Scapulothoracic Joint

Original Editor - <a href="User:Venus Pagare">Venus Pagare</a>

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Description

The ST “joint” is formed by the articulation of the scapula with the thorax. It is not a true anatomic joint because it has none of the usual joint characteristics (union by fibrous, cartilaginous, or synovial tissues). In fact, the articulation of the scapula with the thorax depends on the integrity of the anatomic AC and SC joints. The SC and AC joints are interdependent with the ST joint because the scapula is attached by its
acromion process to the lateral end of the clavicle through the AC joint; the clavicle, in turn, is attached to the axial skeleton at the manubrium of the sternum through the SC joint. Any movement of the scapula on the thorax mustresult in movement at either the AC joint, the SC joint, or both; that is, the functional ST joint is part of a true closed chain with the AC and SC joints and the thorax. Observation and measure-ment of individual SC and AC joint motions are more difficult than observing or measuring motions of the scapula on the thorax. Consequently, ST position and motions are described and measured far more fre-quently than are the SC and AC joint motions upon which ST motions are dependent.