Forearm and Hand muscle chart

What are the major groups of forearm and hand muscles

Forearm flexors, forearm extensors, hand intrinsics

What layers make up the forearm flexors

Superficial (1st), intermediate (2nd), deep (3rd)

What muscles make up the superficial forearm flexors

Pronator teres, FCR, palmaris longus, FCU

What muscles make up the intermediate forearm flexors

Flexor digitorum superficialis

What muscles make up the deep forearm flexors

Flexor digitorum profundus, FPL, pronator quadratus

What subdivisions make up the forearm extensors

Superficial, deep, outcropping

What muscles make up the superficial forearm extensors

Brachioradialis, ECRL, ECRB, extensor digitorum, EDM, ECU

What muscles make up the deep forearm extensors

Supinator, extensor indicis

What muscles make up the outcropping forearm extensors

APL, EPL, EPB

What groups make up the hand intrinsic muscles

Thenar, hypothenar, short muscles

What muscles make up the thenar and hypothenar groups

Thenar: opponens pollicis, APB, FPB, adductor pollicis, hypothenar: ADM, FDMB, ODM, palmaris brevis

What muscles make up the short hand intrinsic group

Lumbricals, dorsal interossei, palmar interossei

What is the Attachment I of Pronator teres

Ulnar head: coronoid process ulna, humeral head: common flexor tendon to medial epicondyle humerus

What is the Attachment II of Pronator teres

Middle lateral radius

What is the innervation of Pronator teres

Median N. (C6, C7)

What is the main action of Pronator teres

Pronate forearm, flex elbow

What is the Attachment I of Flexor carpi radialis (FCR)

Common flexor tendon to medial epicondyle humerus

What is the Attachment II of Flexor carpi radialis (FCR)

Base of MC 2

What is the innervation of Flexor carpi radialis (FCR)

Median N. (C6, C7)

What is the main action of Flexor carpi radialis (FCR)

Flex and abduct wrist

What is the Attachment I of Palmaris longus

Common flexor tendon to medial epicondyle humerus

What is the Attachment II of Palmaris longus

Distal 1/2 flexor retinaculum, palmar aponeurosis

What is the innervation of Palmaris longus

Median N. (C7, C8)

What is the main action of Palmaris longus

Flex wrist, tense palmar aponeurosis

What is the Attachment I of Flexor carpi ulnaris (FCU)

Humeral head: common flexor tendon to medial epicondyle humerus, ulnar head: olecranon and posterior border ulna

What is the Attachment II of Flexor carpi ulnaris (FCU)

Pisiform, hook of hamate, MC 5

What is the innervation of Flexor carpi ulnaris (FCU)

Ulnar N. (C7, C8, T1)

What is the main action of Flexor carpi ulnaris (FCU)

Flex and adduct wrist

What is the Attachment I of Flexor digitorum superficialis (FDS)

Humero-ulnar head: common flexor tendon to medial epicondyle humerus and coronoid process ulna, radial head: superior 1/2 anterior radius

What is the Attachment II of Flexor digitorum superficialis (FDS)

Shafts of middle phalanges digits 2–5

What is the innervation of Flexor digitorum superficialis (FDS)

Median N. (C7, C8, T1)

What is the main action of Flexor digitorum superficialis (FDS)

Flex MCP and PIP digits 2–5, can flex each finger independently

What is the Attachment I of Flexor digitorum profundus (FDP)

Proximal 3/4 medial and anterior ulna and IM

What is the Attachment II of Flexor digitorum profundus (FDP)

Medial part: bases of distal phalanges digits 4–5, lateral part: bases of distal phalanges digits 2–3

What is the innervation of Flexor digitorum profundus (FDP)

Medial part: Ulnar N. (C8, T1), lateral part: Anterior interosseous N. of median N. (C8, T1)

What is the main action of Flexor digitorum profundus (FDP)

Medial part: flex DIP digits 4–5, lateral part: flex DIP digits 2–3

What is the Attachment I of Flexor pollicis longus (FPL)

Anterior radius and IM

What is the Attachment II of Flexor pollicis longus (FPL)

Base of distal phalanx digit 1

What is the innervation of Flexor pollicis longus (FPL)

Anterior interosseous N. of median N. (C8, T1)

What is the main action of Flexor pollicis longus (FPL)

Flex phalanx digit 1

What is the Attachment I of Pronator quadratus

Distal 1/4 anterior ulna

What is the Attachment II of Pronator quadratus

Distal 1/4 anterior radius

What is the innervation of Pronator quadratus

Anterior interosseous N. of median N. (C8, T1)

What is the main action of Pronator quadratus

Pronate forearm (prime mover), deep fibers bind radius and ulna

What is the Attachment I of Brachioradialis

Proximal 2/3 supra-epicondylar ridge humerus

What is the Attachment II of Brachioradialis

Lateral distal radius proximal to styloid process

What is the innervation of Brachioradialis

Radial N. (C5, C6)

What is the main action of Brachioradialis

Weak elbow flexion, strongest in forearm neutral

What is the Attachment I of Extensor carpi radialis longus (ECRL)

