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Muscles/Forearm

Forearm

abductor pollicis longus

ab-DUK-tor POL-iss LON-gus

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.

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Common Pain & Injury

Radial wrist pain from repetitive motion, swelling at base. De Quervain's common. See doc for persistent thumb weakness.

Anatomy & Function

Origin

Posterior surfaces of ulna, radius, and interosseous membrane (back of forearm bones).

Insertion

Base of 1st metacarpal (thumb base bone).

Actions

  • Abduction of thumb (radial abduction)
  • Extension of wrist (bending wrist back)

Innervation

Posterior interosseous nerve (C7-C8).

Muscle Relationships

Antagonists

Flexor pollicis longusAdductor pollicis

Synergists

Extensor pollicis brevisExtensor pollicis longus

Trigger Points

Along forearm near radius, refers to thumb base and dorsal wrist.

Stretches

1Finkelstein stretch
2Thumb extensor stretch
3Wrist radial deviation stretch

Common Conditions

De Quervain's tenosynovitisIntersection syndromeWrist extensor strain

Anatomical Parts

Left abductor pollicis longusRight abductor pollicis longus

FAQ

What is abductor pollicis longus?

Extends and abducts thumb for wrist power in grips.

Wrist thumb pain de Quervain?

Inflammation here; brace and rest first.

Stretch APL muscle?

Finkelstein test as stretch, gently.

Forearm thumb pain running?

Overuse; ice and eccentric wrist work.

Exercises for abductor pollicis longus

20

Also Works abductor pollicis longus

10

Related Forearm Muscles

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 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 abductor pollicis longus

Pinpoint·Interactive 3D Anatomy & Exercise Guide