Effects of optic flow speed and lateral flow asymmetry on locomotion in younger and older adults: a virtual reality study

The purpose of the study is to investigate whether there are age-related differences in locomotion due to changes in presence of vision, optic flow speed, and lateral flow asymmetry using virtual reality technology. Gait kinematics and heading direction were measured using a three-dimensional motion analysis system. Although older and younger adults were affected differentially by the availability of vision, a greater dependence on optic flow information in older adults during walking was not found. Linear relations were observed between walking performance and flow speed as well as heading direction and flow asymmetry. The findings suggest that the ability to integrate optic flow information into the multimodal system for assessment of walking speed and heading direction is comparable in older and younger adults. Key Words: Optic flow speed--Virtual reality--Locomotion--Interlimb coordination--Heading direction--Visual dependence.