Anticipated decreased level of mobility of 5 ± 2 days with a level of activity 1 and 2 at the time of study entry and likely to continue at a lower than pre-morbid activity level after the initial 5 ± 2 day period. PATIENTS DO NOT HAVE TO BE HOSPITALIZED IN ORDER TO BE INCLUDED IN THE STUDY.(Definition of decreased level of mobility: _Level 1:bed rest or sedentary patients _Level 2:level 1 with bathroom privileges)