I know, it's a weird idea. I've been dealing with shoulder issues for about as long as I can remember now. I originally thought it was due to some scoliosis caused by a short leg, but I've pretty much fixed that and leveled everything out down south using soft tissue techniques and unilateral training. Shoulder problems persist.
However, I have managed to isolate the subscapularis as the primary cause of my grief. The issue seems to be that it's just exceptionally tight. I know that tight muscles are weak muscles, so I've done a lot of direct training on the subscap and had some pretty good success. However, I still tire quickly with the arm overhead with any kind of weight in it for long.
We all know straight-legged deadlifts work great for stretch overload of the hamstrings, keeping them strong, supple and at the proper length. In fact, I'm thinking that stretch overload is the holy grail for a lot of chronically tight muscles IF you can do it right. Can behind-the-neck presses do this for the subscap? I'm not talking huge amounts of weight here - maybe just the bar. I've been trying it. It seems I can get a great stretch DEEP in the subscap, but I have to really jiggle around the shoulder girdle to hit it just right.
If my idea sucks, do you have any others? Something that might help develop end ROM strength and flexibility in the subscap is really what I'm searching for. The classic internal rotation exercises really don't develop END ROM strength or flexibility. I want to get back to lifting like a normal person, and a strong, injury-free subscap seems like a great investment.