As a physical therapist, I commonly use exercises like this called rhythmic stabilization to help athletes improve their shoulder stability following an injury. The goal is to hold the arm as stable as possible with the hand pushing into the wall and keep it from moving as the body is then subjected to small random forces from different directions.✅ . You see the shoulder joint is the most mobile joint in the entire body. Only a small portion of the humerus “ball” is in contact with the socket –