Superficial layer of muscles in the posterior compartment of the forearm

Question 1

Brachioradialis

Answer 1

Origin:

• Proximal part of lateral supraepicondylar ridge of humerus and adjacent inter muscular septum

Insertion:

• Lateral surface of distal end of the radius

Innervation:

• Radial nerve (C5,C6) before division into superficial and deep branches

Function:

• Accessory flexor of elbow joint when forearm is midpronated

Question 2

Extensor carpi radialis longus

Answer 2

Origin:

• Distal part of lateral supraepicondylar ridge of humerus
• Adjacent intermuscular spetum

Insertion:

• Dorsal surface of base of metacarpal II

Innervation:

• Radial nerve (C6, C7) before division into superficial and deep branches

Function:

• Extends and abducts the wrist

Question 3

Extensor carpi radialis brevis

Answer 3

Origin:

• Lateral epicondyle fo humerus and adjacent intermuscular septum

Insertion:

• Dorsal surface of base of metacarpal II and III

Innervation:

• Deep branch of radial nerve (C7, C8) before penetrating supinator muscle

Function:

• Extends and abducts the wrist

Question 4

Extensor digitorum

Answer 4

Origin:

• Lateral epicondyle of humorous
• Adjacent inter muscular septum and deep fascia

Insertion:

• Four tendons, which insert via extensor hoods into the dorsal aspects of the bases of the middle and distal phalanges of the index, middle, ring and little fingers

Innervation:

• Posterior interosseous nerve (C7, C8)

Function:

• Extends the index, middle, ring and little fingers, can also extend the wrist

Question 5

Extensor digiti minimi

Answer 5

Origin:

• Lateral epicondyle of humerus and adjacent inter muscular septum together with extensor digitorum

Insertion:

• Extensor hood of the little finger

Innervation:

• Posterior interosseous nerve (C7, C8)

Function:

• Extends the little finger

Question 6

Extensory carpi ulnaris

Answer 6

Origin:

• Lateral epicondyle of humorous and posterior border ulna

Insertion:

• Tubercle on the base of the medial side of the metacarpal V

Innervation:

• Posteriod interosseous nerve (C7, C8)

Function:

• Extends and adducts the wrist

Question 7

Anconeous

Answer 7

Origin:

• Lateral epcondyle of the humerus

Insertion:

• Olecranon and proximal posterior surface of ulna

Innervation:

• Radial nerve (C6, C7, C8) (via branch to medal head of triceps brachii)

Function:

• Abduction of the ulna in pronation; accessory extensor of the elbow joint

Question 8

Origin:

• Proximal part of lateral supraepicondylar ridge of humerus and adjacent inter muscular septum

Insertion:

• Lateral surface of distal end of the radius

Innervation:

• Radial nerve (C5,C6) before division into superficial and deep branches

Function:

• Accessory flexor of elbow joint when forearm is midpronated

Answer 8

Brachioradialis

Question 9

Origin:

• Distal part of lateral supraepicondylar ridge of humerus
• Adjacent intermuscular spetum

Insertion:

• Dorsal surface of base of metacarpal II

Innervation:

• Radial nerve (C6, C7) before division into superficial and deep branches

Function:

• Extends and abducts the wrist

Answer 9

Extensor carpi radialis longus

Question 10

Origin:

• Lateral epicondyle fo humerus and adjacent intermuscular septum

Insertion:

• Dorsal surface of base of metacarpal II and III

Innervation:

• Deep branch of radial nerve (C7, C8) before penetrating supinator muscle

Function:

• Extends and abducts the wrist

Answer 10

Extensor carpi radialis brevis

Question 11

Origin:

• Lateral epicondyle of humorous
• Adjacent inter muscular septum and deep fascia

Insertion:

• Four tendons, which insert via extensor hoods into the dorsal aspects of the bases of the middle and distal phalanges of the index, middle, ring and little fingers

Innervation:

• Posterior interosseous nerve (C7, C8)

Function:

• Extends the index, middle, ring and little fingers, can also extend the wrist

Answer 11

Extensor digitorum

Question 12

Origin:

• Lateral epicondyle of humerus and adjacent inter muscular septum together with extensor digitorum

Insertion:

• Extensor hood of the little finger

Innervation:

• Posterior interosseous nerve (C7, C8)

Function:

• Extends the little finger

Answer 12

Extensor digiti minimi

Question 13

Origin:

• Lateral epicondyle of humorous and posterior border ulna

Insertion:

• Tubercle on the base of the medial side of the metacarpal V

Innervation:

• Posteriod interosseous nerve (C7, C8)

Function:

• Extends and adducts the wrist

Answer 13

Extensory carpi ulnaris

Question 14

Origin:

• Lateral epcondyle of the humerus

Insertion:

• Olecranon and proximal posterior surface of ulna

Innervation:

• Radial nerve (C6, C7, C8) (via branch to medal head of triceps brachii)

Function:

• Abduction of the ulna in pronation; accessory extensor of the elbow joint

Answer 14

Anconeous