Obturator Nerve

What is the origin & root value of Obturator nerve?

Origin: Obturator nerve arises from lumbar plexus.

Root value: It is formed by ventral division of the ventral rami of L2, L3, L4 spinal nerves

Course:

From lumbar region it passes to the upper surface of ala of sacrum.
It then crosses pelvic brim and runs downwards and forwards along the lateral wall of pelvis.
It leaves the pelvis by passing through the obturator canal and enters the medial compartment of thigh.
Here it divides into anterior and posterior division which lie anterior and posterior to adductor brevis respectively.

Branches of anterior division of obturator nerve:
- Muscular branches to gracilis, adductor longus, medial part of pectineus, and usually to adductor brevis.
- Sensory innervation to skin of upper part of medial aspect of thigh.
- Articular branch to hip joint.
Branches of posterior division of obturator nerve
- Muscular branches to obturator externus, sometimes to adductor brevis and adductor part of adductor magnus.
- Articular branch to knee joint.

Obturator nerve

In case of injury to obturator nerve there will be
- Motor loss: Paralysis/weakness of adductor muscles of thigh whic results in loss of adduction of thigh.
- Sensory loss: Skin over lower part of medial aspect of thigh

In case of diseases of hip joint pain is referred to knee joint and vice versa, because both the joints are supplied by branches of obturator and femoral nerve.