Flexor Carpi Ulnaris
Origin: Medial epicondyle & olecranon
Insertion: Pisiform, hamate & 5th metacarpal
Innervation: Ulnar nerve (C7, C8)
Action: Flexes & adducts wrist (ulnar deviation)
Palmaris Longus
Origin: Medial epicondyle
Insertion: Palmar aponeurosis and flexor retinaculum
Innervation: Median nerve (C7, C8)
Action: Flexes wrist & tenses palmar aponeurosis
Flexor Carpi Radialis
Origin: Medial epicondyle
Insertion: Base of metacarpals II & III
Innervation: Median nerve (C6, C7)
Action: Flexes and abducts the wrist
Pronator Teres
Origin: Medial epicondyle & coronoid process
Insertion: Lateral surface mid-shaft of radius
Innervation: Median nerve (C6, C7)
Action: Pronation
Flexor Digitorum Superficialis
Origin: Medial epicondyle & margin coronoid process; oblique line of radius
Insertion: 4 tendons – middle phalanges of the index, middle, ring and little fingers
Innervation: Median nerve (C7, T1)
Action: Flexes wrist, flexes middle and proximal phalanges of digits 2-5
Flexor Digitorum Profundus
Origin: Anterior & medial surface of ulna & interosseous membrane
Insertion: Four tendons – distal phalanges of the index, middle, ring & little fingers
Innervation: Interosseous branch of the medial and ulnar nerves (C8, T1)
Action: Flexes distal interphalangeal joints
Flexor Pollicis Longus
Origin: Anterior surface of radius & interosseous membrane
Insertion: Base of distal phalanx of thumb
Innervation: Medial nerve (C7, C8)
Action: Flexes distal phalanx of the thumb
Pronator Quadratus
Origin: Distal fourth of anterior surface of the ulna
Insertion: Distal fourth of anterior surface of the radius
Innervation: Median nerve (C7, C8)
Action: Pronation
Brachioradialis
Origin: Lateral supraepicondylar ridge
Insertion: lateral side of the base of
the styloid process of the radius
Innervation: Radial nerve (C5, C6)
Action: Flexes the forearm at the elbow
Extensor carpi radialis longus
Origin: Lateral supraepicondylar ridge
Insertion: Base of metacarpaI II
Innervation: Radial nerve (C6, C7)
Action: Extends & abducts the wrist
Extensor carpi radialis brevis
Origin: Lateral epicondyle
Insertion: Base of metacarpal III
Innervation: Deep branch of radial nerve ( C7, C8)
Action: Extends & abducts the wrist
Extensor digitorum
Origin: Lateral epicondyle
Insertion: 4 tendons (extensor hoods) – base of middle & phalanges of index, middle, ring & little fingers
Innervation: Posterior interosseous (C7, C8)
Action: Extends the index, middle, ring & little fingers
Extensor digiti minimi
Origin: Lateral epicondyle
Insertion: Dorsal digital expansion on the 1st phalax of the little finger
Innervation: Posterior interosseous (C7, C8)
Action: Extends the little finger
Extensor carpi ulnaris
Origin: Lateral epicondyle & posterior border of ulna
Insertion: Tubercle on the base of the medial side of metacarpal V
Innervation: Posterior interosseous (C7, C8)
Action: Extends & adducts the wrist
Anconeus
Origin: Lateral epicondyle
Insertion: Olecranon process & proximal posterior surface of ulna
Innervation: Radial nerve (C7, C8)
Action: Abduction of the ulna in pronation - The anconeus abducts the ulna during pronation to maintain the center of the palm over the same point when the hand is flipped. It is also considered to be an accessory
extensor of the elbow joint
Supinator
Origin: Superior – Lateral epicondyle; Deep – Superior crest of ulna
Insertion: Lateral surface of radius superior to the anterior oblique line
Innervation: Posterior interosseous (C6, C7)
Action: Supination
Abductor pollicis longus
Origin: Posterior surface of ulna & radius, and interosseous membrane
Insertion: Lateral side of base of metacarpal I
Innervation: Posterior interosseous (C7, C8)
Action: Abducts carpometacarpal joint of thumb
Extensor pollicis brevis
Origin: Posterior surface of radius & interosseous membrane
Insertion: Dorsal surface of base of proximal phalanx of the thumb
Innervation: Posterior interosseous (C7, C8)
Action: Extension of thumb, adduction of the wrist
Extensor pollicis longus
Origin: Posterior surface of ulna & interosseous membrane
Insertion: Dorsal surface of base of the distal phalanx of thumb
Innervation: Posterior interosseous (C7, C8)
Action: Extension of thumb, abduction of wrist
Extensor indicis
Origin: Posterior surface of ulna & interosseous membrane
Insertion: Extensor hood of index finger
Innervation: Posterior interosseous (C7, C8)
Action: Extension of the wrist and joints of the second digit
Palmaris Brevis
Origin: Flexor reticulum
Insertion: Dermis on the ulnar border
Innervation: Ulnar nerve
Main action: Wrinkles the skin of the palm
Adductor Pollicis
Origin:
Oblique head: 2nd and 3rd metacarpals and capitates
Transverse head: 3rd metacarpal
Insertion: Proximal 1st phalange
Innervation: Ulnar nerve
Main action: Adduction of the thumb
Lumbricals (4)
Origin:
1st and 2nd: lateral tendons of flexor digitorum profundus
3rd and 4th: medial tendons of flexor digitorum profundus
Insertion: Lateral side of the dorsal expansion of 2-5
Innervation:
Median nerve (1st and 2nd lumbricals)
Ulnar nerve (3rd and 4th lumbricals)
Main action: Flexion of the MCP, extension of DIP and PIP
Dorsal Interossei (4)
Origin: Adjacent side of metacarpals
Insertion: Dorsal expansion and base of 2-4 proximal phalanges
Innervation: Ulnar nerve
Main action: Abduction of the digits, flexion of MCP and extension of IP joint
