title: Postural stability in patients with knee osteoarthritis: comparison with controls and evaluation of relationships between postural stability scores and International Classification of Functioning, Disability and Health components.
abstract: OBJECTIVE
  To assess the differences in postural stability between patients with knee osteoarthritis and controls without knee osteoarthritis, and to evaluate possible relations between postural stability scores and International Classification of Functioning, Disability and Health (ICF) components.
  
  
  METHODS
  An age-matched, case-controlled trial with a cross-sectional design.
  
  
  METHODS
  A teaching hospital.
  
  
  METHODS
  Patients with knee osteoarthritis (n=73) and age-matched controls (n=60).
  
  
  METHODS
  Data on patients' postural stability and additional health-related variables were collected using various instruments. These included the Hospital Anxiety and Depression Scale, the Multidimensional Fatigue Inventory, the World Health Organization Quality of Life Brief Version, the physical function test (chair-rising time), the Chinese version of the Western Ontario and McMaster Universities Osteoarthritis Index, the Chinese version of the Knee Injury and Osteoarthritis Outcome Score, and the Biodex Stability System.
  
  
  METHODS
  A comparison of postural stability in patients with knee osteoarthritis versus that of controls was performed. The relation between postural stability scores for patients with knee osteoarthritis and ICF components was evaluated. Pearson correlation tests were used to determine the variables that correlated with postural stability among these patients.
  
  
  RESULTS
  Patients with knee osteoarthritis displayed lower overall postural stability than controls (scores of 0.7 vs. 0.5, P=.006) and scored lower on the environmental domain of the World Health Organization Quality of Life Brief Version (62.2 vs 66.8, P=.014). For patients with knee osteoarthritis, postural stability was weakly associated with the ICF components of body functions and structures, including pain (r=.33-.34, P=.004), physical fatigue (r=.28, P=.016), and reduced motivation (r=.30, P=.011). Weak to moderate associations between postural stability and the ICF components of activities and participation were found; the relevant ICF variables included reduced activity (r=.38, P=.001), physical domain and function (r=.34-.48, P=.001 to P<.004), activities of daily living (r=.51, P<.001), and sports and recreation (r=.35, P=.003). A moderate association between postural stability and the ICF components of personal and environmental factors was observed, including age (r=.52, P<.001) and quality of life (r=0.4, P=.001).
  
  
  CONCLUSIONS
  Patients with knee osteoarthritis displayed lower postural stability and achieved lower scores in the environmental domain of quality-of-life measures than did controls. The postural stability of patients with knee osteoarthritis was weakly to moderately associated with the following ICF components: body functions and structures, activities and participation, and personal and environmental factors.
authors.affiliation: Department of Physical Medicine and Rehabilitation, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan. M001052@ms.skh.org.tw
authors.forename: Ru-Lan
authors.initials: RL
authors.lastname: Hsieh
authors.forename: Wen-Chung
authors.initials: WC
authors.lastname: Lee
authors.forename: Min-Tzu
authors.initials: MT
authors.lastname: Lo
authors.forename: Wei-Cheng
authors.initials: WC
authors.lastname: Liao
mesh_terms: D000203:Activities of Daily Living; D000367:Age Factors; D015992:Body Mass Index; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D005221:Fatigue / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009042:Motivation; D009043:Motor Activity / Q000502:physiology; D020370:Osteoarthritis, Knee / Q000503:physiopathology*; D010146:Pain / Q000503:physiopathology; D004856:Postural Balance / Q000502:physiology*; D011788:Quality of Life; D012720:Severity of Illness Index