Adaptive changes in body-specific attention to the paretic and nonparetic feet contribute to dynamic stability during walking in patients with chronic hemiparesis from stroke

Background Body-specific attention contributes to motor control; however, it is unclear how body-specific attention to the lower limbs is related to dynamic stability during walking. Research question Is body-specific attention to both paretic and nonparetic feet associated with dynamic stability during walking in patients with chronic hemiparesis? Methods This cross-sectional study included 16 patients with chronic hemiparesis, including those with sensory disorders who were capable of walking independently. Body-specific attention was measured using a previously reported visual stimulus detection task. Whole-body angular momentum in the coronal plane, an indicator of dynamic stability during walking, was evaluated using a three-dimensional motion analysis system and force plates. Correlations between body-specific attention, gait parameters, and the subitems of Stroke Impairment Assessment Set were analyzed using either the Pearson product-moment correlation coefficient or the Spearman's rank correlation coefficient. Results Body-specific attention to the nonparetic foot was negatively correlated with the coronal whole-body angular momentum (r = −0.511), and positively correlated with vertical ground reaction force (r = 0.815) in the second half of the single-stance phase on the paretic side. These results suggest that increased body-specific attention to the nonparetic foot may be associated with greater dynamic stability during walking. In addition, body-specific attention to the paretic foot was negatively correlated with the tactile sensation in the paretic foot (r = −0.576). This indicates that increased body-specific attention to the paretic foot was present in patients with severe tactile function impairment. Significance The findings suggest that adaptive changes in body-specific attention to paretic and nonparetic feet, depending on the severity of tactile dysfunction, are associated with dynamic stability during walking.