Posterior Forearm Flashcards
Anconeus
Attachments: lateral epicondyle of humerus, olecranon, and proximal, posterior surface of ulna
Action: assists triceps in extending elbow
Innervation: radial nerve
Blood supply: deep brachial artery
Brachioradialis
Attachments: Proximal part of lateral supracondylar ridge of humerus and distal end of radius
Action: accessory flexor of elbow when joint when forearm is midpronated (developmentally an extensor)
Innervation: radial nerve
Blood supply: radial recurrent artery
Extensor Carpi Radialis longus
Attachments: distal part of lateral supracondylar ridge of humerus and dorsal surface of base of metacarpal 2
Action: extends and abducts wrist
Innervation: radial nerve
Blood supply: radial artery
Extensor Carpi Radialis Brevis
Attachments: lateral epicondyle of humerus, dorsal surface of base of metacarpal 2 and 3
Action: extends and abducts wrist
Innervation: deep branch of radial nerve
Blood supply: radial artery
Extensor Digitorum
Attachments: lateral epicondyle of humerus, base of middle and distal phalanx of digits 2-5
Action: extends medial four fingers (extension of DIP joints (2-4), PIP joints (2-4), MP joints (2-4), and wrist) can also extend wrist
Innervation: posterior interosseous nerve
Blood supply: posterior interosseous artery
Extensor Digiti Minimi
Attachments: lateral epicondyle of humerus, extensor hood of 5th digit
Action: extends 5th digit
Innervation: posterior interosseous nerve
Blood supply: posterior interosseous artery
Extensor Carpi Ulnaris
Attachments: lateral epicondyle of humerus, and posterior border of ulna, dorsomedial aspect of the base of metacarpal 5
Action: extends and adducts wrist
Innervation: posterior interosseous nerve
Blood supply: posterior interosseous artery
Supinator
Attachments: lateral epicondyle of humerus, supinator crest of ulna, lateral surface of proximal radius
Action: supination
Innervation: posterior interosseous nerve, deep branch of radial nerve
Blood supply: radial recurrent artery, posterior interosseous artery
Abductor Pollicis Longus
Beware: this muscles tendon splits in two
Attachments: posterior surfaces of ulna and radius, base of metacarpal 1
Action: abducts 1st metacarpal (carpometacarpal joint of thumb_ accessory extensor of thumb
Innervation: posterior interosseous nerve
Blood supply: posterior interosseous artery
Extensor Pollicus Brevis
Attachments: posterior surface of radius and adjacent interosseous membrane, dorsal surface of base of proximal phalanx of thumb
Action: extends metacarpophalangeal joint of thumb, can also extend carpometacarpal joint of thumb
Innervation: posterior interosseous nerve
Blood supply: posterior interosseous artery
Extensor Pollicus Longus
Attachments: posterior surface of ulna adjacent interosseous membrane, and dorsal surface of base of distal phalanx of thumb
Action: extends interphalangeal joint of thumb, can also extend carpometacarpal and metacarpophalangeal joints of thumb
Innervation: posterior interosseous nerve
Blood supply: posterior interosseous artery
Extensor Indicis
Attachments: posterior surface of ulna and adjacent interosseous membrane, extensor hood of index finger
Action: extends index finger
Innervation: posterior interosseous membrane
Blood supply: posterior interosseous artery
