Pronator Teres

origin - medial epicondyle of humerus

insertion - middle third of the lateral and volar surfaces of the radius

action - strong pronator of forearm, possibly also flexor of forearm at elbow

Flexor Carpi Radialis

origin - medial epicondyle of humerus

insertion - base of 2nd metacarpal

action - flexes wrist

Palmaris Longus

origin - medial epicondyle of humerus

insertion - palmar aponeurosis

action - tenses palmar aponeurosis, flexes wrist

Flexor Carpi Ulnaris

origin - medial epicondyle of humerus

insertion - pisiform bone

action - flexes the wrist

Flexor Digitorum Sublimis

origin - main head from medial epicondyle of humerus

second head from main head

insertion - main portion inserts on middle phalanges of digits 2,3,4,5

action - flexes middle phalanges, then the proximal, then the wrist

Flexor Digitorum Profundus

origin - radial portion from radius and interosseous membrane

ulnar portion mostly from ulna

insertion - radial portion inserts on digits 1,2, and half of 3

ulnar portion on digits 3,4,5, terminal phalanges of digits

action - flexes terminal phalanges and down line to wrist

Pronator Quadratus

origin - distal shaft of ulna (volar surface)

insertion - distal shaft of radius (volar surface)

action - assists in strong pronation of forearm

Brachioradialis

origin - supracondylar or brachioradialis crest

insertion - distal radius

action - strong flexion of forearm at elbow

Extensor Carpi Radialis Longus

origin - from supracondylar crest and perhaps lateral epicondyle

insertion - dorsal face of 2nd metacarpal

action - extends wrist

Extensor Carpi Radialis Brevis

origin - lateral epicondyle of humerus

insertion - base of 3rd metacarpal

action - extends wrist

Extensor Digitorum Communis

origin - lateral epicondyle of humerus

insertion - digits 2,3,4,5, generally to bases of middle phalanges

action - extends relevent digits

Extensor Digiti 2 and 3 Proprius

origin - ulna

insertion - basal phalanges of digits 2,3

action - extends relevent digits

Extensor Digiti 4 and 5 Proprius

origin - lateral epicondyle of humerus

insertion - ulnar side of 4th and 5th digits, on basal or second phalanx

action- extends relevent digits

Extensor Carpi Ulnaris

origin - lateral epicondyle of humerus

insertion - dorsal aspect of base of 5th metacarpal

action - extends wrist

Abductor Pollicis Longus

origin - ulna, radius, and interosseous membrane

insertion - base of 1st metacarpal, adjacent sesamoid bone

action - abducts thumb

Extensor Pollicis Longus

origin - proximal ulna

insertion - terminal phalanx of thumb

action - extends thumb

Supinator

origin - lateral epicondyle of humerus, also lateral border of ulna, proximal end

insertion - proximal half of radial shaft

action - supinates forearm at elbow

Palmaris Brevis

origin - ulnar border of palmar aponeurosis

insertion - skin and pisiform

action - draws hypothenar skin toward palm

Abductor Pollicis Brevis

origin - volar transverse carpal ligament and some hand bones

insertion - radial base of first pollical phalanx

action - abducts thumb

Opponens Pollicis

origin - volar transverse carpal ligament and some hand bones

insertion - radial border of 1st metacarpal

action - rotates the thumb

Flexor Pollicis Brevis

origin - two heads: one from volar transverse carpal ligament

one from some hand bones (trapezoid)

insertion - mostly with abductor pollicis brevis on radial base of 1st pollical phalanx

action - flexes thumb

Adductor Pollicis

origin - bases of 2nd and 3rd metacarpals and central tendon of contrahentes muscles

insertion - ulnar side of base of 1st pollical phalanx, and usually extendin to 2nd phalanx

action - main adductor of thumb

Abductor Digiti Quanti Manus

origin - two heads: one from pisiform bone and volar transverse carpal ligaments

second with flexor digiti quinti brevis from volar transverse carpal ligament

insertion - ulnar side of base of 1st phalanx of digit 5

action - abducts digit 5

Flexor Digiti Quinti Manus

origin - volar transverse carpal ligament with abductor digiti quinti manus

insertion - ulnar side of base of proximal phalanx of digit 5, with extension of to dorsal surface of digit

action - flexes digit 5

Opponens Digiti Quinti Manus

origin - volar transverse carpal ligament and some hand bones

insertion - ulnar border of 5th metacarpal bone

action - rotates digit 5

Lumbricales Manus

origin - tendons of flexor digitorum profundus

insertion - radial side of basal phalanges of digits 2-5, with extension to dorsal surfaces of digits

action - flex proximal phalanges at metacarpophalangeal joints, while maintaining extension at interphalangeal joints

Contrahentes Digitorum Manus

origin - central tendon

insertion - contrahens of digit 5 inserts on radial side of basal phalanx of digit 5; contrahens of digit 4 inserts on radial side of basal phalanx of digit 4; contrahens of digit 2 inserts on ulnar side of basal phalanx of digit 2

action - adducts digits

Interossei Manus

origin - bases of metacarpal bones

insertion

action - dorsal interossei abducts digits; palmar interossei aid contrahens in adducting digits