New Study Reveals Truth Behind Muscle Power

Muscles are a major part of our bodies, doing everything from pumping blood through our heart to allowing us to walk. Now, doctors may have a new way of thinking about how to treat heart and skeletal muscle diseases thanks to a new study that's given researchers an in-depth look as to how muscles generate power.

Muscles generate power when filaments of myosin tugging on filaments of actin shorten, or contract, the muscle. For the past fifty years, researchers believed that this power only came from what happened straight up and down the length of the muscle. Yet this new research seems to indicate otherwise.

In order to learn a bit more about muscles, researchers used computer modeling to test the geometry and physics of how muscles work. The computer results were then validated through X-ray diffraction experiments on moth flight muscle, which is very similar to human cardiac muscle. This allowed the scientists to gather a new understanding of muscle dynamics, which has enormous implications for the research and use of all muscles, including organs.

So what did these new findings show? It turns out that force is generated in multiple directions in a muscle and not just along the long axis of its length. This aspect of muscle power has been unknown for decades and is now becoming a critical feature of scientists' understanding of normal and pathological aspects of muscle.

"In the heart especially, because the muscle surrounds the chambers that fill with blood, being able to account for forces that are generated in several directions during muscle contraction allows for much more accurate and realistic study of how pressure is generated to eject blood from the heart," said Michael Regnier, a UW bioengineering professor, in a news release. "The radial and long axis forces that are generated may be differently compromised in cardiac diseases and these new, detailed models allow this to be studied at a molecular level for the first time."

The findings are crucial for future studies of muscles and could eventually lead to better treatments.

The research is published in the journal Proceedings of the Royal Society B: Biological Sciences.