I fixed the link and took you out of the "newly registered" group, which will give you full user rights.
That looks like external rotation, the one at the bottom here.http://exrx.net/Articulations/Shoulder. ... chor110483
The only difference is laying VS standing. The bottom 3 things there on the shoulder articulation page are the main things you need to fix it. You may need more back work in relation to chest. The main problem seems to be rotator cuff, but an imbalance is possible, particularly if you do chest more. You might have weak rear delts as well. It couldn't hurt to do vertical pull with a more narrow grip and/or add some bent over laterals.