Brachialis

The brachialis (Latin: musculus brachialis) is a thick, broad spindle-shaped muscle of the upper arm that extends between the humerus and ulna. It is located in the anterior compartment of the upper arm under the biceps brachii muscle. The brachialis is one of the forearm flexors acting at the elbow joint.

Brachialis, Muscles of upper arm, Arm muscles, Anterior compartment muscles of upper arm, Anterior compartment muscles, Muscles of upper limb, Lateral view of brachialis
Brachialis by Anatomy Next
Brachialis
OriginAnterior surface of distal humerus
InsertionTuberosity and coronoid process of ulna
ActionFlexion of forearm
InnervationMusculocutaneous nerve, radial nerve
Blood supply Branches of brachial, recurrent radial and ulnar collateral arteries

Origin

The brachialis muscle originates from the anterior surface of the lower part of the humerus.

Brachialis, Origin of brachialis, Insertion of brachialis, Muscles of upper arm, Arm muscles, Anterior compartment muscles of upper arm, Anterior compartment muscles, Muscles of upper limb, Anterior view of brachialis
Origin and insertion of brachialis by Anatomy Next

Insertion

The brachialis inserts on the tuberosity and coronoid process of the ulna.

Action

The primary function of the brachialis muscle is the flexion of the forearm.

Innervation

The brachialis is innervated by the musculocutaneous nerve, a branch of the brachial plexus (C5 - C6). Also, it is supplied by the fibers arising from the C7 root of the brachial plexus (radial nerve).

Blood supply

The brachialis muscle primarily receives arterial blood supply from the branches of the brachial and recurrent radial arteries. Occasionally, the ulnar collateral arteries also provide the supply.