Which muscle inserts on the olecranon of the ulna?

Which muscle inserts on the olecranon of the ulna?

• A. Biceps Brachii
• B. Brachialis
• C. Palmaris Longus
• D. Triceps Brachii

Answer: (D)

The elbow extension action is signaled by muscles that insert on the olecranon. The triceps brachii has a common tendon that attaches directly to the olecranon of the ulna, so when it contracts it straightens the elbow. The other muscles attach elsewhere: biceps brachii to the radial tuberosity and bicipital fascia, brachialis to the coronoid process and anterior ulna, and palmaris longus to the palmar aponeurosis. Therefore, the muscle inserting on the olecranon is the triceps brachii.