Posterior forearm extensors

Question 1

Brachioradialis

Answer 1

Origin: Supracondylar humerus
Insertion: Distal radius
Innervation: Radial nerve
Action: Flex elbow

Question 2

Extensor carpi radialis longus and brevis

Answer 2

Origin: ECRL = Supracondylar humerus ECRB = Lateral epicondyle
Insertion: Metacarpals 2 & 3
Innervation: Radial nerve
Action: Extend + abduct wrist

Question 3

Extensor digitorum communis

Answer 3

Origin: Lateral epicondyle
Insertion: Extensor hood all four digits
Innervation: Radial nerve
Action: Extend medial four fingers and wrist

Question 4

Extensor digiti minimi

Answer 4

Origin: Lateral epicondyle
Insertion: LF extensor hood
Innervation: Radial nerve
Action: Extend LF + wrist

Question 5

Extensor carpi ulnaris

Answer 5

Origin: Lateral epicondyle
Insertion: 5th metacarpal
Innervation: Radial nerve
Action: Wrist flexion + adduction

Question 6

Anconeus

Answer 6

Origin: Lateral epicondyle
Insertion: Olecranon
Innervation: Radial nerve
Action: Elbow stability

Question 7

Supinator

Answer 7

Origin: Lateral epicondyle + Ulna
Insertion: Posterior radius
Innervation: Radial nerve
Action: Supination of forearm

Question 8

Abductor pollicis longus

Answer 8

Origin: Interosseous membrane + Ulna
Insertion: base of 1st metacarpal
Innervation: Radial nerve
Action: Abduct thumb

Question 9

Extensor pollicis brevis

Answer 9

Origin: Distal radius
Insertion: Base of proximal thumb
Innervation: Radial nerve
Action: Extend proximal thumb

Question 10

Extensor pollicis longus

Answer 10

Origin: Ulna
Insertion: Base of distal thumb
Innervation: Radial nerve
Action: Extend distal thumb

Question 11

Extensor Indicis Proprius

Answer 11

Origin: Distal Ulna + Interosseous membrane
Insertion: Extensor hood of the index finger
Innervation: Radial nerve
Action: Extend 2nd digit to help wrist flexion