title: Physical activity in daily life in patients with chronic low back pain.
abstract: OBJECTIVE
  To evaluate disuse (ie, a decreased daily physical activity level) in patients with chronic low back pain (LBP) and to evaluate the construct validity of accelerometry for measuring physical activity in daily life.
  
  
  METHODS
  Case-control study in a cross-sectional design; comparison of accelerometry to the criterion standard (doubly labeled water technique).
  
  
  METHODS
  Normal daily living (unrestricted by the measurement devices).
  
  
  METHODS
  Thirteen patients with chronic nonspecific LBP and 13 age- and gender-matched healthy controls.
  
  
  METHODS
  Physical activity in daily life, expressed as whole-body acceleration measured with a triaxial accelerometer (Tracmor), and as the ratio between average daily metabolic rate (ADMR), measured by the doubly labeled water technique, and resting metabolic rate (RMR), measured by the ventilated hood. Both techniques were used simultaneously for 14 days.
  
  
  RESULTS
  Mean physical activity level in patients and controls did not differ significantly. The correlation between the Tracmor and ADMR and RMR was .72 (p < .01).
  
  
  CONCLUSIONS
  Decreased physical activity levels in this sample of chronic LBP patients was not confirmed. The Tracmor is a valid instrument for measuring daily activity in LBP patients.
authors.affiliation: Rehabilitation Foundation Limburg, Hoensbroek, the Netherlands. J.Verbunt@ivr.nl
authors.forename: J A
authors.initials: JA
authors.lastname: Verbunt
authors.forename: K R
authors.initials: KR
authors.lastname: Westerterp
authors.forename: G J
authors.initials: GJ
authors.lastname: van der Heijden
authors.forename: H A
authors.initials: HA
authors.lastname: Seelen
authors.forename: J W
authors.initials: JW
authors.lastname: Vlaeyen
authors.forename: J A
authors.initials: JA
authors.lastname: Knottnerus
mesh_terms: D000203:Activities of Daily Living; D001823:Body Composition; D015992:Body Mass Index; D016022:Case-Control Studies; D002908:Chronic Disease; D003430:Cross-Sectional Studies; D017666:Deuterium Oxide; D004734:Energy Metabolism / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000534:rehabilitation*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D018709:Statistics, Nonparametric
chemical_list: D017666:Deuterium Oxide