I have impact trauma from childhood accidents.
Nearly ten years (‘97-‘08) of chronic hip and back issues were ultimately resolved by virtue of slowing down and reassessing activation and mobility.
Some time in there I incurred a meniscus tear on the left. On the same side I had an adductor tear. Finally, we found my sciatic nerve had been adhered to part of the hamstring.
And after Lyme disease, the stability in my right knee vanished, leaving me with a very complicated locking issue where it would get “trapped” in different positions.
There was a lot of work and patience to get me back to heavy squat, full ROM lower body work (videos here: https://www.instagram.com/p/BvJcMdyHy3m/).
The answer was never in avoidance of training, but revision of approach. You aren’t going to improve tissue problems by getting weaker. Movement and proper strengthening is the solution.