Forearm Muscles

Front 1

Pronator Teres: Origin, Insertion, Action, Nerve, and Artery

Back 1

Origin:
Humeral Head: from medial epicondylar ridge of humerus and common flexor tendon
Ulnar (deep) Head: Medial side of coronoid process of ulna
Insertion: Middle of lateral surface of radius
Action:Pronates forearm, assists in flexing forearm
Nerve: Median n (c5-t1)
Artery: Anterior ulnar recurrent

Can compress median nerve in pronator syndrome

Front 2

Flexor Carpi Radialis: Origin, Insertion, Action, Nerve, and Artery

Back 2

Origin: Common flexor tendon from medial epicondyle of humerus, fascia of forearm
Insertion: base of 2nd and 3rd metacarpal bones
Action: Flexes wrist, radial deviation (abducting)
Nerve: Median
Artery: Muscular branches of radial

Radial artery is immediately lateral

Front 3

Palmaris Longus: Origin, Insertion, Action, Nerve, and Artery

Back 3

Origin: Common flexor tendon from medial epicondyle of humerus
Insertion: Transverse carpal ligament and pamar aponeurosis
Action: Flex wrist, assists in pronation and flexion of forearm
Nerve: Median (c5-t1)
Artery: Posterior ulnar recurrent

Front 4

Flexor Carpi Ulnaris: Origin, Insertion, Action, Nerve, and Artery

Back 4

Origin:
Humeral Head: From common flexor tendon from medail epicondyle of humerus
Ulnar Head: from olecranon and dorsal border of ulna
Insertion: Pisiform, hook of hamate, 5th metacarpal bones
Action: Flexes wrist and assists in adducting it, assists in flexing forearm
Nerve: Ulnar (c8-t1)
Artery: Posterior ulnar recurrent

Most powerful wrist flexor. May compress ulnar nerve.

Front 5

Flexor digitorum superficialis: Origin, Insertion, Action, Nerve, and Artery

Back 5

Origin:
Humeral head: from common flexor tendon of medial epicondyle of humerus
Ulnar head: from coronoid Process of ulna
Radial Head: from oblique line of radius
Insertion: Middle phalanges of medial 4 digits (no thumb!)
Action: Flexes middle and proximal phalanx of medial 4 digits (flexes PIPJ)
Nerve: Median (c5-t1)
Artery: Muscular branches of ulnar, muscular branches of radial

often considered a "middle flexor" because of its position between muscles

Front 6

Flexor digitorum profundus (FDP): Origin, Insertion, Action, Nerve, and Artery

Back 6

Origin: Medial and anterior surface of ulna, interosseous membrane, deep fascia of forearm
Insertion: Distal phalanges of medial 4 digits
Action: Flexes terminal phalanges of medial 4 digits, aids in flexing wrist
Nerve: Anterior interosseus n ( a branch of the median nerve!) for index and middle finger, Ulnar n for ring and pinky
Artery: Anterior interosseous of ulnar, muscular branches of ulnar

use ok sign to test AIN (innervates the Flexor pollicis longus, Flexor digitorum profundus I & II, and the pronator quadratus)

Front 7

Flexor pollicis longus (FPL): Origin, Insertion, Action, Nerve, and Artery

Back 7

Origin: Volar surface of radius, adjacent interosseous membrane, medial border of coronoid process of ulna
Insertion: Base of distal phalanx of thumb on palmar surface
Action: Flexes thumb
Nerve: Anterior interosseous n of median
Artery: Anterior interosseous of ulnar

Front 8

Pronator Quadratus: Origin, Insertion, Action, Nerve, and Artery

Back 8

Origin: Distal fourth of volar surface of ulna
Insertion: Distal fourth of lateral border on volar surface of radius
Action: Pronates forearm
Nerve: Anterior interosseous nerve (off of median)
Artery: Volar interosseous of ulnar

Front 9

What innervates the three deep flexors of the hand and how is it tested

Back 9

the Anterior Interosseous Nerve, tested by making the "OK" sign

Front 10

Anconeous: Origin, Insertion, Action, Nerve, and Artery

Back 10

Origin: Lateral epicondyle of humerus, posterior ligament of elbow joint
Insertion: Lateral side of olecranon and posterior surface of ulna
Action: Assists tricep in extending forearm
Nerve: Radial (c5-t1)
Artery: Branch of profunda brachii

Front 11

Extensor digitorum communis (EDC): Origin, Insertion, Action, and Nerve

Back 11

aka extensor digitorum

Origin: Common extensor origin on the Lateral epicondyle
Insertion: MCP: Sag band, P2: Central slip, P3: terminal insert
Action: Digit extension
Nerve: Posterior interosseous nerve (of Radial)

