The bones and muscles of your body let you move around. Tough bands called ligaments connect your bones to each other. The connections are called joints. Some joints can move a lot. Your arm at your shoulder joint can move in circles. Your lower leg at your knee joint can only move back and forth. The bones in your skull have special joints that cannot move at all.
Muscles attached to bones pull on them to make your body move. The muscles get their orders to move from your brain and nerves.
