New Theory on Muscle Force Development?

The basics of how a muscle generates power remain the same: Filaments of myosin tugging on filaments of actin shorten, or contract, the muscle – but the power doesn’t just come from what’s happening straight up and down the length of the muscle, as has been assumed for 50 years.

Instead, University of Washington-led research shows that as muscles bulge, the filaments are drawn apart from each other, the myosin tugs at sharper angles over greater distances, and it’s that action that deserves credit for half the change in muscle force scientists have been measuring

http://www.washington.edu/news/2013/07/09/biceps-bulge-calves-curve-50-year-old-assumptions-muscled-aside/