Which muscle flexes the wrist?

• A. Palmaris Longus
• B. Flexor Carpi Ulnaris
• C. Extensor Carpi Radialis Longus
• D. Extensor Digitorum

Answer: (A)

Wrist flexion is produced by muscles in the anterior forearm that cross the wrist joint. Palmaris longus is a superficial flexor of the wrist; when it contracts, it helps bend the hand at the wrist and also tenses the palmar aponeurosis to improve grip. Although it’s a relatively weak flexor and is absent in some people, its action is specifically to flex the wrist, which matches the question. The other muscles listed either extend the wrist (Extensor Carpi Radialis Longus, Extensor Digitorum) or flex but with different primary actions and attachments (Flexor Carpi Ulnaris tends to flex and adduct the wrist, Flexor Carpi Radialis flexes and abducts). Because Palmaris longus directly contributes to wrist flexion, it is the best answer.