Cancellous bone, whose porous structure with small cavities resembles sponge, predominates in the pelvis and the 33 vertebrae from the neck to the tailbone.
Built with foam padding to protect the hip and thigh joints and the tailbone, they also include compression that supports the hamstrings and quads.
The butterfly can be large enough to stretch from one side of the back to the other, or small enough to sit discreetly just above the tailbone.
Press the tailbone toward the pubis and lift the pubis toward the navel, holding the buttocks firm but not in a locked position.
Bend your knees and push your tailbone back as if you were going to sit down on an imaginary chair.
Sacrococcygeal teratoma (SCT)-A tumor occurring at the base of the tailbone in a fetus.
These tumors at the base of the tailbone can grow very large.