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.

Origin

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

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.