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Muscles/Forearm

Forearm

extensor carpi radialis brevis

ek-STEN-sor KAR-py ray-dee-AY-liss BREH-viss

The ECRB is a forearm extensor on the radial side, extending and abducting the wrist. Mid-forearm location builds wrist stability for racquets and grips.

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Common Pain & Injury

Lateral elbow pain (tennis elbow) with wrist extension. Grip weakness persists >2 weeks, see PT.

Anatomy & Function

Origin

Lateral epicondyle of humerus (outer elbow bone)

Insertion

Base of 3rd metacarpal (back hand bone thumb side)

Actions

  • Wrist extension
  • Radial deviation (wrist to thumb side)

Innervation

Radial nerve (C7-C8)

Muscle Relationships

Antagonists

Flexor carpi radialis

Synergists

ECRLExtensor carpi ulnaris

Trigger Points

Proximal forearm; refers to dorsal wrist, thumb.

Stretches

1Wrist flexor stretch
2Prayer stretch reverse
3ECRB specific extension bias

Common Conditions

Lateral epicondylitisECRB tendinopathy

Anatomical Parts

Left extensor carpi radialis brevisRight extensor carpi radialis brevis

FAQ

ECRB tennis elbow?

Yes, primary muscle in lateral epicondylitis.

ECRB pain?

Outer elbow ache extending wrist.

Exercises for extensor carpi radialis brevis

20

Also Works extensor carpi radialis brevis

10

Related Forearm Muscles

abductor pollicis longus
This forearm muscle runs to the thumb base, abducting and extending it for radial deviation. Vital for wrist stability in lifts like deadlifts. Forearm specialists train it for grip resilience.
anconeus
Tiny elbow extensor at back upper forearm, stabilizes during pressing and gripping. Aids triceps in extensions. Powerlifters note its elbow lockout role.
brachioradialis
The brachioradialis is the thick forearm muscle on the radial (thumb) side, visible in hammer curls. It flexes the elbow in neutral grip, stabilizing during pulls and carries. Builds Popeye forearms for grip strength.
extensor carpi radialis longus
The ECRL is the longer radial wrist extensor, more proximal in forearm for powerful extension and abduction. Stabilizes in heavy pulls.
extensor carpi ulnaris
The ECU is the ulnar (pinky) wrist extensor in posterior forearm, balancing extension with deviation. Key for stability in sports.
extensor digiti minimi
The EDM is a thin forearm muscle specifically extending the pinky finger at knuckles and wrist. Lies ulnar to EDM, aids fine grip control.
extensor digitorum
The extensor digitorum is the central posterior forearm muscle, extending fingers 2-5 at knuckles and wrist. Fan-like tendons create dorsal hand ridges for grip extension.
extensor indicis
The extensor indicis is a narrow forearm muscle that specifically extends the index finger (pointer finger), independent of the other fingers. It's essential for precise gripping and pointing motions in sports like tennis or climbing. Fitness pros value it for finger independence in grip training.

Forearm Pain Guide

Common causes and relief

Activities & Sports

See which activities use extensor carpi radialis brevis

Pinpoint·Interactive 3D Anatomy & Exercise Guide