The shoulder joint is one of the most commonly injured parts of the body, due to the incredible capacity of movement the shoulder can perform; it is also the only body part completely supported by its own musculature.

As a result, muscle balance plays a very important role in the life of a healthy shoulder, and it is necessary to understand the mechanics and function of nerves and circulation, which are often neglected by active people, athletes and occupational requirements which involves repetitive motions with muscle groups in the upper body and especially the shoulders and arms.

That means that the joints ability to move in full rotation is allowed by….” 16 muscles that surround the rotator cup that are connected from the collar bone, ribs, neck, shoulder blade (scapula) and muscles from the arm. In essence these muscle and other soft tissues “create a socket” in which the arm rotates. The rotator cup is NOT a socket like the ball and socket of the hip.