Which muscle is commonly absent in a percent of the population?

Which muscle is commonly absent in a percent of the population?

• A. Palmaris longus
• B. Flexor carpi radialis
• C. Flexor digitorum superficialis
• D. Extensor digitorum

Answer: (A)

Forearm muscle presence can vary between individuals, and palmaris longus is a classic example of a muscle that is often absent. This small tendon that teams up with the palmar fascia is functionally minor for wrist action, so many people can lack it without noticeable weakness. Its absence is relatively common—shown across populations in roughly a single-digit to low double-digit percentage of people, and sometimes higher in certain groups. Because other forearm muscles mainly handle wrist and finger flexion, they are almost always present, making palmaris longus the one most frequently missing. Clinically, the tendon is sometimes used for grafts, which reflects its reduced functional role. So the correct choice is palmaris longus.

Forearm muscle presence can vary between individuals, and palmaris longus is a classic example of a muscle that is often absent. This small tendon that teams up with the palmar fascia is functionally minor for wrist action, so many people can lack it without noticeable weakness. Its absence is relatively common—shown across populations in roughly a single-digit to low double-digit percentage of people, and sometimes higher in certain groups. Because other forearm muscles mainly handle wrist and finger flexion, they are almost always present, making palmaris longus the one most frequently missing. Clinically, the tendon is sometimes used for grafts, which reflects its reduced functional role. So the correct choice is palmaris longus.