Forearm and Hand Muscles - Hand Flashcards
brachioradialis origin
Proximal 2/3 of supracondylar ridge of humerus
brachioradialis insertion
lateral surface of distal end of radius proximal to styloid process
brachioradialis action
Weak flexion of forearm; maximal when forearm is mid pronation
brachioradialis innervation
Radial nerve (C5,C6,C7)
extensor carpi radialis longus origin
Lateral supraepicondylar ridge of humerus
extensor carpi radialis longus insertion
Dorsal aspect of base of 2nd metacarpal
extensor carpi radialis longus action
Extend and abduct hand at the wrist joint; active during fist clenching
extensor carpi radialis longus innervation
Radial Nerve (C6,C7)
extensor carpi radialis brevis origin
Lateral epicondyle of humerus (common extensor origin)
extensor carpi radialis brevis insertion
Dorsal aspect of base of 3rd metacarpal
extensor carpi radialis brevis action
Extend and abduct hand at the wrist joint; active during fist clenching
extensor carpi radialis brevis innervation
Deep branch of radial nerve (C7,C8)
extensor digitorum origin
Lateral epicondyle of humerus (common extensor origin)
extensor digitorum insertion
Extensor expansions of medial four digits
extensor digitorum action
Extends medial four digits primarily at MCP joint, secondarily at IP joints
extensor digitorum innervation
Deep branch of radial nerve (C7,C8)
extensor digiti minimi origin
Lateral epicondyle of humerus (common extensor origin)
extensor digiti minimi insertion
Extensor expansion of 5th digit
extensor digiti minimi action
Extends 5th digit primarily at MCP joint, secondarily at IP joint
extensor digiti minimi innervation
Deep branch of radial nerve (C7,C8)
extensor carpi ulnaris origin
Lateral epicondyle of humerus: posterior border of ulna
extensor carpi ulnaris insertion
Dorsal aspect of base of 5th metacarpal
extensor carpi ulnaris action
Extends and adducts hand at wrist joint (Also active during fist clenching)
extensor carpi ulnaris innervation
Deep branch of radial nerve (C7,C8)
supinator origin
Lateral epicondyle of humerus; radial collateral and anular ligaments; supinator fossa; crest of ulna
supinator insertion
Lateral, posterior, and anterior surfaces of proximal third of radius
supinator action
Supinates forearm
supinator innervation
Deep branch of radial nerve (C7,C8)
abductor pollicis longus origin
Posterior surface of proximal halves of ulna, radius, and interosseus membrane
abductor pollicis longus insertion
Base of 1st metacarpal
abductor pollicis longus action
Abducts thumb and extends it at CMC joint
abductor pollicis longus innervation
Posterior interosseus nerve (C7,C8) as a continuation of deep branch of radial nerve
extensor pollicis brevis origin
Posterior surface of distal third of radius and interosseous membrane
extensor pollicis brevis insertion
Dorsal aspect of base of proximal phalanx of thumb
extensor pollicis brevis action
Extends proximal phalanx of thumb at MCP joint; extends CMC joint
extensor pollicis brevis innervation
Posterior interosseous nerve (C7,C8) as a continuation of deep branch of radial nerve
extensor pollicis longus origin
Posterior surface of middle third of ulna and interosseous membrane
extensor pollicis longus insertion
Dorsal aspect of base of distal phalanx of thumb
extensor pollicis longus action
Extends distal phalanx of thumb at IP joint; extends MCP and CMC joints
extensor pollicis longus innervation
Posterior interosseous nerve (C7,C8) as a continuation of deep branch of radial nerve
extensor indicis origin
Posterior surface of lateral third of ulna and interosseous membrane
extensor indicis insertion
Extensor expansion of 2nd digit
extensor indicis action
Extends 2nd digit; helps extend hand at wrist
extensor indicis innervation
Posterior interosseous nerve (C7,C8) as a continuation of deep branch of radial nerve
pronator teres origin
Ulnar Head: coronoid process
Humeral head: medial epicondyle (Common flexor origin)
pronator teres insertion
Middle convexity of lateral surface of radius
pronator teres action
Pronates and flexes forearm at elbow
pronator teres innervation
Median nerve (C6,C7,C8)