title: Software for subjective visual vertical assessment: an observational cross-sectional study.
abstract: Spatial orientation in relation to the gravitational axis is significantly important for the maintenance of the posture, gait and for most of the human's motor activities. The subjective visual vertical exam evaluates the individual's perception of vertical orientation.
  
  
  OBJECTIVE
  The aims of this study were (1) to develop a virtual system to evaluate the subjective visual vertical exam, (2) to provide a simple tool to clinical practice and (3) to assess the subjective visual vertical values of healthy subjects using the new software.
  
  
  METHODS
  observational cross-sectional study.
  
  
  METHODS
  Thirty healthy volunteers performed the subjective visual vertical exam in both static and dynamic conditions. The exam consisted in adjusting a virtual line in the vertical position using the computer mouse. For the static condition, the virtual line was projected in a white background. For the dynamic condition, black circles rotated in clockwise or counterclockwise directions. Six measurements were taken and the mean deviations in relation to the real vertical calculated.
  
  
  RESULTS
  The mean values of subjective visual vertical measurements were: static -0.372º; ± 1.21; dynamic clockwise 1.53º ± 1.80 and dynamic counterclockwise -1.11º ± 2.46.
  
  
  CONCLUSIONS
  This software showed to be practical and accurate to be used in clinical routines.
authors.affiliation: Department of Physics, School of Philosophy, Sciences, and Literature of Ribeirão Preto, University of São Paulo, Ribeirão Preto - SP, Brazil.
authors.forename: Theo Zeferino
authors.initials: TZ
authors.lastname: Pavan
authors.forename: Martha
authors.initials: M
authors.lastname: Funabashi
authors.forename: José Ailton Oliveira
authors.initials: JA
authors.lastname: Carneiro
authors.forename: Taiza Elaine Grespan dos Santos
authors.initials: TE
authors.lastname: Pontelli
authors.forename: Walfred
authors.initials: W
authors.lastname: Tedeschi
authors.forename: José Fernando
authors.initials: JF
authors.lastname: Colafêmina
authors.forename: Antonio Adilton Olivera
authors.initials: AA
authors.lastname: Carneiro
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D012984:Software; D013028:Space Perception / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult