Pedestrian trip and fall events, a major source of accidental injury and death, are often the result of a vertical perturbation that goes undetected by a pedestrian. Inattention is frequently blamed as the underlying root cause of the fall. However, research suggests that a pedestrian’s visual gaze is typically focused out towards the horizon and not towards the ground in the immediate vicinity of their feet, leaving them with poor visual acuity to detect subtle details on the walking surface. To the extent a vertical perturbation is unexpected, the likelihood of a trip event is increased. Relevant research on gait cycles, toe clearance, visual gaze, and expectation is examined to determine why pedestrians may fail to detect walkway hazards that are physically possible to see. Synthesis and future research are also discussed.
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