Using step activity monitoring to characterize ambulatory activity in community-dwelling older adults.
OBJECTIVE
To explore the potential of using step activity monitoring to detect differences in ambulatory activity associated with advancing age and declining function in community-dwelling seniors.


METHODS
Cross-sectional pilot study.


METHODS
General communities of Seattle, Washington; Catonsville, Maryland; and Durham, North Carolina.


METHODS
Thirty healthy younger adults, 28 healthy older adults, and 12 older adults reporting functional limitations.


METHODS
Ambulatory activity data were collected over 6 days with the StepWatch 3. Average daily values were calculated for number of steps, number of minutes of activity, number of activity bouts, variability of minute-to-minute activity, and randomness of minute-to-minute activity fluctuations.


RESULTS
Healthy older adults engaged in fewer bouts of activity (P=.03) and displayed less-variable activity (P=.02) than younger adults. Older adults reporting functional limitations not only engaged in fewer bouts of activity (P=.009) and less variable activity (P<.001) than younger adults, but also accumulated fewer total steps (P=.003) and minutes of activity (P=.008) and had less-random minute-to-minute activity fluctuations (P=.02).


CONCLUSIONS
Step activity monitoring data were useful for detecting differences in ambulatory activity according to age and functional limitation. Monitor-based measures reflecting patterns of ambulatory activity show promise for use in studies of physical functioning.
Cavanaugh
James T
JT
Department of Veterans Affairs Medical Center, Durham, NC 27705, USA. jim.cavanaugh@duke.edu
Coleman
Kim L
KL
Gaines
Jean M
JM
Laing
Linda
L
Morey
Miriam C
MC
D000203:Activities of Daily Living; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D003201:Computers; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D051346:Mobility Limitation; D018670:Monitoring, Ambulatory / Q000295:instrumentation*; D005082:Physical Exertion; D010865:Pilot Projects; D016138:Walking / Q000502:physiology*