title: Postural adjustment errors during lateral step initiation in older and younger adults.
abstract: The purpose was to examine age differences and varying levels of step response inhibition on the performance of a voluntary lateral step initiation task. Seventy older adults (70-94 years) and twenty younger adults (21-58 years) performed visually cued step initiation conditions based on direction and spatial location of arrows, ranging from a simple choice reaction time task to a perceptual inhibition task that included incongruous cues about which direction to step (e.g., a left pointing arrow appearing on the right side of a monitor). Evidence of postural adjustment errors and step latencies were recorded from vertical ground reaction forces exerted by the stepping leg. Compared with younger adults, older adults demonstrated greater variability in step behavior, generated more postural adjustment errors during conditions requiring inhibition, and had greater step initiation latencies that increased more than younger adults as the inhibition requirements of the condition became greater. Step task performance was related to clinical balance test performance more than executive function task performance.
authors.affiliation: Department of Physical Therapy, University of Pittsburgh, 6035 Forbes Tower, Pittsburgh, PA, 15260, USA, psparto@pitt.edu.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Sparto
authors.forename: Susan I
authors.initials: SI
authors.lastname: Fuhrman
authors.forename: Mark S
authors.initials: MS
authors.lastname: Redfern
authors.forename: Subashan
authors.initials: S
authors.lastname: Perera
authors.forename: J
authors.initials: J
authors.lastname: Richard Jennings
authors.forename: Alia A
authors.initials: AA
authors.lastname: Alghwiri
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Furman
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D056344:Executive Function / Q000502:physiology; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D008875:Middle Aged; D004856:Postural Balance / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D016138:Walking / Q000502:physiology*; D055815:Young Adult