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

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

Anatomy

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

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

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

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

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.

Related Terms

• Rotator cuff
• Shoulder girdle
• Scapula
• Humerus

See Also

• Muscular system
• Anatomy of the human body