Obturator Internus Muscle, Posterior View

Description

Running along the posterolateral wall of the male pelvis, the obturator internus arises from the internal surface of the obturator membrane and adjacent pubis and ischium, then converges into a tendon that turns sharply to exit the lesser sciatic foramen. Posteriorly, the tendon passes inferior to the ischial spine and posterior to the hip joint capsule, lying deep to the gluteus maximus and adjacent to the ischial tuberosity. Portions of gluteus medius and minimus sit superolaterally on the ilium, while the proximal hamstrings originate inferiorly from the ischial tuberosity, framing the deep external rotator compartment. Bony landmarks such as the sacrum, ilium, and ischium anchor orientation. That right-angle bend of the obturator internus tendon at the lesser sciatic notch is a high-yield teaching point for hip mechanics and deep gluteal pain syndromes. Hypertrophy or spasm of obturator internus and the closely associated obturator internus bursa can mimic intra-articular hip pathology, and it sits in the same crowded neighborhood as the pudendal neurovascular bundle as it courses around the ischial spine toward Alcock canal. Small space. Big consequences. Orthopedic and pelvic anatomy instructors can drop this posterior view into modules on the deep external rotators, hip stability, and the layered dissection sequence after reflecting gluteus maximus. It also fits well in surgical atlases describing posterior approaches to the hip and in radiology teaching files that correlate MRI findings of obturator internus strain or bursitis with palpable landmarks around the ischial spine and tuberosity. Anatomical accuracy verified by SciePro's Medical Advisory Board.