Navigation Links
Grouping muscles to make controlling limbs easier
Date:4/20/2009

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.


'/>"/>

Contact: Megan Fellman
fellman@northwestern.edu
847-491-3115
Northwestern University
Source:Eurekalert

Related biology news :

1. Genome of saltwater creature could aid understanding of gene grouping
2. As good as it gets: Octogenarian muscles dont get stronger with exercise
3. Motor nerve targeting to limb muscles is controlled by ephrin proteins
4. Post-exercise caffeine helps muscles refuel
5. Stem-cell transplantation improves muscles in MD animal model, UT Southwestern researchers report
6. How molecular muscles help cells divide
7. Probing and controlling molecular rattling may mean better preservatives
8. Controlling cucumber beetles organically
9. Brain enzyme may play key role in controlling appetite and weight gain
10. bioMETRX, Inc. Signs Deal To Acquire Controlling Interest in Biometric Solutions, LLC
11. Hidden infections crucial to understanding, controlling disease outbreaks
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/11/2017)... NXT-ID, Inc. (NASDAQ:   NXTD ) ... appointment of independent Directors Mr. Robin D. Richards ... Directors, furthering the company,s corporate governance and expertise. ... Gino Pereira , Chief Executive ... their guidance and benefiting from their considerable expertise as we ...
(Date:4/5/2017)... April 5, 2017 Today HYPR Corp. ... the server component of the HYPR platform is officially ... the end-to-end security architecture that empowers biometric authentication across ... has already secured over 15 million users across the ... of connected home product suites and physical access represent ...
(Date:4/3/2017)... 3, 2017  Data captured by IsoCode, ... detected a statistically significant association between the ... treatment and objective response of cancer patients ... predict whether cancer patients will respond to ... well as to improve both pre-infusion potency testing ...
Breaking Biology News(10 mins):
(Date:10/10/2017)... ... October 10, 2017 , ... San Diego-based team building ... corporate rebranding initiative announced today. The bold new look is part of a ... company moves into a significant growth period. , It will also expand its service ...
(Date:10/10/2017)... ... October 10, 2017 , ... ... program has won a US2020 STEM Mentoring Award. Representatives of the FirstHand program ... in Volunteer Experience from US2020. , US2020’s mission is to change the trajectory ...
(Date:10/10/2017)... DALLAS , Oct. 10, 2017 International research firm ... IoT Strategy, will speak at the TMA 2017 Annual Meeting , ... key trends in the residential home security market and how smart safety ... ... "The ...
(Date:10/10/2017)... ... October 10, 2017 , ... USDM Life Sciences , ... life sciences and healthcare industries, announces a presentation by Subbu Viswanathan and Jennifer ... “Automating GxP Validation for Agile Cloud Platforms,” will present a revolutionary approach to ...
Breaking Biology Technology: