Physical medicine and rehabilitation (PM&R), also known as physiatry /fᵻˈzaɪ.ətri/ or rehabilitation medicine, or physical and rehabilitation medicine (PRM) outside of United States, is a branch of medicine that aims to enhance and restore functional ability and quality of life to those with physical impairments or disabilities. A physician having completed training in this field is referred to as a physiatrist. Physiatrists specialize in restoring optimal function to people with injuries to the muscles, bones, and nervous system.