The ischial tuberosity is a large round protrusion at the inferoposterior aspect of the ischium. It is also known as the “sitting bone”, as this is where the weight of the body is held when seated.
A number of soft tissue structures attach to this tuberosity. For example, the sacrotuberous ligament, some gluteal muscles (inferior gemellus, quadratus femoris), adductor magnus and the posterior thigh muscles (biceps femoris, semitendinosus, semimembranosus) all attach here.
The two ischial tuberosities are used as a landmark (inter-ischial line) to divide the perineum into the anterior urogenital triangle and the posterior anal triangle. This tuberosity is also used to help locate the sciatic nerve, which descends through the pelvis between the ischial tuberosity and the greater trochanter of femur.
|Terminology||English: Ischial tuberosity
Latin: Tuber ischiadicum
|Definition||Inferior protuberance of the ischium|
Learn more about the pelvic bones with this study unit:© Unless stated otherwise, all content, including illustrations are exclusive property of Kenhub GmbH, and are protected by German and international copyright laws. All rights reserved.