Which muscles are innervated by the femoral nerve?

• A. Rectus femoris, vastus lateralis, vastus medialis, vastus intermedius, iliopsoas, sartorius
• B. Deep gluteal and piriformis
• C. Flexors of the forearm
• D. Lateral and medial hamstring group

Answer: (A)

The femoral nerve is primarily responsible for innervating the anterior compartment of the thigh, which includes several key muscles involved in hip flexion and knee extension. Among these muscles are the rectus femoris, which is part of the quadriceps group and helps in extending the knee while also flexing the hip; the vastus lateralis, vastus medialis, and vastus intermedius, all of which contribute to knee extension; the iliopsoas, a critical muscle for hip flexion; and the sartorius, which assists in flexing the hip and knee while also allowing for lateral rotation of the thigh.

This specific set of muscles makes option A the correct choice because they are all directly innervated by the femoral nerve, thus performing essential functions in movements of the lower extremity. The other options mention muscle groups that are innervated by different nerves: deep gluteal and piriformis muscles are primarily innervated by the sacral plexus, while the flexors of the forearm are innervated by nerves in the brachial plexus, and the hamstring groups are innervated predominantly by the sciatic nerve.