Approximately 300,000 patients are hospitalized each year due to hip fractures in the United States. Hip fractures are very dangerous especially for elderly and frail patients. The risk of dying from the stress of the surgery and the injury in the first few days is high. Immobility subsequent to surgery increases that risk. Problems such as pressure sores, pneumonia, and blood clots are all increased by immobility. One out of five hip fracture patients dies within a year of their injury.