Seniors at higher risk of pedestrian collisions

When driving in a public place, seniors use a different pedestrian avoidance strategy than young people, shows a team from Université Laval following experiments in a virtual environment. The slower reaction time to adjust their movement could lead to unfortunate consequences.

“Our results suggest that older adults need more time to analyze the visual information they collect. As a result, their attention is diverted from obstacles that may be in their way. In seniors with mobility or balance problems, this circumvention strategy could increase the risk of hitting an object or making a misstep resulting in a fall,” says the professor at Université Laval’s Faculty of Medicine and researcher at the Centre interdisciplinaire de recherche en réadaptation et intégration sociale (Cirris) of the CIUSSS de la Capitale-Nationale, Bradford McFadyen.

To arrive at these results, the team studied the circumvention strategies of 14 young people with an average age of 24 and 14 people over the age of 70. Participants were walking through a virtual reality environment representing a shopping mall.

“They were asked to walk with a normal step towards a food counter. During the journey, a virtual pedestrian appeared in their field of vision and walked towards them. Participants had to get around it,” says Professor McFadyen.

During the tests, the research team measured, among other things, the observation time of the virtual pedestrian, the location of the participants looking, the virtual pedestrian-pedestrian distance at the time the bypass was initiated, and the minimum bypass distance.

Their results revealed that older adults:

• look at the virtual pedestrian 70% of the time, compared to 50% for young people;
• spend half as much time as young people looking at the environment;
• spend twice as much time as young people observing the legs of the virtual pedestrian;
• initiate the bypass later when they are 1 m closer to the virtual pedestrian.

When the virtual pedestrian moved without wiggling the limbs, members of both groups began the bypass earlier, but the difference was more pronounced among the elderly. “This indicates that the movements of the virtual pedestrian limbs are being used to plan the bypass. When deprived of this information, participants, especially older people, are more cautious,” says Professor McFadyen.

To improve the avoidance strategy of older adults and prevent accidents, Professor McFadyen points out that the virtual environment used in the study could serve as a training tool for people whose mobility is reduced due to age or health problems such as stroke.

This study was published in the scientific journal Human Movement Science. The authors are Félix Fiset and Bradford McFadyen of Université Laval and Anouk Lamontagne of McGill University.


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Université Laval