Advanced Extensor Carpi Radialis Brevis Quiz

Q1. Extensor carpi radialis brevis is particularly associated with which common overuse disorder at the elbow?

• Cubital tunnel syndrome
• Carpal tunnel syndrome
• Lateral epicondylitis
• Medial epicondylitis

Q2. Which attachment of extensor carpi radialis brevis is commonly involved in lateral epicondylitis?

• Proximal attachment at the common extensor origin
• Attachment to the olecranon
• Distal attachment at the third metacarpal only
• Attachment to the radial styloid

Q3. Which resisted movement may reproduce lateral elbow pain when extensor carpi radialis brevis is involved in lateral epicondylitis?

• Thumb opposition
• Wrist extension
• Wrist flexion
• Finger adduction

Q4. Why is extensor carpi radialis brevis particularly important during a powerful hand grip?

• It stabilizes the wrist against the flexion produced by the finger flexors
• It directly flexes the fingers during gripping
• It directly adducts all five digits
• It locks the elbow in full extension

Q5. Which tendons cross superficially over the extensor carpi radialis longus and brevis tendons in the distal forearm at the proximal intersection region?

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

Q6. Which clinical disorder can occur where the first dorsal compartment tendons cross the second compartment tendons in the distal forearm?

• Cubital tunnel syndrome
• Pronator syndrome
• Guyon's canal syndrome
• Intersection syndrome

Q7. A lesion affecting the deep branch of the radial nerve proximal to the branch for extensor carpi radialis brevis would most directly weaken which movement produced by this muscle?

• Wrist flexion with ulnar deviation
• Wrist extension with radial deviation
• Forearm pronation
• Thumb opposition

Q8. Why can wrist extension remain possible despite paralysis of extensor carpi radialis brevis?

• Pronator quadratus substitutes for wrist extension
• Flexor carpi radialis becomes a wrist extensor
• Biceps brachii directly extends the wrist
• Other wrist extensors can still produce extension

Q9. What functional effect would simultaneous contraction of extensor carpi radialis brevis and extensor carpi ulnaris have at the wrist?

• Wrist extension with reduced side-to-side deviation
• Finger extension without wrist extension
• Wrist flexion with strong radial deviation
• Forearm supination without wrist movement

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

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