Forearm Flashcards
What is the insertion of pronator teres?
Middle of convexity of lateral surface of radius
What is the origin of pronator teres?
Ulnar head: coronoid process of ulna
Humeral head: medial epicondyle of humerus
What innervates pronator teres?
Median nerve (C6, C7)
What is the action of pronator teres?
Pronates and flexes forearm
What is the origin of flexor carpi radialis?
Medial epicondyle of humerus
What is the insertion of flexor carpi radialis?
Base of 2nd (3rd) metacarpal
What innervates flexor carpi radialis?
Median nerve (C6, C7)
What is the action of flexor carpi radialis?
Flexes and abducts hand at wrist
What is the origin of palmaris longus?
Medial epicondyle of humerus
What is the insertion of palmaris longus?
Distal half of flexor retinaculum, palmar aponeurosis
What innervates palmaris longus?
Median nerve (C7, C8)
What is the action of palmaris longus?
Flexes hand (at wrist) and tenses palmar aponeurosis
What is the origin of flexor carpi ulnaris?
Olecranon and posterior border of ulna (via aponeurosis)
What is the insertion of flexor carpi ulnaris?
Pisiform, hook of hamate, 5th metacarpal
What innervates flexor carpi ulnaris?
Ulnar nerve (C7, C8)
What is the action of flexor carpi ulnaris?
Flexes & adducts hand at wrist
What is the origin of flexor digitorum superficialis?
Humero-ulnar head: medial epicondyle of humerus & coronoid process of ulna
Radial head: oblique line of radius
What is the insertion of flexor digitorum superficialis?
Shafts (bodies) of middle phalanges of medial four digits
What innervates flexor digitorum superficialis?
Median nerve (C7, C8, T1)
What is the action of flexor digitorum superficialis?
Flexes wrist joint, proximal interphalangeal joints of middle four digits, & proximal phalanges at metacarpophalangeal joints
What is the origin of flexor digitorum profundus?
Proximal three quarters of medial and anterior surfaces of ulna and interosseous membrane
What is the insertion of flexor digitorum profundus?
Bases of distal phalanges of 2nd, 3rd, 4th, & 5th digits
What innervates flexor digitorum profundus?
Lateral part (digits 2 & 3): median nerve (C8, T1) (anterior interosseous branch) Medial part (digits 4 & 5): ulnar nerve (C8, T1)
What is the action of flexor digitorum profundus?
Flexes wrist joint; flexes distal interphalangeal joints of 2, 3, 4, & 5; assists with wrist flexion
What is the origin of flexor pollicis longus?
Anterior surface of radius and adjacent interosseous membrance
What is the insertion of flexor pollicis longus?
Base of distal phalanx of thumb
What innervates flexor pollicis longus?
Anterior interosseous nerve, from median nerve (C8, T1)
What is the action of flexor pollicis longus?
Flexes wrist; flexes metacarpophalangeal and interphalangeal joints of thumb
What is the origin of pronator quadratus?
Distal quarter of anterior surface of ulna
What is the insertion of pronator quadratus?
Distal quarter of anterior surface of radius
What innervates pronator quadratus?
Anterior interosseous nerve, from median nerve (C8, T1)
What is the action of pronator quadratus?
Pronates forearm; deep fibers bind radius & ulna together
What is the origin of brachioradialis?
Proximal two thirds of lateral supra-epicondylar ridge of humerus
What is the insertion of brachioradialis?
Lateral surface of distal end of radius proximal to styloid process
What innervates brachioradialis?
Radial nerve (C5, C6, C7)
What is the action of brachioradialis?
Weak flexion of elbow joint, maximal when forearm is in mid-pronated position
What is the origin of extensor carpi radialis longus?
Lateral supra-epicondylar ridge of humerus
What is the insertion of extensor carpi radialis longus?
Dorsal aspect of base of 2nd metacarpal
What innervates extensor carpi radialis longus?
Radial nerve (C6, C7)
What is the action of extensor carpi radialis longus?
