Blog 3 Shoulder

The scapulohumeral rhythm is the movement of the scapula with the humerus. It is important for these two bones to move together in order for the human body to achieve full range of motion. These structures move in a 2:1 ratio meaning for every two degrees the humerus moves, the scapula moves one degree. The muscles producing this movement help to stabilize the head of the humerus in the glenoid fossa by not allowing it to come out of the "socket". If a person does not have scapulohumeral rhythm, then they will not be able to have full range of motion which would decrease you measurements in the shoulder.  The humerus could hit the acromion from being pulled up too far also not allowing full 180 degrees ROM. Movement of the scapula provides the sliding motion of the humerus to allow this much motion.