Exercises with a shoulder taking part and breast spine side.

As to train a shoulder blades.
A lie on the spine, under waist put rolled towel, bended legs in knees under straightened cover, feet are on the floor, under head a stand of books.
Stretched hands up, wrists are crossed locked, stretch with wrists and both hands up, and raise shoulder joints up, try to raise together with shoulder blades,and exercises you can doing as isometric where stretching hands up and keeping position within 30 sec, after is rest, repeat for three times.
Dynamic as stretching up hands,keeping for three sec theirs, returning back, repeats are 15 times.