To study the impact of a standardized twice daily inpatient rehabilitation program on ambulation, ability to perform transfers and self-care, and muscle strength at hospital discharge in older adults hospitalized for an acute medical condition. We will study individuals who have either lost the ability to ambulate independently (within the two weeks before hospitalization), or have limited ability to ambulate (less than 150 feet at a functional velocity). The primary outcome measure for this objective will be the Timed Up and Go (TUG) test (41). Ambulation, transfers, and self-care also will be assessed using the locomotion, mobility and self care subscales of the Functional Independence Measure (FIM) (15, 22-24). The Microfit 2 hand-held dynamometer (HHD) will be used to test muscle strength of six lower extremity muscle groups and three upper extremity muscle groups (44). An important outcome assessment will be the proportion of subjects that regain independence in ambulation by hospital discharge.