title: Obstacle crossing with dual tasking is a danger for individuals with Alzheimer's disease and for healthy older people.
abstract: OBJECTIVE
  The aim of this study was to analyze the effects of dual tasking on obstacle crossing during walking by individuals with Alzheimer's disease (AD) and by healthy older people.
  
  
  METHODS
  Thirty four elderly individuals (16 healthy subjects and 18 individuals with AD) were recruited to participate in this study. Three AD individuals and one control participant were excluded due to exclusion criteria. The participants were instructed to walk barefoot at their own speed along an 8 m long pathway. Each participant performed five trials for each condition (unobstructed walking, unobstructed walking with dual tasking, and obstacle crossing during walking with dual tasking). The trials were completely randomized for each participant. The mid-pathway stride was measured in the unobstructed walking trials and the stride that occurred during the obstacle avoidance was measured in the trials that involved obstacle crossing.
  
  
  CONCLUSIONS
  The behavior of the healthy elderly subjects and individuals with AD was similar for obstacle crossing during walking with dual tasking. Both groups used the "posture first" strategy to prioritize stability and showed decreased attention to executive tasking while walking. Additionally, AD had a strong influence on the modifications that are made by the elderly while walking under different walking conditions.
authors.affiliation: UNESP, Univ Estadual Paulista at Rio Claro, Rio Claro/SP, Brazil.
authors.forename: Lucas
authors.initials: L
authors.lastname: Simieli
authors.affiliation: UNESP, Univ Estadual Paulista at Rio Claro, Rio Claro/SP, Brazil UNESP, Univ Estadual Paulista at Bauru/Brazil, Presidente G/Bauru/SP, Brazil.
authors.forename: Fabio Augusto
authors.initials: FA
authors.lastname: Barbieri
authors.affiliation: UNESP, Univ Estadual Paulista at Rio Claro, Rio Claro/SP, Brazil.
authors.forename: Diego
authors.initials: D
authors.lastname: Orcioli-Silva
authors.affiliation: UNESP, Univ Estadual Paulista at Rio Claro, Rio Claro/SP, Brazil.
authors.forename: Ellen
authors.initials: E
authors.lastname: Lirani-Silva
authors.affiliation: UNESP, Univ Estadual Paulista at Rio Claro, Rio Claro/SP, Brazil UNICAMP - Campinas State University at Campinas/Brazil, Campus Universitário Zeferino Vaz, Campinas/SP, Brazil.
authors.forename: Florindo
authors.initials: F
authors.lastname: Stella
authors.affiliation: UNESP, Univ Estadual Paulista at Rio Claro, Rio Claro/SP, Brazil.
authors.forename: Lilian Teresa Bucken
authors.initials: LT
authors.lastname: Gobbi
mesh_terms: D000058:Accidental Falls / Q000517:prevention & control*; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D000544:Alzheimer Disease / Q000150:complications*; D016022:Case-Control Studies; D005260:Female; D020233:Gait Disorders, Neurologic / Q000209:etiology / Q000517:prevention & control; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011597:Psychomotor Performance / Q000502:physiology*; D012678:Sensation Disorders / Q000209:etiology* / Q000517:prevention & control*; D016138:Walking / Q000502:physiology*
keywords: Alzheimer's disease; dual task; obstacle avoidance; posture first; variability