Control of lead and trail limbs during obstacle crossing following stroke.

BACKGROUND AND PURPOSE Obstacle crossing is compromised following stroke. The purpose of this study was to quantify modifications during obstacle clearance following stroke. SUBJECTS Twelve subjects with stroke and 12 subjects without stroke participated in the study. METHODS Kinematic variables were measured while participants crossed a 4-cm-high obstacle. Subjects with stroke walked at a self-selected speed; subjects without stroke walked at a comparable speed and at a self-selected speed. RESULTS Several modifications were observed following stroke with both groups walking at self-selected speeds. The affected lead limb was positioned closer to the obstacle before crossing. Affected trail-limb clearance over the obstacle was reduced. Both affected and unaffected lead and trail limbs landed closer to the obstacle after clearance. Swing time was increased in the affected lead limb after obstacle clearance. Fewer modifications were detected at matched walking speed; the trail limb still landed closer to the obstacle. DISCUSSION AND CONCLUSION Modifications during obstacle crossing following stroke may be partly related to walking speed. The findings raise issues of safety because people with stroke demonstrated reduced clearance of a 4-cm obstacle and limb placement closer to the obstacle after clearance.