Elbow, forearm, and hand muscles

Extensor digitorum origin

Common extensor tendon from lateral epicondyle of the humerus and deep antebrachial fascia

Extensor digitorum insertion

Dorsal surface of digits 2-5 into the base of the middle and distal phalanges

Extensor digitorum action

Extends the knuckle, digits 2-5, and the wrist; assists in abduction of digits 2, 4, and 5 as well as the wrist

Extensor digitorum innervation

Radial nerve (C6-8)

Flexor digitorum superficialis origin

Humoral head - Common flexor tendon from medial epicondyle of humerus, ulnar collateral ligament, deep antebrachial fascia;

Ulnar head - Medial side of coronoid process

Radial head - oblique line of the radius

Flexor digitorum superficialis insertion

Sides of the middle phalanges of digits 2-5

Flexor digitorum superficialis action

Flexes proximal joints digits 2-5; assists in flexion of the knuckles and wrist

Flexor digitorum superficialis innervation

Median nerve (C7-T1)

Flexor digitorum profundus origin

Anterior and medial surface or the proximal 3/4 of the ulna, interosseous membrane, deep antebrachial fascia

Flexor digitorum profundus insertion

Anterior surface at the base of distal phalanges

Flexor digitorum profundus action

Flexes distal phalanges 2-5; assists in flexion of the proximal interphalangeal joints and metacarpiphalangeal(knuckles) joints and wrist

Flexor digitorum profundus innervation

Digits 2 & 3 - median nerve (C7-T1); digits 4 & 5 - ulnar nerve (C7-T1)

Flexor carpi radialis origin

Common flexor tendon from medial epicondyle of the humerus, deep antebrachial fascia

Flexor carpi radialis insertion

Base of the metacarpal bones 2 & 3

Flexor carpi radialis action

Flexes and abducts wrist; may assist in pronation of the forearm and flexion of the elbow

Flexor carpi radialis innervation

Median nerve (C6-7)

Flexor carpi ulnaris origin

Humoral head: common flexor tendon from medial epicondyle of humerus;

Ulnar head: olecranon, proximal 2/3 of the posterior border of the ulna, deep antebrachial fascia

Flexor carpi ulnaris insertion

pisiform, hamate, 5th metacarpal bone

Flexor carpi ulnaris action

Flexes and adducts the wrist; assists in flexion of the elbow

Flexor carpi ulnaris innervation

Ulnar nerve (C8)

Extensor carpi radialis longus origin

Distal 1/3 of the lateral supracondylar ridge of the humerus

Extensor carpi radialis longus insertion

Dorsal surface of the base of the second metacarpal bone

Extensor carpi radialis longus action

Extends and abducts the wrist; assists in flexion of the elbow

Extensor carpi radialis longus innervation

Radial nerve (C6-7)

Extensor carpi radialis brevis origin

Common extensor tendon of the lateral epicondyle of the humerus, radial collateral ligament of elbow joint, deep antebrachial fascia

Extensor Carpi radialis brevis insertion

Dorsal surface at the base of 3rd metacarpal

Extensor carpi radialis brevis action

Extends the wrist; assists in radial deviation of the wrist

Extensor carpi radialis brevis innervation

Radial nerve (C6-C7)

Extensor carpi ulnaris origin

Common extensor tendon of the lateral epicondyle of humerus, posterior border of the ulna, deep antebrachial fascia

Extensor carpi ulnaris insertion

Base of the 5th metacarpal bone

Extensor carpi ulnaris action

Extends and ulnarly deviates the wrist

Extensor carpi ulnaris innervation

Radial nerve (C7-8)

Pronator Teres origin

Humoral head: Medial epicondyle of the humerus , common flexor tendon, and deep antebrachial fascia

Ulnar side: coronoid process of the ulna

Pronator Teres insertion

middle of the lateral surface of radius

Pronator Teres action

Pronates the forearm and assists in flexion of the elbow joint

Pronator Teres innervation

Median nerve (C6-7)

Pronator quadratus origin

Medial side, anterior surface of distal 1/4 of ulna

Pronator quadratus insertion

Lateral, anterior surface of 1/4 distal radius

pronator quadratus action

Pronates the forearm

Pronator quadratus innervation

Median nerve (C8-T1)

Supinator origin

Lateral epicondyle of the humerus and supinator crest of the ulna, annular ligament of the radius

Supinator insertion

Lateral surface of the upper 1/3 of the radius

Supinator action

Supinates the forearm at the radioulnar joint

Supinator innervation

Deep radial nerve (C6)

Biceps brachii origin

Short head - apex of the coracoid process of the scapula;

long head - supraglenoid tubercle of the scapula

Biceps brachii insertion

Tuberosity of the radius, aponerurosis of the biceps brachii

Biceps brachii action

Flexes the shoulder joint; long head can assist with abduction if humerus is externally rotated; origin fixed - flexes the elbow joint (forearm moves toward humerus); with insertion fixed flexes elbow joint (humerus toward forearm)

Biceps brachii innervation

Musculocutaneous nerve (C5-6)

Brachialis origin

Distal 1/2 of the anterior surface of the humerus

Brachialis insertion

Ulnar tuberosity and coronoid process of ulna

Brachialis action

Origin fixed - flexes the elbow joint (forearm towards humerus); insertion fixed - flexes the elbow joint (humerus towards forearm)

Brachialis innervation

Musculocutaneous nerve (C5-6)

