He ischium is the bone which, together with pubis and at ilium (or ileum ), make up the unnamed bone . The term comes from the Greek word ischon.

Unnamed bones are found in the hips , forming the pelvis with the coccyx and the sacrum . In the case of the ischium, it constitutes its posterior sector.
It is important to mention that ischium is a serious word which, by its accentuation, does not carry tilde. In any case, it is common for confusion to be generated and for many to refer to ischium , with tilde in the OR .
In the ischium two parts are recognized: the body and the branch (inferior and superior). In the posterior and superior region of the branch, the promontory of the ischium , also know as ischial tuberosity . This bulge establishes the lower opening of the pelvis in conjunction with the tip of the coccyx.
When sitting, one person it must rest on the ischia, or more precisely on the ischial tuberosity. This posture is considered the healthiest, as it guarantees a balanced position of the pelvis. On the contrary, when someone sits on the sacrum or coccyx, the physiological curve of the lumbar spine is impaired and the hamstring is shortened, a situation that can cause contractures and the appearance of pain.
At yoga The importance of recognizing the ischium is often emphasized in order to adopt a convenient posture. The objective is to minimize the disorders in the coccyx, the sacrum, the lumbar area, the cervical region and the shoulders, all sectors that can be harmed by bad body postures.