Extend and abduct wrist joint
What is the origin of extensor carpi radialis brevis?
Lateral epicondyle of humerus (common extensor origin)
What is the insertion of extensor carpi radialis brevis?
Dorsal aspect of base of 3rd metacarpal
What innervates extensor carpi radialis brevis?
Deep branch of radial nerve (C7, C8)
What is the action of extensor carpi radialis brevis?
Extend and abduct wrist joint; active during fist clenching
What is the origin of extensor digitorum?
Lateral epicondyle of humerus (common extensor origin)
What is the insertion of extensor digitorum?
Extensor expansions of medial four fingers
What innervates extensor digitorum?
Posterior interosseous nerve (C7, C8), continuation of deep branch of radial nerve
What is the action of extensor digitorum?
Extend wrist joint; extend medial four fingers primarily at metacarpophalangeal joints, secondarily at interphalangeal joints
What is the origin of extensor digiti minimi?
Lateral epicondyle of humerus (common extensor origin)
What is the insertion of extensor digiti minimi?
Extensor expansion of 5th finger
What innervates extensor digiti minimi?
Posterior interosseous nerve (C7, C8), continuation of deep branch of radial nerve
What is the action of extensor digiti minimi?
Extends wrist joint; extends 5th finger primarily at metacarpophalangeal joint, secondarily at interphalangeal joint
What is the origin of extensor carpi ulnaris?
Lateral epicondyle of humerus; posterior border of ulna via shared aponeurosis
What is the insertion of extensor carpi ulnaris?
Dorsal aspect of base of 5th metacarpal
What innervates extensor carpi ulnaris?
Posterior interosseous nerve (C7, C8), continuation of deep branch of radial nerve
What is the action of extensor carpi ulnaris?
Extends and adducts wrist joint (also active during fist clenching)
What is the origin of supinator?
Lateral epicondyle of humerus, radial collateral and anular ligaments, supinator fossa, crest of ulna
What is the insertion of supinator?
Lateral, posterior, and anterior surfaces of proximal third of radius
What innervates supinator?
Deep branch of radial nerve (C7, C8)
What is the action of supinator?
Supinates forearm; rotates radius to turn palm anteriorly or superiorly (if elbow is flexed)
What is the origin of abductor pollicis longus?
Posterior surface of proximal halves of ulna, radius, and interosseous membrane
What is the insertion of abductor pollicis longus?
Base of 1st metacarpal
What innervates abductor pollicis longus?
Posterior interosseous nerve (C7, C8), continuation of deep branch of radial nerve
What is the action of abductor pollicis longus?
Extends wrist joint; abducts thumb and extends it at carpometacarpal joint
What is the origin of extensor pollicis longus?
Posterior surface of middle third of ulna and interosseous membrane
What is the insertion of extensor pollicis longus?
Dorsal aspect of base of distal phalanx of thumb
What innervates extensor pollicis longus?
Posterior interosseous nerve (C7, C8) continuation of deep branch of radial nerve
What is the action of extensor pollicis longus?
Extends wrist joint; extends distal phalanx of thumb at interphalangeal joint; extends metacarpophalangeal and carpometacarpal joints
What is the origin of extensor pollicis brevis?
Posterior surface of distal third of radius and interosseous membrane
What is the insertion of extensor pollicis brevis?
Dorsal aspect of base of proximal phalanx of thumb
What innervates extensor pollicis brevis?
Posterior interosseous nerve (C7, C8) continuation of deep branch of radial nerve
What is the action of extensor pollicis brevis?
Extends wrist joint; extends proximal phalanx of thumb at metacarpophalangeal joint; extends carpometacarpal joint
What is the origin of extensor indicis?
Posterior surface of distal third of ulna and interosseous membrane
What is the insertion of extensor indicis?
Extensor expansion of 2nd finger
What innervates extensor indicis?
Posterior interosseous nerve (C7, C8) continuation of deep branch of radial nerve
What is the action of extensor indicis?
Extends wrist joint; extends 2nd finger (enabling its independent extension); helps extend hand at wrist