Pinpoint
Muscles/Forearm

Forearm

extensor carpi ulnaris

ek-STEN-sor KAR-py ul-NAY-riss

The ECU is the ulnar (pinky) wrist extensor in posterior forearm, balancing extension with deviation. Key for stability in sports.

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Common Pain & Injury

Ulna-sided wrist or elbow pain twisting. Snapping or instability flags subluxation.

Anatomy & Function

Origin

Lateral epicondyle and posterior humerus (outer elbow and back arm)

Insertion

Base 5th metacarpal via ECU sheath (pinky hand bone)

Actions

  • Wrist extension
  • Ulnar deviation (wrist to pinky)

Innervation

Posterior interosseous nerve (C7-C8)

Muscle Relationships

Antagonists

Flexor carpi radialis

Synergists

Extensor digiti minimi

Trigger Points

Distal ulnar forearm; refers to wrist, ring/pinky.

Stretches

1Ulnar wrist flexor stretch
2ECU tendon glide stretch

Common Conditions

ECU tendon subluxationUlnar impaction syndrome

Anatomical Parts

Right extensor carpi ulnarisRight extensor carpi ulnarisLeft extensor carpi ulnarisLeft extensor carpi ulnaris

FAQ

ECU pain wrist?

Pinky side ache from extension or deviation.

ECU snapping?

Tendon subluxation over ulna.

Exercises for extensor carpi ulnaris

20

Also Works extensor carpi ulnaris

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 brevis
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.
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 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 ulnaris

Pinpoint·Interactive 3D Anatomy & Exercise Guide