title: How does the extent of central visual field loss affect adaptive gait?
abstract: Visual impairment is one of the most important clinical risk factors associated with falls. Currently it remains unclear whether adaptive gait is progressively affected as the extent of central visual field loss (CFL) increases, or when CFL exceeds a certain size. 10 participants (aged 22 ± 3 years) negotiated a floor based obstacle in full vision (no occlusion) and wearing custom made contact lenses which simulated 10° CFL and 20° CFL. Movement kinematics assessed the period immediately prior to and during obstacle crossing. In the 20° CFL condition, participants exhibited adaptations in gait which were consistent with being more cautious and more variable during the approach to and crossing of the obstacle, when compared to both 10° CFL and full vision conditions. Specifically, in the 20° CFL condition participants placed their lead foot further from the obstacle, lifted both their lead and trail feet higher and slower over the obstacle, and took longer to negotiate the obstacle when compared to the 10° CFL and full vision conditions. Data highlights differences in adaptive gait as a function of the extent of CFL when compared to full vision. More importantly, these adaptations were only associated with loss of the central 20° of the visual field, suggesting that gait is compromised only after central visual field loss exceeds a certain level.
authors.affiliation: Vision & Eye Research Unit, Postgraduate Medical Institute, Anglia Ruskin University, Cambridge, UK; Sports & Exercise Sciences Research Group, Department of Life Sciences, Anglia Ruskin University, Cambridge, UK. Electronic address: Matthew.timmis@anglia.ac.uk.
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Timmis
authors.affiliation: Vision & Eye Research Unit, Postgraduate Medical Institute, Anglia Ruskin University, Cambridge, UK; Department of Clinical Engineering, Medical Imaging and Medical Physics Directorate, Sheffield Teaching Hospitals NH Foundation Trust, Sheffield, UK.
authors.forename: Amy C
authors.initials: AC
authors.lastname: Scarfe
authors.affiliation: Vision & Eye Research Unit, Postgraduate Medical Institute, Anglia Ruskin University, Cambridge, UK.
authors.forename: Shahina
authors.initials: S
authors.lastname: Pardhan
mesh_terms: D000222:Adaptation, Physiological; D005260:Female; D005684:Gait / Q000502:physiology*; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D014786:Vision Disorders / Q000503:physiopathology*; D014794:Visual Fields / Q000502:physiology*; D055815:Young Adult
keywords: Central visual field loss; Falling; Gait; Obstacle crossing