title: Examining the stability of dual-task posture and reaction time measures in older adults over five sessions: a pilot study.
abstract: OBJECTIVE
  Improved performance may be inherent due to repeated exposure to a testing protocol. However, limited research has examined this phenomenon in postural control. The aim was to determine the influence of repeated administration of a dual-task testing protocol once per week for 5 weeks on postural sway and reaction time.
  
  
  METHODS
  Ten healthy older adults (67.0 ± 6.9 years) stood on a force plate for 30 s in feet apart and semi-tandem positions while completing simple reaction time (SRT) and choice reaction time (CRT) tasks. They were instructed to stand as still as possible while verbally responding as fast as possible to the stimuli.
  
  
  RESULTS
  No significant differences in postural sway were shown over time (p > 0.05). A plateau in average CRT emerged as the time effect revealed longer CRT during session 1 compared to sessions 3-5 (p < 0.05). Furthermore, the time effect for within-subject variability of CRT uncovered no plateaus as it was less variable in session 5 than sessions 1-4 (p < 0.05).
  
  
  CONCLUSIONS
  The lack of a plateau in variability of CRT may have emerged as older adults may require longer to reach optimal performance potential in a dual-task context.
  
  
  CONCLUSIONS
  Postural sway and SRT were stable over the 5 testing sessions, but variability of CRT continued to improve over time. These findings form a basis for future studies to examine performance-related improvements due to repeated exposure to a testing protocol in a dual-task setting.
authors.affiliation: School of Human Kinetics, University of Ottawa, 125, University Avenue, Ottawa, ON, K1N 6N5, Canada.
authors.forename: Deborah A
authors.initials: DA
authors.lastname: Jehu
authors.affiliation: School of Human Kinetics, University of Ottawa, 125, University Avenue, Ottawa, ON, K1N 6N5, Canada. npaquet@uottawa.ca.|School of Rehabilitation Sciences, University of Ottawa, 451 Smyth Road, Ottawa, ON, K1H 8M5, Canada. npaquet@uottawa.ca.
authors.forename: Nicole
authors.initials: N
authors.lastname: Paquet
authors.affiliation: School of Human Kinetics, University of Ottawa, 125, University Avenue, Ottawa, ON, K1N 6N5, Canada.
authors.forename: Yves
authors.initials: Y
authors.lastname: Lajoie
mesh_terms: D000368:Aged; D001288:Attention; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D004856:Postural Balance / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology*
keywords: Dual-task; Older adults; Posture; Reaction time; Repeated assessment; Task complexity