Long, heavy limbs such as arms or legs differ fundamentally from short, light limbs such as fingers in their ability to execute fast movements. While the central nervous system has actively controls fast movements of large limbs, passive muscle force can suffice for the movement velocity and movement amplitude of small and light limbs. That is the result of a study conducted on the stick insect by the zoologists Ansgar Bueschges, Arndt von Twickel and Christoph Guschlbauer at the University of Cologne in cooperation with the visiting scientist Scott Hooper from Ohio University. The paper, “Swing Velocity Profiles of Small Limbs Can Arise from Transient Passive Torques of the Antagonist Muscle Alone,” has been published in Current Biology.