Scapulohumeral muscles

Scapulohumeral muscles are a group of muscles that connect the scapula and the humerus. They are responsible for the movement of the upper limb. The group includes four muscles: the deltoid, the supraspinatus, the infraspinatus, and the teres major.

Etymology[edit]

The term "scapulohumeral" is derived from the Latin words "scapula," meaning shoulder blade, and "humerus," meaning upper arm bone.

Anatomy[edit]

The scapulohumeral muscles originate from the scapula and insert into the humerus. They are responsible for various movements of the upper limb, including abduction, adduction, flexion, extension, and rotation.

Deltoid[edit]

The deltoid is a large, triangular muscle that covers the shoulder joint. It is responsible for the abduction of the arm at the shoulder joint.

Supraspinatus[edit]

The supraspinatus is a small muscle that sits in the supraspinous fossa of the scapula. It assists the deltoid in the abduction of the arm.

Infraspinatus[edit]

The infraspinatus is a thick triangular muscle, which occupies the chief part of the infraspinatous fossa. It is responsible for the lateral rotation of the arm.

Teres Major[edit]

The teres major is a thick and ovoid muscle in the upper arm. Despite its name, it is not part of the rotator cuff. It is a powerful adductor, internal rotator, and extensor of the arm.