Stroke-related differences in axial body segment coordination during preplanned and reactive changes in walking direction

This study quantitatively describes differencesbetween participants with hemiparetic stroke and agematchedhealthy participants in axial body segment and gaitkinematics during a direction change task. Participants wererequired to change walking direction by 45�, either to theirleft or right, at the midpoint of a 6-m path. Participants werevisually cued either at the start of the walk (pre-planned) orone stride before they reached the turn point (reactive). Thesequence and inter-segmental timing of axial orientationonset was preserved in participants with stroke. Analysis ofa subgroup of stroke survivors indicated that participantswith lesions affecting the basal ganglia (BG) took significantlylonger time than control participants to initiate thereorientation synergy when making turns to their nonpareticside. We hypothesize that these differences are aproduct of asymmetrical activity of dopaminergic pathwaysin the brain resulting from compromised BG function