Which muscle contributes to internal rotation of the glenohumeral joint and is often found short in postural assessment?

The subscapularis muscle plays a significant role in the internal rotation of the glenohumeral joint, which is the ball-and-socket joint of the shoulder. This muscle is located on the anterior surface of the scapula and attaches to the lesser tubercle of the humerus. When the subscapularis contracts, it pulls the humerus inward towards the body, facilitating internal rotation.

In postural assessments, the subscapularis can often appear short, particularly in individuals who regularly engage in activities that involve significant forward shoulder positioning, such as computer work or sports that emphasize the anterior chain of the body. This shortening can lead to alterations in shoulder mechanics and may contribute to postural imbalances.

Understanding the function and common postural tendencies associated with the subscapularis helps in designing rehabilitation and strengthening programs for individuals who may have issues with shoulder mobility or alignment.