Most often, a person will not remember an inciting event. In these cases, the tailbone pain is called idiopathic. It may be that degenerative wear and tear due to arthritis is the cause.
During childbirth, there is significant temporary bony displacement in order to make a passage for the baby. This may lead to tailbone pain, it explains why women are five times more likely to develop coccydynia than men.
Another common cause of tailbone pain is trauma from either a direct fall or a traffic accident. In these cases, the coccyx can fracture and then heal in an abnormal position.
There are instances of the coccyx shifting from its normal position, either due to poor posture or repetitive activities. This can lead to chronic pain.