title: Contributions of cognitive function to straight- and curved-path walking in older adults.
abstract: OBJECTIVE
  To determine whether the cognitive function contribution to straight- and curved-path walking differs for older adults.
  
  
  METHODS
  Cross-sectional observational study.
  
  
  METHODS
  Ambulatory clinical research training center.
  
  
  METHODS
  People (N=106) aged 65 to 92 years, able to walk household distances independently with or without an assistive device, and who scored 24 or greater on the Mini-Mental State Examination.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Cognitive function was assessed using the Digit Symbol Substitution Test (DSST) as a measure of psychomotor speed, and Trail Making Test Parts A and B (TMT-A and TMT-B) and the Trail Making Test difference score (TMT-B-A) as executive function measures of complex visual scanning and set shifting. Gait speed recorded over an instrumented walkway was used as the measure of straight-path walking. Curved-path walking was assessed using the Figure-of-8 Walk Test (F8W) and recorded as the total time and number of steps for completion.
  
  
  RESULTS
  Both DSST and TMT-A independently contributed to usual gait speed (P<.001). TMT-A performance contributed to F8W time (P<.001). Neither TMT-B nor TMT-B-A contributed to usual gait speed or time to complete the F8W. For the number of steps taken to complete the F8W, TMT-A, TMT-B, and TMT-B-A (all P<.001) were independent contributors, while DSST performance was not.
  
  
  CONCLUSIONS
  Curved-path walking, as measured by the F8W, involves different cognitive processes compared with straight-path walking. Cognitive flexibility and set-shifting processes uniquely contributed to how individuals navigated curved paths. The measure of curved-path walking provides different and meaningful information about daily life walking ability than usual gait speed alone.
authors.affiliation: Department of Medicine, Division of Geriatric Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA. kal121@pitt.edu
authors.forename: Kristin A
authors.initials: KA
authors.lastname: Lowry
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Brach
authors.forename: Robert D
authors.initials: RD
authors.lastname: Nebes
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Studenski
authors.forename: Jessie M
authors.initials: JM
authors.lastname: VanSwearingen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003071:Cognition / Q000502:physiology; D056344:Executive Function / Q000502:physiology*; D005260:Female; D005684:Gait; D006801:Humans; D008297:Male; D009048:Motor Skills / Q000502:physiology*; D011594:Psychometrics; D018709:Statistics, Nonparametric; D013647:Task Performance and Analysis; D013997:Time Factors; D016138:Walking / Q000502:physiology* / Q000523:psychology*