title: Lateral trunk motion and knee pain in osteoarthritis of the knee: a cross-sectional study.
abstract: BACKGROUND
  Patients with osteoarthritis of the knee may change their gait in an attempt to reduce loading of the affected knee, thereby reducing pain. Especially changes in lateral trunk motion may be potentially effective, since these will affect the position of the centre of mass relative to the knee, enabling minimization of the load on the knee and thereby knee pain. The aim of the study was to test the hypothesis that a higher level of knee pain is associated with higher lateral trunk motion in patients with knee OA.
  
  
  METHODS
  Fifty-two patients with OA of the knee were tested. Lateral trunk motion was measured during the stance phase of walking with an optoelectronic motion analysis system and a force plate. Knee pain was measured with the VAS and the WOMAC pain questionnaire. Regression analyses were performed to assess the relationship between lateral trunk motion and knee pain.
  
  
  RESULTS
  It was shown that in bivariate analyses knee pain was not associated with lateral trunk motion. In regression analyses, pain was associated with more lateral trunk motion. In addition, more lateral trunk motion was associated with younger age, being female, higher self-reported knee stiffness and higher maximum walking speed.
  
  
  CONCLUSIONS
  Pain is associated with lateral trunk motion. This association is weak and is influenced by age, gender, self-reported stiffness and maximum walking speed.
authors.affiliation: Reade, Center for Rheumatology and Rehabilitation, Department of Rehabilitation Research, Amsterdam, The Netherlands. M.vd.esch@reade.nl
authors.forename: Martin
authors.initials: M
authors.lastname: van der Esch
authors.forename: Martijn P M
authors.initials: MP
authors.lastname: Steultjens
authors.forename: Jaap
authors.initials: J
authors.lastname: Harlaar
authors.forename: Josien C
authors.initials: JC
authors.lastname: van den Noort
authors.forename: Dirk L
authors.initials: DL
authors.lastname: Knol
authors.forename: Joost
authors.initials: J
authors.lastname: Dekker
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D000368:Aged; D018771:Arthralgia / Q000503:physiopathology*; D001696:Biomechanical Phenomena / Q000502:physiology; D003430:Cross-Sectional Studies; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000502:physiology*; D020370:Osteoarthritis, Knee / Q000503:physiopathology*; D010147:Pain Measurement / Q000379:methods; D004856:Postural Balance / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology; D013909:Thorax / Q000502:physiology*; D016138:Walking / Q000502:physiology; D016474:Weight-Bearing / Q000502:physiology