I've been working with a shoulder injury for over a year now. I think it started with a tear in the brachialis or maybe the deltoid insertion; it only really impacted chaturanga (I could lift from low plank to high plank all day, support myself in Pincha Mayurasana, but lowering down - ouch!) and working around or compensating for that; I messed up the right shoulder. I suspect balloon chasing (specifically, the crown line) as responsible, although lots of chaturangas and carrying extra weight would be exacerbating factors.
I've been living with it for a long while; knowing that having a daily yoga practice was not giving it a lot of time / space to heal up, not wanting to go to the doc (cost and really, I'd be advised to rest it!). So the last year has been a time of humility as I drop my knees for chaturanga and avoid really strong upper arm / shoulder work. I'd toss in a full chaturanga once in a while just to see where I was at, but other than that, I've been good.
But lately I've been feeling pretty good about it all; tossing in more full chaturangas, taking stronger postures. Today, in Marcia's hot class, I did pretty much every chaturanga with knees up, jumped (as opposed to stepped) back and forward about half the time, and to prove a point, took Urdhva Dhanurasana or Wheel - definitely outside my normal "still injured" comfort zone.
I'm not about to go into kick ass shoulder work just yet (or ever!), and ought to drop some pounds before moving forward into advanced arm balance work, but it does feel good to be getting that shoulder / upper arm back, and to reclaim parts of my practice that perhaps might have seemed lost for good.
Time (and a little wisdom and loving kindness) heals....