Legged locomotion undoubtedly promises to offer the best mobility over complex terrain. Part of my research concentrates on the design, analysis and implementation of locomotion controllers for legged robots. My emphasis is on understanding and using the underlying dynamics, which I believe is necessary to achieve the speed and agility demonstrated by legged animals -- a long-time source of inspiration for researchers in robot locomotion. In our research, we adopt functional biomimesis, using specific principles from biomechanics of locomotion both for modeling and controller design.