title: Quantifying Habitual Levels of Physical Activity According to Impact in Older People: Accelerometry Protocol for the VIBE Study.
abstract: Physical activity (PA) may need to produce high impacts to be osteogenic. The aim of this study was to identify threshold(s) for defining high impact PA for future analyses in the VIBE (Vertical Impact and Bone in the Elderly) study, based on home recordings with triaxial accelerometers. Recordings were obtained from 19 Master Athlete Cohort (MAC; mean 67.6 years) and 15 Hertfordshire Cohort Study (HCS; mean 77.7 years) participants. Data cleaning protocols were developed to exclude artifacts. Accelerations expressed in g units were categorized into three bands selected from the distribution of positive Y-axis peak accelerations. Data were available for 6.6 and 4.4 days from MAC and HCS participants respectively, with approximately 14 hr recording daily. Three-fold more 0.5-1.0g impacts were observed in MAC versus HCS, 20-fold more 1.0-1.5g impacts, and 140-fold more impacts ≥ 1.5g. Our analysis protocol successfully distinguishes PA levels in active and sedentary older individuals.
authors.affiliation: Musculoskeletal Research Unit, School of Clinical Sciences, University of Bristol, Bristol, UK.
authors.forename: Kevin C
authors.initials: KC
authors.lastname: Deere
authors.forename: Kimberly
authors.initials: K
authors.lastname: Hannam
authors.forename: Jessica
authors.initials: J
authors.lastname: Coulson
authors.forename: Alex
authors.initials: A
authors.lastname: Ireland
authors.forename: Jamie S
authors.initials: JS
authors.lastname: McPhee
authors.forename: Charlotte
authors.initials: C
authors.lastname: Moss
authors.forename: Mark H
authors.initials: MH
authors.lastname: Edwards
authors.forename: Elaine
authors.initials: E
authors.lastname: Dennison
authors.forename: Cyrus
authors.initials: C
authors.lastname: Cooper
authors.forename: Adrian
authors.initials: A
authors.lastname: Sayers
authors.forename: Matthijs
authors.initials: M
authors.lastname: Lipperts
authors.forename: Bernd
authors.initials: B
authors.lastname: Grimm
authors.forename: Jon H
authors.initials: JH
authors.lastname: Tobias
mesh_terms: D000054:Acceleration; D061725:Accelerometry; D000368:Aged; D015992:Body Mass Index; D015331:Cohort Studies; D015444:Exercise / Q000502:physiology; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D009043:Motor Activity; D057185:Sedentary Behavior