The anterior compartment of the forearm - superficial muscles (dave's notes)

Question 1

List the superficial muscles of the forearm

Answer 1

Pronator teres 
Flexor carpi radialis
Flexor digitorum superficialis
Palmaris longus
Flexor carpi ulnaris

Question 2

What is the origin of pronator teres?

Answer 2

Humeral head: medial epicondyle, medial supracondylar ridge and medial intermuscular septum
Ulnar head: medial border of coronoid process

Question 3

What is the insertion of pronator teres?

Answer 3

Just posterior to the most prominent part of the lateral convexity of the radius

Question 4

What is the action and innervation of pronator teres?

Answer 4

Pronates forearm and flexes elbow.

Median nerve C6,7 from the lateral and medial cords

Question 5

What passes between the two heads of pronator teres?

Answer 5

The median nerve

Question 6

What forms the medial border of the cubital fossa?

Answer 6

Pronator teres

Question 7

Flexor muscles of the forearm are arranged in groups of ………… muscles that ……. the ………, and deep muscles that … …… . There are …….. wrist flexors, ……… digit flexors, and ….. pronators

Answer 7

superficial muscles that cross the elbow, and deep muscles that do not. There are 3 wrist flexors, 3 digit flexors, and 2 pronators.

Question 8

What is the origin and insertion of flexor carpi radialis?

Answer 8

Origin: the common flexor origin - a smooth area on the anterior surface of the medial epicondyle

Question 9

Where is the common flexor origin? Which muscles originate here?

Answer 9

A smooth area on the anterior surface of the medial epicondyle
FCR
PT
FDS
Palmaris longus
FCU

Question 10

What is the action and nerve supply of flexor carpi radialis?

Answer 10

Flexes and abducts wrist

Median nerve C6,7 from lateral and medial cords

Question 11

What is the origin of flexor digitorum superficialis?

Answer 11

Humeral head: common flexor origin, medial ligament of elbow,
Ulnar head: sublime tubercle and fibrous arch
Radial head: Whole length of anterior oblique line

Question 12

What is the insertion of flexor digitorum superficialis?

Answer 12

Tendons split to insert onto sides of the middle phalanges of the medial four fingers

Question 13

What is the action and innervation of flexor digitorum superficialis?

Answer 13

Flexes the proximal interphalangeal joints and the MCP/Wrist.
Nerve is the median nerve (C7,8,T1) from the medial and lateral cords

Question 14

What nerve is closely related to flexor digitorum superficialis and how?

Answer 14

The median nerve is applied to the under surface of the muscle

Question 15

What is the origin and insertion of palmaris longus?

Answer 15

The common flexor origin and the medial epicondyle of humerus
Inserts into the flexor retinaculum and palmar aponeurosis

Question 16

What is the action and innervation of palmaris longus?

Answer 16

Palmaris longus flexes the wrist and tenses the palmar aponeurosis
Supplied by the median nerve C7,8 from the lateral and medial cords

Question 17

Which muscle is sometimes absent from the anterior compartment of the forearm? How often?

Answer 17

Palmaris longus, 13% of individuals

Question 18

What is the origin and insertion of flexor carpi ulnaris?

Answer 18

Origin: Humeral head originates from the common flexor origin and the ulnar head from the medial olecranon and upper 3/4 of ulna
Insertion: Pisiform, hook of the hamate, base of the fifth metacarpal via pisometacarpal and pisohamate ligaments

Question 19

What is the action and innervation of flexor carpi ulnaris?

Answer 19

Flexes and adducts wrist. Fixes pisiform during action of hypothenar muscles.
Innervated by the ULNAR NERVE C7,8, T1, lateral cord

Question 20

What nerve is closely associated with flexor carpi ulnaris and how?

Answer 20

The ulnar nerve passes between the two heads.

Question 21

If you place the heel of the palm of the hand over the opposite medial epicondyle, palm lying on the forearm, the digits point to the five superficial muscles. Name the muscle for each digit.

Answer 21

Thumb - pronator teres
Index - flexor carpi radialis
Middle - FDS
Ring - Palmaris longus
Little - FCU