Article

Calibration of accelerometer output for
ambulatory adults with multiple sclerosis. OBJECTIVES: To examine the association
between the rates of accelerometer activity counts and energy expenditure during
walking in persons with multiple sclerosis (MS) versus controls and then to
calibrate the output of accelerometers for computing time spent in light,
moderate, and vigorous physical activity based on common metabolic equivalent
unit categories in persons with MS. DESIGN: Mixed-model design. SETTING:
Laboratory. PARTICIPANTS: People with MS (n=24) and people without MS (n=24) who
were similar in age, sex, height, and weight. INTERVENTIONS: The participants
undertook three 6-minute periods of walking at 3.2, 4.8, and 6.4km.h(-1) on a
motor-driven treadmill. MAIN OUTCOME MEASURES: Activity counts and energy
expenditure were measured with an accelerometer worn on the right hip and
open-circuit spirometry, respectively. RESULTS: The results indicated that (1)
persons with MS had greater energy expenditure, but not activity counts, during
walking on a treadmill than did controls; (2) there was a strong linear
relationship between activity counts and energy expenditure during treadmill
walking, but the slope of the relationship was steeper in persons with MS than in
controls; and (3) the cut-points for light, moderate, and vigorous physical
activity were lower in persons with MS than in controls. CONCLUSIONS: Such
findings provide evidence for a strong linear relationship between activity
counts and energy expenditure during walking in persons with MS and cut-points
based on counts per minute for quantifying time spent in light, moderate, and
vigorous physical activity using accelerometers in this population.

Langue : ANGLAIS