title: Effects of balance status and age on muscle activation while walking under divided attention.
abstract: We examined the role of attention during different phases of the gait cycle by using a dual-task paradigm. Younger and older adults performed a self-paced treadmill walking task, a semantic judgment task, and both tasks simultaneously. We recorded vocal reaction time for the judgment task, and we recorded muscle activity by the use of electromyography. We derived dual-task costs from difference scores (single vs dual task). Our analysis of the judgment task showed that both groups responded more quickly during dual-task conditions than during single-task conditions. In five of eight muscle groups, stance-phase muscle activity decreased significantly from dual to single task. For older adults, individuals with poor balance increased their muscle activity during dual-task performance. These results suggest that, during moderately demanding walking and cognitive performance, poor balancers can compensate successfully for their motoric vulnerability.
authors.affiliation: Center for Research in Human Development, Department of Psychology, Concordia University, 7141 Sherbrooke Street West, Montréal, Québec, H4B 1R6, Canada. sfraser@alcor.concordia.ca
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Fraser
authors.forename: Karen Z H
authors.initials: KZ
authors.lastname: Li
authors.forename: Richard G
authors.initials: RG
authors.lastname: DeMont
authors.forename: Virginia B
authors.initials: VB
authors.lastname: Penhune
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001288:Attention / Q000502:physiology*; D004576:Electromyography; D005260:Female; D005684:Gait / Q000502:physiology; D006801:Humans; D007206:Individuality; D007537:Isometric Contraction / Q000502:physiology*; D007600:Judgment; D008297:Male; D008875:Middle Aged; D004856:Postural Balance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D012660:Semantics; D014706:Verbal Learning / Q000502:physiology; D016138:Walking / Q000502:physiology*; D014888:Wechsler Scales