Muscles Of The Forearm: Origins, Insertions, Actions, And Innervations

Front 1

Pronator Teres: Origin(s)

Back 1

Humeral head: medial epicondyle

Ulnar head: coronoid process

Front 2

Pronator Teres: Insertion

Back 2

Middle of lateral shaft of radius

Front 3

Pronator Teres: Innervation

Back 3

Median nerve (C6, 7)

Front 4

Pronator Teres: Action(s)

Back 4

Pronation of forearm

Assist flexion of pronated elbow

Front 5

Flexor Carpi Radialis (FCR): Origin

Back 5

Medial epicondyle of humerus (common flexor tendon)

Front 6

Flexor Carpi Radialis (FCR): Insertion

Back 6

Bases of 2nd and 3rd metacarpals

Front 7

Flexor Carpi Radialis (FCR): Innervation

Back 7

Median nerve (C6, 7)

Front 8

Flexor Carpi Radialis (FCR): Action(s)

Back 8

Flexes hand at wrist

Wrist abduction (radial deviation) with ECRL

Front 9

Palmaris Longus: Origin

Back 9

Medial epicondyle of humerus (common flexor tendon)

Front 10

Palmaris Longus: Insertion(s)

Back 10

Palmar aponeurosis and flexor retinaculum

Front 11

Palmaris Longus: Innervation

Back 11

Median nerve (C7, 8)

Front 12

Palmaris Longus: Action(s)

Back 12

Tightens palmar aponeurosis

Assists in flexion of hand at wrist

Front 13

Flexor Carpi Ulnaris (FCU): Origin(s)

Back 13

Humeral head: medial epicondyle (common flexor tendon)

Ulnar head: proximal posterior ulna and olecranon process of ulna

Front 14

Flexor Carpi Ulnaris (FCU): Insertion(s)

Back 14

Pisiform, hammate, and base of 5th metacarpal

Front 15

Flexor Carpi Ulnaris (FCU): Innervation

Back 15

Ulnar nerve (C7, 8)

Front 16

Flexor Carpi Ulnaris (FCU): Action(s)

Back 16

Wrist flexion in ulnar direction

Wrist adduction (ulnar deviation) with ECU

Fixes pisiform when hypothenar muscles act

Front 17

Flexor Digitorum Superficialis (FDS): Origin(s)

Back 17

Humeral head: medial epicondyle (common flexor tendon)

Ulnar head: coronoid process of ulna

Radial head: anterior oblique line of radius

Front 18

Flexor Digitorum Superficialis (FDS): Insertion(s)

Back 18

Sides of shafts of middle phalanges of 4 fingers

Front 19

Flexor Digitorum Superficialis (FDS): Innervation

Back 19

Median nerve (C7, 8, T1)

Front 20

Flexor Digitorum Superficialis (FDS): Action(s)

Back 20

Flexion of 4 fingers at PIP joints

Continuous actions: assists in flexion of MP joints and wrist

Front 21

Flexor Digitorum Profundus (FDP): Origin

Back 21

Proximal 3/4 of anterior ulna and interosseous membrane

Front 22

Flexor Digitorum Profundus (FDP): Insertion (s)

Back 22

Bases of distal phalanges of 4 fingers

Front 23

Flexor Digitorum Profundus (FDP): Innervation(s)

Back 23

Lateral 2 fingers: median nerve--anterior interosseous nerve (C8, T1)

Medial 2 fingers: ulnar nerve (C8, T1)

Front 24

Flexor Digitorum Profundus (FDP): Action(s)

Back 24

Flexion of 4 fingers at DIP joints

Continuous actions: assists in flexion of PIP, MP, and wrist joints

Front 25

Flexor Pollicis Longus (FPL): Origin

Back 25

Middle of anterior radius and interosseous membrane

Front 26

Flexor Pollicis Longus (FPL): Insertion

Back 26

Distal phalanx of thumb

Front 27

Flexor Pollicis Longus (FPL): Innervation

Back 27

Median nerve--anterior interosseous nerve (C8, T1)

Front 28

Flexor Pollicis Longus (FPL): Action(s)

Back 28

Flexion of thumb at IP joint

Continuous actions: assists in flexion of MP and CMC joints of 1st digit and wrist

Front 29

Pronator Quadratus: Origin

Back 29

Distal 1/4 of anterior ulna

Front 30

Pronator Quadratus: Insertion

Back 30

Distal 1/4 of anterior radius

Front 31

Pronator Quadratus: Innervation

Back 31

Median nerve--anterior interosseous nerve (C8, T1)

Front 32

Pronator Quadratus: Action(s)

Back 32

Pronates forearm (*prime mover)

Deep fibers bind radius and ulna together to stabilize distal radioulnar joint

Front 33

Extensor Carpi Radialis Longus (ECRL): Origin

Back 33

Lateral supracondylar ridge of humerus and lateral epicondyle of humerus

Front 34

Extensor Carpi Radialis Longus (ECRL): Insertion

Back 34

Base of 2nd metacarpal

Front 35

Extensor Carpi Radialis Longus (ECRL): Innervation

Back 35

Radial nerve (C6, 7)

Front 36

Extensor Carpi Radialis Longus (ECRL): Action(s)

