Walking is a vital means of mobility for most people. While walking is easy for healthy people, for individuals who have suffered a stroke and have partial paralysis of one side of their body (hemiparesis), walking can be difficult. Often, these people will avoid walking, because their gait requires nearly twice the metabolic energy of healthy gait. These increased energy demands may partially explain why stroke patients tend to walk slowly and avoid carrying heavy loads, impairing their daily activities. Dr. Max Donelan’s research aims to advance our understanding of the fundamental principles that underlie locomotion physiology and to apply these principles to directly improve human health. Across the range of his research, he uses a combination of mathematical modeling and empirical experimentation, which involves techniques from biomechanics, energetics and neurophysiology. To study the metabolic cost of gait after stroke, Dr. Donelan is determining the important mechanisms that make normal walking easy and energy-efficient, and how these mechanisms are compromised in individuals with stroke-related paralysis. The results of his research will guide the design of rehabilitation strategies and devices aimed at lowering metabolic cost and increasing patient mobility.