Deltoid

Musculus deltoideus

A thick, triangular muscle covering the shoulder joint. It originates from the lateral third of the clavicle, acromion, and spine of the scapula, and inserts on the deltoid tuberosity of the humerus. Innervated by the axillary nerve (C5, C6).

Type Muscle
Body System Muscular
Body Region Shoulder
Latin Name Musculus deltoideus
FMA ID 32521

Function

The primary abductor of the shoulder joint. The anterior fibers flex and medially rotate the arm. The posterior fibers extend and laterally rotate the arm. Gives the shoulder its rounded contour.

Clinical Significance

Deltoid paralysis from axillary nerve injury prevents arm abduction. The deltoid is a common site for intramuscular injections. Rotator cuff tears may cause compensatory deltoid overuse.

Frequently Asked Questions

What is the Deltoid?
A thick, triangular muscle covering the shoulder joint. It originates from the lateral third of the clavicle, acromion, and spine of the scapula, and inserts on the deltoid tuberosity of the humerus. Innervated by the axillary nerve (C5, C6).
What is the function of the Deltoid?
The primary abductor of the shoulder joint. The anterior fibers flex and medially rotate the arm. The posterior fibers extend and laterally rotate the arm. Gives the shoulder its rounded contour.
What body system is the Deltoid part of?
The Deltoid is part of the Muscular.
What conditions affect the Deltoid?
Deltoid paralysis from axillary nerve injury prevents arm abduction. The deltoid is a common site for intramuscular injections. Rotator cuff tears may cause compensatory deltoid overuse.
Where is the Deltoid located?
The Deltoid is located in the Shoulder region of the body.

Related Structures

anterior internodal tract anterior internodal fasciculus aponeurosis aponeuroses atrioventricular node A-V node Bachmann's bundle anterior interatrial band Biceps brachii Musculus biceps brachii bundle of His A-V bundle cardiac muscle tissue of myocardium cardiac Purkinje fiber cardiac Purkinje fiber

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