Muscle
Obturator externus
Deep hip rotator arising outside the obturator membrane
High-yield
Among the six short hip rotators, it is distinguished by obturator nerve supply from the lumbar plexus. The similarly named obturator internus instead receives its own nerve from the sacral plexus.
Overview
Obturator externus covers the outer face of the obturator membrane. Its fibers converge into a tendon that passes behind the femoral neck to a recessed attachment on the inner side of the greater trochanter.
Reference facts
- Origin
- External obturator membrane and the surrounding pubic and ischial margins
- Insertion
- Trochanteric fossa on the medial side of the greater trochanter
- Action
- Externally rotates the hip, helps support the femoral head and can assist adduction
- Innervation
- Posterior division of the obturator nerve, from the L2-L4 lumbar plexus pathway
- Blood supply
- Obturator and medial circumflex femoral arterial branches, with variable contributions
Frequently asked questions
What does the obturator externus do?
The obturator externus externally rotates the hip, helps support the femoral head and can assist adduction.
What nerve innervates the obturator externus?
Posterior division of the obturator nerve, from the L2-L4 lumbar plexus pathway.
Where does the obturator externus attach?
The obturator externus originates from the external obturator membrane and the surrounding pubic and ischial margins and inserts on the trochanteric fossa on the medial side of the greater trochanter.
What is the blood supply of the obturator externus?
The obturator externus is supplied by the obturator and medial circumflex femoral arterial branches, with variable contributions.