Simulation posits why legendary leapers have different 'spring' stiffness

A new research paper tells a story of the grasshopper and the bullfrog, but it's no children's tale. Instead, it describes biomechanical simulations that help to explain why the two jumping animals have very different stiffnesses in the springs—tendons in the frogs and tendon counterparts called apodemes in the grasshoppers—that store energy for their leaps. The difference, the science suggests, is the time they typically take before they take off.