Movement of the Stick Insect (image) University of Cologne Share Print E-Mail Caption While the central nervous system has to actively control fast movements of large limbs, passive muscle force can suffice for the movement velocity and movement amplitude of small and light limbs. Credit Arndt von Twickel et al. Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.