Friday, January 13, 2012

Obturator Nerve

The obturator nerve is a nerve which arises from the lumbar plexus (L2–L4) and provides motor innervation to the adductor muscles of the thigh. Medial to the greater psoas muscle, the obturator nerve extends along the lateral wall of the small pelvis down to the obturator canal through which it passes to reach the thigh. It gives off a muscular branch to the external obturator muscle and then divides into a superficial branch and a deep branch. The superficial branch runs between the long adductor muscle and short adductor muscle and innervates both. The nerve also gives off branches to the pectineal muscle and the gracilis muscle and finally terminates in a cutaneous branch to the distal region of the medial aspect of the thigh. The deep branch runs along the external obturator muscle and then down to the great adductor muscle. Paralysis of the obturator nerve, for example, as a result of pelvic fracture, causes loss of adductor muscle function. This restricts standing and walking, and the affected leg can no longer be crossed over the other leg.