As Logan jumps on the bed, what is it that keeps his body moving up and down? The Bod Squad sets out to help prevent him from falling. They shrink down to explore the muscular system, traveling from Logan's skeletal muscle to bones and back again. An adventure-filled graphic novel that provides young readers information about the human body and how its muscular system works. Includes contemporary full-color graphic artwork, fun facts, additional information, and a glossary.