With the aging of the population, the burden of disability will have an increasingly profound influence across a number of domains ranging from health care expenditures and provision of care to older persons' quality of life. Although a slow but steady decline in older Americans' disability rates was documented during the last 2 decades of the 20th century, recent national data suggest that this decline may have ended, with disability rates increasing among community-dwelling adults aged 65 years or older during the first 5 years of the 21st century.1 Among the potential reasons for this trend are greater morbidity accompanying better chronic disease survival rates, increasing obesity among midlife and older adults, and the effects of aging-associated patterns of disuse and deconditioning—all of which are linked with functional impairment.1,2 Such factors are exacerbated by reduced socioeconomic circumstances.3