Anconeus muscle
Encyclopedia
The anconeus muscle is a small muscle
on the posterior aspect of the elbow joint.
Some consider anconeus to be a continuation of the triceps brachii muscle
. Some sources consider it to be part of the posterior compartment of the arm
, while others consider it part of the posterior compartment of the forearm
.
The Anconeus muscle can easily be palpated just lateral to the olecranon process of the ulna.
during extension of the elbow. Anconeus also abducts the ulna and stabilizes the elbow joint.
(cervical roots 6, 7, and 8) from the posterior cord of the brachial plexus
. The somatomotor portion of radial nerve innervating anconeus bifurcates from the main branch in the radial groove of the humerus
. This innervation pattern follows the rules of innervation of the musculature of the posterior forearm (extensor) compartment by the radial nerve.
Muscle
Muscle is a contractile tissue of animals and is derived from the mesodermal layer of embryonic germ cells. Muscle cells contain contractile filaments that move past each other and change the size of the cell. They are classified as skeletal, cardiac, or smooth muscles. Their function is to...
on the posterior aspect of the elbow joint.
Some consider anconeus to be a continuation of the triceps brachii muscle
Triceps brachii muscle
The triceps brachii muscle is the large muscle on the back of the upper limb of many vertebrates. It is the muscle principally responsible for extension of the elbow joint .-Terminology:...
. Some sources consider it to be part of the posterior compartment of the arm
Posterior compartment of the arm
The posterior compartment of the arm is an anatomic compartment which contains muscles which are all supplied by the radial nerve. This compartment is also known as the "extensor compartment", extension being its main action.-Contents:...
, while others consider it part of the posterior compartment of the forearm
Posterior compartment of the forearm
The posterior compartment of the forearm contains the following muscles:-Muscles:* "E/I" refers to "extrinsic" or "intrinsic"....
.
The Anconeus muscle can easily be palpated just lateral to the olecranon process of the ulna.
Function
Its function is trivial in humans. It assists in extension of the elbow, where the triceps brachii is the principal agonist. It also prevents the elbow joint capsule being pinched in the olecranon fossaOlecranon fossa
The olecranon fossa is a deep triangular depression on the posterior side of the humerus, superior to the trochlea, in which the summit of the olecranon is received during extension of the forearm.-External links: *...
during extension of the elbow. Anconeus also abducts the ulna and stabilizes the elbow joint.
Innervation
Anconeus is innervated by the radial nerveRadial nerve
The radial nerve is a nerve in the human body that supplies the upper limb. It supplies the medial and lateral heads of the triceps brachii muscle of the arm, as well as all 12 muscles in the posterior osteofascial compartment of the forearm and the associated joints and overlying skin.It...
(cervical roots 6, 7, and 8) from the posterior cord of the brachial plexus
Brachial plexus
The brachial plexus is a network of nerve fibers, running from the spine, formed by the ventral rami of the lower four cervical and first thoracic nerve roots...
. The somatomotor portion of radial nerve innervating anconeus bifurcates from the main branch in the radial groove of the humerus
Humerus
The humerus is a long bone in the arm or forelimb that runs from the shoulder to the elbow....
. This innervation pattern follows the rules of innervation of the musculature of the posterior forearm (extensor) compartment by the radial nerve.
