Street Crossing Performance In Persons With Multiple Sclerosis

Abstract

The ability to cross the street successfully requires both physical and cognitive proficiency. Multiple sclerosis (MS), a progressive, neurological disease affecting the central nervous system, leads to impairments in physical and cognitive functioning, and thus might impact the ability to safely navigate a roadway environment. PURPOSE: To examine (1) differences in street crossing performance between people with MS and non-MS controls and (2) fitness and functional outcomes as correlates of street crossing performance within the MS sample. METHODS: Participants included 27 persons with MS and 19 controls who completed 60 trials of a virtual street crossing task that involved walking on a manual treadmill through a 3-dimensional roadway environment. There were 3 crossing conditions (i.e., no distraction, phone, digits), and participants performed 20 trials per condition. Participants were instructed to cross the street successfully across all conditions. Street crossing performance was assessed as trial duration, success rate, and collision rate. Participants further completed measures of overground walking speed and endurance, cognition, aerobic capacity, and muscular strength. RESULTS: Participants with MS took longer to cross the street than controls (p = .003), but there were no differences in success and collision rates. Participants with moderate MS had lower success rates (p = .03) and higher collision rates (p = .03) than people with mild MS. Among those with MS, walking speed correlated with trial duration, success rate and collision rate (r = .52-.58, all p < .05). Walking endurance correlated with trial duration, success rate and collision rate (r = .55-.59, p < .05). Aerobic capacity correlated with success rate and collision rate (both r = .42, p = .03). Regression analyses revealed that walking speed and endurance explained a significant amount of variance in street crossing performance (R2>.27, all p < .01). CONCLUSION: Street crossing performance is impaired in persons with MS compared to controls, and further as a function of disability level in persons with MS. Rehabilitation interventions should target walking ability for improving real world street crossing and pedestrian safety in MS. Supported, in part, by National MS Society IL 0003.