title: A comparison study of local dynamic stability measures of daily life walking in older adult community-dwelling fallers and non-fallers.
abstract: In the present study we compared the performance of three different estimations of local dynamic stability λ to distinguish between the dynamics of the daily-life walking of elderly fallers and non-fallers. The study re-analyses inertial sensor data of 3-days daily-life activity originally described by Weiss et al. (2013). The data set contains inertial sensor data from 39 older persons who reported less than 2 falls and 31 older persons who reported two or more falls the previous year. 3D-acceleration and 3D-velocity signals from walking epochs of 50s were used to reconstruct a state space using three different methods. Local dynamic stability was estimated with the algorithms proposed by Rosenstein et al. (1993), Kantz (1994), and Ihlen et al. (2012a). Median λs assessed by Ihlen׳s and Kantz׳ algorithms discriminated better between elderly fallers and non-fallers (highest AUC=0.75 and 0.73) than Rosenstein׳s algorithm (highest AUC=0.59). The present results suggest that the ability of λ to distinguish between fallers and non-fallers is dependent on the parameter setting of the chosen algorithm. Further replication in larger samples of community-dwelling older persons and different patient groups is necessary before including the suggested parameter settings in fall risk assessment and prediction models.
authors.affiliation: Department of Neuroscience, Norwegian University of Science and Technology, N-7489 Trondheim, Norway. Electronic address: espen.ihlen@ntnu.no.
authors.forename: Espen A F
authors.initials: EAF
authors.lastname: Ihlen
authors.affiliation: Center for the Study of Movement, Cognition, and Mobility, Department of Neurology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.
authors.forename: Aner
authors.initials: A
authors.lastname: Weiss
authors.affiliation: Center for the Study of Movement, Cognition, and Mobility, Department of Neurology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel; Graduate Training Centre of Neuroscience/IMPRS for Cognitive and Systems Neuroscience, Tübingen, Germany.
authors.forename: Yoav
authors.initials: Y
authors.lastname: Beck
authors.affiliation: Department of Neuroscience, Norwegian University of Science and Technology, N-7489 Trondheim, Norway; Clinic for Clinical Services, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway.
authors.forename: Jorunn L
authors.initials: JL
authors.lastname: Helbostad
authors.affiliation: Center for the Study of Movement, Cognition, and Mobility, Department of Neurology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel; Department of Physical Therapy, Sackler School of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Hausdorff
mesh_terms: D000054:Acceleration; D000058:Accidental Falls; D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D005260:Female; D006801:Humans; D008297:Male; D004856:Postural Balance; D012111:Residence Characteristics; D018570:Risk Assessment; D016138:Walking / Q000502:physiology*
keywords: Fall; Gait; Local dynamic stability; Old; Variability; Walking