I tweaked my right shoulder playing disc golf, back in the fall - tried to throw backhand around a tree in a way that shoulder joints can't actually do. It only hurt in certain motions, and I could usually avoid them. So, I assumed it couldn't be too bad. I played through it for a couple of months, but it never stopped being sore in certain positions. When the weather got bad in January, I decided to try taking a few weeks off to let it heal for real. That didn't work. Went to the doctor in early February, she sent me to physical therapy. By the time I started PT in March, I'd lost a lot of my internal rotation in that shoulder - I can't touch my back above my waist with my right hand, can't put my right hand on my hip, etc.. I have "impingement syndrome" and possibly some adhesion. Sweet. Basically, the injury healed rapidly and messily and made a bunch of scar tissue, and some ligament or tendon or something is in the wrong place and is blocking the shoulder joint along one axis. That's what I get for stopping!
So, while I deal with my busted right wing, twice a week at PT and painful stretches twice a day, I'm learning to throw lefty! Took about five hours (across two weeks) to where throwing with my left hand didn't feel totally ridiculous. After that, it still felt like I was just pushing the disc out of my hand - I had no feel for the weight or shape of the disc, no sense that I could control it in any way. Took a couple more weeks to get through that. This was all just putting and very short distances (less than 50 feet) around the yard. Then I started trying to get a feel for distances. That took some time. And now I've played a couple of rounds at the local community college course (wide open fields, no hills). My scores are exactly as bad as they were when I started throwing right handed, last year. So that's acceptable.
I can throw maybe 80% of my right-hand distance, but with much reduced accuracy. And strangest of all, the course feels like it's been reversed. When you throw right hand (backhand) most discs will naturally fade to the left as they slow down and lose spin. And so you learn where and how each of your discs fades, and that info becomes part of the calculation you make when deciding how to throw each shot. But throwing left handed flips that - discs fade to the right. So all of that muscle memory I've accumulated about how to approach a shot is now backwards. And I have to relearn each disc. Plus, my form is crap and I can't control anything anyway.
But, progress is being made.
[Hope I don't bust my left shoulder too, because Mrs has already refused to be sympathetic if I do.]