Forearm Muscles: Anatomy and Function of Flexor & Extensor Muscles

The forearm is the region between the elbow joint and the wrist. Its muscles are arranged into two groups, based on their location and function.

Volar (anterior) forearm:

- Flexor Carpi Radialis: Flexes (bends) the wrist and hand towards the palm.

- Palmaris Longus: Flexes the wrist.

- Flexor Carpi Ulnaris: Flexes and deviates (moves from the midline) the wrist towards the ulnar (small finger) side.

- Flexor Digitorum Superficialis: Flexes the middle phalanges of fingers 2-5 (index to pinky finger).

- Flexor Digitorum Profundus: Flexes the distal (end) phalanges of all fingers.

- Flexor Pollicis Longus: Flexes the thumb at its interphalangeal joint (near the tip).

- Pronator Teres: Rotates the forearm to face the palm down (pronation).

Dorsal (posterior) forearm:

- Extensor Carpi Radialis Longus: Extends and deviates the wrist radially (towards the thumb).

- Extensor Carpi Radialis Brevis: Assists the Extensor Carpi Radialis Longus in wrist extension.

- Extensor Carpi Ulnaris: Extends and deviates the wrist ulnarly (toward the small finger side).

- Extensor Digitorum: Extends the fingers 2-5 at their proximal and distal interphalangeal joints.

- Extensor Indicis: Assists the Extensor Digitorum in extending the index finger.

- Abductor Pollicis Longus: Abducts the thumb (moves it away from the midline).

- Extensor Pollicis Brevis: Extends the thumb at the metacarpophalangeal joint.

- Extensor Pollicis Longus: Extends the thumb at the interphalangeal joint.

- Supinator: Rotates the forearm so the palm faces up (supination).