Published May 12, 2010
Researchers used high-speed cameras and slowed the video to study the jumping abilities of frogs. The team found that the frogs can use their very stretchy muscles to create energy to jump up to more than ten times their length.
© 2010 National Geographic; Manny Azizi, Tom Roberts and Emily Abbott
Researchers used high-speed cameras to study frog muscles, and the slowed-down video helps reveal secrets of the frog’s jumping abilities.
The researchers from Brown University studied the video frame by frame. The videos you’re seeing were shot at 500 frames per second.
Before the frogs jump, they stretch most of their hindlimb muscles, and increase their length, which may be part of their secret.
The Brown University research paper, published recently in the Proceedings of the Royal Society B, focused on bull frogs. But other frogs were filmed with high-speed cameras as well, revealing stunning video of the amphibians’ ability to jump.
Here, the champion jumper, a Cuban tree frog, is seen as muscles stretch, contract and then stretch again at the height of its jump.
The frog jump has three simultaneous movements: the forelegs flex; the hind leg swings to a vertical position and locks; and the thigh swings in a horizontal plane.
Some bull frogs, which average about 7 inches in length, have been recorded jumping as much as 7 feet— that’s more than ten times their length!
The study focused on the plantaris muscle, a smaller leg muscle. Researchers implanted sensors and electrodes on the plantaris to gather data.
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.
The frogs’ secret trick to get past the law of physics just might be the ability to use their very stretchy muscles to create a force of nature that no mammal – four-legged – or human, can even come close to.
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