title: Validation and comparison of 3 accelerometers for measuring physical activity intensity during nonlocomotive activities and locomotive movements.
abstract: BACKGROUND
  The current study evaluated the validity of 3 commercially-available accelerometers to assess metabolic equivalent values (METs) during 12 activities.
  
  
  METHODS
  Thirty-three men and thirty-two women were enrolled in this study. The subjects performed 5 nonlocomotive activities and 7 locomotive movements. The Douglas bag method was used to gather expired air. The subjects also wore 3 hip accelerometers, a Lifecorder uniaxial accelerometer (LC), and 2 triaxial accelerometers (ActivTracer, AT; Actimarker, AM).
  
  
  RESULTS
  For nonlocomotive activities, the LC largely underestimated METs for all activities (20.3%-55.6%) except for desk work. The AT overestimated METs for desk work (11.3%) and hanging clothes (11.7%), but underestimated for vacuuming (2.3%). The AM underestimated METs for all nonlocomotive activities (8.0%-19.4%) except for hanging clothes (overestimated by 16.7%). The AT and AM errors were significant, but much smaller than the LC errors (23.2% for desk work and -22.3 to -55.6% for the other activities). For locomotive movements, the 3 accelerometers significantly underestimated METs for all activities except for climbing down stairs.
  
  
  CONCLUSIONS
  We conclude that there were significant differences for most activities in 3 accelerometers. However, the AT, which uses separate equations for nonlocomotive and locomotive activities, was more accurate for nonlocomotive activities than the LC.
authors.affiliation: Faculty of Engineering, Chiba Institute of Technology, Narashino, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Hikihara
authors.forename: Shigeho
authors.initials: S
authors.lastname: Tanaka
authors.forename: Kazunori
authors.initials: K
authors.lastname: Ohkawara
authors.forename: Kazuko
authors.initials: K
authors.lastname: Ishikawa-Takata
authors.forename: Izumi
authors.initials: I
authors.lastname: Tabata
mesh_terms: D061725:Accelerometry / Q000295:instrumentation*; D000328:Adult; D001837:Body Weights and Measures; D005260:Female; D006801:Humans; D008124:Locomotion / Q000502:physiology*; D008297:Male; D055686:Metabolic Equivalent; D008875:Middle Aged; D005082:Physical Exertion / Q000502:physiology*