[Moto7451]

Boosting this comment, you want to talk to someone with a Masters or Doctorate in Kinesiology. Some Physical Therapists will have this or equivalent training. Some other specialists will fit the bill as well but not all.

My wife had back pain due to a disfigured vertebrae. That’s something they do not want to operate in until every other option is exhausted. Much of her pain and numbness is caused by imbalanced muscle development from a lifetime of incorrect posture and movements that compensated for the defective vertebrae. She’s worked with both a Physical Therapist and a Trainer to improve her strength and how she moves to the point that she is pain free 90% of the time. Both were referred to her by her doctors. They’re not part of a PT chain or gym.

[ianai]

50/50. The problem with going to fitness/sports people is they may get "distracted" with other concerns of theirs and ignore your central complaint. So if that fitness instructor is incredibly informed and clearly taking your priorities straight then, sure, go there. But if they seem to have a chronic case of "jock brain" and seem to be only concerned with your physical appearance then go elsewhere.

[Moto7451]

These aren’t fitness instructors. The trainer in this medical setting is someone that has you perform exercises to restore mobility rather than for general fitness. There’s certainly a link between the two but that’s not why you go to a hospital to work out.

Kinesiology is the study of how the body moves. While the largest target audience for that is going to be people looking for a standard gym fitness trainer, the higher degrees are wasted on that sort of thing and are better used to restore the range of motion of an elbow after a car accident.