title: Avoidance of activities in early symptomatic knee osteoarthritis: results from the CHECK cohort.
abstract: BACKGROUND
  Pain-related avoidance of activities is hypothesized to lead to lower muscle strength and thereby activity limitations. Negative affect (e.g., low vitality, depression) is thought to strengthen the tendency to avoid activities.
  
  
  OBJECTIVE
  The aim of this study was to assess the validity of this "avoidance model" in patients with early symptomatic knee osteoarthritis (OA).
  
  
  METHODS
  Cross-sectional data (n=151) were used. The associations between pain, negative affect, avoidance, muscle strength, and activity limitations were modeled using structural equation modeling.
  
  
  RESULTS
  Pain and negative affect were associated with lower muscle strength via avoidance (mediation by avoidance). Avoidance was associated with activity limitations via lower muscle strength (mediation by muscle strength). There were also direct associations between pain, negative affect, avoidance, muscle strength, and activity limitations.
  
  
  CONCLUSIONS
  The results support the validity of the avoidance model, which explains the associations between pain, negative affect, avoidance, muscle strength, and activity limitations in patients with early symptomatic knee OA.
authors.affiliation: Amsterdam Rehabilitation Research Center, Reade, P.O. Box 58271, 1040 HG Amsterdam, The Netherlands. j.holla@reade.nl
authors.forename: Jasmijn F M
authors.initials: JF
authors.lastname: Holla
authors.forename: Marike
authors.initials: M
authors.lastname: van der Leeden
authors.forename: Dirk L
authors.initials: DL
authors.lastname: Knol
authors.forename: Wilfred F H
authors.initials: WF
authors.lastname: Peter
authors.forename: Leo D
authors.initials: LD
authors.lastname: Roorda
authors.forename: Willem F
authors.initials: WF
authors.lastname: Lems
authors.forename: Janet
authors.initials: J
authors.lastname: Wesseling
authors.forename: Martijn P M
authors.initials: MP
authors.lastname: Steultjens
authors.forename: Joost
authors.initials: J
authors.lastname: Dekker
mesh_terms: D000203:Activities of Daily Living / Q000523:psychology*; D000339:Affect / Q000502:physiology; D000368:Aged; D003430:Cross-Sectional Studies; D003863:Depression / Q000523:psychology / Q000534:rehabilitation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008960:Models, Psychological; D053580:Muscle Strength / Q000502:physiology; D020370:Osteoarthritis, Knee / Q000503:physiopathology / Q000523:psychology* / Q000534:rehabilitation; D010146:Pain / Q000523:psychology* / Q000534:rehabilitation; D057566:Self Report