Advanced Extensor Carpi Radialis Longus Quiz

Q1. A radial nerve lesion proximal to the motor branch for extensor carpi radialis longus would directly weaken which combination of movements?

• Wrist extension and radial deviation
• Wrist flexion and ulnar deviation
• Forearm pronation and wrist flexion
• Finger flexion and thumb opposition

Q2. Why can extensor carpi radialis longus remain functional in some lesions affecting the posterior interosseous nerve?

• It is supplied by the median nerve
• It is supplied by the ulnar nerve
• Its motor branch arises proximal to the posterior interosseous nerve
• It receives no motor innervation

Q3. Which tendons cross superficially over the extensor carpi radialis longus and brevis tendons at the proximal intersection in the distal forearm?

• Abductor pollicis longus and extensor pollicis brevis
• Flexor pollicis longus and flexor carpi radialis
• Extensor pollicis longus and extensor indicis
• Extensor carpi ulnaris and extensor digiti minimi

Q4. Which overuse disorder can develop near the crossing of the first dorsal compartment tendons over the extensor carpi radialis longus and brevis tendons?

• Pronator syndrome
• Intersection syndrome
• Cubital tunnel syndrome
• Carpal tunnel syndrome

Q5. Which tendon crosses the extensor carpi radialis longus tendon more distally near the dorsal wrist?

• Flexor carpi ulnaris
• Flexor pollicis longus
• Palmaris longus
• Extensor pollicis longus

Q6. A patient can extend the wrist, but the hand deviates radially during extension after a radial nerve branch lesion. Preservation of which muscle can contribute to this pattern?

• Extensor carpi radialis longus
• Flexor carpi ulnaris
• Flexor digitorum profundus
• Pronator quadratus

Q7. Why does contraction of extensor carpi radialis longus help optimize force produced by the long finger flexors during gripping?

• It prevents the median nerve from entering the hand
• It flexes the metacarpophalangeal joints during gripping
• It directly shortens the finger flexor tendons
• It prevents excessive wrist flexion and maintains favorable finger flexor length

Q8. Which anatomical feature most clearly differentiates the proximal attachment of extensor carpi radialis longus from that of extensor carpi radialis brevis?

• Origin from the lateral supracondylar ridge
• Origin from the olecranon
• Origin from the common flexor tendon
• Origin from the medial supracondylar ridge

Q9. What is the likely wrist action when extensor carpi radialis longus contracts simultaneously with flexor carpi radialis?

• Ulnar deviation with strong extension
• Radial deviation with reduced flexion or extension
• Finger extension without wrist movement
• Pure forearm pronation

Q10. Which description best summarizes the anatomy of extensor carpi radialis longus?

• It is a superficial posterior forearm muscle supplied by the radial nerve that inserts on the second metacarpal and extends and radially deviates the wrist
• It is a deep anterior forearm muscle supplied by the median nerve that inserts on the third metacarpal and flexes the wrist
• It is an intrinsic hand muscle supplied by the ulnar nerve that inserts on the proximal phalanx and abducts the index finger
• It is a superficial anterior forearm muscle supplied by the median nerve that inserts on the fifth metacarpal and pronates the forearm