The hamstring/medial portion of the adductor magnus is innervated by which nerve?

• A. Tibial division of the sciatic nerve
• B. Common fibular division of the sciatic nerve
• C. Obturator nerve
• D. Femoral nerve

Answer: (A)

The hamstring portion of the adductor magnus is innervated by the tibial division of the sciatic nerve. This part of the muscle behaves like a hamstring and shares its innervation with the other hamstring muscles (semimembranosus, semitendinosus, long head of biceps femoris), which are all supplied by the tibial component of the sciatic nerve. The adductor portion, by contrast, is innervated by the obturator nerve. The femoral nerve does not supply this region, and the common fibular division supplies the short head of the biceps femoris and other non-hamstring muscles, not the hamstring portion of adductor magnus.