title: Quantification of gait changes in subjects with visual height intolerance when exposed to heights.
abstract: BACKGROUND
  Visual height intolerance (vHI) manifests as instability at heights with apprehension of losing balance or falling. We investigated contributions of visual feedback and attention on gait performance of subjects with vHI.
  
  
  METHODS
  Sixteen subjects with vHI walked over a gait mat (GAITRite®) on a 15-m-high balcony and at ground-level. Subjects walked at different speeds (slow, preferred, fast), during changes of the visual input (gaze straight/up/down; eyes open/closed), and while doing a cognitive task. An rmANOVA with the factors "height situation" and "gait condition" was performed. Subjects were also asked to estimate the height of the balcony over ground level. The individual estimates were used for correlations with the gait parameters.
  
  
  RESULTS
  Study participants walked slower at heights, with reduced cadence and stride length. The double support phases were increased (all p < 0.01), which correlated with the estimated height of the balcony (R (2) = 0.453, p < 0.05). These changes were still present when walking with upward gaze or closure of the eyes. Under the conditions walking and looking down to the floor of the balcony, during dual-task and fast walking, there were no differences between the gait performance on the balcony and at ground-level.
  
  
  CONCLUSIONS
  The found gait changes are features of a cautious gait control. Internal, cognitive models with anxiety play an important role for vHI; gait was similarly affected when the visual perception of the depth was prevented. Improvement by dual task at heights may be associated by a reduction of the anxiety level.
  
  
  CONCLUSIONS
  It is conceivable that mental distraction by dual task or increasing the walking speed might be useful recommendations to reduce the imbalance during locomotion in subjects susceptible to vHI.
authors.affiliation: Department of Neurology, University of Munich Munich, Germany ; German Center for Vertigo and Balance Disorders (DSGZ), University of Munich Munich, Germany.
authors.forename: Roman
authors.initials: R
authors.lastname: Schniepp
authors.affiliation: German Center for Vertigo and Balance Disorders (DSGZ), University of Munich Munich, Germany ; Institute for Clinical Neurosciences, University of Munich Munich, Germany.
authors.forename: Günter
authors.initials: G
authors.lastname: Kugler
authors.affiliation: German Center for Vertigo and Balance Disorders (DSGZ), University of Munich Munich, Germany.
authors.forename: Max
authors.initials: M
authors.lastname: Wuehr
authors.affiliation: Institute for Clinical Neurosciences, University of Munich Munich, Germany.
authors.forename: Maria
authors.initials: M
authors.lastname: Eckl
authors.affiliation: German Center for Vertigo and Balance Disorders (DSGZ), University of Munich Munich, Germany ; Institute for Clinical Neurosciences, University of Munich Munich, Germany.
authors.forename: Doreen
authors.initials: D
authors.lastname: Huppert
authors.affiliation: German Center for Vertigo and Balance Disorders (DSGZ), University of Munich Munich, Germany.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Huth
authors.affiliation: German Center for Vertigo and Balance Disorders (DSGZ), University of Munich Munich, Germany.
authors.forename: Cauchy
authors.initials: C
authors.lastname: Pradhan
authors.affiliation: Department of Neurology, University of Munich Munich, Germany ; German Center for Vertigo and Balance Disorders (DSGZ), University of Munich Munich, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Jahn
authors.affiliation: German Center for Vertigo and Balance Disorders (DSGZ), University of Munich Munich, Germany ; Institute for Clinical Neurosciences, University of Munich Munich, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Brandt
keywords: dual task; gait; gait variability; visual height intolerance; visual input