title: Variability of human gait: effect of backward walking and dual-tasking on the presence of long-range autocorrelations.
abstract: Information from the central and peripheral nervous systems is continuously integrated to produce a stable gait pattern. However, stride duration fluctuates in a complex manner in healthy subjects, exhibiting long-range autocorrelations that can span over hundreds of consecutive strides. The present study was conducted to explore the mechanisms controlling the long-term fluctuation dynamics of gait. In the first part of the study, stride duration variability was evaluated on a treadmill during forward (FW) and backward walking (BW). Despite the modification of the biomechanical constraints imposed on the locomotor system, the characteristics of the long-range autocorrelations remained unchanged in both modes of locomotion (FW: H = 0.79 ± 0.04 and α = 0.58 ± 0.13; BW: H = 0.79 ± 0.11 and α = 0.53 ± 0.25). In the second part of the study, stride duration variability was assessed while the subjects were performing a dual-task paradigm that combined gait and mental calculation. The long-term variability of stride duration was similar during usual walking (H = 0.80 ± 0.06 and α = 0.57 ± 0.13) and in dual-tasking (H = 0.77 ± 0.06 and α = 0.52 ± 0.16), whereas walking altered the performance of the cognitive task. Hence, the biomechanical and cognitive interferences imposed in the present study were not sufficient to induce a modification of the long-range autocorrelations highlighted in walking variability. These observations underline the robustness of the long-range autocorrelations.
authors.affiliation: Institute of Neuroscience, Université Catholique de Louvain, Avenue Mounier, 53 - B1.53.04, 1200, Brussels, Belgium, benjamin.bollens@uclouvain.be.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Bollens
authors.forename: Frédéric
authors.initials: F
authors.lastname: Crevecoeur
authors.forename: Christine
authors.initials: C
authors.lastname: Detrembleur
authors.forename: Thibault
authors.initials: T
authors.lastname: Warlop
authors.forename: Thierry M
authors.initials: TM
authors.lastname: Lejeune
mesh_terms: D000328:Adult; D003071:Cognition; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D008297:Male; D016138:Walking / Q000502:physiology*; D055815:Young Adult