This is a bit of an aside, but I have to say this: even as a young person, take falls very seriously . I was 22 or so when I slipped in the shower. I was falling to the side and was going to hit my head, so I decided to twist so that I'd fall flat on my back, figuring I'd be fine. Well, I was, until a few hours later, when I started having chest pain and my left arm went numb and started getting shooting pains. Think…
I some similar problems along with significant pain, also caused by falls (and a fairly serious injury that compounded things). I had pain for years, until I stumbled onto a combination of things that completely resolve the issues as long as I stick to them. I'm telling you in case they help. If nothing else it shouldn't hurt anything. In order of importance: 1. Develop & maintain significant muscle mass, specificall…
What has really helped me is doing handstand-pushups. You do a handstand against a wall, and then do a push up, lowering your head towards the floor. It really engages all the muscles in the shoulders/back. You'll probably start off by just doing a handstand and then go from there slowly. Once you are a bit more confident you can also arch your back away from the wall engaging muscles lower in your back.
Just like with any exercise, don't push yourself too much and make sure to keep proper form.