The way muscles work changes when a person goes from slow, even movements to rapid, unsteady movements. Anyone who’s pulled a muscle after a sudden motion knows that. What we don’t know is exactly how muscle function changes when dynamic movement is introduced. A new NSF-funded project co-led by Simon Sponberg, Dunn Family Associate Professor in the School of Physics and School of Biological Sciences, will examine dynamic muscle function of humans and animals with the goal of creating improved physical therapy and rehabilitation programs and mobility assistance devices. That translates to more humans who can move with less pain.