Posterior Forearm And Hand

Question 1

What is the common extensor origin and what muscles take origin from it?

Answer 1

Common extensor origin = LATERAL EPICONDYLE

extensor carpi radialis brevis
Extensor digitorum
Extensor carpi ulnaris
Extensor digiti minimi

Question 2

What is the origin of the extensor carpi radialis longus muscle?

Answer 2

Lateral supracondylar ridge

Question 3

What nerve supplies the superficial extensors?

Answer 3

Extensor carpi radialis longus = RADIAL NERVE

Rest = POSTERIOR INTEROSSEUS BRANCH of radial nerve

Question 4

What is wrist drop?

Answer 4

Paralysis of the radial nerve which causes paralysis of the extensor muscles in the wrist. Flexor bring the wrist into a flexed position.

Question 5

What are the deep extensor muscles of the forearm?

Answer 5

Long abductor
Extensors of thumb
Extensor indicis

Question 6

Where does the extensor pollicis longus lie?

Answer 6

Winds round Lister’s tubercle (dorsal tubercle) of radius and inserts into distal phalanx of thumb

Question 7

What is the extensor indicis?

Answer 7

Additional extensor for index finger. It’s tendon joins the ulnar side of the extensor digitorum of the index finger

Question 8

Where does the supinator lie and what is it closely related to?

Answer 8

Covers the upper part of the back of the radius and inserts into its posterolateral aspect
Closely related to RADIAL NERVE - the posterior interosseous branch passes through the supinator and supplies extensors of forearm

Question 9

What does the supinator do?

Answer 9

Supinator forearm in extended position