Subscapularis

A key muscle located in the shoulder, it plays a critical role in arm movement and stabilization.

Subscapularis is one of the four rotator cuff muscles located in the shoulder. It originates from the subscapular fossa of the scapula and attaches to the lesser tubercle of the humerus. This muscle is crucial for internal rotation of the arm and plays a significant role in the stability of the glenohumeral joint.

Terminologia Anatomica

musculus-subscapularis

System

Muscular system

Function

The primary function of the subscapularis muscle is to facilitate internal rotation of the humerus. This action is vital during many activities that involve raising the arm, such as reaching or throwing. Additionally, the subscapularis acts as a stabilizer for the shoulder joint, counterbalancing the forces exerted by other muscles, thus preventing dislocations or injuries. Its role becomes particularly important in overhead motions, where the shoulder is at risk of instability. Furthermore, it is involved in various sports and activities that require dynamic movements of the upper limb, including swimming, throwing, and weightlifting, making it an essential component for athletic performance.

Location

The subscapularis is located on the anterior (front) surface of the shoulder blade, or scapula. It covers a large portion of the subscapular fossa and extends laterally to attach to the humerus. The muscle lies underneath the scapula, hidden from direct view, and can only be accessed by penetrating through other structures such as the deltoid and supraspinatus muscles. Given its positioning, the subscapularis is strategically situated to provide necessary range of motion and support to the shoulder, allowing it to function effectively in various arm movements while maintaining joint integrity.

Did You Know?

The subscapularis muscle is sometimes referred to as the 'forgotten' rotator cuff muscle, despite its essential functions.
Injury to the subscapularis can lead to significant limitations in shoulder movements and pain, particularly during activities that require internal rotation.
It is the largest and strongest of the rotator cuff muscles, having a key role in preventing shoulder dislocations.
Physical therapists often focus on strengthening the subscapularis to rehabilitate shoulder injuries, highlighting its importance in maintaining shoulder health.