Back 36

Wrist extension radially

Wrist abduction (radial deviation) with FCR

Stabilizes wrist during finger flexion

Front 37

Extensor Carpi Radialis Brevis (ECRB): Origin

Back 37

Lateral epicondyle of humerus (common extensor tendon)

Front 38

Extensor Carpi Radialis Brevis (ECRB): Insertion

Back 38

Base of 3rd metacarpal (dorsal surface)

Front 39

Extensor Carpi Radialis Brevis (ECRB): Innervation

Back 39

Deep branch of radial nerve (C6, 7)

Front 40

Extensor Carpi Radialis Brevis (ECRB): Action(s)

Back 40

Extension of wrist in midline

Stabilizes wrist during finger flexion

Front 41

Extensor Digitorum Communis (EDC): Origin

Back 41

Lateral epicondyle of humerus (common extensor tendon)

Front 42

Extensor Digitorum Communis (EDC): Insertion

Back 42

Extensor expansion of 4 fingers

Front 43

Extensor Digitorum Communis (EDC): Innervation

Back 43

Radial nerve--posterior interosseous nerve (C6, 7, 8)

Front 44

Extensor Digitorum Communis (EDC): Action(s)

Back 44

Extension of 4 fingers at MP joints

Continuous action: assists in wrist extension

Front 45

Extensor Digiti Minimi (EDM): Origin

Back 45

Lateral epicondyle of humerus (common extensor tendon)

Front 46

Extensor Digiti Minimi (EDM): Insertion

Back 46

Extensor expansion of little finger (with EDC tendon)

Front 47

Extensor Digiti Minimi (EDM): Innervation

Back 47

Radial nerve--posterior interosseous nerve (C7, 8)

Front 48

Extensor Digiti Minimi (EDM): Action(s)

Back 48

Extension of little finger at MP joint

Continuous action: assists in wrist extension

Front 49

Extensor Carpi Ulnaris (ECU): Origin(s)

Back 49

Humeral head: lateral epicondyle of humerus (common extensor tendon)

Ulnar head: posterior proximal ulna

Front 50

Extensor Carpi Ulnaris (ECU): Insertion

Back 50

Base of 5th metacarpal (ulnar side)

Front 51

Extensor Carpi Ulnaris (ECU): Innervation

Back 51

Radial nerve--posterior interosseous nerve (C7, 8)

Front 52

Extensor Carpi Ulnaris (ECU): Action(s)

Back 52

Extension of wrist with ECRB and ECRL

Adduction of wrist (ulnar deviation) with FCU

Front 53

Abductor Pollicis Longus (APL): Origin

Back 53

Posterior radius, ulna, and interosseous membrane

Front 54

Abductor Pollicis Longus (APL): Insertion

Back 54

Base of 1st metacarpal

Front 55

Abductor Pollicis Longus (APL): Innervation

Back 55

Radial nerve--posterior interosseous nerve (C7, 8)

Front 56

Abductor Pollicis Longus (APL): Action(s)

Back 56

Radial abduction of thumb at CMC joint

Continuous action: assists in wrist abduction

Front 57

Extensor Pollicis Brevis (EPB): Origin

Back 57

Posterior radius and interosseous membrane

Front 58

Extensor Pollicis Brevis (EPB): Insertion

Back 58

Base of proximal phalanx of thumb

Front 59

Extensor Pollicis Brevis (EPB): Innervation

Back 59

Radial nerve--posterior interosseous nerve (C7, 8)

Front 60

Extensor Pollicis Brevis (EPB): Action(s)

Back 60

Extension of thumb at MP joint

Continuous actions: radially abducts CMC joint, wrist extension/abduction

Front 61

Extensor Pollicis Longus (EPL): Origin

Back 61

Posterior ulna (middle 1/3) and interosseous membrane

Front 62

Extensor Pollicis Longus (EPL): Insertion

Back 62

Base of distal phalanx of thumb

Front 63

Extensor Pollicis Longus (EPL): Innervation

Back 63

Radial nerve--posterior interosseous nerve (C7, 8)

Front 64

Extensor Pollicis Longus (EPL): Action(s)

Back 64

Extension of thumb at IP joint

Continuous actions: extends MP joint of thumb, radially abducts thumb at CMC joint, assists wrist abduction

Front 65

Extensor Indicis (EI): Origin

Back 65

Posterior ulna and interosseous membrane

Front 66

Extensor Indicis (EI): Insertion

Back 66

Extensor expansion of index finger with EDC tendon

Front 67

Extensor Indicis (EI): Innervation

Back 67

Radial nerve--posterior interosseous nerve (C7, 8)

Front 68

Extensor Indicis (EI): Action(s)

Back 68

Extension of index (2nd) finger at MP joint

Continuous action: assists wrist extension

Front 69

Supinator: Origin

Back 69

Lateral epicondyle of humerus, annular and radial collateral ligaments, and proximal ulna at supinator crest

Front 70

Supinator: Insertion

Back 70

Lateral surface of proximal 1/3 of radius

Front 71

Supinator: Innervation

Back 71

Radial nerve--deep branch (C7, 8)

Front 72

Supinator: Action(s)

Back 72

Supination of forearm