Scapulohumeral Rhythm

Scapulohumeral rhythm is the kinematic interaction between the scapula and the humerus. In the scapulohumeral rhythm, the scapula needs to tilt back. For full range of motion, the humeral head must rotate laterally. Scapulohumeral rhythm permits good length tension relationships. It also helps with assessing muscle function and shoulder joint motion in the clinical environment. The primary movements that a practitioner looks for with the scapula is upward rotation, posterior tilt, and lateral rotation. When the practitioner notices that there is a change of the primary positioning between the scapula and the humerus,  they know that the scapulohumeral rhythm has been damaged. When this happens the scapula can become "winged". You would be able to notice this if you had a client put their hands on the wall and lean in like they were doing a push up. You would be able to see the scapula poking out. The shoulder has the greatest range of motion (ROM) in the body. It has a full 180° of motion. The scapulohumeral rhythm is very important to achieve the full 180° of motion. For every 3° of shoulder movement, there is 1° of scapulothoracic joint movement and 2° of glenohumeral joint movement. To reach full range of motion, the scapulothoracic joint must produce 60° of movement and the glenohumeral joint must have 120° of movement. If the scapulohumeral rhythm is damaged, then a client cannot achieve the full 180° of motion.