Deltoid: Origin, Insertion, Action & Nerve Supply


The deltoid is a thick muscle that covers the shoulder. The deltoid muscle is separated into three parts -an anterior, middle and posterior part.DELTOID MUSCLE

Attachments of the Deltoid

Origin: Originates from the scapula and clavicle

Insertion: Attaches to the deltoid tuberosity of the humerus.

Nerve Supply of the Deltoid

Axillary nerve

Function of the Deltoid

The anterior fibers of the deltoid flex the arm at the shoulder.The middle fibers are the major abductor of the arm – it takes over from the supraspinatus, which abducts the first 15 degrees. The posterior fibers extend the arm at the shoulder.deltoid muscle