: dorsa), is the large posterior area of the human body, rising from the top of the buttocks to the back of the neck.

The kidneys are situated beneath the muscles in the area below the end of the ribcage, loosely connected to the peritoneum.

The upper-middle back is also the one area of the body which a typical human under normal conditions might be unable to physically touch.

The upper back has the most structural support, with the ribs attached firmly to each level of the thoracic spine and very limited movement.

The back comprises interconnecting nerves, bones, muscles, ligaments, and tendons, all of which can be a source of pain.

This happens for a variety of reasons- the lower waist area is a pivot point for the body and lengthens and arches as a person sits or bends.

Secondly, woman's fashion typically favors tops that are waist length, allowing the back to be left bare during slight movement, bending or sitting.

"Wetback" is a derogatory name in American English for immigrants who cross the US-Mexico border illegally (purportedly swimming though the Rio Grande).

This is one method of mortification, the practice of inflicting physical suffering on oneself with the religious belief that it will serve as penance for one's own sins or those of others.

While more moderate forms of mortification are widely practiced—particularly in the Catholic Church—self flagellation is not encouraged by mainstream religions or religious leaders.