Extensor Carpi Radialis Longus and Brevis: Pain Pattern and Treatment
The two radial wrist extensors run from the outside of the elbow down the thumb side of the back of the forearm to the back of the hand. They cock the wrist back and hold it steady while the fingers grip. Their documented pattern is pain at the outer elbow and at the back of the wrist and hand on the thumb side, with a grip that is weak and drops things. The brevis is the tendon most tennis elbow treatment aims at; the trigger points in the muscles above it are what the treatment misses. This is a sub-page of the forearm extensor group page.
Attachments and action
Origin: Longus: the lower third of the lateral supracondylar ridge of the humerus. Brevis: the lateral epicondyle of the humerus through the common extensor tendon.
Insertion: Longus: the base of the second metacarpal. Brevis: the base of the third metacarpal.
Action: Extension of the wrist and radial deviation, tilting the hand toward the thumb; they fix the wrist during a grip.
Where the pain is felt: At the outside of the elbow. At the back of the wrist on the thumb side. In the back of the hand at the base of the thumb. With a weak grip that drops cups and keys.
Common causes: Tennis, especially a late backhand; a mouse and keyboard with the wrist cocked up; hammering; carrying a heavy bag; gardening with a trowel; painting; a long stretch of work with the wrist held back against a load.
Patients say: "Tennis elbow, and the injection wore off." "The back of my wrist aches more than the elbow." "I drop my coffee cup." A weak handshake on that side.
When to get evaluated: Elbow pain after a fall, with swelling, a visible deformity, or an inability to bend or straighten the joint needs an X-ray first. Wrist pain after a fall on the hand, especially with tenderness in the hollow at the base of the thumb, needs an X-ray for a scaphoid fracture. Numbness or weakness lifting the fingers needs a nerve assessment.
How this muscle is examined and treated
Examination tests wrist extension against resistance with the elbow straight, then with the middle finger held down (the brevis test), presses the two muscles along the thumb side of the back of the upper forearm for the points that reproduce the elbow and wrist pain, and measures grip strength. Needling here addresses the muscles below the outer elbow, not the tendon at the epicondyle. Assessment and treatment happen in the same visit.
Related conditions
TendinitisSports & Performance InjuriesChronic Pain Patterns
This page is educational. It describes muscle referral patterns commonly associated with pain; it does not diagnose your condition. Individual patterns vary. For evaluation of your specific pain, see a licensed clinician. Seek immediate medical care for emergencies. Eugene Baek, L.Ac. · New Jersey License 25MZ00080600