Pectineus Pectineus is a muscle of the medial compartment of the thigh. Most of the muscles in this compartment are adductors and medial rotators, innervated by the obturator nerve. However, pectineus is the exception of the medial compartment--it's innervated by the femoral nerve, and it's a hip flexor. So, damage to the obturator nerve would not affect pectineus!
Adductor brevis, adductor longus, and gracilis are muscles of the medial compartment which adduct and medially rotate the thigh--they are all innervated by the obturator nerve. Obturator externus is also innervated by the obturator nerve--it is a lateral rotator found in the medial compartment of the thigh.