Lateral supra-epicondylar ridge humerus

What is the Attachment II of Extensor carpi radialis longus (ECRL)

Dorsal base MC 2

What is the innervation of Extensor carpi radialis longus (ECRL)

Radial N. (C6, C7)

What is the main action of Extensor carpi radialis longus (ECRL)

Extend and abduct wrist, active during fist clenching

What is the Attachment I of Extensor carpi radialis brevis (ECRB)

Common extensor tendon to lateral epicondyle humerus

What is the Attachment II of Extensor carpi radialis brevis (ECRB)

Dorsal base MC 3

What is the innervation of Extensor carpi radialis brevis (ECRB)

Deep branch radial N. (C7, C8)

What is the main action of Extensor carpi radialis brevis (ECRB)

Extend and abduct wrist, active during fist clenching

What is the Attachment I of Extensor digitorum

Common extensor tendon to lateral epicondyle humerus

What is the Attachment II of Extensor digitorum

Extensor expansions digits 2–5

What is the innervation of Extensor digitorum

Deep branch radial N./posterior interosseous N. (C7, C8)

What is the main action of Extensor digitorum

Extend digits primarily at MCP, secondarily at IP

What is the Attachment I of Extensor digiti minimi (EDM)

Common extensor tendon to lateral epicondyle humerus

What is the Attachment II of Extensor digiti minimi (EDM)

Extensor expansion digit 5

What is the innervation of Extensor digiti minimi (EDM)

Deep branch radial N./posterior interosseous N. (C7, C8)

What is the main action of Extensor digiti minimi (EDM)

Extend digit 5 primarily at MCP, secondarily at IP

What is the Attachment I of Extensor carpi ulnaris (ECU)

Lateral epicondyle humerus, posterior border ulna

What is the Attachment II of Extensor carpi ulnaris (ECU)

Dorsal base MC 5

What is the innervation of Extensor carpi ulnaris (ECU)

Deep branch radial N./posterior interosseous N. (C7, C8)

What is the main action of Extensor carpi ulnaris (ECU)

Extend and adduct wrist, active during fist clenching

What is the Attachment I of Supinator

Lateral epicondyle humerus, radial collateral and annular ligaments, supinator fossa and crest ulna

What is the Attachment II of Supinator

Proximal 1/3 radius, lateral/posterior/anterior surfaces

What is the innervation of Supinator

Deep branch radial N. (C6, C7)

What is the main action of Supinator

Supinate forearm, rotate radius

What is the Attachment I of Extensor indicis

Posterior distal 1/3 ulna and IM

What is the Attachment II of Extensor indicis

Extensor expansion digit 2

What is the innervation of Extensor indicis

Posterior interosseous N. (C7, C8)

What is the main action of Extensor indicis

Extend digit 2 independently

What is the Attachment I of Abductor pollicis longus (APL)

Posterior proximal 1/2 radius and ulna, IM

What is the Attachment II of Abductor pollicis longus (APL)

Base MC 1

What is the innervation of Abductor pollicis longus (APL)

Posterior interosseous N. (C7, C8)

What is the main action of Abductor pollicis longus (APL)

Abduct and extend CMC joint

What is the Attachment I of Extensor pollicis longus (EPL)

Posterior middle 1/3 ulna, IM

What is the Attachment II of Extensor pollicis longus (EPL)

Dorsal base distal phalanx digit 1

What is the innervation of Extensor pollicis longus (EPL)

Posterior interosseous N. (C7, C8)

What is the main action of Extensor pollicis longus (EPL)

Extend distal phalanx digit 1 at IP, MCP, CMC

What is the Attachment I of Extensor pollicis brevis (EPB)

Posterior distal 1/3 radius, IM

What is the Attachment II of Extensor pollicis brevis (EPB)

Dorsal base proximal phalanx digit 1

What is the innervation of Extensor pollicis brevis (EPB)

Posterior interosseous N. (C7, C8)

What is the main action of Extensor pollicis brevis (EPB)

Extend proximal phalanx digit 1 at MCP, CMC

What is the innervation of Opponens pollicis

Recurrent branch median N. (C8, T1)

What is the main action of Opponens pollicis

Oppose digit 1 at CMC

What is the innervation of Abductor pollicis brevis

Recurrent branch median N. (C8, T1)

What is the main action of Abductor pollicis brevis

Abduct digit 1, help oppose

What is the innervation of Flexor pollicis brevis (FPB)

Superficial head: recurrent branch median N. (C8, T1), deep head: deep branch ulnar N. (C8, T1)

What is the main action of Flexor pollicis brevis (FPB)

Flex digit 1

What is the innervation of Adductor pollicis

Deep branch ulnar N. (C8, T1)

What is the main action of Adductor pollicis

Adduct digit 1 toward lateral border palm

What is the innervation of Abductor digiti minimi

Deep branch ulnar N. (C8, T1)

What is the main action of Abductor digiti minimi

Abduct digit 5, assist proximal phalanx flexion

What is the innervation of Flexor digiti minimi brevis

Deep branch ulnar N. (C8, T1)

What is the main action of Flexor digiti minimi brevis

Flex proximal phalanx digit 5