title: Executive functions are associated with gait and balance in community-living elderly people.
abstract: BACKGROUND
  Cognition influences gait and balance in elderly people. Executive functions seem to play a key role in this mechanism. Previous studies used only a single test to probe executive functions, and outcome measures were restricted to gait variables. We extend this prior work by examining the association between two different executive functions and measures of both gait and balance, with and without two different cognitive dual tasks.
  
  
  METHODS
  This is a cross-sectional study with randomly selected community-living elderly people. Executive functions were tested with the Trail Making Test Parts A and B and the Stroop Color Word Test; memory with Cambridge Neuropsychological Test Automated Battery (CANTAB) subtests. Patients walked without and with two dual tasks (subtracting serial sevens and animal naming). Main outcomes focused on gait (velocity, stride length, and stride time variability), measured on an electronic walkway, and balance, measured as trunk movements during walking. Associations were assessed with multiple regression models.
  
  
  RESULTS
  One hundred elderly people, with a mean age 80.6 years (range 75-93 years) participated. Both dual tasks decreased gait velocity and increased variability and trunk sway. Executive functions were associated with only stride length variability and mediolateral trunk sway during performance of animal naming as the dual task. Memory was not associated with the gait and balance variables.
  
  
  CONCLUSIONS
  In community-living elderly people, executive functions are associated with gait and balance impairment during a challenging dual-task condition that also depends on executive integrity. Next steps will be to explore the value of executive functions in defining fall-risk profiles and in fall-prevention interventions for frail patients.
authors.affiliation: Radboud University Nijmegen Medical Centre, Department of Geriatrics, 6500 HB Nijmegen, the Netherlands. m.vaniersel@ger.umcn.nl
authors.forename: Marianne B
authors.initials: MB
authors.lastname: van Iersel
authors.forename: Roy P C
authors.initials: RP
authors.lastname: Kessels
authors.forename: Bastiaan R
authors.initials: BR
authors.lastname: Bloem
authors.forename: André L M
authors.initials: AL
authors.lastname: Verbeek
authors.forename: Marcel G M
authors.initials: MG
authors.lastname: Olde Rikkert
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003071:Cognition / Q000502:physiology*; D003430:Cross-Sectional Studies; D005260:Female; D005684:Gait / Q000502:physiology*; D015577:Geriatric Assessment; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology; D004856:Postural Balance / Q000502:physiology*; D013647:Task Performance and Analysis