Comment by gregwebs
There are case reports of people achieving remarkable rehabilitation by stressing their bones and muscles with weight lifting, for example: https://startingstrength.com/article/barbell_training_as_reh...
In general the theory I usually see now is that rehabilitation is best achieved by putting pain-free stress on the thing being healed, with some arguing for low levels of pain in some circumstances.
I fractured my greater trocahnter (not sure if this is the proper english name) in a bike crash 2 years ago. My doctor, seeing the MRI told me I need an operation asap. None of the hospitals that he sent me to (including a sports clinic) wanted to operate it, and just told me to let it heal, with check-ups every 4 weeks. Another doctor in another country told me to get the operation, stay in bed 3 months and get blood thinners. 1 month after the accident I couldn’t take it to stay at home and stand still so I started walking again quite a lot and started weight lifting (upper body and trying to not stress the hip too much). 4 months later you couldn’t even notice that I had the accident, no limping, could start running again, fracture was fully “welded” on its own.