Forearm muscles Origins, Insertions, Actions Flashcards
Pronator teres
O: Humeral head - medial supracondylar ridge
Ulnar head - coronoid process
I: Lateral surface of radius distal to supinator insertion
A: Pronates forearm; assist forearm flexion
Flexor carpi radialis
O: Medial epicondyle of humerus
I: Base of 2nd and 3rd metacarpals
A: Flex wrist, radial deviation of hand, assist pronation & elbow flexion
Palmaris longus
O: Medial epicondyle of humerus
I: Palmar aponeurosis
A: Flex wrist, tighten palmar aponeurosis, assists elbow flexion
Flexor carpi ulnaris
O: Humeral head - medial epicondyle
Ulnar head - olecranon
I: Pisiform, hook of hamate, base of 5th metacarpal
A: Flex wrist, ulnar deviation of hand, assist elbow flexion
Flexor digitorum superficialis
O: Humero-ulnar head - medial epicondyle
Radial head - anterior upper 1/2 of radius
I: Splits to attach to lateral aspects of base of the middle phalanx of digits 2-5
A: Flex middle phalanges at PIP joint; assist MCP flexion & flexion at wrist, weak elbow flexor
Flexor digitorum profundus
O: Proximal 2/3 of anteromedial shaft of ulna & interosseus membrane
I: Base of the distal phalanx of digits 2-5
A: Flex DIP of fingers 2-5, secondary flexor at PIP & MCP joints; assists flexion at the wrist
Flexor pollicis longus
O: Middle anterior surface of radius & adjacent interosseus membrane
I: Base of distal phalanx of thumb (palmar)
A: Flex thumb at CMC, MCP, and IP joint
Pronator quadratus
O: Distal 1/4 of the anterior surface of the ulna
I: Distal 1/4 of the anterior surface of the radius
A: Pronate forearm, distal radioulnar stabilization
Brachioradialis
O: Lateral supracondylar ridge, intermuscular septum
I: Lateral side of distal radius (styloid process)
A: Flex elbow; assist pronation & supination (return to neutral)
Extensor carpi radialis longus
O: Lateral supracondylar ridge, lateral intermuscular septum
I: Dorsum of base of 2nd metacarpal
A: Extend wrist, radially deviate hand
Extensor carpi radialis brevis
O: Lateral epicondyle of humerus
I: Dorsum of base of 3rd metacarpal
A: Extend wrist; assist radial deviation of hand
Extensor digitorum
O: Lateral epicondyle of humerus (via common extensor tendon)
I: Extensor expansion of digits 2-5 (to proximal, middle, distant phalanges)
A: Extend at MCP & IP joints; assist extension at wrist
Extensor digiti minimi
O: Lateral epicondyle of humerus
I: Extensor expansion of pinky finger
A: Extension at MCP & IP joints of pinky finger; weak wrist extension, ulnar deviation and abduction of 5th digit
Extensor carpi ulnaris
O: Lateral epicondyle of humerus & midshaft of posterior ulna
I: Dorsum of base of 5th metacarpal
A: Extend & ulnarly deviate hand (at wrist)
Supinator
O: Lateral epicondyle of humerus, lateral collateral and annular ligaments, supinator crest of ulna (on olecranon)
I: Lateral and anterior surface of proximal 1/3 of radius
A: Supinate forearm