Front 12

Extensor digit minimi: Origin, Insertion, Action, Nerve, and Artery

Back 12

Origin: Common extensor tendon from lateral epicondyle of the humerus, intermuscular septa
Insertion: Dorsum of proximal phalanx of 5th digit
Action:Extends 5th digit
Nerve: Posterior interosseous of radial
Artery: Posterior interosseous of ulnar

Front 13

Extensor Carpi Ulnaris: Origin, Insertion, Action, Nerve, and Artery

Back 13

Origin: Freem common extensor tendon from lateral epicondyle of humerus and from posterior border of ulna
Insertion: Medial side of base of 5th metacarpal bone
Action: Extends wrist, adducts hand
Nerve: Posterior interosseus of radial
Artery: Posterior interosseous of ulnar

Front 14

Brachioradialis: Origin, Insertion, Action, Nerve, and Artery

Back 14

Origin: Proximal two thirds of lateral supracondylar ridge of humerus, lateral IM seputm
Insertion: Lateral side of base of styloid process of radius
Action: Flexes forearm after flexion has been started by biceps and brachialis, may also act as a semipronator and semisupinator
Nerve: Radial (C5-T1)
Artery: Radial recurrent

Front 15

Extensor carpi radialis longus: Origin, Insertion, Action, Nerve, and Artery

Back 15

Origin: Lateral third of lateral supracondylar ridge of humerus, lateral IM septum
Insertion: Dorsal surface of base of 2nd metacarpal bone
Action: Extend wrist, adbucts hand
Nerve: Radial (c5-t1)
Artery: Muscular branches of radial, radial recurrent

Front 16

Extensor carpi radialis brevis: Origin, Insertion, Action, Nerve, and Artery

Back 16

Origin: From common extensor from lateral condyle of humerus, radial collateral ligament of elbow joint, intermuscular septa
Insertion: Dorsal surface of base of 3rd metacarpal bone
Action: Extends wrist, abducts hand
Nerve: Posterior interosseous nerve of radial
Artery: Muscular branches of radial, radial recurrent

Front 17

Supinator: Origin, Insertion, Action, Nerve, and Artery

Back 17

Origin: Lateral epicondyle of humerus, lateral ligament of elbow joint and annular ligament of radius, supinator crest and fossa of ulna
Insertion: Latera and anterior surface of upper thrid of radius
Action: supinates forearm
Nerve:Deep branch of radial
Artery: radial recurrent, and posterior interosseous of ulnar

Front 18

Abductor pollicis longus: Origin, Insertion, Action, Nerve, and Artery

Back 18

Origin: posterior surface of ulna, interossesous membrane, middle third of posterior surface of radius
Insertion: radial side of base of 1st metacarpal bone
Action: Abducts and extends thumb and wrist (CMCJ)
Nerve: Posterior interosseous of radial
Artery: Posterior interosseous of ulnar

Front 19

Extensor pollicis longus: Origin, Insertion, Action, Nerve, and Artery

Back 19

Origin: Middle third of posterior surface of ulna, interosseous membrane
Insertion: Base of distal phalanx of thumb
Action: Extends terminal phalanx of thumb (IPJ)
Nerve: Posterior interosseous of radial
Artery: Posterior interosseous of ulnar

tendon turns 45 degrees on Lister's tubercle

Front 20

Extensor polllicis brevis: Origin, Insertion, Action, Nerve, and Artery

Back 20

Origin: Posterior surface of radius, interosseous membrane
Insertion: Base of proxima phalanx of thumb
Action: Extends proximal phalanx of thumb (MCPJ)
Nerve: Posterior interosseous of radial
Artery: Posterior interosseous of ulnar

radial border of snuffbox

Front 21

Extensor indicis proprius: Origin, Insertion, Action, Nerve, and Artery

Back 21

Origin: Posterior surface of ulna, interosseous membrane
Insertion: Dorsum of proximal phalanx of index finger
Action: Extends proximal phalanx of index finger
Nerve: Posterior interosseous of radial
Artery: Posterior interosseous of ulnar

Front 22

Abductor pollicis brevis: Origin, Insertion, Action, Nerve, and Artery

Back 22

Origin: Transverse carpa ligament, scaphoid and trapezium
Insertion: Radial side of base of proximal phalanx of thumb
Action: palmar pronation, abducts thumb, draws thumb at right anges to thumb. Primary muscle in opposition
Nerve: Median (muscular branches)
Artery: Superficial volar branch of radial

