Watching this resources will notify you when proposed changes or new versions are created so you can keep track of improvements that have been made.
Favoriting this resource allows you to save it in the “My Resources” tab of your account. There, you can easily access this resource later when you’re ready to customize it or assign it to your students.
The ischium forms the lower and back part of the hip bone . Situated below the ilium and behind the pubis, it is one of these three bones whose fusion creates the coxa . The word comes from the Greek ischion, meaning "hip. " The superior portion of this bone forms approximately one third of the acetabulum.
Lateral View of Ischium
Left hip-joint, opened by removing the floor of the acetabulum from within the pelvis. (Ischium labeled at bottom left. )
The ischium is located below the ilium and behind the pubis.
The ischium is divisible into three portions:
The body contains a prominent spine that is the origin for the gemellus superior muscle. The indentation inferior to the spine is the lesser sciatic notch. Continuing down the posterior side, the ischial tuberosity is a thick, rough prominence below the lesser sciatic notch. This element supports weight while sitting and is the origin for the gemellus inferior and adductor magnus muscles.
The superior ramus of the ischium is the partial origin for the obturator internus and obturator externus muscles.
The inferior ramus of the ischium is the partial origin for the gracillis and adductor magnus muscles.
One of the most common clinical problems regarding the ischium are avulsion fractures. Avulsion fractures result in a small part of bone (typically the ischial tuberosity) being broken when a piece of attached tendon or ligament is torn away (avulsed). These fractures occur at apophyges (bony projections that lack secondary ossification centers). Avulsion fractures of the hip bone may occur in adolescents and young adults during sports that require sudden acceleration or deceleration forces, such as sprinting or kicking in football, soccer, jumping hurdles, basketball, and martial arts.
the ischium fuses with the pubis and the ilium to form the os coxa, the ischium forms one-third of the acetabulum, the ischium may suffer from avulsion fractures when a piece of bone is broken by a torn tendon, and the ischuim forms the posterior inlet where it attaches to the sacrum