Watching these in action is surreal. The panning-shot at 5:00 is feels like science-fiction: the sheer ease and grace of his stride’s almost spooky. After losing his lower-legs to frostbite, Herr started developing simple prosthetics so he could resume rock-climbing. Then he started adding computers and actuators into the mix. The current generation senses nerve impulses and intelligently mimics a biological limb to such an extent that little training or acclimation is required.