Department of Physical Therapy, High Point University, High Point, North Carolina, United States of America.
Department of Physiotherapy and Rehabilitation, Faculty of Health Sciences, Eastern Mediterranean University, Famagusta, North Cyprus, Turkey.
PLoS One. 2020 Mar 20;15(3):e0230479. doi: 10.1371/journal.pone.0230479. eCollection 2020.
Compared to controlled laboratory settings, the real world is highly distracting with constant demands on visual attention to avoid hazards and falling. Fall-risk assessments do not adequately take into account the potential role of everyday distractions and environmental hazards. The purpose of this project was to identify the effect of the environment on gait and gaze behavior during walking in older adult fallers relative to non-fallers.
Thirteen older adult fallers (76.8±9.4 years, 3.2±2.3 falls in last year) and 13 age-matched non-fallers (78.3±7.3 years, 0 falls in last year) participated. Participants walked in a real-world and lab setting while gait and gaze were recorded. Gait variables were stride length variability, stride duration variability, and stride velocity. Gaze was analyzed for percentage of time fixating and average fixation duration coded across 6 areas of interest (AOIs) in the visual surroundings.
Non-fallers walked faster than fallers, but there were no other group or environment effects on gait. For gaze behavior, fallers had shorter fixation durations on the near environment than non-fallers, but only in the real world. In the real world relative to the lab, fallers decreased fixation durations on the near environment but increased durations on near people. In the real world, participants spent a greater proportion of time fixating on people than on the walking path or the near environment compared to the lab. After adjusting for baseline gait speed, fallers had shorter fixation durations than non-fallers in both environments.
Our results indicate that in a busy environment, older adults concentrate most of their overt visual attention on people when navigating their walking path. Fallers in particular focus longer on people near to them and have overall shorter fixations than non-fallers. Visual focus while walking in a busy environment should be further explored as a fall-risk factor.
相较于受控的实验室环境，现实世界充满了各种干扰，人们需要时刻注意视觉以避免危险和摔倒。现有的跌倒风险评估并未充分考虑到日常干扰和环境危害的潜在作用。本研究旨在确定环境对老年跌倒者和非跌倒者行走时步态和注视行为的影响。
13 名老年跌倒者（76.8±9.4 岁，去年跌倒 3.2±2.3 次）和 13 名年龄匹配的非跌倒者（78.3±7.3 岁，去年无跌倒）参与了本研究。参与者在现实世界和实验室环境中行走，同时记录步态和注视行为。步态变量包括步长变异性、步幅时长变异性和步速。注视行为则分析了注视时间百分比和平均注视持续时间，注视时间百分比和平均注视持续时间在 6 个感兴趣区域（AOIs）的视觉环境中进行编码。
非跌倒者的行走速度快于跌倒者，但在步态方面没有其他组间或环境差异。对于注视行为，跌倒者在近环境中的注视持续时间短于非跌倒者，但仅在现实世界中。在现实世界中，与实验室相比，跌倒者减少了对近环境的注视持续时间，但增加了对近人的注视持续时间。在现实世界中，与实验室相比，参与者在行走路径、近环境和人身上的注视时间比例更大。调整基线行走速度后，跌倒者在两个环境中的注视持续时间均短于非跌倒者。
本研究结果表明，在繁忙的环境中，老年人在行走时会将大部分注意力集中在周围的人身上。特别是跌倒者会更多地关注身边的人，且整体注视时间比非跌倒者短。在繁忙环境中行走时的视觉焦点应作为跌倒风险因素进一步研究。
