Coccyx

The coccyx, commonly known as the tailbone, is the final segment of the vertebral column in humans and tailless primates. Located at the very end of the spine, it is an evolutionary remnant of a vestigial tail. The coccyx is typically composed of three to five fused vertebral segments, although the number can vary between individuals. These segments are smaller and simpler in structure compared to the vertebrae found higher up in the spine.

The primary function of the coccyx is to provide an attachment point for various muscles and ligaments of the pelvic floor. These muscles play a crucial role in supporting pelvic organs, bowel control, and maintaining continence. Ligaments attached to the coccyx also contribute to the stability of the pelvis and sacroiliac joints.

While often considered non-essential, the coccyx can be a source of pain, a condition known as coccydynia or coccyalgia. This pain can be caused by a variety of factors, including trauma (such as a fall onto the buttocks), repetitive strain, childbirth, or, in some cases, no identifiable cause. Treatment for coccydynia typically involves conservative measures such as pain medication, physical therapy, and the use of cushions to reduce pressure on the area. In rare and severe cases, surgical removal of the coccyx (coccygectomy) may be considered.