Front 23

Flexor pollicis brevis: Origin, Insertion, Action, Nerve, and Artery

Back 23

Origin:
1. Superficial head - transverse carpal ligament
2. Deep head - trapezium
Insertion:
1. Superficial head - base of thumb
2. Proximal phalanx
Action: Thumb MPC flexion
Nerve: dual innervation
1. Superficial head: Median
2. Deep head: deep branch of ulnar nerve
Artery: Superficial volar branch of radial

Front 24

Opponens pollicis: Origin, Insertion, Action, Nerve, and Artery

Back 24

Origin: Transverse carpal ligament, trapezium
Insertion: Anterior surface of radial side of 1st metacarpal bone
Action: Oppose (flex / abduct) thumb
Nerve: Muscular branch of median
Artery: Superficial volar branch of radial

pronates / stabilizes thumb MC

Front 25

Adductor pollicis: Origin, Insertion, Action, Nerve, and Artery

Back 25

Origin:
Oblique head: from trapezium, trapezoid, and capitate as well as base of 2nd and 3rd metacarpals
Transverse head: from volar surface of 3rd metacarpal
Insertion: Ulnar side of proximal phalanx of thumb
Action: Adducts thumb, aids in opposition
Nerve: Deep volar branch of ulnar
Artery:Deep volar arch

Test function with froment's test

Front 26

Palmaris brevis: Origin, Insertion, Action, Nerve, and Artery

Back 26

Origin: Ulnar side of transverse carpal ligament, palmar aponeurosis
Insertion: Skin of ulnar border (medial) palm
Action: Wrinkles skin on ulnar side of palm, deeps the hollow of the hand
Nerve: Superficial volar branch of ulnar
Artery: Superficial volar arch

Front 27

Abductor digiti minimi: Origin, Insertion, Action, Nerve, and Artery

Back 27

Origin: Pisifiorm bone, tendon of flexor carpi ulnaris
Insertion: Medial side of base of proximal phalanx of pinky and aponeurosis of extensor digiti minimi
Action: Abducts 5th digit (pinky) from 4th digit
Nerve: Deep volar branch of ulnar
Artery: Deep volar branch of ulnar, dorsal carpal branch of ulnar

Front 28

Flexor Digiti Minimi brevis: Origin, Insertion, Action, Nerve, and Artery

Back 28

Origin: Transverse carpal ligament, hamulus of hamate bone
Insertion: ulnar side of base of proximal phalanx of pinky
Action: Flexes proximal phalanx of 5th digit (flexes MCP of pinky)
Nerve: Deep volar branch of ulnar
Artery: Deep volar branch of ulnar, dorsal carpal branch of ulnar

Front 29

Opponens digiti minimi: Origin, Insertion, Action, Nerve, and Artery

Back 29

Origin: Transverse carpal ligament, hamulus of hamate bone
Insertion: Ulnar margin of 5 metacarpal bone
Action: Draws 5th metacarpal bone forward to face thumb, deeps hollow of hand
Nerve: Deep volar branch of ulnar
Artery: Deep volar branch of ulnar, dorsal carpal branch of ulnar

Front 30

Lumbricals 1&2: Origin, Insertion, Action, Nerve, and Artery

Back 30

Origin: Arise from the corresponding tendons of flexor digitorum profundus.
Insertion: With tendons of extensor digotorum and interossei into bases of terminal phalanges
Action: Flexes fingers at MCP, extends fingers and interphalangeal joints
Nerve: Median
Artery: Superficial and deep volar arches

only muscle to insert on their own antagonist (FDP)

Front 31

Lumbricals 3&4: Origin, Insertion, Action, Nerve, and Artery

Back 31

Origin: Arise from the corresponding tendons of flexor digitorum profundus.
Insertion: With tendons of extensor digotorum and interossei into bases of terminal phalanges
Action: Flexes fingers at MCP, extends fingers and interphalangeal joints
Nerve: Ulnar
Artery: Superficial and deep volar arches

only muscle to insert on their own antagonist (FDP)

Front 32

Interosseous dorsal: Origin, Insertion, Action, Nerve, and Artery

Back 32

Origin: Adjacent metacarpals
Insertion: Proximal phalanx and extensor expansion (lateral bands). Bipennate, each belly has separate insertion
Action: Digit abduction and MCP flexion
Nerve: Deep volar branch of ulnar
Artery: Deep volar arch

DAB PAD: dorsal abduct, palmar adduct

Front 33

Interossei palmar: Origin, Insertion, Action, Nerve, and Artery

Back 33

Origin: Adjacent metacarpals
Insertion: Extensor expansion (lateral bands)
Action: Digit adduction
Nerve: Deep volar branch of Ulnar
Artery: Deep volar arch

Unipennate, PAD