How active are people with stroke?: use of accelerometers to assess physical activity

Abstract

Background and purpose: Accelerometers are a unique tool used to objectively measure free-living physical activity, but their reliability for people with stroke has not been established. The primary aim was to assess the day-to-day reliability of these instruments for the paretic and nonparetic hips. The secondary aims were to measure the amount of physical activity with accelerometers that people with stroke undertake in the community and its relationship with walking capacity (6-minute walk test distance).

Methods: Forty people with stroke wore one Actical accelerometer on each hip for 3 consecutive days at home and during the 6-minute walk test in the laboratory. The accelerometer measured physical activity using total activity counts per day and energy expenditure (kcal/d).

Results: Excellent intraclass correlation coefficients (ICCs) for the activity counts (paretic hip ICC([1,3])=0.95, nonparetic hip ICC([1,3])=0.94) and for the energy expenditure (paretic hip ICC([1,3])=0.95, nonparetic hip ICC([1,3])=0.95) were found across the 3 consecutive days at home. Excellent ICCs were also found between the paretic versus the nonparetic hips for the activity counts (ICC([1,3])=0.98) and for the energy expenditure (ICC([1,3])=0.96). Free-living physical activity was very low and 58% of the participants did not meet recommended physical activity levels. Only moderate correlations (r=0.6 to 0.73, P<0.001) were found between the 6-minute walk test distance in the laboratory and 3-day physical activity recording at home.

Conclusions: The accelerometer was found to be a reliable objective instrument. The use of accelerometers quantified the low level of free-living physical activity of people with stroke.