Obturator neurpathy

Clinical presentation is weakness of externally rotating, or adducting the thigh, or crossing the legs. Sensory involvement is minor.  Small areas of skin over the hip joint and the interior middle of thigh may have sensory loss. 

Anatomically, the posterior branch innervates the obturator externa and adductor magnus.  The anterior branch innervates the adductor longus and brevis and gracilis.  Both come from L2-4 lumbar plexus and are affected by same processes as femoral neuropathy, such as gravid uterus.

Howship-Romberg syndrome (historical) refers to pressure on obturator nerve by a rare obturator hernia.  It consists of pain that radiates down the thigh and is most marked at the knee.