title: Relative association of processing speed, short-term memory and sustained attention with task on gait speed: a study of community-dwelling people 50 years and older.
abstract: BACKGROUND
  For single gait tasks, associations have been reported between gait speed and cognitive domains. However, few studies have evaluated if this association is altered in dual gait tasks given gait speed changes with complexity and nature of task. We evaluated relative contributions of specific elements of cognitive function (including sustained attention and processing speed) to dual task gait speed in a nationally representative population of community-dwelling adults over 50 years.
  
  
  METHODS
  Gait speed was obtained using the GaitRite walkway during three gait tasks: single, cognitive (alternate letters), and motor (carrying a filled glass). Linear regression models, adjusted for covariates, were constructed to predict the relative contributions of seven neuropsychological tests to gait speed differences and to investigate gait task effects.
  
  
  RESULTS
  The mean age and gait speed of the population (n = 4,431, 55% women) was 62.4 years (SD = 8.2) and 135.85 cm/s (SD = 20.20, single task), respectively. Poorer processing speed, short-term memory, and sustained attention were major cognitive contributors to slower gait speed for all gait tasks. Both dual gait tasks were robust to covariate adjustment and had a significant additional executive function element not found for the single gait task.
  
  
  CONCLUSIONS
  For community-dwelling older adults processing speed, short-term memory and sustained attention were independently associated with gait speed for all gait tasks. Dual gait tasks were found to highlight specific executive function elements. This result forms a baseline value for dual task gait speed.
authors.affiliation: Trinity Centre for Bioengineering, School of Engineering, killani@tcd.ie.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Killane
authors.affiliation: The Irish Longitudinal Study on Ageing, and.
authors.forename: Orna A
authors.initials: OA
authors.lastname: Donoghue
authors.affiliation: The Irish Longitudinal Study on Ageing, and School of Medicine, Trinity College, the University of Dublin, Ireland. School of Nursing Sciences, University of East Anglia, UK.
authors.forename: George M
authors.initials: GM
authors.lastname: Savva
authors.affiliation: The Irish Longitudinal Study on Ageing, and.
authors.forename: Hilary
authors.initials: H
authors.lastname: Cronin
authors.affiliation: The Irish Longitudinal Study on Ageing, and School of Medicine, Trinity College, the University of Dublin, Ireland.
authors.forename: Rose Anne
authors.initials: RA
authors.lastname: Kenny
authors.affiliation: Trinity Centre for Bioengineering, School of Engineering, School of Medicine, Trinity College, the University of Dublin, Ireland.
authors.forename: Richard B
authors.initials: RB
authors.lastname: Reilly
mesh_terms: D000368:Aged; D000375:Aging / Q000502:physiology* / Q000523:psychology*; D001288:Attention / Q000502:physiology*; D056344:Executive Function / Q000502:physiology; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D008875:Middle Aged; D008959:Models, Neurological; D008960:Models, Psychological; D009483:Neuropsychological Tests; D011597:Psychomotor Performance; D016138:Walking / Q000502:physiology / Q000523:psychology
keywords: Cognitive Function.; Community Dwelling; Gait Speed