7 origin Insertion N.S. actions Add. longus Front of body of pubis below pubic tubercleLinea aspraAnterior branch of obturator nerveAdduction.Flexion.Lat.rotation.Add. brevisBody of pubis + inf. Pubic ramusLower part of line between lesser trochanter and L. aspra + L.aspraAnterior branch of obturatorAdductionFlexionLat. rotationAdd magnusPubic part (conjoint ramus)Ischial part (ischial tuberosityPubic part (gluteal tuberosity, L.aspra, med.Supracondylr ridge)Ischial part(add. tubercle of femur)Pubic part (post. Branch of obturator).Ischial part (sciatic n.)Pub.part; addction, flexion, lat, rotation)Ischial part; extension of hip)gracilisConjoint ram.tibiaAnt. B.otur.Add. ThighFlex knee
8 Obturator nerve (L2,3,4) Origin: It is a branch of the lumbar plexus. It arises from the ventral divisions of the ventral rami of L2,3,4.
12 Course& relations:It reaches the thigh by passing through the obturator canal.Immediately it divides into anterior and posterior branches. The anterior branch descends infront of the adductor brevis and infront of adductor longus and pectineus.The posterior branch passes through the obturator externus and then behind adductor brevis and infront of adductor magnus.
15 Anterior branch:It gives the following branches:Articular branch to the hip.Muscular branch to adductor brevis.Muscular branch to adductor longus.Muscular branch to gracilis.Cutaneous branch which supplies the skin on the middle 1/3 of the medial side of the thigh.
18 Posterior branch:It gives the following branches:Muscular branch to obturator externus.Muscular branch to pubic part of adductor magnus.Genicular branch.N.B. Obturator nerve carries vasoconstrictor fibers from the lumbar part of sympathetic trunk to the obturator artery and its branches.
20 Accessory obturator nerve: An occasional branch of the lumbar plexus.Only found in 12% of subjects.It descends close to medial side of psoas major muscle behind inguinal ligament.It gives branches to pectineus and hip joint.
22 Injury of obturator nerve: It leads to marked weakness of adduction of thigh however slight degree of adduction can be done by pectineus.
23 Obturator artery: Origin: It is a branch of anterior division of the internal iliac artery.Course & relations:It enters the thigh by passing through obturator canal and immediately divides into anterior and posterior branches.The two branches diverge and runs on the outer aspect of obturator membrane along the margin of obturator foramen and under cover of obturator externus.
24 Distribution:The two branches anastomose together to form an arterial circle.It gives the following branches:Muscular branches to:Obturator externus, adductors, pectineus and gracilis.Acetabular branch, to the hip joint.Anastomotic twigs to the medial circumflex femoral and inferior gluteal artery.