Muscles of the Posterior Forearm-Superficial Layer

Question 1

brachioradialis

Answer 1

origin: lateral epicondyle and supracondylar ridge of the humerus
insertion: styloid process of the radius
innervation: radial nerve (C5-T1)
action: flexion at the elbow joint

Question 2

extensor carpi radialis longus

Answer 2

origin: lateral epicondyle and supracondylar ridge of the humerus
insertion: base of the 2nd metacarpal
innervation: radial nerve (C5-T1)
action: extension at the wrist joint, abduction at the wrist

Question 3

extensor carpi radialis brevis

Answer 3

origin: lateral epicondyle and supracondylar ridge of the humerus
insertion: base of the 3rd metacarpal
innervation: deep radial n.
action: extension at the wrist joint, abduction at the wrist

Question 4

extensor digitorum

Answer 4

origin: lateral epicondyle and supracondylar ridge of the humerus
insertion: middle and distal phalanges of digits 2-5 via extensor expansion
innervation: posterior interosseus n.
action: extension of the MP joint of digits 2-5

Question 5

extensor digiti minimi

Answer 5

origin: lateral epicondyle and supracondylar ridge of the humerus
insertion: extensor expansion
innervation: posterior interosseus n.
action: extension of the MP joint of digit 5

Question 6

extensor carpi ulnaris

Answer 6

origin: lateral epicondyle and supracondylar ridge of the humerus
insertion: base of the 5th metacarpal
innervation: posterior interosseus n.
action: extension at the wrist joint, adduction at the wrist