Tempo-spatial gait adaptations in stroke patients when approaching and crossing an elevated surface

Abstract

Background: In ambulatory stroke survivors, outdoor walking is important for participation, so adapting to heightened levels (e.g. curbs) is essential. This needs precise step regulation and foot positioning and has to be achieved despite impaired balance and motor regulation.

Research question: How do stroke patients approach and cross elevated surfaces?

Methods: Gait of 12 hemiparetic stroke patients (62.8 ± 10.3 years; Functional Ambulatory Category 3-5) and 13 controls (60.0 ± 12.4 years) was compared using a sensor carpet and 3D motion capturing to collect tempo-spatial parameters and foot trajectories in two conditions: flat walking vs. approaching to and stepping onto an elevated surface (height 15 cm) in a self-selected manner (6 trials each). Tempo-spatial adaptations were normalized to flat walking while trajectory analysis focused on foot clearance and placement. Complementary assessments included the Dynamic-Gait-Index, the Berg-Balance-Test and the Falls Efficacy Scale.

Results: Patients showed significantly worse Dynamic-Gait-Indices, less balance and more fear of falling. During the approach phase, patients slowed down, partly accompanied by shorter steps which controls did not. During crossing, no preference for a specific leading leg was detected. Clearance of the leading leg on average was not reduced but patients landed closer to the edge. Still clearance of the paretic leg was less than that of the non-paretic leg and the minimal clearance across all trials suggested an increased tripping risk, most evident for the trailing leg. In particular slower approaching caused difficulties to ensure sufficient leg clearance and to place the foot safely. Independent from that, better balance correlated with safer clearance.

Significance: When managing elevated levels, leading with the paretic leg causes more difficulties to safely clear the legs which is considerably dependent upon speed. Therapists should consider that slow walking may not increase safety while faster gait and aspects of postural control potentially facilitate crossing a curb.

Keywords: Foot clearance; Gait adaptability; Hemiparesis; Obstacle; Stroke.