Obturator Foramen: This is the area formed by the pubis and ischium bones from the pelvis and allows the nerves and muscles to pass.

The ischium “ramus” is the flattened, thin area of the ischium which is the largest share of the coxal bone. This arises from the area of the body that is lowest and connects the “inferior ramus” of the pubis – the intersection being specified in an adult human by a line that is raised. The combined rami are often called the “ischiopublic ramus”. This ischium is the posterior inferior compact of the pelvis. Posteriorly, bony distinctions from the “ischial tuberosity” or from each side of the interior pelvis maintain the weight support of the body in a position of sitting. The large open referred to as the “obturator foramen” is fashioned by both the ischium rami with the pubis and generates an opening that permits the passage of major nerves and the blood vessels of the feet and legs.