Author: Dr Peter de Souza
Last modified: 7 November 2022

The obturator externus muscle is one of the 6 muscles of the medial compartment of the thigh. The obturator externus is a flat fan-shaped muscle which attaches to the outer aspect of the obturator membrane (the obturator internus attaches on the inner surface).

The medial compartment of the thigh includes the following 6 muscles:

  • Pectineus
  • Gracilis
  • Adductor longus
  • Adductor brevis
  • Adductor magnus
  • Obturator externus

Origin

  • External surface of the obturator membrane
  • Adjacent borders of the obturator foramen

Insertion

  • Trochanteric fossa (posteromedial surface of greater trochanter of femur)

Action

  • Lateral rotation of hip
  • Assists hip adduction

Innervation

  • Obturator nerve: L2, L3, L4

Blood Supply

  • Obturator artery
  • Medial circumflex femoral artery