O, I, A, N forearm muscles

Brachialis Origin

Distal 1/3 of anterior humerus

Brachialis Insertion

Coronoid process of ulna and tuberosity of ulna

Brachialis Action

Elbow flexion when pronated

Brachialis innervation

Musculocutaneous n + branches from radial n.

Brachioradialis Origin

Proximal 2/3 of lateral supracondylar ridge of humerus

Brachioradialis insertion

Styloid process of radius

Brachioradialis action

Elbow flexion when in neutral position (assists in pronation and supination of forearm when resisted)

Brachioradialis innervation

Radial n

Anconeus Origin

Lateral epicondyle of humerus

Anconeus insertion

Olecranon process and posterior, proximal surface of ulna

Anconeus Action

Elbow extension

Anconeus innervation

Radial n

Pronator teres origin

Medial epicondyle of the humerus and coranoid process

Pronator teres insertion

Middle lateral aspect of radius

Pronator teres action

Pronation, and assist w elbow flexion

Pronator teres innervation

Median nerve

Flexor carpi ulnaris origin

Medial epicomdyle of humerus

Flexor carpi radialis insertion

Base of 2nd and 3rd metacarpal

Flexor Carpi radialis action

Wrist flexion, radial deviation, and may assist in elbow flexion

Flexor carpi radialis innervation

Median n.

Palmaris longus origin

Medial epicondyle of humerus

Palmaris longus insertion

Flexor retinaculum and palmar aponeurosis

Palmaris longus action

Tenses hand, wrist flexion, and may assist in elbow flexion

Palmaris longus innervation

Median n.

Flexor carpi ulnaris origin

Medial epicondyle and posterior surface of proximal 2/3 of ulna

Flexor carpi ulnaris insertion

Pisiform, hamate, and base of 5th metacarpal

Flexor carpi ulnaris action

Ulnar deviation, wrist flexion, may assist in elbow flexion

Flexor carpi ulnaris innervation

Ulnar n.

Flexor digitorum superficialis origin

Medial epicondyle of humerus, coranoid process of ulna, ulnar collateral ligament, interosseus membrane, and proximal shaft of radius

Flexor digitorum superficialis insertion

Sides of middle phalanges 2-5

Flexor digitorum superficialis action

Flex mcp joint (2-5) and flex PIP joint (2-5)

Flexor digitorum superficialis innervation

median n.

Flexor digitorum profoundus origin

Anteriomedial surface of proximal ¾ of ulna

Flexor digitorum profundus insertion

Distal phalanx of 2-5 and palmar surface

Flexor digitorum profundas action

Flex DIP (2-5) and MCP joint (2-5)

Flexor digitorum profundus innervation

Ulnar n (4-5) median n (2-3)

Flexor pollicis longus origin

Anterior distal surface of radius and interosseous membrane

Flexor pollicis longus insertion

Base of distal phalanx phalanx of thumb

Flexor pollicis longus action

Flexion of IP, MCP, and CMC

Flexor pollicis longus innervation

Median n

Pronator quadratus origin

Medial, anterior surface of distal shaft of ulna

Pronator quadratus insertion

Lateral, anterior surface of distal shaft of radius

Pronator quadratus action

Pronation of forearm

Pronator quadratus innervation

Median n.

Extensor carpi radialis longus origin

Distal 1/3 of lateral supracondylar ridge

Extensor carpi radialis longus insertion

Base of 2nd MC

Extensor carpi radialis longus action

Extend the wrist, radial deviation, assists w elbow flexion

Extensor carpi radialis longus innervation

Radial n.

Extensor carpi radialis brevis origin

Lateral epicondyle of humerus

Extensor carpi radialis brevis insertion

Base of 3rd MC

Extensor carpi radialis brevis action

Extend the wrist, radial deviation, and assists with elbow flexion

Extensor carpi radialis brevis innervation

Radial n.

Extensor digitorum origin

Lateral epicondyle of humerus

Extensor digitorum

Middle and distal phalanx of 2-5

Extensor digitorum action

Extension of MCP and IP joints, and wrist extension

Extensor digitorum innervation

Radial n.

Extensor digiti minimi origin

Lateral epicondyle of humerus

Extensor digiti minimi insertion

Distal phalanx of 5th finger

Extensor digiti minimi action

Extension of 5th finger at MCP, DIP, PIP

Extensor digiti minimi innervation

Radial n

Extensor carpi ulnaris origin

Lateral epicondyle of humerus

Extensor carpi ulnaris insertion

Base of 5th MC

Extensor carpi ulnaris action

Extend wrist, ulnar deviation, and assists w elbow flexion

Extensor carpi ulnaris innervation

Radial n

Supinator origin

Lateral epicondyle of humerus, supinator crest of ulna, radial collateral ligament, and annular ligament

Supinator insertion

Anterior lateral surface of proximal 1/3 of radius

Supinator action

Forearm supination

Supinator innervation

Radial n

Abductor pollicis longus origin

Posterior proximal surface of radius and ulna and interosseous membrane

Abductor pollicis longus insertion

Base of 1st MC

Abductor pollicis longus action

Abduct the thumb, extend the thumb and abduct wrist

Abductor pollicis longus innervation

Radial n.

Extensor brevis origin

Posterior distal surface of radius and interosseous membrane

Extensor pollicis brevis insertion

Base of proximal phalanx of thumb

Extensor pollicis Brevis action

Extension of thumb at MCP and CMC joint, and wrist abduction

Extensor pollicis Brevis innervation

Radial n.

Extensor pollicis Longus origin

Posterior distal surface of ulna and interosseous membrane

Extensor pollicis Longus insertion

Base of distal phalanx of thumb

Extensor pollicis Longus action

Extend thumb at MCP, CMC, and IP joints, and wrist abduction

Extensor pollicis Longus innervation

Radial n.

Extensor indicis origin

Posterior distal surface of ulna and interosseous membrane

Extensor indicis insertion

Tendon of ED at 2nd MC

Extensor indicis action

Extends and adducts finger may assist in wrist extension

Extensor indicis innervation

Radial n.