Which muscle is not part of the quadriceps group?

Which muscle is not part of the quadriceps group?

• A. Rectus femoris
• B. Vastus lateralis
• C. Biceps femoris
• D. Vastus medialis

Answer: (C)

The main idea here is identifying which muscle groups belong to the quadriceps. The quadriceps are the four muscles on the front of the thigh that extend the knee. Those four are rectus femoris and the three vastus muscles (vastus lateralis, vastus medialis, and vastus intermedius). The muscle in question belongs to the hamstrings, which are on the back of the thigh and primarily bend the knee. That muscle is the biceps femoris. Because it is part of the posterior thigh flexors, not the anterior knee-extending group, it is not a component of the quadriceps. So among the options, the one not part of the quadriceps is the biceps femoris. The other listed muscles are all part of the quadriceps.

The main idea here is identifying which muscle groups belong to the quadriceps. The quadriceps are the four muscles on the front of the thigh that extend the knee. Those four are rectus femoris and the three vastus muscles (vastus lateralis, vastus medialis, and vastus intermedius).

The muscle in question belongs to the hamstrings, which are on the back of the thigh and primarily bend the knee. That muscle is the biceps femoris. Because it is part of the posterior thigh flexors, not the anterior knee-extending group, it is not a component of the quadriceps.

So among the options, the one not part of the quadriceps is the biceps femoris. The other listed muscles are all part of the quadriceps.