Tendinosis is the keyword you need to type in for your search. I agree with the last post, ultrasound is not your first choice of treatment, although mobs to the shoulder, thoracic and cervical may all be useful.

You should be looking at the biomechanics and recruitment patterns of the whole shoulder complex, together with the client's posture. From that you should be able to establish where you need to stretch, strengthen and stabilise in order to facilitate optimal recruitment patterns. Not easy in the shoulder as so many structures are involved, but you have to get beyond the basic us/mobs to give yourself a chance. When you get it right it is very rewarding for you, and the client thinks you're great.