Cortical Activation During Walking in Stroke

After stroke, damage to one cerebral hemisphere disrupts the normal balance of activity between the two hemispheres. The affected hemisphere typically exhibits reduced excitability, whereas the unaffected side may demonstrate increased excitability. This phenomenon, referred to as interhemispheric imbalance, further inhibits activity in the affected hemisphere, thereby restricting motor recovery. According to the interhemispheric competition model, enhancing excitability in the affected hemisphere and/or suppressing excitability in the unaffected hemisphere may contribute to the improvement of motor function in individuals with stroke. Furthermore, as motor function recovers, the balance of interhemispheric activation in motor-related cortical areas undergoes corresponding changes. Previous studies have shown that treadmill training enhances the excitability of the primary motor cortex in both hemispheres of stroke patients, as well as increases excitability across multiple cortical and subcortical regions in both hemispheres. However, it remains unclear whether treadmill training can normalize the interhemispheric imbalance in stroke patients. Additionally, the effects of forward and backward walking on the activity of motor-related brain regions in individuals with stroke are still unclear. Therefore, this cross-sectional study aims to investigate the changes in motor-related brain activity during forward walking and backward walking in individuals with chronic stroke.