Brown University researchers used a special high-speed videocamera capable of recording 500 frames per second to capture the majestic leap of bull frogs. Viewing the video in super slow motion enabled them to study how frogs can jump more than ten times their length. From NatGeo:
Lead researcher Manny Azizi says a conclusion from the study is the frogs' muscles have tremendous passive flexibility, unlike mammals, whose muscles are mostly 'stiff.' The frogs generate a 'ton' of mechanical energy during their jumps.
Azizi says the frogs are in some ways, "cheating the limits of what muscles alone should be capable of doing."
The frog first stretches most of its hindlimb muscles while in a crouching position, making the muscles longer so they can produce much more force. That force is what propels them into the air.