Falls in older adults are a major public health concern due to their prevalence as well as age-related declines in proprioception, balance, and motor control. Obstacle clearance is a common assessment for fall risk and gait analysis, however, majority of literature to date gives insight to gait adaptations only in physical environments. Despite having several applications, there has been little research on how augmented reality affects visual and sensory integration during a task like obstacle clearance. Augmented reality could offer a more controlled and safer alternative, assuming it doesn't cause significant enough changes in gait patterns. The purpose of the study was to compare obstacle clearance strategies between younger and older adults across different environments; physical reality (PR), mixed reality (MR), and virtual reality (VR). . 12 healthy younger adults and 12 healthy older adults cleared a 15" obstacle in the 3 environments. Lower limb kinematics, step time and spatial parameters like toe and heel clearance of both leading and trailing limbs were analyzed to determine differences between age groups, and how each of them performed in all 3 environments. Several variables showed significant differences between the age groups, among the environments as well as interaction between the two factors. More significant differences were seen in the trailing limb compared to the leading limb. It was found that older adults reacted most variably to the MR environment, suggesting the visual and sensory information was disproportionately unreliable as compared to VR. Further examination of these gait adaptations can help inform clinical practices on how to reduce fall risk in MR environments.
