Validity of physical activity measures in ambulatory individuals with multiple sclerosis

Purpose. The literature suggests that individuals with multiple sclerosis ( MS) engage in less physical activity than non-diseased individuals. That conclusion, however, depends upon the validity of scores from measures of physical activity among the MS population. This study evaluated the validity of scores from two self-report surveys, a pedometer, and an accelerometer and during seven days of free-living conditions among individuals with MS. Method. Participants were 30 individuals ( 28 females, two males) with an established definite diagnosis of MS. The participants wore a pedometer and a single-axis accelerometer during the waking hours of a 7-day period. After the 7-day period, participants returned to the lab and completed a self- administered physical activity questionnaire and then underwent a 7-day physical activity recall. Results. There were strong correlations ( a) between scores from the two self- report measures of physical activity and ( b) between scores from the two objective measures of physical activity, and ( c) weaker, but moderate-to-strong correlations between scores from the self- report and objective measures of physical activity. Conclusion. Our results support the quantification of physical activity among those with MS using validated self- report and objective measures.