Reactive stepping strategies after lateral perturbations in people with multiple sclerosis.

Abstract

BACKGROUND: People with multiple sclerosis (PwMS) experience impaired balance and elevated fall risk, yet research on reactive stepping responses to lateral perturbations remains limited. This study examined spatiotemporal characteristics and step choices following lateral perturbations in PwMS compared to healthy controls (HC). METHODS: Seventeen individuals with relapsing-remitting MS and fourteen age- and gender-matched HCs completed lateral perturbation trials. Step latency, length, velocity, and step type were analyzed. A total of 60 valid perturbations in PwMS and 56 in HC were evaluated. RESULTS: PwMS exhibited a higher frequency of steps or falls following perturbations compared to HC (38.2% vs. 12.5%, p = 0.0013). No statistically significant differences in step latency, length, or velocity were found between groups. However, step choice differed as PwMS more frequently employed crossover and medial steps, while HC primarily used lateral steps. PwMS also showed greater reliance on multiple steps for recovery. CONCLUSIONS: While spatiotemporal stepping measures were similar between groups, PwMS demonstrated distinct compensatory stepping strategies compared to healthy controls. These findings highlight the need for targeted interventions aimed at improving lateral balance reactions and reducing fall risk in PwMS.