Chinese T'ai Chi, incorporating graceful, slow, gentle movements, and deep, even breathing, helps integrate the mind and body. It is a perfect exercise for persons of any age, as well as those with disabilities. T'ai Chi provides a myriad of other benefits, including decreased blood pressure, and increased flexibility, strength, endurance, balance, and body awareness.
For examples of a T'ai Chi program developed for persons with disabilities, see the current article by Shihui Chen in Palaestra:
Chen S. A Modified Tai Chi Program for Individuals with Physical Disabilities. 2002. Palaestra.18 (2): 43-47.
Also consult the NCHPAD factsheet, T'ai Chi at http://www.ncpad.org/36/283/Tai~Chi for a basic overview and resources.