From years of skating (and falling), my shoulders have taken a beating from absorbing the shock of those falls. A trainer friend of mine repeatedly has said to treat your shoulders like glass. Well, that doesn’t give much credit to the structural integrity of the joint, but it does point to it’s vulnerability.
There are others, of course that offer useful tips for keeping the shoulder’s range of motion (ROM) at optimum. One of the more interesting of these comes from another well-known kettlebell and martial artist, Steve Cotter.
Here is Steve performing the teacup shoulder mobility exercise.
Try it! It looks easier than it is. The exercise opens the shoulders in all planes of movement.