The project will examine how mobility performance in real life tasks and environments is impacted by the use of specific types of wheeled mobility devices (wheeled walker, manual wheelchair, power wheelchair/scooter). Specifically, the project will: 1) randomly recruit persons who were prescribed a mobility aid within the preceding 1 year and currently use the mobility aid, 2) define key mobility tasks within a public environment, 3) measure mobility performance of subjects as they perform the mobility tasks in each of the four devices, and 4) synthesize and disseminate the results. Study results will be used to establish baseline performance data for researchers and clinicians and to identify design improvements for wheelchairs used by community dwelling elders.