Ischium jumping hurdles, basketball, and martial arts. These fractures occur at tubercles (bony projections that lack secondary ossification centers). Avulsion fractures occur where muscles are attached: anterior superior and inferior iliac spines, ischial tuberosities, and ischiopubic rami. A small part of bone with a piece of a tendon or ligament attached is avulsed (torn away). Ischial bursitis (also known as "weaver's bottom") is inflammation of the synovial bursa located between the gluteus maximus muscle and the ischial tuberosity, and is usually caused by prolonged sitting on a hard surface. Adoption of "ischium" into English-language medical literature dates back to c. 1640;
Mastoid part of the temporal bone is derived from the Greek word for “breast,” a reference to the shape of this bone. Mastoid part of the temporal bone The mastoid part of the temporal bone is the back part of the temporal bone. Its rough surface gives attachment to various muscles and it has openings for the transmission of blood vessels. From its borders the mastoid part articulates with two other bones. Its outer surface is rough, and gives attachment to the occipitalis and posterior auricular muscles. It is perforated by numerous foramina (holes); one of these, of large size, situated near the posterior border, is