title: The use of a neck brace does not influence visual vertical perception.
abstract: Subjective visual vertical (SVV) evaluates the individual's capacity to determine the vertical orientation. Using a neck brace (NB) allow volunteers' heads fixation to reduce cephalic tilt during the exam, preventing compensatory ocular torsion and erroneous influence on SVV result.
  
  
  OBJECTIVE
  To analyze the influence of somatosensory inputs caused by a NB on the SVV.
  
  
  METHODS
  Thirty healthy volunteers performed static and dynamic SVV: six measures with and six without the NB.
  
  
  RESULTS
  The mean values for static SVV were -0.075º±1.15º without NB and -0.372º±1.21º with NB. For dynamic SVV in clockwise direction were 1.73º±2.31º without NB and 1.53º±1.80º with NB. For dynamic SVV in counterclockwise direction was -1.50º±2.44º without NB and -1.11º±2.46º with NB. Differences between measurements with and without the NB were not statistically significant.
  
  
  CONCLUSIONS
  Although the neck has many sensory receptors, the use of a NB does not provide sufficient afferent input to change healthy subjects' perception of visual verticality.
authors.affiliation: Department of Neuroscience and Behavior, Faculty of Medicine at Ribeirão Preto, University of São Paulo, Brazil.
authors.forename: Martha
authors.initials: M
authors.lastname: Funabashi
authors.forename: Natya N L
authors.initials: NN
authors.lastname: Silva
authors.forename: Luciana M
authors.initials: LM
authors.lastname: Watanabe
authors.forename: Taiza E G
authors.initials: TE
authors.lastname: Santos-Pontelli
authors.forename: José Fernando
authors.initials: JF
authors.lastname: Colafêmina
authors.forename: Antonio A O
authors.initials: AA
authors.lastname: Carneiro
authors.forename: Osvaldo M
authors.initials: OM
authors.lastname: Takayanagui
mesh_terms: D000328:Adult; D001915:Braces; D002574:Cervical Vertebrae; D005260:Female; D006801:Humans; D008297:Male; D012016:Reference Values; D013028:Space Perception / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*