Muscle
Obturator internus
Lateral rotator of the hip
High-yield
Exits the lesser sciatic foramen; lateral rotator of the extended thigh. Nerve to obturator internus (L5-S2).
Overview
A muscle arising inside the pelvis that turns 90° around the lesser sciatic notch to laterally rotate the hip.
Reference facts
- Origin
- Pelvic surface of the obturator membrane and surrounding bone
- Insertion
- Medial surface of the greater trochanter of the femur
- Action
- Laterally rotates the extended thigh; abducts the flexed thigh; steadies the hip
- Innervation
- Nerve to obturator internus (L5, S1, S2)
- Blood supply
- Internal pudendal / inferior gluteal arteries
Frequently asked questions
What does the obturator internus do?
The obturator internus laterally rotates the extended thigh; abducts the flexed thigh; steadies the hip.
What nerve innervates the obturator internus?
The obturator internus is innervated by the nerve to obturator internus (L5, S1, S2).
Where does the obturator internus attach?
The obturator internus originates from the pelvic surface of the obturator membrane and surrounding bone and inserts on the medial surface of the greater trochanter of the femur.
What is the blood supply of the obturator internus?
The obturator internus is supplied by the internal pudendal / inferior gluteal arteries.