Muscles of the posterior compartment of the forearm Flashcards Preview

MSK anatomy > Muscles of the posterior compartment of the forearm > Flashcards

Flashcards in Muscles of the posterior compartment of the forearm Deck (38)
Loading flashcards...
1

What are the superficial muscles of the posterior compartment of the forearm?

Brachioradialis, extensor carpi radialis longus and brevis, extensor digitorum, extensor digit minimi, extensor carpi ulnaris, anconeus.

2

Why is the brachioradialis a paradoxical muscle?

It's origin and innervation are characteristic of an extensor muscle, but it is actually a flexor muscle at the elbow.

3

When is the brachioradialis most visible?

Forearm half pronated and flexing at the elbow against resistance.

4

Brachioradialis attachments

Origionates from the proximal aspect of the lateral supracondylar ridge of humerus, and attaches to the distal end of the radius, just before the radialstyloid process.

5

Brachioradialis actions

Flexes at the elbow

6

Brachioraialis innervation

Radial nerve

7

Extensor carpi radialis longus and brevis attachments

The ECRL origionates from the supracondylar ridge, while the ECRB origionaes from the lateral epicondyle. Their tendons attach to metacarpals II and III.

8

Extensor carpi radialis longus and brevis actions

Extends and abducts the wrist

9

Extensor carpi radialis longus and brevis innervation

Radial nerve

10

Extensor digitorum attachments

Origionates from the lateral epicondyle. The tendon continues into the distal part of the forearm, where it splits into four and inserts into the extenor hood of each finger.

11

Extensor digitorum actions

Extends the medial four fingers and the MCP and IP joints

12

Extensor digitorum innervation

Deep branch of the radial nerve

13

Extensor digit minimi attachments

Origionates from the lateral epicondyle of the humerus. It attaches, with the extensor digitorum tendon, into the extensor hood of the little finger.

14

Extensor digit minimi actions

Extends the little finger and contributes to extension at the wrist.

15

Extension digit minimi innervation

Deep branch of the radial nerve

16

Extensor carpi ulnaris attchments

Origionates from the lateral epicondyle of the humerus, and attaches to the base of metacrpal V.

17

Extensor carpi ulnaris actions

Extension and adduction of the wrist

18

Extensor carpi ulnaris innervation

Deep branch of radial nerve

19

Anconeus attachments

Origionates from the lateral epicondyle, and attaches to the posterior and lateral part of the olecranon.

20

Anconeus actions

Extends and stabilises the elbow joint. Abducts the ulna during pronation of the forearm.

21

Anconeus innervation

Radial nerve

22

What are the deep muscles of the posterior forearm?

Supinator, abductor pollicus longus, extensor pollicus brevis, extensor pollicus longus and extensor indicis proprius.

23

Supinator attachments

It has two heads of origin. One origionates from the lateral epicondyle of the humerus, the other from the posterior surface of the ulna. They insert together into the posterior surface of the radius.

24

Supinator actions

Supinates the forearm

25

Supinator innervation

Deep branch of radial nerve

26

Abductor pollicus longus attachments

Origionates from the interosseous membrane and the adjacent posterior surfaces of the radius and ulna. It attaches to the lateral side of the base of metacaroal I.

27

Abductor pollicus longus actions

Abducts the thumb

28

Abductor pollicus longus innervation

Posterior interosseous branch of the radial nerve

29

Extensor pollicus brevis attachments

Origionates from the posterior surface of the radius and interosseus membrane. It attaches to the base of the proximal phalanx of the thumb.

30

Extensor pollicus brevis actions

Extends the metacarpophalangeal and carpometacarpal joints of the thumb