title: Do radiographic disease and pain account for why people with or at high risk of knee osteoarthritis do not meet physical activity guidelines?
abstract: OBJECTIVE
  Knee osteoarthritis (OA) and pain are assumed to be barriers to meeting physical activity guidelines, but this has not been formally evaluated. The purpose of this study was to determine the proportions of people with and those without knee OA and knee pain who meet recommended physical activity levels through walking.
  
  
  METHODS
  We performed a cross-sectional analysis of community-dwelling adults from the Multicenter Osteoarthritis Study who had or who were at high risk of knee OA. Participants wore a StepWatch activity monitor to record steps per day for 7 days. The proportion of participants who met the recommended physical activity levels was defined as those accumulating≥150 minutes per week at ≥100 steps per minute in bouts lasting ≥10 minutes. These proportions were also determined for those with and those without knee OA, as classified by radiography and by severity of knee pain.
  
  
  RESULTS
  Of the 1,788 study participants (mean±SD age 67.2±7.7 years, mean±SD body mass index 30.7±6.0 kg/m2, 60% women), lower overall percentages of participants with radiographic knee OA and knee pain met recommended physical activity levels. However, these differences were not statistically significant between those with and those without knee OA; 7.3% and 10.1% of men (P=0.34) and 6.3% and 7.8% of women (P=0.51), respectively, met recommended physical activity levels. Similarly, for those with moderate/severe knee pain and those with no knee pain, 12.9% and 10.9% of men (P=0.74) and 6.7% and 11.0% of women (P=0.40), respectively, met recommended physical activity levels.
  
  
  CONCLUSIONS
  Disease and pain have little impact on achieving recommended physical activity levels among people with or at high risk of knee OA.
authors.affiliation: Boston University, Clinical Epidemiology Research and Training Unit, and Massachusetts General Hospital Institute of Health Professions, Boston, Massachusetts 02118, USA. dwtbn@bu.edu
authors.forename: Daniel K
authors.initials: DK
authors.lastname: White
authors.forename: Catrine
authors.initials: C
authors.lastname: Tudor-Locke
authors.forename: David T
authors.initials: DT
authors.lastname: Felson
authors.forename: K Douglas
authors.initials: KD
authors.lastname: Gross
authors.forename: Jingbo
authors.initials: J
authors.lastname: Niu
authors.forename: Michael
authors.initials: M
authors.lastname: Nevitt
authors.forename: Cora E
authors.initials: CE
authors.lastname: Lewis
authors.forename: James
authors.initials: J
authors.lastname: Torner
authors.forename: Tuhina
authors.initials: T
authors.lastname: Neogi
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging*; D010146:Pain / Q000000981:diagnostic imaging*; D017410:Practice Guidelines as Topic; D011859:Radiography; D012307:Risk Factors; D012720:Severity of Illness Index; D016138:Walking