I have a bad shoulder (pain) from having it dislocated several times over the years.
When I first started swimming (only breaststroke), I felt tingles of pain pretty quickly. Outside of swimming, I would feel it if I raised my arm over my head in certain angles.
After about 6 months of regular swimming, literally all the pain went away. Clearly my body developed strength around the injury. My shoulders feel better because of swimming.
In a similar vein... I used to have terrible RSI from typing. I randomly started rock climbing. After a while, my hands strengthened and the RSI pain went away. I climbed actively for about 8 years. I stopped climbing years ago (kept typing) and the pain never returned to the same degree as before. When I started swimming more recently, the current hand pain went away again as well.