Obturator Internus, Posterior View

Description

Posteriorly, the obturator internus lines the internal surface of the obturator membrane and adjacent pubis and ischium, then its fibers converge toward the lesser sciatic foramen. After making the characteristic turn around the ischium, the tendon exits the pelvis deep to the gluteal region to course laterally toward the medial surface of the greater trochanter. The ischial spine and ischial tuberosity frame this path, with the posterior pelvis and proximal femur providing bony orientation around the acetabulum and hip joint. Male pelvic proportions are maintained. This posterior perspective matters because the obturator internus is both a deep external rotator of the hip and a key landmark for the lesser sciatic foramen, where the pudendal neurovascular bundle hooks around the ischial spine and re-enters the perineum. Entrapment or irritation along this route can present as pudendal neuralgia, and obturator internus trigger points are a recognized source of buttock and deep pelvic pain that can mimic intra-articular hip pathology. Tightness in the obturator internus can also narrow the ischioanal fossa corridor and complicate transgluteal or perineal approaches. Use this plate when you need to teach pelvic wall anatomy and the transition of structures through the greater and lesser sciatic foramina in gross anatomy, pelvic floor courses, or advanced musculoskeletal instruction. It also fits surgical atlases discussing posterior hip exposure, deep gluteal space pain generators, and regional anesthesia discussions around pudendal nerve blocks. Anatomical accuracy verified by SciePro's Medical Advisory Board.