Which nerve provides motor innervation to the pectineus muscle?

Which nerve provides motor innervation to the pectineus muscle?

• A. Obturator nerve
• B. Femoral nerve
• C. Sciatic nerve
• D. Lumbosacral trunk

Answer: (B)

The pectineus is innervated mainly by the femoral nerve, which supplies most of the muscles in the anterior compartment of the thigh, including the pectineus, sartorius, and quadriceps. The femoral nerve arises from L2–L4 and travels into the thigh beneath the inguinal ligament to reach these muscles, aligning with the pectineus’s role as a hip flexor and thigh adductor in the anterior compartment. In some individuals, a branch from the obturator nerve (accessory obturator) can contribute to proximal fibers of the pectineus, but the primary motor input is the femoral nerve. The other nerves listed do not provide the main motor supply: the sciatic nerve serves the posterior thigh and leg, the lumbosacral trunk contributes to the sacral plexus rather than directly to this muscle, and the obturator nerve mainly targets other medial thigh adductors.

The pectineus is innervated mainly by the femoral nerve, which supplies most of the muscles in the anterior compartment of the thigh, including the pectineus, sartorius, and quadriceps. The femoral nerve arises from L2–L4 and travels into the thigh beneath the inguinal ligament to reach these muscles, aligning with the pectineus’s role as a hip flexor and thigh adductor in the anterior compartment. In some individuals, a branch from the obturator nerve (accessory obturator) can contribute to proximal fibers of the pectineus, but the primary motor input is the femoral nerve. The other nerves listed do not provide the main motor supply: the sciatic nerve serves the posterior thigh and leg, the lumbosacral trunk contributes to the sacral plexus rather than directly to this muscle, and the obturator nerve mainly targets other medial thigh adductors.