Forearm Extensors Flashcards
Two groups of Forearm extensors (All posterior)
Origins?
Innervation?
Superficial (BR, ECRL, ECRB, EF, EDM, ECU, Anconeous) - Origin at lateral epicondyle
Deep:
Supinator, APL, EPB, EPL, EI) Origin elsewhere - Not at lateral epo
Innervation: Radial nerve
Brachioradialis origin
Proximal 2/3s of supracondylar ridge
Brachioradialis insertion
Lateral surface of distal end of radius
Brachioradialis innervation
Radial
Brachioradialis blood supply
Radial recurrent artery
Brachioradialis action
Flexion of the forearm
Muscles that extend and abduct or adduct the hand at the wrist joint: (3)
ECRB, ECRL, ECU
Muscles that extend the medial 4 digits: (3)
Extensor digitorum, extensor indicis, extensor digiti minimi
Muscles that extend or abduct the thumb: (3)
Abductor pollicis longus, extensor policis brevis, extensor pollicis longus
Extensor tendons are held in place by? Prevents? Covered by?
- Extensor retinaculum
- Bowstringing at the tendons that pass over the dorsum of the wrist
- Covered by synovial tendons sheaths that reduce friction
Four superficial extensors are attached by?
Lateral epicondyle
Which muscle is the “drinking muscle”?
Brachioradialis
Extensor capri radialis longus origin
Lateral supracondylar ridge of humerus, lateral intramuscular septum, and lateral epicondyle
Extensor capri radialis longus insertion
Base of 2nd metacarpal
Extensor capri radialis longus innervation
Radial nerve
Extensor capri radialis longus action
Extension of hand at wrist and radial deviation
Extensor carpi radialis brevis innervation
Radial nerve
Extensor carpi radialis brevis action
Extension of hand at wrist
Extensor digitorum insertion
Middle and distal phalanges
Extensor digitorum action
Extend all joints of fingers
When can Extensor digitorum not end all joint of fingers?
Can only extend IP joints when MP joints are not hyperextended
Extensor Digiti Minimi, digitorum and carpi radialis brevis origin
Lateral epicondyle, intermuscular septa and antebrachial fascia
Extensor carpi ulnaris origin
Lateral epicondyle and more than 1/2 of proximal posterior border of ulna
Extensor carpi ulnaris insertion
Base of metacarpal of 5th digit
Extensor carpi ulnaris innervation
Radial
Extensor carpi ulnaris action
Aids in extension and ulnar deviation of hand at wrist
Extensor digitorum origin
Lateral epicondyle, intermuscular septa and antebrachial fascia
Extensor carpi radialis origin
Lateral epicondyle, intermuscular septa and antebrachial fascia
