Superficial Muscles of Posterior Forearm

Question 0

Extensor Carpi Radialis Longus

Answer 0

Origin: Lateral Supracondylar Ridge of Humerus
Insertion: Base of 2nd Metacarpal
Action: Extends and Abducts (Radially Deviates) Wrist; Weakly Flexes Forearm
Nerve: Radial

Question 1

Brachioradialis

Answer 1

Origin: Lateral Supracondyle ridge of Humerus
Insertion: Distal Radius Styloid Process
Action: Semipronation; Flexes forearm when forearm in mid-prone position
Nerve: Radial

Question 2

Extensor Carpi Radialis Brevis

Answer 2

Origin: Lateral Epicondyle of Humerus
Insertion: Base of 3rd Metacarpal
Action: Extends and Abducts (Radially Deviates) Wrist
Nerve: Radial

Question 3

Extensor Digitorum

Answer 3

Origin: Lateral Epicondyle of Humerus
Insertion: Medial and Distal Phalanges of Digits 2-5 via extensor expansions
Action: Extends digits 2-5 at MP, PIP, and DIP joints and extends hand at wrist
Nerve: Radial (via Deep Branch)

Question 4

Extensor Digiti Minimi

Answer 4

Origin: Lateral Epicondyle of Humerus
Insertion: Medial and Distal Phalanges of 5th Digit via extensor expansion
Action: Extends 5th Digit and wrist
Nerve: Radial (via deep branch)

Question 5

Extensor Carpi Ulnaris

Answer 5

Origin: Lateral Epicondyle of Humerus (Common Head), Ulnar Mid-shaft
Insertion: Base of 5th Metacarpal
Action: Extends and Adducts (ulnar deviates) Wrist
Nerve: Radial (via Deep Branch)