Forearms & HandsSource-checked

Wrist extensors (extensor carpi radialis longus/brevis, extensor carpi ulnaris)

Extensor carpi radialis longus, extensor carpi radialis brevis, extensor carpi ulnaris

Pronunciation: eks-TEN-sor KAR-py ul-NAIR-iss

For beginners

These muscles on the back of your forearm lift your wrist upward — and importantly, they also quietly hold your wrist steady whenever you grip something firmly.

Show the advanced explanation

Because a stable, slightly extended wrist lets the finger flexors generate more force, the wrist extensors are heavily active (isometrically) during almost any strong gripping task, which is one reason they're prone to overuse.

Structure & function

Location: A group of muscles on the back-of-hand side of the forearm, sharing a common tendinous origin at the elbow.
Origin: Lateral epicondyle of the humerus (a shared 'common extensor origin').
Insertion: Metacarpal bones of the hand.
Main action(s): Extends the wrist; assists radial/ulnar deviation depending on the specific muscle.
Joint(s) crossed: Wrist (radiocarpal) joint
Movement plane: sagittal
Innervation: Radial nerve
In daily movement: Lifting the back of the hand upward, and stabilizing the wrist in a slightly extended position during most gripping tasks (so the finger flexors can work efficiently).
In exercise: Prime mover of wrist extension in reverse wrist curls; a key stabilizer during heavy gripping exercises.
Commonly confused with: Their stabilizing role during gripping is often overlooked — people assume grip strength is 'just' the fingers and forget the wrist extensors' supporting job.
Common misconceptions: 'Tennis elbow only happens to tennis players' is a myth — it results from wrist-extensor tendon overuse from many repetitive gripping activities.

Exercises that use this muscle

As a primary mover

Eccentric Wrist Extension

As a secondary / stabilizer

Farmer's Carry (secondary)

⚠ Safety note

Pain at the outer elbow that worsens with gripping or wrist-extension tasks may indicate tennis elbow and should be assessed if persistent.

Sources

“The wrist extensor group originates at the lateral epicondyle of the humerus and extends the wrist.”

Anatomy and Physiology 2e — OpenStax, Rice University · Ch. 11.5 Muscles of the Pectoral Girdle and Upper Limbs

Peer-reviewed textbook · License: CC BY-NC-SA 4.0 · Last checked 2026-07-19

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