April 20, 2009

Grouping muscles makes limb control easier

Researchers at Northwestern University in Chicago say it may be possible to control a limb by stimulating groups of muscles rather than individual muscles.

Matthew Tresch and colleagues from the Rehabilitation Institute of Chicago said with more than 30 muscles in an 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.

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 researchers can control the limb using muscle groups just about as well as if they controlled individual muscles.

By controlling muscle groups instead of individual muscles, we're reducing the variables, but we're not losing efficiency, Tresch said in a statement.

The findings were published in the Proceedings of the National Academy of Sciences.