Relative importance of physical and psychological factors to slowness in people with mild to moderate multiple sclerosis.

BACKGROUND: Mobility impairment is common in people with multiple sclerosis (MS). Gait speed has shown strong correlations with other mobility measures in MS. The purpose of this study was to assess the relative importance of a battery of factors in determining gait speed among people with MS.

METHODS: Thirty-one individuals with MS (the mean (standard deviation) of the Patient Determined Disability Steps: 3.68(1.70)) participated in this cross-sectional observational study. Their gait speed was assessed using the Timed-25-Foot Walking test. Six factors which could slow gait speed in MS, including the strength capacity at knee joints, functional mobility, body balance, dorsiflexion range of motion of ankle joints, bilateral foot cutaneous sensation level, and the fear of falling, were also assessed. Multiple regression and relative weight analysis were used to identify the relative importance of each factor in explaining the gait speed variation.

RESULTS: All six factors together accounted for about 86% of the observed variation in gait speed; each explaining a statistically significant amount. The most important factor was the strength measurement (relative weight = 0.321) which accounted for 37.2% of the explained variation in gait speed.

CONCLUSION: Muscle strength, particularly the knee joint strength capacity, could be a principal factor determining gait speed in people with mild to moderate MS. Other factors also significantly affect gait speed in this population. The findings from this study could provide guidance in terms of prioritizing actions to improve gait speed in people with MS.