[TA] intrapelvic muscle extending into gluteal region; origin, pelvic surface of obturator membrane and margin of obturator foramen; insertion, passes out of pelvis through lesser sciatic foramen, in so doing, making a 90° turn to insert into the medial surface of greater trochanter; action, rotates thigh laterally; nerve supply, nerve to obturator internus (sacral plexus). SYN: musculus obturator internus [TA], internal obturator muscle.
