Protective stepping in multiple sclerosis: Impacts of a single session of in-place perturbation practice.

OBJECTIVES: To evaluate the impact of a single day of protective stepping practice in individuals with Multiple Sclerosis (MS).

BACKGROUND: Multiple Sclerosis is a leading cause of disability among young adults in the United States. Gait and balance dysfunction are both widespread in MS and strong predictors of falls, disability, and quality of life among those with MS.

METHOD: Fourteen participants with MS and 11 neurotypical, age-matched control participants were exposed to repeated support surface perturbations over the course of 2 days: one "training" day and one "retention" day. Perturbations were elicited on an instrumented treadmill and marker data were collected to evaluate five outcomes (Margin of Stability, Step Length, Step Latency, Leg Angle, and Trunk Angle).

ANALYTIC METHOD: Repeated measures data were analyzed using linear growth models and mixed effects models to evaluate the effects of group (MS or Control), trial, and the interaction of group by trial.

RESULTS: Significant improvements in Step Length and Leg Angle and a trend for improvement in Margin of Stability among those with MS were observed. Step Latency and Trunk Angle did not show significant changes. Retention analyses revealed significant retention of improvements in Step Length and Leg Angle among MS participants.

DISCUSSION: Protective step characteristics have been shown to be important predictors of fall risk in populations affected by neurological disorders. The present study indicates that these characteristics may be amenable to intervention through exposure to repeated, perturbations requiring protective stepping. Further research is needed to establish the predictive utility of these biomechanical markers for falls in MS specifically; however, the present findings suggest that perturbation training may be a valuable means of decreasing fall risk among those affected by MS.