This one goes out to a client of mine who experiences shoulder pain any time she raises her arm overhead. Often the reason we have shoulder pain is that the humerus or arm bone has come so far forward in the shoulder socket and rubs up against the front of the shoulder capsule.
The One arm shoulder swimmer is an awesome drill to glide the shoulder back in it's socket and get you back to action. Pay attention to my form cues in the video and perform this as part of an upper body warm up or as a stand alone exercise in your mobility routine!