Calibration of accelerometer output for ambulatory adults with multiple sclerosis.
Motl RW, Snook EM, Agiovlasitis S, Suh Y. Calibration of accelerometer output for ambulatory adults with multiple sclerosis.


OBJECTIVE
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.


METHODS
Mixed-model design.


METHODS
Laboratory.


METHODS
People with MS (n=24) and people without MS (n=24) who were similar in age, sex, height, and weight.


METHODS
The participants undertook three 6-minute periods of walking at 3.2, 4.8, and 6.4km.h(-1) on a motor-driven treadmill.


METHODS
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.
Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL, USA. robmotl@uiuc.edu
Robert W
RW
Motl
Erin M
EM
Snook
Stamatis
S
Agiovlasitis
Yoojin
Y
Suh
D000328:Adult; D002138:Calibration; D004734:Energy Metabolism; D005080:Exercise Test / Q000295:instrumentation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000378:metabolism / Q000503:physiopathology*; D005082:Physical Exertion; D016138:Walking