Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Grouping muscles to make controlling limbs easier

22.04.2009
With more than 30 muscles in your arm, controlling movement -- whether it's grasping a glass or throwing a baseball -- is a complex task that potentially takes into account thousands of variables.

But researchers at Northwestern University have shown that it could be possible to control a limb by stimulating groups of muscles rather than individual muscles -- a finding that could make it easier to restore muscle movements in people who have become paralyzed.

The researchers used a model of the muscles in a frog's hind leg to perform a computational analysis that, when run as a simulation, shows that researchers can control the limb using muscle groups just about as well as if they controlled individual muscles. The findings were published last week by the Proceedings of the National Academy of Sciences.

"By controlling muscle groups instead of individual muscles, we're reducing the variables, but we're not losing efficiency," said Matthew Tresch, assistant professor of biomedical engineering at the McCormick School of Engineering and Applied Science and of physical medicine and rehabilitation at the Feinberg School of Medicine. Tresch and colleagues from the Rehabilitation Institute of Chicago conducted the research.

The idea that the body's nervous system controls a limb using muscle groups, or "synergies," has been a controversial hypothesis in the research community for the last decade. If this were the case, it would reduce the number of variables that the nervous system needs to control.

"We still don't know if that's how the central nervous system works, but what has been missing from the rhetoric is the question of whether this is a viable way to produce behavior," said Tresch. "That's what our experiment tried to do."

Using both analytical approaches and techniques from control theory, the researchers chose the muscle combinations that let the frog's hind leg do what it wants to do most effectively. The simulation showed that by choosing the most effective balance of muscle synergies, the researchers could control movement without degrading performance.

"Having all these muscle variables complicates control of behavior, but it also makes certain behavior easier," said Tresch. "The complexity might be there to make certain kinds of movements more efficient than others."

By having this framework, researchers might be able to predict how muscle activation changes when a person loses a muscle or becomes paralyzed.

"Whether or not the nervous system uses this, it does seem like an approach that can simplify control for a complicated mechanical system, like a limb," said Tresch. "For people with spinal cord injuries, you can put electrodes into their muscles and stimulate them. We can use this synergies approach to make controlling a limb simpler."

Next Tresch will perform similar research using a rat model, and he is currently working with other professors at Northwestern to bring the research to patients.

"The end goal is to restore movement in people who are paralyzed," he said.

Megan Fellman | EurekAlert!
Further information:
http://www.northwestern.edu

More articles from Health and Medicine:

nachricht New malaria analysis method reveals disease severity in minutes
14.08.2017 | University of British Columbia

nachricht New type of blood cells work as indicators of autoimmunity
14.08.2017 | Instituto de Medicina Molecular

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>