What Is the Obturator Externus?
The obturator externus is a muscle located within the human pelvis. Though it is situated just inferior to or beneath the external rotators of the hip, muscles like the quadratus femoris and the piriformis, unlike these it is found not on the back of the pelvis but on the front side. Also, while involved in lateral or external rotation of the thigh as well as in hip adduction, this muscle is not a prime mover of the hip joint. In other words, it assists larger muscles of the hip and thigh in performing both of these actions. Triangular in shape, the obturator externus finds its origins along a length of the pubis and ischium bones in the pelvis. The pubis is the more medial of the two lower bones of the pelvis, found closer to the pubic region, while the ischium is the more lateral of the two, situated nearer to the hip joint. These two curved bones meet in the middle to form a loop known as the obturator foramen; the obturator externus arises from within this loop. Specifically, it or
