From what I know....We usually stop growing at 18 If you look at the attached image you will see. Our bodies have something called "Osteoblast" these make our bones grow. There will be loads of these when we are little. There is also another factor "Osteoclast". These demolish the old pieces so that the osteoblast can make new ones. The growth hormones stimulate the osteoblast so that they work faster. Thats how we grow. At the start theres more osteoblast and less osteoclast. As we age the balance goes other way and less osteoblast more osteoclast. This causes our bones to lose it grip.
