Excellent points. Yes a good PT, or even a trainer with a strong education in kinesiology can be very helpful with function. This is no small point, as so many things people do at the gym have no basis in function - how we move throughout the day, and night I suppose.

And you mention "physiatrist" and I would call that a "doctor of physical medicine", sometimes referred to as sports medicine, although that is misleading. These are MDs with a vast knowledge of how the body works and how to diagnose a problem. In most cases, they will refer you to a specialist, but they are invaluable and go well beyond what a primary care dr can offer.

Hopefully this is all useful in response to Doug's initial question.