Effect of environmental factors on how older pedestrians detect an upcoming step

Abstract

The relationships between environmental features and older people's ability to safely move around a complex pedestrian environment are, as yet, poorly understood. Specifically, the impact of light levels on trip hazard detection during walking has received relatively little attention. This study investigates the effect of illuminance on people's ability to detect steps of different heights in a laboratory-based controlled environment. Sixteen young and 15 older participants walked along a 13.2 m walkway towards an either ascending or descending step at 200 lux or 4 lux light levels. Trial time, gaze behaviour and distance at which the step was first visually fixated (detection distance) were measured using an eye-tracker. It was found that both the trial time and detection distance of older participants were affected by light level whereas the fixation number and fixation duration of young participants were affected by step-height. Shorter detection distance, greater number of fixations and longer fixation duration were found among older participants as opposed to young participants. The results suggest that the processing efficiency for visual information on an upcoming step is slower among older people than among young people. This implies that the vulnerability of older pedestrians maybe be reduced if better lighting or a simplified visual environment is provided.

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References

Help the Aged. Preventing falls. Retrieved 24 June 2014, from http://www.ageuk.org.uk/documents/en-gb/for-professionals/health-and-wellbeing/id6910_preventing_falls_2007_pro.pdf?dtrk=true.

Sonmez

Malkoc

Altug

. Evaluation of elderly people's requirements in public open spaces: A case study in Bornova District (Izmir, Turkey). Building and Environment 2007; 42: 2035–2045.

Burton

Mitchell

. Inclusive Urban Design: Streets For Life, Oxford: Routledge, 2006.

Inclusive Design for Getting Outdoors. I'DGO design guides. Retrieved 1 August 2015, from http://www.idgo.ac.uk/design_guidance/index.htm (2007).

Raynham

. An examination of the fundamentals of road lighting for pedestrians and drivers. Lighting Research and Technology 2004; 36: 307–313.

Uttley J, Fotios S, Cheal C. Effect of illuminance and spectrum on peripheral obstacle detection by pedestrians. Lighting Research and Technology First published 22 September 2015. DOI: 1477153515602954.

Fotios S, Uttley J. Illuminance required to detect a pavement obstacle of critical size. Lighting Research and Technology First published 20 July 2016. DOI: 1477153516659783.

Campbell S. Deteriorating Vision, Falls and Older People: The Links. Glasgow, UK: Visibility.

Lord

Dayhew

. Visual risk factors for falls in older people. Journal of the American Geriatrics Society 2001; 49: 508–515.

10.

Darowski

. Falls: The Facts, Oxford: Oxford University Press, 2008.

11.

The Chartered Institution of Highways and Transportation. Manual for Streets 2. London: CIHT. Retrieved 25 May 2016, from https://www.gov.uk/government/publications/manual-for-streets-2.

12.

British Standards Institution. Code of Practice for the Design of Road Lighting. Lighting of Roads and Public Amenity Areas. BS 5489-1:2013. London: BSI, 2012.

13.

British Standards Institution. Road Lighting. Performance Requirements. BS EN 13201-2:2003. London: BSI, 2003.

14.

Department for Transport. Inclusive Mobility. Retrieved 15 December 2010, from thttp://www.dft.gov.uk/transportforyou/access/peti/inclusivemobility.

15.

Pickett A, Gallagher A. The Ukpms user manual volume 2. PCIS Support Contract, Retrieved 1 August 2013, from http://www.pcis.org.uk/index.php?p=6/12/0/detail,0,644.

16.

Patla

Vickers

. Where and when do we look as we approach and step over an obstacle in the travel path? Neuroreport 1997; 8: 3661–3665.

17.

Patla

Vickers

. How far ahead do we look when required to step on specific locations in the travel path during locomotion? Experimental Brain Research 2003; 148: 133–138.

18.

Marigold

Patla

. Gaze fixation patterns for negotiating complex ground terrain. Neuroscience 2007; 144: 302–313.

19.

Fotios

Cheal

. Obstacle detection: A pilot study investigating the effects of lamp type, illuminance and age. Lighting Research and Technology 2009; 41: 321–342.

20.

Fotios

Cheal

. Using obstacle detection to identify appropriate illuminances for lighting in residential roads. Lighting Research and Technology 2013; 45: 362–376.

21.

Hausdorff

Nelson

Kaliton

Layne

Bernstein

Neurnberger

Singh

. Etiology and modification of gait instability in older adults: A randomized controlled trial of exercise. Journal of Applied Physiology 2001; 90: 2117–2129.

22.

Hausdorff

. Gait variability: Methods, modeling and meaning. Journal of NeuroEngineering and Rehabilitation 2005; 2: 19.

23.

National Institute for Health and Care Excellence. Clinical Knowledge Summaries: Falls - Risk Assessment. Retrieved 22 January 2013, from http://www.cks.nhs.uk/falls_risk_assessment/evidence/supporting_evidence/up_go_test_and_turn_180o_test#.

24.

Murray

. Gait as a total pattern of movement. American Journal of Physical Medicine 1967; 46: 290–333.

25.

Montgomery

. Design and Analysis of Experiments, 8th. Hoboken, NJ: John Wiley and Sons, 2012.

26.

Zar

. Biostatistical Analysis, 5th. Upper Saddle River, NJ: Pearson, 2009.

27.

Miyasike-daSilva

McIlroy

. Does it really matter where you look when walking on stairs? Insights from a dual-task study. PLoS ONE 2012; 7: e44722.

28.

Chapman

Hollands

. Evidence for a link between changes to gaze behaviour and risk of falling in older adults during adaptive locomotion. Gait and Posture 2006; 24: 288–294.

29.

Chapman

Hollands

. Evidence that older adult fallers prioritise the planning of future stepping actions over the accurate execution of ongoing steps during complex locomotor tasks. Gait and Posture 2007; 26: 59–67.