[Music] scapulo humoral rhythm is the coordinated movement of the scapula across the thoracic cage called scapulo thoracic movement together with the movement of the humoris to the glenoid or glenohumeral movement correct scapulohumeral rhythm is required to achieve full Upper Limb elevation scapular Superior rotation upon the thorax tilts the glenoid fosser upwards this change in its orientation accentuates the movement occurring at the glenohumeral Joint this coordinated movement occurs in a predictable fashion and any disturbance to this pattern is evidence of a muscular or joint dysfunction generally in the first 30° of shoulder Abduction the scapular remains stationary against the rib cage with the movement occurring only at the glenohumeral joint as shoulder abduction continues the inferior angle of the scapula begins to shift outwards as it undergo Superior rotation on average there is approximately 2 degrees of glenohumeral movement for every one degree of scapulothoracic movement from this point this means that as the upper extremity moves on through abduction to 90° The glenohumeral Joint contributes 40° for a total of 70 while the scapulothoracic joint has only contributed 20 this ratio continues above 90° so that by the time the arm has been raised to 150° the contributions of each joint would be 110 for the glenohumeral and 40 for the scapulothoracic the actual ratio can vary during different portions of the Arc of elevation and can be different from Individual to individual therefore It's always important to compare the involved side with the uninvolved the muscles primarily responsible for the scapulothoracic stability and motion are seratus anterior rhomboids levat scapula and trapezius to assess the scapular humoral Rhythm The Examiner observes from behind with the patient standing the patient is asked to abduct the upper extremity in the scapular plane which is approximately 30° forward from the coronal plane The Examiner observes for the smooth and coordinated motion of the glenohumeral and scapulothoracic joints and Compares this to the uninvolved side [Music]