The SIPP asks questions about disability status to determine whether a person uses a wheelchair, has used a cane, crutches or walker for at least 6 months, or has a mental disability. Functional activities measured by the SIPP include the ability to perform specific sensory and physical activities such as seeing ordinary newspaper print, hearing normal conversation, having speech understood, lifting or carrying 10 pounds, walking a quarter of a mile without resting, or climbing a flight of stairs without resting. Difficulty in performing any of these activities is considered a functional limitation. The percentage employed drops sharply for people with different functional limitations and other disabilities. There is great variation in employment, depending on the type of limitation, with lower rates in mobility-related impairments.
Employment is lowest for people with mobility impairments.
Chartbook on Work and Disability in the United States, 1998. An InfoUse Report.