Extensor Carpi Radialis Brevis

General information

A fusiform muscle in the posterior forearm, lateral region. It is part of the superficial forearm extensor group, along with the anconeus, brachioradialis, extensor carpi radialis longus, extensor digitorum, extensor digiti minimi and extensor carpi ulnaris.

Literal meaning

The short muscle on the radial side that straightens the wrist.

Interesting information

The Extensor Carpi Radialis Longus and Extensor Carpi Radialis Brevis muscles share a tendon synovial sheath. The Brevis muscle is located superficially.

Origin

Lateral epicondyle of humerus (common extensor tendon).

Insertion

Posterior aspect of base of 3rd metacarpal bone.

Function 

Wrist joints: Hand extension, hand abduction (radial deviation).

Nerve supply

Radial nerve (C5- C6).

Blood supply

Radial recurrent artery, radial artery, deep brachial artery.

Relevant research

Lateral epicondylitis, also known as tennis elbow, is common injury that occurs at the musculotendinous region of the common extensor tendon; however, the extensor carpi radialis brevis muscle is the most common muscle to be affected. Symptoms include lateral elbow pain or burning and/or a weak grip strength that gets worse with activity.

Wrist drop is a condition caused by radial nerve palsy. This then affects the wrist extensors and digits causing the hand to ‘drop’ or hang in a flexed position.

Walkowski AD, Goldman EM. Anatomy, Shoulder and Upper Limb, Forearm Extensor Carpi Radialis Brevis Muscle. [Updated 2019 Mar 22]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan

Tosti, R., Jennings, J., & Sewards, J. M. (2013). Lateral epicondylitis of the elbow. The American journal of medicine, 126(4), 357.e1–357.e3576.

Extensor carpi radialis brevis exercises

Most of the research recommends including eccentric exercise in a programme for lateral epicondylitis to improve patient outcomes.Cullinane, F. L., Boocock, M. G., & Trevelyan, F. C. (2014). Is eccentric exercise an effective treatment for lateral epicondylitis? A systematic review. Clinical rehabilitation, 28(1), 3–19.

Strengthening:

Eccentric wrist extension

Rest your arm on a table with your hand hanging over the edge of the table with the palm facing down. Hold a light dumbbell and lift your hand up using your other hand. Then controlling the movement, allow the weight to lower your hand downwards. At the end of the movement, repeat by lifting your hand up again and repeat the downwards controlled movement.

Stretching:

Wrist extension stretch

Hold your arm and hand out in front of you, face your fingers to the floor and pull them backwards, towards you.