The coccyx or tailbone is the final section of the spine in humans and many other mammals. It is small, with a triangular shape, and resembles a very short tail. Typically, the coccyx consists of between three and five vertebrae. In some individuals, the vertebrae fuse together to form a single solid bone. In others, up to the third vertebrae may remain separate from the remaining vertebrae. Research shows the coccyx performs some potentially important functions and acts as a connection for many muscles and ligaments.


1. Structure of the Tailbone

The anterior or frontal surface of the coccyx is slightly concave, crossed with several grooves. This area connects to important ligaments and muscles and provides support for a portion of the rectum. The posterior area is convex and possesses similar grooves. A row of paired round projections lies on either side of the posterior surface. The largest pair, the coccygeal cornua, project towards the spine and connect the coccyx to the sacrum.

pelvic bones tailbone newannyart / Getty Images


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