The several segments of the coccyx are held together by the anterior and posterior longitudinal ligaments, which completely cover the bony nodules on their anterior and posterior aspects. Laterally, the sacro-sciatic ligaments, being attached to nearly the whole length of the coccyx, serve to connect them. Between the first and second pieces of the coccyx there is a very perfect amphiarthrodial joint, with a well-marked intervertebral substance.
Movements. - But little movement occurs as a rule at the sacro-coccygeal and inter-coccygeal joints, but when the head of the child is passing through the pelvic outlet at birth, the tip of the coccyx is displaced backward, it may be to the extent of one inch.