Advanced Posterior Compartment of the Forearm Quiz

Q1. Compression of the deep branch of the radial nerve near the proximal edge of the supinator may occur at which structure?

• Arcade of Frohse
• Bicipital aponeurosis
• Flexor retinaculum
• Guyon's canal

Q2. A posterior interosseous nerve lesion would most directly produce which deficit?

• Loss of forearm pronation
• Weakness of finger and thumb extension
• Loss of finger abduction
• Loss of thumb opposition

Q3. Why does an isolated posterior interosseous nerve lesion generally not cause cutaneous sensory loss?

• It contains only autonomic fibers
• It has no cutaneous sensory distribution
• It terminates before entering the forearm
• It supplies the skin exclusively through the median nerve

Q4. Why may wrist extension remain possible in a posterior interosseous nerve lesion?

• Some wrist extensors receive innervation proximal to the posterior interosseous nerve
• Flexor carpi radialis becomes an extensor after nerve injury
• The posterior interosseous nerve supplies no extensor muscles
• Wrist extension is performed entirely by the median nerve

Q5. Which artery crosses the floor of the anatomical snuffbox?

• Radial artery
• Anterior interosseous artery
• Brachial artery
• Ulnar artery

Q6. Which carpal bone is clinically examined for tenderness through the anatomical snuffbox after a fall on an outstretched hand?

• Triquetrum
• Scaphoid
• Hamate
• Pisiform

Q7. Which tendon uses the dorsal tubercle of the radius as a pulley as it changes direction toward the thumb?

• Abductor pollicis longus tendon
• Extensor pollicis brevis tendon
• Extensor carpi ulnaris tendon
• Extensor pollicis longus tendon

Q8. Which tendons occupy the first dorsal extensor compartment at the wrist?

• Extensor digitorum and extensor indicis
• Abductor pollicis longus and extensor pollicis brevis
• Extensor carpi radialis longus and extensor carpi ulnaris
• Extensor pollicis longus and extensor indicis

Q9. Inflammation involving the tendons of the first dorsal extensor compartment is characteristic of which condition?

• Pronator syndrome
• Carpal tunnel syndrome
• De Quervain tenosynovitis
• Dupuytren contracture

Q10. Which description best summarizes the anatomical organization of the posterior compartment of the forearm?

• It is a flexor-pronator compartment supplied primarily by the median nerve
• It contains only muscles acting at the elbow and no muscles acting on the wrist or digits
• It is an extensor-supinator compartment with superficial and deep muscle groups supplied by branches of the radial nerve
• It is supplied exclusively by the ulnar nerve and contains the digital flexors