Dip into Muscles and Bones to see how your skeleton holds you together in one neat, highly mobile package. It’s so strong it can last for millions of years! Find out how bones can bend in almost any direction, thanks to the clever engineering of joints; and how you can move in all kinds of ways because of the pulling power of muscles – whether you want to pick up a pencil or run along a race track. Even the least sporty of us have lots of muscle – we all have around 640, and if they all worked together they could lift a bus