Subscapularis

The subscapularis is an intrinsic muscle located in the shoulder region and is one of the four muscles that make up the rotator cuff. It plays a crucial role in stabilising the shoulder joint and facilitating arm movements.

The subscapularis originates from the subscapular fossa on the anterior surface of the scapula and inserts into the lesser tubercle of the humerus. This positioning allows it to effectively contribute to shoulder movements.

The primary action of the subscapularis muscle is the medial rotation of the arm. This function is essential for various shoulder movements, especially during activities that require internal rotation.

The subscapularis muscle is innervated by the upper and lower subscapular nerves. This innervation is vital for muscle contraction and proper function of the shoulder.

The subscapularis muscle receives its blood supply from the subscapular artery. This vascular supply is important for delivering oxygen and nutrients to the muscle tissue, supporting its function.