I have impingement of my supraspinitus in my right shoulder (doctor diagnosed). I'm 24. As long as I don't do too much full range pressing or stick to using chains and reverse bands on bench it doesn't bother me too much (gainst bands can be hard on it). I've also done a lot to strengthen my upper back and rotator cuff via facepulls, cuban presses, etc. I've also done a lot tennis ball work on the area.
But now, I want to take it a step further. I want to improve the mobility of that shoulder. I can't overhead squat with just a bb to save my life. My shoulders just won't get into that position. I can however do a power snatch pain free (sometimes I do them to make the shoulder feel better). Cleans are different. There the worst trigger. Heavy db presses also agravates it a lot. Weighted Pull up can aggravate but a neutral or underhand grip gives me no issues.
Now the issue doesn't seem like much, but I'm only 24 and I'd like to keep the shoulder relatively healthy for many years down the road. What can I do to improve flexibility and mobility? I think I've learned pretty well what works for strengthening the rotator cuff which had gone a long way, but I think I'm going to need more. Especially as I'm approaching a 315+lb bench.