This doctor I saw Monday for my back problem is a physiatrist. This is not a physical therapist. They go to med school and then 4 more years. It's kind of complicated. They treat a wide variety of patients----those with arthritis, back problems, fibro, muscular dystrophy, celebral palsy, etc.
The one I saw is affiliated with a spine clinic. He examined me, ordered an MRI and reviewed the results with me, diagnosed the problem and then referred me for further care (which includes PT). He also does spinal injections, if needed.
I had never heard of this kind of doctor until a friend of mine, who's a nurse, recommended him. I liked him because he looked at the whole picture instead of just one aspect---and helped me with rehabilitation.