Featured Research

from universities, journals, and other organizations

Toad Research Could Leapfrog To New Muscle Model

Date:
June 3, 2008
Source:
Northern Arizona University
Summary:
The deceptively simple, remarkably fast feeding action of toads and chameleons offers a new look at how muscles work. This fresh perspective could lead to designing more efficient electric motors, better prostheses and new medical treatments for neuromuscular diseases like Parkinson's. Science has long held that muscles behave largely like motors. Northern Arizona University researcher Kiisa Nishikawa suggests that muscle acts more like a spring.

A cane toad from Suriname is helping NAU Regents Professor Kiisa Nishikawa understand the speed, power and energy behind the toad's ability to capture prey with its tongue. Her studies offer insight into how muscles function more as springs than motors.
Credit: Danielle Borth

A toad sits at a pond's edge eyeing a cricket on a blade of grass. In the blink of an eye, the toad snares the insect with its tongue. This deceptively simple, remarkably fast feeding action offers a new look at how muscles work.

Related Articles


This fresh perspective could lead to designing more efficient electric motors, better prostheses and new medical treatments for neuromuscular diseases like Parkinson's.

Science has long held that muscles behave largely like motors. Northern Arizona University researcher Kiisa Nishikawa suggests that muscle acts more like a spring.

"Existing theories don't explain how muscles shorten rapidly," Nishikawa said. "Muscles can only shorten to do work; they can't do work by lengthening." A spring also can only do work by shortening.

By example, Nishikawa explains that the jaw muscles in toads and chameleons shorten in the lower jaw, and the opening of the jaws causes the tongue to stretch by its own momentum.

"When a toad or chameleon captures prey with its tongue, it exerts force over a distance. Figuring out how they do it has immense application to any device that actually moves."

A toad's jaw muscles can produce forces greater than 700 times the animal's weight. "The best electric motor achieves about one-third of that force-to-weight ratio," Nishikawa noted.

Muscles also function as self-stabilizing springs.

"They have built-in self-correcting mechanisms. Before the brain can even react, muscles are changing their elasticity adaptively," she said. Think of walking down a flight of steps and missing a step. Leg muscles instantly become less stiff to afford better shock absorption. "It's an intrinsic property of muscle," Nishikawa said.

Tom Sugar and his colleagues Arizona State University have been inspired by biology in designing a robotic tendon. After meeting with Nishikawa about her work, Sugar said, "We were amazed at the speed, energy storage and power of muscle. We learned how a frog tongue will store energy and release it in a powerful burst."

At ASU's Human Machine Integration Laboratory, Sugar and his team are building "SPARKy" (Spring Ankle with Regenerative Kinetics) that mimics biology by storing and releasing energy during the ankle gait cycle.

"Energy is stored as the leg and body rolls over the ankle, and then this energy is released in a powerful burst to propel the user forward. By mimicking biology, we are able to build a very lightweight and functional device," Sugar said.

"Putting motors and springs together in a smart way is something nature hit on about 600 million years ago (with the earliest vertebrates)," Nishikawa said.

It's a notion that captured the interest of Discovery Channel Canada, which spent a day at NAU and a day at ASU taping for a segment of its Daily Planet show that will air in the fall.

The NAU researcher wants to know more about how the brain controls movement. About decade ago Nishikawa realized that how the brain and body work together to produce coordinated movement means understanding what muscles contribute to the whole process.

"Understanding what the neurological part is and what the muscular part is can help establish cause and effect," she said. Identifying these mechanisms at the molecular level might aid medical research in developing better treatments for sufferers of Parkinson's, whose low force output results in stiff movements.

Nishikawa's studies of the neuromuscular basis for extremely rapid movements in animals, such as the toad snaring prey with its tongue, could leapfrog to a new model of muscle function, changing the standard representation of muscle as a motor.


Story Source:

The above story is based on materials provided by Northern Arizona University. Note: Materials may be edited for content and length.


Cite This Page:

Northern Arizona University. "Toad Research Could Leapfrog To New Muscle Model." ScienceDaily. ScienceDaily, 3 June 2008. <www.sciencedaily.com/releases/2008/06/080602144411.htm>.
Northern Arizona University. (2008, June 3). Toad Research Could Leapfrog To New Muscle Model. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2008/06/080602144411.htm
Northern Arizona University. "Toad Research Could Leapfrog To New Muscle Model." ScienceDaily. www.sciencedaily.com/releases/2008/06/080602144411.htm (accessed October 25, 2014).

Share This



More Plants & Animals News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Reuters - Innovations Video Online (Oct. 24, 2014) Miniature deep sea animals discovered off the Australian coast almost three decades ago are puzzling scientists, who say the organisms have proved impossible to categorise. Academics at the Natural History of Denmark have appealed to the world scientific community for help, saying that further information on Dendrogramma enigmatica and Dendrogramma discoides could answer key evolutionary questions. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Black Bear Cub Goes Sunday Shopping

Black Bear Cub Goes Sunday Shopping

Reuters - Light News Video Online (Oct. 23, 2014) Price check on honey? Bear cub startles Oregon drugstore shoppers. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Dances With Wolves in China's Wild West

Dances With Wolves in China's Wild West

AFP (Oct. 23, 2014) One man is on a mission to boost the population of wolves in China's violence-wracked far west. The animal - symbol of the Uighur minority there - is under threat with a massive human resettlement program in the region. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
Breakfast Debate: To Eat Or Not To Eat?

Breakfast Debate: To Eat Or Not To Eat?

Newsy (Oct. 23, 2014) Conflicting studies published in the same week re-ignited the debate over whether we should be eating breakfast. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins