AnatoMemory

Muscle

Brachialis

Workhorse elbow flexor

Upper limbMuscular system

High-yield

Prime elbow flexor regardless of forearm position; dual innervation (musculocutaneous + a twig from radial nerve).

Overview

The main flexor of the elbow in all positions, lying deep to biceps and inserting on the ulna so its action is independent of forearm rotation.

Reference facts

Origin
Distal half of the anterior surface of the humerus
Insertion
Coronoid process and tuberosity of the ulna
Action
Flexes the forearm at the elbow in all positions
Innervation
Musculocutaneous nerve (C5, C6); small contribution from the radial nerve (C7)
Blood supply
Brachial and radial recurrent arteries

Frequently asked questions

What does the brachialis do?

The brachialis flexes the forearm at the elbow in all positions.

What nerve innervates the brachialis?

The brachialis is innervated by the musculocutaneous nerve (C5, C6); small contribution from the radial nerve (C7).

Where does the brachialis attach?

The brachialis originates from the distal half of the anterior surface of the humerus and inserts on the coronoid process and tuberosity of the ulna.

What is the blood supply of the brachialis?

The brachialis is supplied by the brachial and radial recurrent arteries.