Russian and American engineers have teamed up to develop a new, natural feeling prosthetic foot. It was invented in the mid 1970s by Mark Pitkin, a Russian born professor of mechanical engineering at Tufts University School of Medicine in Boston. Pitkin's work caught the eye of Mort Lieberman, an engineer at Albuquerque's Sandian National Laboratories. He along with his colleagues will use their skills in materials sciences, stress analysis and computer modeling to help develop the foot.