title: Is lower peripheral information weighted differently as a function of step number during step climbing?
abstract: The importance of peripheral visual information during stair climbing and how peripheral visual information is weighted as a function of step number during step climbing is unclear. Previous authors postulated that the knowledge of predictable characteristics of the steps may decrease reliance on foveal vision and transfer the online visual guidance of stair climbing to peripheral vision. Hence the aim of this study was to investigate if and how the occlusion of the lower peripheral visual field influenced stair climbing and if peripheral visual information was weighted differently between steps. Ten young adult male participants ascended a 5-step staircase under 2 visual conditions: full vision (FV) and lower visual occlusion (LO). Kinematic data (100Hz) were collected. The effect of Vision and Step condition on vertical forefoot clearance was examined with a Repeated Measures 2-way ANOVA. Tukey's HSD test was used for post-hoc comparisons. A significant interaction Vision x Step and main effect of Step were found (p<=0.04): vertical forefoot clearance was greater in LO compared to FV condition only on the 1st and the 2nd steps (p<0.013) and on the last step compared to the other steps (p<0.01). These findings suggest that online peripheral visual information is more relevant when negotiating the first two steps, rather than the end of a staircase and that the steps subsequent the first few ones may require different information likely based on proprioception or working memory of the step height.
authors.affiliation: University of Maryland Baltimore School of Medicine, Department of Neurology, 110 S. Paca St, Baltimore, MD 21202, USA.
authors.forename: Valentina
authors.initials: V
authors.lastname: Graci
authors.affiliation: IRCCS Fondazione Don Carlo Gnocchi ONLUS, Biomedical Technology Department, via Capecelatro 66, 20148 Milano, Italy. Electronic address: mrabuffetti@dongnocchi.it.
authors.forename: Marco
authors.initials: M
authors.lastname: Rabuffetti
authors.affiliation: Politecnico di Milano, Department of Electronics, Information and Bioengineering, via Golgi 39, 20133 Milano, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Frigo
authors.affiliation: IRCCS Fondazione Don Carlo Gnocchi ONLUS, Biomedical Technology Department, via Capecelatro 66, 20148 Milano, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Ferrarin
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena / Q000502:physiology; D056228:Feedback, Sensory / Q000502:physiology; D006801:Humans; D008124:Locomotion / Q000502:physiology*; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology; D009949:Orientation / Q000502:physiology; D011434:Proprioception / Q000502:physiology; D014794:Visual Fields / Q000502:physiology*; D016138:Walking / Q000502:physiology; D055815:Young Adult
keywords: Lower peripheral visual information; Online visual control; Stair ascend; Stair climbing; Step