title: Dual-task-related gait changes in transitionally frail older adults: the type of the walking-associated cognitive task matters.
abstract: BACKGROUND
  Changes in gait patterns due to a simultaneously performed cognitive task have been reported previously and associated with an increased falling risk among older adults. Little is known whether the type of cognitive task performed while walking is important concerning possible gait interference in older fall-prone individuals.
  
  
  OBJECTIVE
  To quantify and compare the effects of two different cognitive tasks on gait in transitionally frail older adults.
  
  
  METHODS
  Gait was tested in 30 transitionally frail older adults (mean age 82.6 +/- 7.1 years, 90% female) while either walking alone, performing a simple arithmetic task, or performing a task of verbal fluency. Walking time in seconds, number of steps, frequency of lateral line stepping-over, and stops were recorded. Health status was assessed using standard instruments of geriatric assessment. The classification of Speechley and Tinetti was used to define the participants' degree of frailty.
  
  
  RESULTS
  Walking time and number of steps increased significantly under both dual-task conditions compared to walking alone (p < 0.001) without reaching a significant difference between the two dual-task conditions (respectively, p = 0.131 and p = 0.407), whereas lateral gait instability (frequency of lateral line stepping-over) increased significantly in association with counting backward (p = 0.006) but not with the verbal fluency task (p = 1).
  
  
  CONCLUSIONS
  Among the studied sample of transitional older adults, a walking- associated arithmetic task significantly interfered with lateral gait stability, whereas no lateral gait deviations were seen in association with a verbal fluency task. We, therefore, suggest that the choice of the attention-splitting task in dual-task gait assessment among older adults must be made carefully.
authors.affiliation: Department of Rehabilitation and Geriatrics, Geneva University Hospitals, Geneva, Switzerland.
authors.forename: Olivier
authors.initials: O
authors.lastname: Beauchet
authors.forename: Véronique
authors.initials: V
authors.lastname: Dubost
authors.forename: Régis
authors.initials: R
authors.lastname: Gonthier
authors.forename: Reto W
authors.initials: RW
authors.lastname: Kressig
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D016330:Frail Elderly; D005684:Gait / Q000502:physiology*; D015438:Health Behavior; D006304:Health Status; D006801:Humans; D008297:Male; D013997:Time Factors