<.001). Specifically, the ΔPF(sym) with speed modulation was positively related to the Δspeed (p=.03) in those with greater CS(PF), but was not related in those with poor CS(PF) (p=.30). CONCLUSIONS: Symmetry of the corticomotor input to the plantarflexors influences the propulsive strategy used to increase post-stroke walking speed. SIGNIFICANCE: Rehabilitation strategies that promote corticomotor symmetry may positively influence gait mechanics and enhance post-stroke walking function.
OBJECTIVE: A deficit in paretic limb propulsion has been identified as a major biomechanical factor limiting walking speed after stroke. The purpose of this study was to determine the influence of corticomotor symmetry between paretic and nonparetic plantarflexors on the propulsive strategy used to increase walking speed. METHODS: Twenty-three participants with post-stroke hemiparesis underwent transcranial magnetic stimulation and biomechanical testing at their self-selected and fastest walking speeds. Plantarflexor corticomotor symmetry (CS(PF)) was calculated as a ratio of the average paretic versus nonparetic soleus motor evoked potential amplitude. The ratio of the paretic and nonparetic peak ankle plantarflexion moments (PF(sym)) was calculated at each speed. RESULTS:CS(PF) predicted the ΔPF(sym) from self-selected and fastest speeds (R(2)=.629, F(1,21)=35.56, p<.001). An interaction between CS(PF) and ΔPF(sym) (β=.596, p=.04) was observed when predicting Δspeed ((adj)R(2)=.772, F(3,19)=20.48, p<.001). Specifically, the ΔPF(sym) with speed modulation was positively related to the Δspeed (p=.03) in those with greater CS(PF), but was not related in those with poor CS(PF) (p=.30). CONCLUSIONS: Symmetry of the corticomotor input to the plantarflexors influences the propulsive strategy used to increase post-stroke walking speed. SIGNIFICANCE: Rehabilitation strategies that promote corticomotor symmetry may positively influence gait mechanics and enhance post-stroke walking function.
Authors: Jacqueline A Palmer; Ryan Zarzycki; Susanne M Morton; Trisha M Kesar; Stuart A Binder-Macleod Journal: J Neurophysiol Date: 2017-01-11 Impact factor: 2.714
Authors: Charalambos C Charalambous; Jing Nong Liang; Steve A Kautz; Mark S George; Mark G Bowden Journal: J Vis Exp Date: 2019-02-19 Impact factor: 1.355
Authors: Jacqueline A Palmer; Trisha M Kesar; Steven L Wolf; Michael R Borich Journal: Neurorehabil Neural Repair Date: 2021-09-27 Impact factor: 3.919