Effects of leading limb choice and obstacle height on gait characteristics during obstacle crossing in people post stroke.

Abstract

During obstacle crossing, both obstacle height and leading limb choice may influence gait characteristics and fall risk in people post stroke. This study compared their gait characteristics when leading with different limbs to cross obstacles of varying heights, aiming to inform targeted rehabilitation. Twenty people post stroke were recruited. A motion capture system and two force plates were used to record marker positions and ground reaction forces as participants crossed the 10% and 20% leg-length obstacle, leading with either the paretic or non-paretic limb. The results demonstrated that, regardless of the leading limb, participants exhibited significantly lower gait velocity, COM velocity, and COM-COP distance when crossing the 20% versus 10% leg-length obstacle (P < 0.05). The obstacle-heel distance of the leading limb was also significantly greater for the higher obstacle (P < 0.05). At all tested obstacle heights, when participants led with their paretic limb, obstacle-heel distance of the leading limb, toe- obstacle clearance of the trailing limb, mediolateral COM-COP distance (when the leading limb's toe was above the obstacle), and anteroposterior COM velocity (when the trailing limb's toe was above the obstacle, T2) were significantly greater compared to leading with their non-paretic limb (P < 0.05). However, toe clearance of the leading limb and mediolateral COM-COP distance (when T2) were significantly lower (P < 0.05). These results suggest that people post stroke adopt a conservative crossing strategy to maintain stability when crossing 20% leg-length obstacle. Regardless of the leading limb, they exhibited impaired spatial regulation of the paretic foot relative to the obstacle and reduced paretic stance stability.