title: Postural balance, visual verticality perception, and its association in individuals with and without neck pain.
abstract: OBJECTIVE
  To compare postural balance and visual verticality perception between neck pain and asymptomatic subjects; to determine its association within groups.
  
  
  METHODS
  Fourteen neck pain and 14 asymptomatic subjects participated in the study. Subjects stood on a force platform to measure the displacement of the center of pressure in the medial-lateral and anterior-posterior directions, total path length, and sway velocity. Subjects performed 10 patterns of the rod and frame test in the sitting position to measure absolute errors of visual verticality perception. Postural balance variables between neck pain and asymptomatic participants were determined by Independent t-test. Two-way analysis of variance determined the effect of absolute errors of visual verticality perception, groups and its interaction. The association between postural balance variables and absolute errors of visual verticality perception was determined by Pearson's correlation.
  
  
  RESULTS
  Neck pain patients showed greater total path length and sway velocity than asymptomatic subjects. Similar absolute errors of visual verticality perception between groups were shown. No correlation between postural balance variables and absolute errors of visual verticality perception within groups was demonstrated.
  
  
  CONCLUSIONS
  Postural balance, not visual verticality perception was disturbed in individuals with neck pain. Postural balance was not associated with visual verticality perception in individuals with and without neck pain.
authors.forename: Vimonwan
authors.initials: V
authors.lastname: Hiengkaew
authors.forename: Wanvisa
authors.initials: W
authors.lastname: Panichaporn
authors.forename: Sumethee
authors.initials: S
authors.lastname: Thanungkul
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019547:Neck Pain / Q000453:epidemiology / Q000503:physiopathology*; D004856:Postural Balance / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*