Foster, RJ, Whitaker, D, Scally, AJ, Buckley, JG and Elliott, DB (2015) What You See Is What You Step: The Horizontal-Vertical Illusion Increases Toe Clearance in Older Adults During Stair Ascent. Investigative Ophthalmology & Visual Science, 56 (5). 2950.-2957. ISSN 0146-0404
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Foster et al (2015) What you see is what you step - the horizontal vertical illusion increases toe clearance in older adults during stair ascent.pdf - Published Version Available under License Creative Commons Attribution Non-commercial No Derivatives. Download (531kB) | Preview |
Abstract
Purpose.: Falls on stairs are a significant cause of morbidity and mortality in elderly people. A simple safety strategy to avoid tripping on stairs is increasing foot clearance. We determined whether a horizontal–vertical illusion superimposed onto stairs to create an illusory perceived increase in stair-riser height would increase stair ascent foot clearance in older participants.
Methods.: Preliminary experiments determined the optimum parameters for the horizontal–vertical illusion. Fourteen older adults (mean age ± 1 SD, 68.5 ± 7.4 years) ascended a three-step staircase with the optimized version of the horizontal–vertical illusion (spatial frequency: 12 cycles per stair riser) positioned either on the bottom or top stair only, or on the bottom and top stair simultaneously. These were compared to a control condition, which had a plain stair riser with edge highlighters positioned flush with each stair-tread edge. Foot clearance and measures of postural stability were compared across conditions.
Results.: The optimized illusion on the bottom and top stair led to a significant increase in foot clearance over the respective stair edge, compared to the control condition. There were no significant decreases in postural stability.
Conclusions.: An optimized horizontal–vertical visual illusion led to significant increases in foot clearance in older adults when ascending a staircase, but the effects did not destabilize their postural stability. Inclusion of the horizontal–vertical illusion on raised surfaces (e.g., curbs) or the bottom and top stairs of staircases could improve stair ascent safety in older adults.
Item Type: | Article |
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Uncontrolled Keywords: | 11 Medical and Health Sciences, 06 Biological Sciences |
Subjects: | Q Science > QP Physiology R Medicine > RE Ophthalmology |
Divisions: | Sport & Exercise Sciences |
Publisher: | Association for Research in Vision and Ophthalmology (ARVO) |
Related URLs: | |
Date Deposited: | 24 Mar 2020 09:45 |
Last Modified: | 04 Sep 2021 07:36 |
DOI or ID number: | 10.1167/iovs.14-16018 |
URI: | https://researchonline.ljmu.ac.uk/id/eprint/12586 |
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