The irregular bones are: the vertebr, sacrum, coccyx, temporal, sphenoid, ethmoid, zygomatic, maxilla, mandible, palatine, inferior nasal concha, and hyoid.
en.wikipedia.org The coccyx is cut away from the surrounding tissues, cut off at the joint with the sacrum, and removed.
en.wikipedia.org A simple test to determine whether the coccyx is involved is injection of local anesthetic into the area.
en.wikipedia.org A wetsuit over the legs protects against abrasions, and can somewhat cushion bumps to shins, knees, and the coccyx.
en.wikipedia.org