Featured Research

from universities, journals, and other organizations

One step at a time, researchers learning how humans walk

Date:
January 17, 2014
Source:
Oregon State University
Summary:
Humans and some of our hominid ancestors such as Homo erectus have been walking for more than a million years, and researchers are close to figuring out how we do it. The research could find some of its earliest applications in improved prosthetic limbs, and later on, a more complete grasp of these principles could lead to walking or running robots that are far more agile and energy-efficient than anything that exists today.

New research at Oregon State University has created a better understanding of how humans walk with such agility and energy efficiency.
Credit: Graphic courtesy of Daniel Renjewski, Oregon State University

Humans and some of our hominid ancestors such as Homo erectus have been walking for more than a million years, and researchers are close to figuring out how we do it.

Related Articles


It's never been completely clear how human beings accomplish the routine, taken-for-granted miracle we call walking, let alone running. But findings published last month in the Journal of Experimental Biology outline a specific interaction between the ankle, knee, muscles and tendons that improve the understanding of a leg moving forward in a way that maximizes motion while using minimal amounts of energy.

The research could find some of its earliest applications in improved prosthetic limbs, said researchers in the College of Engineering at Oregon State University. Later on, a more complete grasp of these principles could lead to walking or running robots that are far more agile and energy-efficient than anything that exists today.

"Human walking is extraordinarily complex and we still don't understand completely how it works," said Jonathan Hurst, an OSU professor of mechanical engineering and expert in legged locomotion in robots. There's a real efficiency to it -- walking is almost like passive falling. The robots existing today don't walk at all like humans, they lack that efficiency of motion and agility.

"When we fully learn what the human leg is doing," Hurst added, "we'll be able to build robots that work much better."

Researchers have long observed some type of high-power "push off" when the leg leaves the ground, but didn't really understand how it worked. Now they believe they do. The study concluded there are two phases to this motion. The first is an "alleviation" phase in which the trailing leg is relieved of the burden of supporting the body mass.

Then in a "launching" phase the knee buckles, allowing the rapid release of stored elastic energy in the ankle tendons, like the triggering of a catapult.

"We calculated what muscles could do and found it insufficient, by far, for generating this powerful push off," said Daniel Renjewski, a postdoctoral research associate in the Dynamic Robotics Laboratory at OSU. "So we had to look for a power-amplifying mechanism.

"The coordination of knee and ankle is critical," he said. "And contrary to what some other research has suggested, the catapult energy from the ankle is just being used to swing the leg, not add large amounts of energy to the forward motion."

Walking robots don't do this. Many of them use force to "swing" the leg forward from something resembling a hip point. It can be functional, but it's neither energy-efficient nor agile. And for more widespread use of mobile robots, energy use is crucially important, the researchers said.

"We still have a long way to go before walking robots can move with as little energy as animals use," Hurst said. "But this type of research will bring us closer to that."

The research was supported by the German Research Foundation. The Dynamic Robotics Laboratory at OSU is supported by the Human Frontier Science Program, the National Science Foundation and the Defense Advanced Research Projects Agency, and has helped create some of the leading technology in the world for robots that can walk and run.

One model can run a nine-minute mile and step off a ledge, and others are even more advanced. Robots with the ability to walk and maneuver over uneven terrain could ultimately find applications in prosthetic limbs, an exo-skeleton to assist people with muscular weakness, or use in the military, disaster response or any dangerous situation.


Story Source:

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


Journal Reference:

  1. S. Lipfert, M. Gunther, D. Renjewski, A. Seyfarth. Impulsive ankle push-off powers leg swing in human walking. Journal of Experimental Biology, 2013; DOI: 10.1242/jeb.097345

Cite This Page:

Oregon State University. "One step at a time, researchers learning how humans walk." ScienceDaily. ScienceDaily, 17 January 2014. <www.sciencedaily.com/releases/2014/01/140117090611.htm>.
Oregon State University. (2014, January 17). One step at a time, researchers learning how humans walk. ScienceDaily. Retrieved December 17, 2014 from www.sciencedaily.com/releases/2014/01/140117090611.htm
Oregon State University. "One step at a time, researchers learning how humans walk." ScienceDaily. www.sciencedaily.com/releases/2014/01/140117090611.htm (accessed December 17, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Wednesday, December 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

UN: Up to One Million Facing Hunger in Ebola-Hit Countries

UN: Up to One Million Facing Hunger in Ebola-Hit Countries

AFP (Dec. 17, 2014) Border closures, quarantines and crop losses in West African nations battling the Ebola virus could lead to as many as one million people going hungry, UN food agencies said on Wednesday. Duration: 00:52 Video provided by AFP
Powered by NewsLook.com
When You Lose Weight, This Is Where The Fat Goes

When You Lose Weight, This Is Where The Fat Goes

Newsy (Dec. 17, 2014) Can fat disappear into thin air? New research finds that during weight loss, over 80 percent of a person's fat molecules escape through the lungs. Video provided by Newsy
Powered by NewsLook.com
Why Your Boss Should Let You Sleep In

Why Your Boss Should Let You Sleep In

Newsy (Dec. 17, 2014) According to research out of the University of Pennsylvania, waking up for work is the biggest factor that causes Americans to lose sleep. Video provided by Newsy
Powered by NewsLook.com
Flu Outbreak Closing Schools in Ohio

Flu Outbreak Closing Schools in Ohio

AP (Dec. 17, 2014) A wave of flu illnesses has forced some Ohio schools to shut down over the past week. State officials confirmed one pediatric flu-related death, a 15-year-old girl in southern Ohio. (Dec. 17) Video provided by AP
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


Health & Medicine

Mind & Brain

Living & Well

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