Innervation Sensory medial aspect of the thigh articular branches to hip and knee joints Motor obturator externus adductor longus adductor magnus adductor brevis gracilis Course of Obturator Nerve Origin obturator nerve comes from L2, L3, and L4 Course substance of psoas the obturator decends through the substance of the psoas and exits medially near pelvic brim behind common iliac vessels passes behind common iliac vessels, lateral to the hypogastric vessels anterior to obturator vessels runs along lateral wall of lesser pelvis, anterior to the obturator vessels enters obturator foramen enters the superior aspect of the obturator foramen it then enters the thigh through the obturator canal Terminal branches anterior branch innervates adductor longus gracilis posterior branch innervates adductor magnus adductor brevis these branches are separated by the obturator externus and adductor brevis Clinical Conditions Obturator nerve block