Navigation Links
Frogs' amazing leaps due to springy tendons
Date:11/16/2011

PROVIDENCE, R.I. [Brown University] Some species of frogs and many other animals are able to jump far beyond what appear to be their capabilities. The trained contestants in the frog-jumping competition in Calaveras County, Calif., come to mind, but even ordinary frogs can leap several times farther than their physiology would seem to allow.

"Muscles alone couldn't produce jumps that good," said Henry Astley, who studies the biomechanics of frog jumping at Brown University.

In a paper published in Biology Letters, Astley and Thomas Roberts, associate professor of biology, show that the key to frogs' leaping lies in their stretchy tendons: Before jumping, the leg muscle shortens, loading energy into the tendon, which then recoils like a spring to propel the frog up, up and away. Even though as much as a quarter of a frog's body mass is in its legs, it would be physically incapable of jumping as far without the tendon's services.

"In order to get truly exceptional jumping performance, you need some sort of elastic structure," said Astley, a fourth-year graduate student in Roberts's lab in the Department of Ecology and Evolutionary Biology.

Astley and Roberts examined jumps by the northern leopard frog (Rana pipiens), a pond frog common in the northeast United States. The pair implanted metal beads into the shin bone, ankle bone and leg muscle of four frogs and then recorded their leaps with 3-D X-ray video technology developed at Brown. The video, filmed at 500 frames per second and displaying the jump about 17 times slower than normal, tracks the changes in the leg muscle's length and joint movement before, during and after a jump.

As the frog readies itself to leap, its calf muscle shortens. After about 100 milliseconds, the calf muscle stops moving, and the energy has been fully loaded into the stretched tendon. At the moment the frog jumps, the tendon, which wraps around the ankle bone, releases its energy, much like a catapult or archer's bow, causing a very rapid extension of the ankle joint that propels the frog forward. The entire jump from preparation to leap lasts about a fifth of a second, the experiments showed. Other frog species jump much faster.

"It's the first time we've really gotten the inner workings, that we've put all the pieces (to frog jumping) together," Astley said. "We now have a clearer idea what's going on."

How the tendons, muscles and joints work in frog jumping may help explain how other animals are such head-scratching leapers invertebrates like the humble flea or the grasshopper or vertebrates like guinea fowl and bush babies.

"Frogs are interesting in their own right, but we are also confident that this study gives us insight into how muscles and tendons work together in animal movement," said Roberts. "Other studies have presented evidence for an elastic mechanism, but Henry's gives us the first glimpse of how it actually works."


'/>"/>

Contact: Richard Lewis
Richard_Lewis@brown.edu
401-863-3766
Brown University
Source:Eurekalert  

Related biology news :

1. Tree frogs chill out to collect precious water
2. Fitness tests for frogs?
3. Inventions of evolution: What gives frogs a face
4. New sensor derived from frogs may help fight bacteria and save wildlife
5. Frogs evolution tracks rise of Himalayas and rearrangement of Southeast Asia
6. Research of cell movements in developing frogs reveals new twists in human genetic disease
7. Primitive frogs do a belly flop
8. Prehistoric frogs face extinction
9. Counting frogs: Why monitoring our amphibian populations is important
10. Frogs, foam and fuel: University of Cincinnati researchers convert solar energy to sugars
11. Pesticide atrazine can turn male frogs into females
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Frogs' amazing leaps due to springy tendons
(Date:5/16/2017)... , May 16, 2017  Veratad Technologies, LLC ( ... online age and identity verification solutions, announced today they ... Conference 2017, May 15 thru May 17, 2017, in ... and International Trade Center. Identity impacts ... and in today,s quickly evolving digital world, defining identity ...
(Date:4/18/2017)...  Socionext Inc., a global expert in SoC-based imaging and computing ... M820, which features the company,s hybrid codec technology. A demonstration utilizing ... Inc., will be showcased during the upcoming Medtec Japan at Tokyo ... Las Vegas Convention Center April 24-27. ... Click here for an image ...
(Date:4/11/2017)... -- Research and Markets has announced the addition of ... offering. ... market to grow at a CAGR of 30.37% during the period ... has been prepared based on an in-depth market analysis with inputs ... growth prospects over the coming years. The report also includes a ...
Breaking Biology News(10 mins):
(Date:10/11/2017)... (PRWEB) , ... October 11, 2017 , ... Personal eye wash is a basic first ... eye at a time. So which eye do you rinse first if a dangerous substance ... Plum Duo Eye Wash with its unique dual eye piece. , “Whether its ...
(Date:10/11/2017)... ... 11, 2017 , ... Disappearing forests and increased emissions are the main causes ... each year. Especially those living in larger cities are affected by air pollution related ... the most pollution-affected countries globally - decided to take action. , “I knew I ...
(Date:10/10/2017)... ... 10, 2017 , ... For the second time in three ... Mentoring Award. Representatives of the FirstHand program travelled to Washington, D.C. Tuesday, October ... US2020’s mission is to change the trajectory of STEM education in America by ...
(Date:10/10/2017)... ... 10, 2017 , ... The Pittcon Program Committee is pleased ... scientists who have made outstanding contributions to analytical chemistry and applied spectroscopy. Each ... leading conference and exposition for laboratory science, which will be held February 26-March ...
Breaking Biology Technology: