title: Self-efficacy mediates walking performance in older adults with knee osteoarthritis.
abstract: BACKGROUND
  Self-efficacy is a determinant of walking performance in older adults with knee osteoarthritis. We examined whether self-efficacy mediated the effect of age, psychosocial, impairment, and mechanical factors on walking performance.
  
  
  METHODS
  Fifty-four participants with knee osteoarthritis completed the Six Minute Walk test and Arthritis Self-Efficacy Scale. Independent variables reflected age, psychosocial (depressive symptoms), impairment (pain, stiffness), and mechanical (strength, obesity) factors.
  
  
  RESULTS
  Self-efficacy fully mediated the effect of age and impairments on walking. The effects of strength were only partially mediated by self-efficacy. Depressive symptoms and obesity were not mediated by self-efficacy.
  
  
  CONCLUSIONS
  These findings are consistent with Social Cognitive Theory, according to which age may alter outcome expectations, and impairments like pain and stiffness provide negative physiological feedback to influence performance. Mechanical factors like strength and obesity may better represent a person's capabilities and interact with other variables to influence physical performance in older adults with knee osteoarthritis.
authors.affiliation: Elborn College, University of Western Ontario, London, Ontario, Canada. mmaly@uwo.ca
authors.forename: Monica R
authors.initials: MR
authors.lastname: Maly
authors.forename: Patrick A
authors.initials: PA
authors.lastname: Costigan
authors.forename: Sandra J
authors.initials: SJ
authors.lastname: Olney
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D003863:Depression / Q000209:etiology / Q000503:physiopathology; D005080:Exercise Test; D006801:Humans; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology; D009765:Obesity / Q000150:complications / Q000503:physiopathology / Q000523:psychology; D020370:Osteoarthritis, Knee / Q000150:complications / Q000503:physiopathology* / Q000523:psychology*; D020377:Self Efficacy; D012720:Severity of Illness Index; D016138:Walking / Q000502:physiology*