title: Gait disturbances as specific predictive markers of the first fall onset in elderly people: a two-year prospective observational study.
abstract: Falls are common in the elderly, and potentially result in injury and disability. Thus, preventing falls as soon as possible in older adults is a public health priority, yet there is no specific marker that is predictive of the first fall onset. We hypothesized that gait features should be the most relevant variables for predicting the first fall. Clinical baseline characteristics (e.g., gender, cognitive function) were assessed in 259 home-dwelling people aged 66 to 75 that had never fallen. Likewise, global kinetic behavior of gait was recorded from 22 variables in 1036 walking tests with an accelerometric gait analysis system. Afterward, monthly telephone monitoring reported the date of the first fall over 24 months. A principal components analysis was used to assess the relationship between gait variables and fall status in four groups: non-fallers, fallers from 0 to 6 months, fallers from 6 to 12 months and fallers from 12 to 24 months. The association of significant principal components (PC) with an increased risk of first fall was then evaluated using the area under the Receiver Operator Characteristic Curve (ROC). No effect of clinical confounding variables was shown as a function of groups. An eigenvalue decomposition of the correlation matrix identified a large statistical PC1 (termed "Global kinetics of gait pattern"), which accounted for 36.7% of total variance. Principal component loadings also revealed a PC2 (12.6% of total variance), related to the "Global gait regularity." Subsequent ANOVAs showed that only PC1 discriminated the fall status during the first 6 months, while PC2 discriminated the first fall onset between 6 and 12 months. After one year, any PC was associated with falls. These results were bolstered by the ROC analyses, showing good predictive models of the first fall during the first six months or from 6 to 12 months. Overall, these findings suggest that the performance of a standardized walking test at least once a year is essential for fall prevention.
authors.affiliation: Laboratory "Motricité, Interactions, Performance" (UPRES EA 4334), University of Nantes Nantes, France ; Up-COURTINE Lab, Centre for Neuroprosthetics and Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne Lausanne, Switzerland.
authors.forename: Jean-Baptiste
authors.initials: JB
authors.lastname: Mignardot
authors.affiliation: Laboratory "Motricité, Interactions, Performance" (UPRES EA 4334), University of Nantes Nantes, France.
authors.forename: Thibault
authors.initials: T
authors.lastname: Deschamps
authors.affiliation: Unité de Biologie Intégrative des Adaptations à l'Exercice (Inserm U902) Genople, Université d'Evry Val d'Essonne Évry, France ; GABI, UMR-1313, INRA Jouy-en-Josas, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Barrey
authors.affiliation: Service de Rhumatologie, Centre Hospitalier de Laval Laval, France.
authors.forename: Bernard
authors.initials: B
authors.lastname: Auvinet
authors.affiliation: Laboratory "Motricité, Interactions, Performance" (UPRES EA 4334), University of Nantes Nantes, France ; Gérontopôle des Pays de la Loire, CHU de Nantes Nantes, France.
authors.forename: Gilles
authors.initials: G
authors.lastname: Berrut
authors.affiliation: Laboratory "Motricité, Interactions, Performance" (UPRES EA 4334), University of Nantes Nantes, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Cornu
authors.affiliation: Geriatrics Department, Centre Hospitalier Universitaire de Tours Tours, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Constans
authors.affiliation: Gérontopôle des Pays de la Loire, CHU de Nantes Nantes, France.
authors.forename: Laure
authors.initials: L
authors.lastname: de Decker
keywords: accelerometric device; fall-related injuries; gait analysis; gait speed; gait variability; home-dwelling people; principal components analysis; risk of fall