Singing or Screaming Muscles?

This segment NPR Weekend Edition Saturday March 26, 2016 got me thinking. The segment was titled Glitch In Your Golf Swing? Listen To It Sing “Stanford professor Jonathan Berger turns golf stroke data into sound. A nice sound means it's a good swing, a sour sound means something's not right. In this revealing piece he tells Scott Simon how that helps people learn.” The same can be said for EMG data. If you isolate a muscle and put it a position of mechanical disadvantage it will scream at you – in other words it will show high level of activity. On the other hand when that muscle is integrated into a functional movement it will sing, it will show periods of high activity, less activity or even no activity when it works synergistically with it’s partners to produce smooth efficient coordinated movement. So the take home message when interpreting research from EMG data ask if the muscle is screaming or singing. If the muscle is singing then the EMG data is more valuable than if it is screaming. Just because you have high muscle activity does not mean it will transfer to efficient movement.