Elbow Joint Muscles

The elbow joint is a simple hinge joint but most movements involving the elbow joint also involve the radioulnar joint where the forearm bones (radius and ulna) join at the elbow joint. Muscles producing movements at the elbow and forearm are the triceps brachii, brachioradialis, brachialis, biceps brachii, and the anconeus.

Pronator Teres

Pronator Teres Muscle

Pronator Teres works the hardest when the elbow is flexing the hand simultaneously pronating.

Origin: Medial supracondylar ridge of the humerus

Medial side of the coronoid process of the ulna

Insertion: Middle 1/3 of the outer surface of the radius

Actions: Pronation. Elbow flexion

Innervation: Median nerve

Daily uses: Turning a screwdriver

Triceps Brachii

Triceps Brachii Muscle

The Triceps Brachii also assists Latissimus Dorsi in extending the shoulder joint. It contracts strongly during the up phase of a push-up, to straighten the arm.

Origin: Long head – Lower part of the glenoid cavity of the scapula.
Lateral head – Upper half of the posterior surface of the humerus.
Medial head – Lower 2/3 of the posterior surface of the humerus

Insertion: Olecranon process of the ulna

Actions: Elbow  extension

Innervation: Radial nerve

Daily uses: Pushing a door closed

Example strengthening exercises: Tricep extension.
Overhead tricep extension.
Tricep dips

Example stretches: Tricep stretch


Brachioradialis Muscle

The Brachioradialis muscle acts to supinate the forearm from a pronated position when it flexes the elbow. When starting in a supinated position, it acts to pronate the hand as it flexes the elbow.

Origin: Lower 2/3 of the lateral supracondylar ridge of the humerus.

Insertion: Styloid process of the radius.

Actions: Elbow flexion. Pronation. Supination

Innervation: Radial nerve.

Daily uses: Turning a corkscrew.

Example strengthening exercises: Bicep curls using a resistance band.


Brachialis Muscle

The Brachialis acts to flex the elbow whether in pronation or supination, along with Biceps Brachii. As Brachialis is attached to the Ulna, which cannot rotate, it is the only true flexor of the elbow.

Origin: Lower half of the anterior humerus.

Insertion: Coronoid process of the ulna.

Actions: Elbow flexion.

Innervation: Musculocutaneous nerve.

Daily uses: Picking up shopping bags.

Example strengthening exercises: Bicep curls using a resistance band.

Biceps Brachii

Biceps Brachii Muscle

The Biceps brachii crosses both the elbow and shoulder joints. Its action on the shoulder joint is very weak flexion.

The Biceps Brachii works most efficiently in flexing the elbow joint when the forearm is supinated (palm facing up). The bicep curl is the most commonly used exercise to strengthen this muscle.

Origin: Long head – top of the glenoid fossa.

Short head – coracoid process.

Insertion: Bicipital tuberosity of the radius.
Bicipital aponeurosis into the deep fascia of the forearm.

Actions: Elbow flexion.
Supination of the forearm.

Innervation: Musculocutaneous nerve.

Daily uses: Picking up a shopping bag.
Biceps curl using a resistance band or dumbbell.

Example exercises: Bicep curl.


Anconeus Muscle

The Anconeus works alongside Triceps Brachii in extending the elbow. It also acts to pull the synovial membrane out of the way of the olecranon process when the elbow is extending.

Origin: Posterior surface of the lateral condyle of the humerus.

Insertion: Posterior surface of the upper ulna and its olecranon process.

Actions: Elbow extension.

Innervation: Radial nerve.

Daily uses: Pushing a door closed.

Example strengthening exercises: Tricep extension with a resistance band.
Overhead triceps extension with a resistance band.

Example stretches: Tricep stretch.


Pronator Quadratus

This article has been written with reference to the bibliography.