title: Use of accelerometry to measure physical activity in older adults at risk for mobility disability.
abstract: The authors explored using the ActiGraph accelerometer to differentiate activity levels between participants in a physical activity (PA, n = 54) or "successful aging" (SA) program (n = 52). The relationship between a PA questionnaire for older adults (CHAMPS) and accelerometry variables was also determined. Individualized accelerometry-count thresholds (ThreshIND) measured during a 400-m walk were used to identify "meaningful activity." Participants then wore the ActiGraph for 7 days. Results indicated more activity bouts/day > or =10 min above ThreshIND in the PA group than in the SA group (1.1 +/- 2.0 vs 0.5 +/- 0.8, p = .05) and more activity counts/day above ThreshIND for the PA group (28,101 +/- 27,521) than for the SA group (17,234 +/- 15,620, p = .02). Correlations between activity counts/hr and CHAMPS ranged from .27 to .42, p < .01. The ActiGraph and ThreshIND might be useful for differentiating PA levels in older adults at risk for mobility disability.
authors.affiliation: Stanford Prevention Research Center, Stanford University School of Medicine, Stanford, CA,USA.
authors.forename: Leslie A
authors.initials: LA
authors.lastname: Pruitt
authors.forename: Nancy W
authors.initials: NW
authors.lastname: Glynn
authors.forename: Abby C
authors.initials: AC
authors.lastname: King
authors.forename: Jack M
authors.initials: JM
authors.lastname: Guralnik
authors.forename: Erin K
authors.initials: EK
authors.lastname: Aiken
authors.forename: Gary
authors.initials: G
authors.lastname: Miller
authors.forename: William L
authors.initials: WL
authors.lastname: Haskell
mesh_terms: D000054:Acceleration; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D005080:Exercise Test; D005260:Female; D016330:Frail Elderly; D006266:Health Education; D006801:Humans; D008297:Male; D051346:Mobility Limitation; D009043:Motor Activity / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D010865:Pilot Projects; D012306:Risk; D012656:Self-Help Devices; D011795:Surveys and Questionnaires; D016138:Walking / Q000502:physiology*