Posterior Arm

Question 1

Triceps Brachii

Answer 1

O: LH - infraglenoid tubercle; medial head - posterior surface of humerus inferior to spiral groove; lateral head - posterior surface of humerus superior to spiral groove
I: olecranon process of ulna
A: extend forearm
N: radial

Question 2

Anconeus (not considered part of posterior compartment)

Answer 2

O: lateral epicondyle of humerus
I: lateral surface of olecranon process and posterior ulna
A: extension of forearm
N: radial