Which of the following are extensors of the thumb at the carpometacarpal and metacarpophalangeal joints?

Question

Quizplus · Accepted Answer

The extensor pollicis longus and extensor pollicis brevis are the only muscles listed that extend the thumb at both the carpometacarpal and metacarpophalangeal joints. The flexor pollicis brevis and flexor pollicis longus are flexors of the thumb, while the abductor pollicis longus is an abductor of the thumb and the extensor digitorum extends the fingers but not the thumb.

Which of the Following Are Extensors of the Thumb at the Carpometacarpal