Physical meicine and rehabilitation (PM&R), or physiatry, is a branch of medicine dealing with functional restoration of a person affected by physical disability. A physician who has completed training in this field is referred to as a physiatrist [fɪz'aiətrɪst]. In order to be a physiatrist in the United States, one must complete four years of medical school, one year of internship and three years of residency. Physiatrists specialize in restoring optimal function to people with injuries to the muscles, bones, tissues, and nervous system (such as stroke patients).