Muscles: Deep Layer

Question 1

Supinator: O&I

Answer 1

O: From lateral epicondyle and ulna, wraps around radius
I: On Medial surface of radius

Question 2

Supinator: Innervation

Answer 2

Innervated by deep branch of radial nerve

Question 3

Abductor Pollicis Longus: O&I

Answer 3

O: From radius and ulna
I: On base of 1st metacarpal

Question 4

Abductor Pollicis Longus: Pathway and Innervation

Answer 4

Passes through 1st compartment under extensor retinaculum

Innervated by posterior interosseous nerve

Question 5

Extensor Pollicis Brevis: O&I

Answer 5

O: From radius
I: On proximal phalanx of thumb

Question 6

Extensor Pollicis Brevis: Pathway and Innervation

Answer 6

Passes through 1st compartment under extensor retinaculum

Innervated by posterior interosseous nerve

Question 7

Extensor Pollicis Longus: O&I

Answer 7

O: From ulna
I: On base of distal phalanx of thumb

Question 8

Extensor Pollicis Longus: Pathway and Innervation

Answer 8

Passes through 3rd compartment and changes direction at the dorsal radial tubercle (Lister’s Tubercle)

Innervated by posterior interosseous nerve

Question 9

Extensor Indicis: O&I

Answer 9

O: From Ulna
I: On extensor hood of index finger

Question 10

Extensor Indicis: Pathway and Innervation

Answer 10

Passes through 4th compartment under extensor retinaculum

Innervated by posterior interosseous nerve