Muscles help you run, jump, play sports, and even sit still long enough to read this book. Your bony skeleton holds you up and keeps everything in its place. Let the Stickmen give you a tour of your incredible body! Find out why muscles are strong and how they get even stronger, how many bones make up your skeleton, and how your body twists, bends, and moves. Along the way, you'll discover the world's oldest skeleton, the longest and strongest muscle, and more. Colorful illustrations and fascinating facts reveal the inner workings of your muscles and bones.