title: Gait differs between unilateral and bilateral knee osteoarthritis.
abstract: OBJECTIVE
  To compare walking biomechanics in the most painful leg, and symmetry in biomechanics between legs, in individuals with (1) unilateral pain and structural osteoarthritis (OA), (2) unilateral pain, but bilateral structural OA, and (3) bilateral pain and structural OA and in (4) an asymptomatic control group.
  
  
  METHODS
  Cohort study.
  
  
  METHODS
  Laboratory based.
  
  
  METHODS
  Participants with symptomatic and/or radiographic medial tibiofemoral OA in one or both knees (n=91), and asymptomatic control participants (n=31).
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  The peak knee adduction moment, peak knee flexion moment, knee varus-valgus angle, peak knee flexion angle, toe-out, and trunk lean were computed from 3-dimensional analysis of walking at a self-selected speed.
  
  
  RESULTS
  After controlling for walking speed, greater trunk lean toward the more painful knee and reduced flexion in the more painful knee were observed in all OA groups compared with the control group. Between-knee asymmetries indicating greater varus angle and a lower external flexion moment in the painful knee were present in those with unilateral pain and either unilateral or bilateral structural OA. Knee biomechanics were symmetrical in those with bilateral pain and structural OA and in the pain free control group.
  
  
  CONCLUSIONS
  The presence of pain unilaterally appears to be associated with asymmetries in knee biomechanics. Contrary to this, bilateral pain is associated with symmetry. This suggests that the symptomatic status of both knees should be considered when contemplating unilateral or bilateral biomechanical interventions for medial knee OA.
authors.affiliation: Centre of Physical Activity Across the Lifespan, School of Exercise Science, Australian Catholic University, Brisbane, Queensland, Australia. mark.creaby@acu.edu.au
authors.forename: Mark W
authors.initials: MW
authors.lastname: Creaby
authors.forename: Kim L
authors.initials: KL
authors.lastname: Bennell
authors.forename: Michael A
authors.initials: MA
authors.lastname: Hunt
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D018771:Arthralgia / Q000503:physiopathology*; D001696:Biomechanical Phenomena; D016009:Chi-Square Distribution; D015331:Cohort Studies; D016001:Confidence Intervals; D003430:Cross-Sectional Studies; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000503:physiopathology*; D016138:Walking / Q000502:physiology