Obturator externus (Musculus obturator externus)
Educational content only — not medical advice.
Anatomy
A triangular fan on the anterior pelvic outer surface wrapping under the femoral neck to the trochanteric fossa; its spiral course makes its superior border a surgical reference in hip replacement.
Origin & insertion
Posterior two-thirds of the external obturator membrane and bony margins.
Action
Laterally rotates the femur and stabilises the head in the acetabulum in loaded movements.
Innervation
Posterior branch of the obturator nerve (L3–L4).
Clinical notes
The medial circumflex artery crosses its superior border — the famous "T-shape" of surgical anatomy; its relation to trochanteric fractures guides preoperative imaging.
Related structures
Educational references
FAQ
What is the role of the Obturator externus?
A triangular fan on the anterior pelvic outer surface wrapping under the femoral neck to the trochanteric fossa; its spiral course makes its superior border a surgical reference in hip replacement.
Why is the Obturator externus clinically important?
The medial circumflex artery crosses its superior border — the famous "T-shape" of surgical anatomy; its relation to trochanteric fractures guides preoperative imaging.
Source & license
BodyParts3D, © The Database Center for Life Science licensed under CC Attribution 4.0 International (https://creativecommons.org/licenses/by/4.0/). license details