What is the tailbone/coccyx?

What is the tailbone/coccyx?

Your coccyx is made up of three to five fused vertebrae (bones). It lies beneath the sacrum, a bone structure at the base of your spine. Several tendons, muscles and ligaments connect to it. Both the coccyx and the ischial tuberosities (two bones that make up the bottom of your pelvis) bear your weight when you sit down. Two-thirds of adults have a coccyx that curves a bit instead of pointing straight down, but one that is curved too far is abnormal and, therefore, painful.