His primary research interest is the biomechanical basis for the energetic cost of locomotion. Rodger studies basic scientific aspects of walking and running in healthy, young people, and how obesity, aging, prosthetics and shoes affect locomotion energetics and biomechanics. In addition to his human studies, Rodger has studied more than 40 animal species ranging in size from ants to elephants and in speed from tortoises to pronghorn antelope. He invented the first useful force-measuring treadmill and enjoys devising novel devices to facilitate his research. He has published approximately 100 peer-reviewed scientific articles, including some in prestigious journals including Nature, Science and the Proceedings of the Royal Society.