Posterior/Dorsal Forearm

Question 1

Abductor pollicis longus

Answer 1

Attaches to the flexor retinaculum, tubercles of scaphoid and trapezium to base of the 1st met
Innervated by the radial N (posterior interosseus)
Actions: abducts and extends thumb at the CMC joint

Question 2

Brachioradialis

Answer 2

Attaches to the proximal 2/3 of lateral supracondylar ridge to the lateral side of the distal radius
Innervated by the radial N
Actions: weak flex of the forearm when it is in neutral

Question 3

ECRB

Answer 3

Attaches to the lateral epicondyle to dorsal base of the 2nd/3rd met
Innervated by the deep branch of the radial N
Actions: extends and abducts hand at the wrist

Question 4

ECRL

Answer 4

Attaches to the distal 1/3 of the lateral supracondylar ridge to the dorsal base of the 2nd/3rd met
Innervated by the radial N
Actions: extends and abducts hand at wrist

Question 5

ECU

Answer 5

Attaches to the lateral epicondyle of the humerus and posterior ulna t the dorsal base of the 5th met
Innervated by the radial N (posterior interosseus)
Actions: extends and adducts hand at wrist

Question 6

EDM

Answer 6

Attaches to the lateral epicondyle to the extensor expansion of the 5th digit
Innervated by the radial N (posterior interosseus)
Actions: extends 5th digit

Question 7

Extensor digitorum

Answer 7

Attaches to the lateral epicondyle to the extensor expansions of medial 4 digits
Innervated by the radial N (posterior interosseus)
Actions: extends medial 4 digits, assists in wrist ext

Question 8

Extensor indicis

Answer 8

Attaches to the posterior ulna and interosseus membrane and extensor expansion of the 2nd digit
Innervated by the radial N (posterior interosseus)
Actions: extends 2nd digit and helps extend hand at wrist

Question 9

Extensor pollicis brevis

Answer 9

Attaches to the posterior radius and interosseous membrane to the dorsal base