Brachioradialis origin

Proximal 2/3 of the lateral supracondylar ridge of the humerus

Brachioradialis insertion

styloid process of radius

Brachioradialis action

Flexes the elbow joint and pronates the forearm

Brachioradialis innervation

Radial nerve (C5-6)

Adductor pollicis origin

Oblique fibers - Capitate bone and the 2nd and 3rd metacarpal bones;

Transverse fibers - palmar surface of third metacarpal

Adductor pollicis insertion

Transverse: ulnar side of base of proximal phalanx of thumb

Oblique: extensor expansion

Adductor pollicis action

Adducts carpometacarpal joint of thumb, adducts the metacarpophalangeal joint; assists in flexion of metacarpophalangeal joint

Adductor pollicis innervation

Ulnar nerve (C8-T1)

Abductor pollicis brevis origin

Flexor retinaculum, tubercle of the trapezium bone, tubercle of the scaphoid bone

Abductor pollicis brevis insertion

Base of the proximal phalanx of the thumb on the radial side

Abductor pollicis brevis action

Abducts the carpometacarpal and metacarpophalangeal joints of the thumb ventrally to the plane of the palm; assists in opposition and may assist is flexion and medial rotation of the metacarpophalangeal joint.

Abductor Pollicis brevis innervation

Median nerve (C6-T1)

Opponens pollicis origin

Flexed retinaculum and tubercle of the trapezium bone

Opponens pollicis insertion

Radial side of 1st metacarpal

Opponens pollicis action

Opposes carpometacarpal joint of the thumb towards fifth digit

Opponens pollicis innervation

Median nerve (C6-T1)

Flexor pollicis longus origin

Anterior side of the body of the radius below the tuberosity, interosseous membrane, medial border of the coronoid process of the ulna, medial epicondyle of the humerus

Flexor pollicis longus insertion

Base of distal phalanx of the thumb on the Palmer side

Flexor pollicis longus action

Flexes the interphalangeal joint of the thumb; assists in flexion of the metacarpophalangeal and carpometacarpal joints and wrist joint

Flexor pollicis longus innervation

Median nerve (C8-T1)

Flexor pollicis brevis origin

Superficial head - flexor retinaculum and trapezium bone; deep head - trapezoid and capitate bones

Flexor pollicis brevis insertion

Base of the proximal phalanx of the thumb on the radial side and extensor expansion

Flexor pollicis brevis action

Flexes metacarpophalangeal and carpometacarpal joints of thumb; assists in opposition of the thumb towards the fifth digit

Flexor pollicis brevis innervation

Superficial head - median nerve (C6-T1); Deep head - ulnar nerve (C8-T1)

Extensor pollicis longus origin

Middle 1/3rd of the posterior surface of the ulnar distal to abductor pollicis longus

Extensor pollicis longus insertion

Base of the distal phalanx of the thumb on the dorsal surface

Extensor pollicis longus action

Extends the interphalangeal joint; assists in extension of the metacarpophalangeal and carpometacarpal joints of the thumb; assists in abduction and extension of the wrist

Extensor pollicis longus innervation

Radial nerve (C7-8)

Extensor pollicis brevis origin

Posterior surface of the body of the radius distal to origin of abductor pollicis longus, and to the interosseous membrane

Extensor pollicis brevis insertion

base of proximal phalanx of thumb

Extensor pollicis brevis action

extends metacarpophalangeal and carpometacarpal joints of thumb as well as abduction of the carpometacarpal joint; assists in abduction of the wrist

Extensor pollicis brevis innervation

Radial nerve (C7-8)

Abductor pollicis longus origin

posterior surface of the body of the ulna distal to origin of the supinator, interosseous membrane, and posterior surface of middle 1/3 of the body of the radius

Abductor pollicis longus insertion

Base of the first metacarpal bone on the radial side

Abductor pollicis longus action

Abducts and extends the carpometacarpal joint of the thumb and abducts the wrist; assists in flexion of the wrist

Abductor pollicis longus innervation

Radial nerve (C7-8)

Opponens digiti minimi origin

hook of hamate and flexor retinaculum

Opponens digiti minimi insertion

entire length of 5th metacarpal, ulnar side

Opponens digiti minimi action

Opposes the carpometacarpal joint of the fifth digit, lifts ulnar side of hand to a position where the metacarpopharangeal flexors can oppose the fifth digit to the thumb, helps to cup the palm of the hand

Opponens digiti minimi innervation

Ulnar nerve (C8-T1)

Abductor digiti minimi origin

Tendon of the flexor carpi ulnaris and pisiform bone

Abductor digiti minimi insertion

Two slips - one into the base of the proximal phalanx of the fifth digit on the ulnar side, and one into the ulnar border of the extensor expansion

Abductor digiti minimi action

Abducts the metacarpophalangeal joint of the fifth digit; assists in opposition of the metacarpophalangeal joint; potentially assists in flexion of the metacarpophalangeal joint and extension of the interphalangeal joints

Abductor digiti minimi innervation

Ulnar nerve (C8-T1)

Flexor digiti minimi origin

hook of hamate bone and flexor retinaculum

Flexor digiti minimi insertion

Base of the proximal phalanx of the fifth digit on the ulnar side

Flexor digiti minimi action

Flexes the metacarpophalangeal joint of the fifth digit; assists in opposition of the fifth digit toward the thumb

Flexor digiti minimi innervation

Ulnar nerve (C8-T1)