I guess the good thing about the Harvard system is the wealth of resources even beyond the Physiatrists in the PM&R department. If you are interested in acupuncture,
Dr. Audette would definitely be the attending to rotate with. There are also other attendings who do acupuncture as well, but not as much. On the other hand, we have attendings (both Physiatrists and Anesthesiologists) where you literally do interventional pain procedures all day. In fact, you could spend most of the 4th year doing your own personal fellowship in whatever area of Pain Management you wanted. There are a few residents who did just that and that's probably why they felt they didn't need to do a fellowship after residency. During your PGY-3 year, we do three required Spine rotations that mainly focuses on an intensive spine therapy program and injections.
So basically, if you wanted to, you could spend most of your 4th year being a disc jockey, treating chronic pain, or doing acupuncture. That would be at the extreme of things, but hopefully you'd be motivated to find a good balance. Our program is unique in the number of electives you can do inside the Harvard system or if you wanted to you could fly out to Baylor, Hospital of Special Surgery, Kessler, Stanford, etc. We don't rely on PGY-4s to cover clinics, inpatient rotations, or try to keep them inside the system. A program actually loses money when residents rotate outside the system that's why it is usually kept to a minimum. These are questions that may not seem important now, but when interviewing ask about the number of electives and selectives you can do.