Question

which muscle of the posterior forearm is responsible for extension and adduction of the wrist?

a.) extensor digitorum
b.) extensor carpi radialis longus
c.) extensor carpi ulnaris
d.) extensor carpi radialis brevis

Explanation:

Analyze the actions of each listed muscle

• Extensor Digitorum: Extends the medial four digits (fingers) and assists in wrist extension.
• Extensor Carpi Radialis Longus: Extends and abducts (deviates radially) the wrist.
• Extensor Carpi Ulnaris: Extends and adducts (deviates ulnarly) the wrist.
• Extensor Carpi Radialis Brevis: Extends and abducts (deviates radially) the wrist.

Identify the muscle matching both criteria

• The question asks for a muscle of the posterior forearm that performs both extension and adduction (ulnar deviation) of the wrist.
• The extensor carpi ulnaris is located on the ulnar side of the posterior forearm, allowing it to pull the hand toward the ulna (adduction) while extending it.

Answer:

• a.) Extensor Digitorum
• b.) Extensor Carpi Radialis Longus
• c.) Extensor Carpi Ulnaris (Correct answer)
• d.) Extensor Carpi Radialis Brevis