Before revision: In 2008, researchers from Rensselaer Polytechnic Institute, West Chester University and the University of California, Santa Cruz used digital particle image velocimetry to prove Gray wrong .
After revision: In 2008, researchers from Rensselaer Polytechnic Institute, West Chester University and the University of California, Santa Cruz used digital particle image velocimetry to prove that Gray's assumptions about the relationship between muscle power and drag force were mistaken .