5 Forearm

Question 1

Interosseous membrane:
1. holds … together
2. site of attachment for …
3. transfers forces from …. to ….
4. holes for …

Answer 1

1. radius and ulna
2. muscles
3. radius , ulna
4. vessels

Question 2

Which muscle attaches to radial tuberosity ?

Answer 2

biceps brachii

Question 3

Which muscle attaches to tuberosity of ulna ?

Answer 3

brachialis

Question 4

How can fracture of olecranon occurr ?

Answer 4

• direct trauma
• avulsion by triceps

Question 5

radioulnar joints permit action?

Answer 5

pronation & supination

Question 6

supination is controlled by what muscles ?

Answer 6

biceps
supinator

Question 7

What articulates with radius ?

Answer 7

scaphoid & lunate

Question 8

Forearm 2 compartments ?

Answer 8

anterior - flexor & pronator , mostly median n. some ulnar n.
posterior - extensor, supinator & thumb abductor, all radial n. or its posterior interosseous branch

Question 9

Anterior compartment of superficial forearm muscles ? & function & nerve

Answer 9

• all median nerve apart from flexor carpi ulnaris
• pronator teres - forearm pronator
• flexor carpi radialis - wrist flexor & abductor - laterally at wrist
• flexor carpi ulnaris - wrist flexor & abductor - medially at wrist
• palmaris longus - wrist flexor
• flexor digitorum superficialis - finger flexor to PIP, attachments to radius & ulna

Question 10

superficial muscles of forearm involved in wrist flexion ?

Answer 10

• flexor carpi radialis
• flexor carpi ulnaris
• palmaris longus

Question 11

Forearm anterior compartment deep muscles ? & function & nerve

Answer 11

• flexor pollicis longus - median n. = thumb flexor to DIP
• flexor digitorum profundus - 1/2 median & 1/2 ulnar n. = finger flexor to DIP
• pronator quadratus - median n. = foerarm pronator

Question 12

Differences between testing of flexor digitorum superficialis & flexor digitorum profundus ?

Answer 12

• FDS: flexion at PIP joint
• FDP: only forearm flexor that flexes at DIP joints

Question 13

Lateral epicondyle forms a common extensor origin for which tendons of foerarm ?

Answer 13

• Extensor digitorum
• Extensor carpi radialis brevis
• Extensor digiti minimi
• Extensory carpi ulnaris

Question 14

1st layer Posterior compartment forearm muscles & function

Answer 14

• anconeus = elbow extensor
• extensor digitorum = finger extensor to DIP
• extensor digiti minim = 5th digit extensor to DIP
• extensor carpii ulnaris = wrist extensor & adductor
• Extensor carpi radialis longus & brevis = wrist extensor & abductor

Question 15

Difference between action of extensor carpi radialis brevis & longus and extensor carpi ulnaris ?

Answer 15

both wrist extensor but carpi ulnaris adductor whilst radialis brevis / longus is abductor

Question 16

Regional inflammation & pain/ tenderness of lateral epicondyle suggests what ?

Answer 16

lateral epicondylitis (tennis elbow)

Question 17

2nd layer Posterior compartment forearm muscles & function

Answer 17

• supinator = forearm supination
• extensor pollicis longus = thumb extension
• extensor pollicis brevis = thumb extension
• extensor indicis = extension of 2nd digit
• abductor pollicis longus = thumb abduction

Question 18

What are contents of cubital fossa from lateral to medial ?

Answer 18

radial nerve, biceps tendon, brachial artery, median nerve

ulnar nerve is not included in contents of cubital fossa