Forearm Muscles

Question 1

Pronator teres (anterior)

Answer 1

-origin: medial epicondyle of the humerus and coronoid process of the ulnar.

-insertion: lateral surface of the radius

-action: pronates and flexes the forearm

-innervation: median nerve

Question 2

Extensor digitorum communis (posterior)

Answer 2

-origin: lateral epicondyle of the humerus

-insertion: extensor hoods of digits 2-5

-action: extends the wrist and digits 2-5

-innervation: radial nerve

Question 3

Flexor digitorum superficialis (intermediate layer)

Answer 3

-origin: medial epicondyle of the humerus, coronoid process of the ulnar and anterior surface of the radius.

-insertion: middle phalanges of digits 2-5

-action: flexes the wrist,MCP joints and PIP joints.

Innervation: median nerve

Question 4

Flexor digitorum profundus (deep layer)

Answer 4

-origin: proximal three quarters of the anterior and medial surfaces of the Ulnar and interosseus membrane.

-insertion: bases of the distal phalanges of digits 2-5

-action: flexes the DIP joints, wrist and MCP joints

-innervation: lateral half (digits 2-5) is median nerve

-Medial half (digits 4-5) is the ulnar nerve

Question 5

Flexor pollicis longus (deep layer)

Answer 5

-origin: anterior surface of the radius and interosseous membrane.

-insertion: base of the distal phalanx of the thumb.

-action: flexes the thumb at the IP joint

-innervation: median nerve Medial half

Question 6

Pronator quadratus (deep layer)

Answer 6

-Origin: distal anterior surface of the ulnar

-insertion: distal anterior surface of the radius

-Action: pronates the forearm

-Innervation: median nerve