Forearm muscles - Anterior compartment

Question 1

Intermuscular septum function?

Answer 1

Divides forearm into anterior & posterior compartments

Question 2

How many layers in the anterior/flexor compartment?

Answer 2

1. superficial layer (4)
2. intermediate layer (1)
3. deep layer (3)

Question 3

M. in the superficial layer?

Answer 3

1. Prontator Teres
2. Flexor carpi radialis
3. Palmaris Longus
4. Flexor Carpi Ulnaris

Question 4

M. in the intermediate layer?

Answer 4

1. Flexor digitorum superficialis

Question 5

M. in the deep layer?

Answer 5

1. Flexor Pollicis longus
2. Flexor digitorum profundus
3. Pronator Quadratus

Question 6

Nerve innervation of the anterior forearm compartment ?

Answer 6

Median N

Except FCU & FDP = ulnar n.

Question 7

Primary actions for anterior forearm muscles (3)?

Answer 7

1. wrist flexion
2. digit flexion
3. protonation

Question 8

common origin of anterior forearm muscles?

Answer 8

medial epicondyle via common flexor tendon
(superficial & intermediate layers)

Question 9

flexor retinaculum?

Answer 9

-holds most tendons from anterior forearm compartment
-fascia that thickens anteriorly, wall of carpal tunnel
FUNCTION: prevents bowstringing of the tendons when hand is flexed

**same for extensor except called extensor retinaculum & thickens posteriorly over distal ends of radius & ulna

Question 10

Pronator teres O, I, Function? (2 heads)

Answer 10

O:
humeral head: medial epicondyle CFT
ulnar head: coronoid process
I: Radius
Function:
1. Protonation
2. Flex forearm (weak)

Question 11

Protonator syndrome?

Answer 11

impeachment of median N. between 2 heads

Question 12

Flexor Carpi Radialis O, I & function?

Answer 12

O: medial epicondyle via CFT
I: base of 2 & 3 metacarpals

Function:
1. Flex wrist
2. Flex forearm (weak)
3. Radial deviation

Question 13

Radial a pulse is lateral to?

Answer 13

flexor carpi radialis

Question 14

Palmaris longus O, I, & function?

Answer 14

O: Medial epicondyle CFT
I: Palmar aponeurosis & flexor retinaculum

Function:
1. Flex wrist
2. Flex Forearm (weak)

Question 15

What percent of the population is palmaris longus absent in?

Answer 15

12-20%, one or both sides

Question 16

Flexor Carpi Ulnaris O, I & function? (2 heads)

Answer 16

O:
Humeral head: Medial epicondyle via CFT
Ulnar head: Olecranon & post border of ulna

I: Base of 5th metacarpal, hook of hamate & pisiform

Function:
1. Flex wrist
2. Ulnar deviate
3. Flex forearm (weak)

Question 17

What nerve innervates FCU?

Answer 17

Exception: Innervated by ulnar n. & travels between its 2 heads.

**rest of anterior forearm is median n.

Question 18

Flexor digitorum superficialis O, I & function? (2 heads)

Answer 18

O:
Humero-ulnar head: Medial epicondyle via CFT
Radial head: Radius

I: Base of middle phalanges 2-5

Function:
1. Flex wrist
2. flex digits 2-5 @ MCP & PIP joints
3. Forearm flexion (weak)

Question 19

FDS note?

Answer 19

irritation in tendon health can occur and will press on median n in carpal tunnel

Question 20

Flexor Digitorum Profundus O, I & Function?

Answer 20

O: Ulna & interosseous membrane
I: Base of distal phalanges (2-5)

Function:
1. Flex wrist
2. Flex phalanges & MCP, PIP & DIP joints

Question 21

FDP notes(2)?

Answer 21

Dual innervation:
Phalanges 2 & 3 = median n.
Phalanges 4 & 5 = ulnar n.

and in carpal tunnel

Question 22

Flexor Pollicis Longus O, I, & Function?

Answer 22

O: Radius & Interosseous membrane
I: Base of distal phalanx

Function:
1. flex wrist
2. flex thumb @ CMC, MCP, IP Joints

Question 23

FPL notes?

Answer 23

in carpal tunnel

Question 24

Pronator quadratus O, I & function?

Answer 24

O: Ulna
I: Radius
F: protonation