I have heard people say that physical therapy is quite painful. I don't know as I have never broken anything (maybe stubbing a toe but nothing can be done about that).
Is losing weight physical therapy? I guess if we thought about it, losing weight is physical therapy. Adjusting food intake and energy output can be viewed as painful.
Physical therapy is used to get back to normal movement and range of motion. It is painful because the body is pushed to new limits for the purpose of returning to normal.
I'll bet when the physical therapy is completed the patient is glad for the pain that had to be endured in order to get full use of his or her body again. Won't we say it was worth it when we get our weight off?
The only difference is after an injury we are working with a physical therapist who tells us what to do and helps the patient to perform the exercise that will return him/her to normal or very close to it. We have to be our own physical therapist when it comes to exercising and weight loss. Can we be hard enough on ourselves?
Same for a personal trainer. Would we push ourselves to the limits that a personal trainer pushes us? Probably not. It's the job of the personal trainer to push us. We will do for a personal trainer or a physical therapist more than we would ever do on our own.
I read a funny story once somewhere and it mentioned how we willingly take our clothes off for a doctor but if our mechanic did the same thing we would be insulted. It's our perception of the other person and our trust in their skills that causes us to do as they say. I probably wouldn't trust my doctor to put a new transmission in my car either.
Maybe we just don't know what we are doing and therefore don't trust ourselves to do it right. We would gladly pay someone else to do it for us. In fact, we tried it. I wonder how much money I have wasted on gimmicks, equipment, and other things that I convinced myself would do it for me.
You just can't get good help these days.