Waterloo Vision and Mobility Study: gait adaptations to altered surfaces in individuals with age-related maculopathy.

Walking is an extremely complex task that can become seriously challenged if one of the sensory systems which provides input to the motor system is compromised. The present study evaluated gait adaptations to altered surface characteristics and high and low ambient light conditions by subjects with age-related maculopathy (ARM). Twenty subjects with ARM and 20 control subjects walked along a 6 m path, along which they met 1 of 3 altered surfaces (compliant, uneven, or shiny). Kinematic data and ground reaction forces information were analyzed to discern gait adaptation strategies used by the ARM group. Ten trials on each surface were collected under both high and low ambient light levels. The ARM subjects were found to be generally more cautious when walking on the altered surfaces. For example, they walked more slowly, with a longer swing time. However, gait adaptations in the ARM group were not merely scaled versions of normal gait but were adjustments to adapt to environmental changes. Gait was modified to avoid tripping over a surface edge, to prevent slipping at heel contact, and to balance during stance. These adaptations enabled subjects to maintain safe mobility when walking in a challenging environment.