Chronic conditions affect 99 million Americans and limit the daily lives of 41 million (Institute for Health & Aging 1996). Moreover, these conditions are often unrecognized. Myriad reasons contribute to the under-diagnosis of chronic conditions, including problems with patient-clinician communication, providers' lack of awareness of the prevalence of these conditions or how to screen for them, and abbreviated office visits (e.g., Beckman 1999). Many conditions are difficult to ascertain, such as depression and pain, without objective and readily apparent indicators of impairment. Some persons believe that mobility difficulties are an inevitable consequence of aging, and something that physicians can do little to help, and primary care physicians generally have little formal training in mobility assessments (Iezzoni 2003a). An accurate, timely, and inexpensive way to identify and address chronic conditions could potentially transform the care of patients, enhance their quality of life, improve clinicians' work life, and mitigate the social cost of these conditions.