http://science.sciencemag.org/content/263/5145/370
The
biology behind a frog’s ability to jump comes from their tendons, their muscles
work like a spring that stretches as it begins to lurch forward and then
recoils itself. Frogs must generate a high level of mechanical power so when
they jump, their muscular system is designed to deliver these high
powers. Some tendons do much more than just
transmit energy, they can also store it. I read an article that compared
their tendons to an elastic bands. When you stretch an elastic band the energy
is stored in the elastic so when you let go the energy is released
the effect is the band will shoot across the room.
The
frog’s crouched starting position is how they being to build up and store
energy. A lot of energy is required to move the legs from this into a
straighter position and until the muscle has produced enough energy to move the
joints, the power output is stored in the tendon. This trigger is created
by the change in posture, from crouched to straight leg. As the tendon gets filled
with energy, the muscle continues to slowly contract. This slow, forceful
contraction is enough to drag the leg into a less crouched position. The shift
in posture encourages the tendon to give up its stored energy. The elastic
component, having been stretched by the contracting muscle,
suddenly realizing and explosively pulling the back legs into full
extension, which catapults the frog’s body upwards and forwards.
I personally think along with jaguars, frogs are incredible creatures. Their morphology is unique because they lack tails as adults and their legs are more suited to jumping than walking. They also are the best jumpers of all the vertebrates, some species can cover over 50times its body length.
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