title: Analysis of dual-task elderly gait in fallers and non-fallers using wearable sensors.
abstract: Dual-task (DT) gait involves walking while simultaneously performing an attention-demanding task and can be used to identify impaired gait or executive function in older adults. Advancment is needed in techniques that quantify the influence of dual tasking to improve predictive and diagnostic potential. This study investigated the viability of wearable sensor measures to identify DT gait changes in older adults and distinguish between elderly fallers and non-fallers. A convenience sample of 100 older individuals (75.5±6.7 years; 76 non-fallers, 24 fallers based on 6 month retrospective fall occurrence) walked 7.62m under single-task (ST) and DT conditions while wearing pressure-sensing insoles and tri-axial accelerometers at the head, pelvis, and left and right shanks. Differences between ST and DT gait were identified for temporal measures, acceleration descriptive statistics, Fast Fourier Transform (FFT) quartiles, ratio of even to odd harmonics, center of pressure (CoP) stance path coefficient of variation, and deviations to expected CoP stance path. Increased posterior CoP stance path deviations, increased coefficient of variation, decreased FFT quartiles, and decreased ratio of even to odd harmonics suggested increased DT gait variability. Decreased gait velocity and decreased acceleration standard deviations (SD) at the pelvis and shanks could represent compensatory gait strategies that maintain stability. Differences in acceleration between fallers and non-fallers in head posterior SD and pelvis AP ratio of even to odd harmonics during ST, and pelvis vertical maximum Lyapunov exponent during DT gait were identified. Wearable-sensor-based DT gait assessments could be used in point-of-care environments to identify gait deficits.
authors.affiliation: Department of Systems Design Engineering, University of Waterloo, Waterloo, Canada. Electronic address: jirwin02@gmail.com.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Howcroft
authors.affiliation: Department of Systems Design Engineering, University of Waterloo, Waterloo, Canada.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Kofman
authors.affiliation: Centre for Rehabilitation, Research and Development, Ottawa Hospital Research Institute, Ottawa, Canada; Faculty of Medicine, University of Ottawa, Ottawa, Canada.
authors.forename: Edward D
authors.initials: ED
authors.lastname: Lemaire
authors.affiliation: Department of Kinesiology, University of Waterloo, Waterloo, Canada.
authors.forename: William E
authors.initials: WE
authors.lastname: McIlroy
mesh_terms: D000054:Acceleration; D000058:Accidental Falls; D000328:Adult; D001288:Attention; D005260:Female; D005583:Fourier Analysis; D005684:Gait; D006801:Humans; D008297:Male; D008991:Monitoring, Physiologic / Q000295:instrumentation*; D011312:Pressure; D012189:Retrospective Studies; D016138:Walking / Q000502:physiology
keywords: Accelerometer; Dual task gait; Dynamic stability control; Elderly; Gait variability; Older adults; Plantar pressure; Wearable sensors