Elbow Muscles

The elbow muscles include the triceps brachii, brachioradialis, brachialis, biceps brachii, pronator teres, pronator quadratus and the anconeus. Here we explain the muscle which enable the elbow to move.

What movements are available at the elbow?

Elbow joint bones

The elbow joint consists of the humerus bone (upper arm) and the radius and ulna in the forearm. Movements, or joint actions available at the elbow joint are flexion (bending) and extension (straightening). Additionally, pronation (turning inwards) and supination (outwards) are available at the joint between the radius and ulna.

Pronator Teres

Pronator teres elbow muscles

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

Elbow muscles - triceps brachii

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



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.



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

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



The Anconeus is one of the small elbow muscles. It 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.


Supinator muscle

The supinator muscle is an elbow joint muscle which is used most when your arm is straight and your are turning your forearm outwards. Or to use the correct terminology, extended and supinating.

  • Origin: Lateral epicondyle of the humerus and posterior part of the ulna.
  • Insertion: Lateral surface of the radius.
  • Actions: Supination of the forearm.
  • Innervation: Radial nerve (C6).
  • Daily uses: Unscrewing a screwdriver
  • Example strengthening exercises: Anything that resists forearm supination.
  • Example stretches: Maximal pronation of the forearm.

Pronator Quadratus

Pronator quadratus muscle

The pronator quadratus muscle pronates the forearm and helps the triceps muscle extend the elbow.

  • Origin: Distal quarter of the anterior side of the ulna.
  • Insertion: Distal quarter of the anterior side of the radius.
  • Actions: Pronation of the forearm
  • Innervation: Median nerve
  • Daily uses: Screwing in a screw with a screwdriver
  • Example stretches: Maximum supination of the forearm.

Which elbow muscles extend (straighten) the elbow?

  • Triceps brachii
  • Anconeus

Which elbow muscles flex (bend) the elbow?

  • Biceps brachii
  • Brachialis
  • Bracioradialis
  • Pronator teres

Related articles

  • Human muscles anatomy

    Here we explain the major muscles of the human body. If you know where muscles attach and how they contract then you can know how…

  • The hamstring muscles

    The knee joint muscles are those which cause the knee to either bend or straighten. They include the hamstrings and gastrocnemius at the back, which…

  • Hip muscles

    The hip muscles include pelvic and groin muscles. They are important for stabilising the body and for moving the legs. Here we explain the hip…

  • Tennis elbow

    Tennis elbow is also known as lateral epicondylitis, lateral elbow tendinopathy, or extensor tendinopathy. It is a common term used to describe long-term, chronic pain…

  • Shoulder girdle muscles

    The Shoulder girdle muscles move the clavicle (collar bone) and the scapula (shoulder blade). These generally move together as a unit. The muscles of the…

  • Shoulder pain

    Shoulder muscles consist of muscles of the shoulder joint, as well as shoulder girdle muscles. The shoulder girdle muscles make the scapula (shoulder blade) move.…

  • Wrist muscles

    The wrist and hand muscles include the flexor pollicis longus, flexor digitorum superficialis, flexor carpi ulnaris, flexor carpi radialis, extensor digitorum communis, extensor carpi ulnaris…

Scroll to Top