If our bodies didn’t have joints, it would be impossible for us to live as we do. We would have to lie absolutely still always, unable to move our heads, walk, raise our arms, or move a single finger! Our ability to move is possible because of the existence of joints.

Wherever two bones glide over one another, a joint exists. A joint allows the bones to glide smoothly with very little friction. This is because the ends of the bones are covered by cartilage so that they don’t really rub against each other.