title: Changes in step-width during dual-task walking predicts falls.
abstract: The aim was to evaluate whether gait pattern changes between single- and dual-task conditions were associated with risk of falling in older people. Dual-task cost (DTC) of 230 community living, physically independent people, 75 years or older, was determined with an electronic walkway. Participants were followed up each month for 1 year to record falls. Mean and variability measures of gait characteristics for 5 dual-task conditions were compared to single-task walking for each participant. Almost half (48%) of the participants fell at least once during follow-up. Risk of falling increased in individuals where DTC for performing a subtraction task demonstrated change in mean step-width compared to single-task walking. Risk of falling decreased in individuals where DTC for carrying a cup and saucer demonstrated change compared to single-task walking in mean step-width, mean step-time, and step-length variability. Degree of change in gait characteristics related to a change in risk of falling differed between measures. Prognostic guidance for fall risk was found for the above DTCs in mean step-width with a negative likelihood ratio of 0.5 and a positive likelihood ratio of 2.3, respectively. Findings suggest that changes in step-width, step-time, and step-length with dual tasking may be related to future risk of falling. Depending on the nature of the second task, DTC may indicate either an increased risk of falling, or a protective strategy to avoid falling.
authors.affiliation: Department of Community Medicine and Rehabilitation, Physiotherapy, Umeå University, S-901 87 Umeå, Sweden. ellinor.nordin@physiother.umu.se
authors.forename: E
authors.initials: E
authors.lastname: Nordin
authors.forename: R
authors.initials: R
authors.lastname: Moe-Nilssen
authors.forename: A
authors.initials: A
authors.lastname: Ramnemark
authors.forename: L
authors.initials: L
authors.lastname: Lundin-Olsson
mesh_terms: D000058:Accidental Falls / Q000706:statistics & numerical data; D000368:Aged; D000369:Aged, 80 and over; D001288:Attention / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D005684:Gait / Q000502:physiology*; D006801:Humans; D008297:Male; D011597:Psychomotor Performance / Q000502:physiology*; D018570:Risk Assessment; D016138:Walking / Q000502:physiology*