part of part of attached to attached to has muscle insertion has muscle insertion greater trochanter musculature of pelvic girdle obturator muscle obturator internus http://upload.wikimedia.org/wikipedia/commons/5/55/Posterior_Hip_Muscles_1.PNG UMLS:C1518529 Definition generalized to accommodate AAO class - 'Originates on the entire lateral surface of the pelvic rim. Dorsal fibers insert distally to the dorso-medial surface of the caput femoris and ventral fibers extend around the acetabulum to insert on the tendon of the caput femoris.' [AAO:0010052] Wikipedia:Obturator_internus_muscle NCIT:C33192 The obturator internus muscle originates on the medial surface of the obturator membrane, the ischium near the membrane, and the rim of the pubis. It exits the pelvic cavity through the lesser sciatic foramen. The obturator internus is situated partly within the lesser pelvis, and partly at the back of the hip-joint. It functions to help laterally rotate extended thigh and abduct flexed thigh, as well as to steady the femoral head in the acetabulum. internal obturator SCTID:245025008 musculus obturator internus FMA:22298 UBERON:0011048 obturatorius internus musculus obturatorius internus Originates on the entire lateral surface of the pelvic rim. Dorsal fibers insert distally to the dorso-medial surface of the caput femoris and ventral fibers extend around the acetabulum to insert on the tendon of the caput femoris.[AAO] AAO:0010052 obturator internus muscle EMAPA:36237 internus obturator