Fast motions in biomechanics and robotics : optimization and feedback control In the past decades much progress has been made in the field of walking robots. The current state of technology makes it possible to create humanoid robots that nearly walk like a human being climb stairs or avoid small stacles. However the dream of a robot running as fast and as elegantly as a human is still far from becoming reality. Control of such fast motions is still a big technological issue in robotics and the maximum running speed of contemporary robots is still much smaller than that of human track runners. The conventional control approach that most of these robots are based on does not seem to be suitable to increase the running speeds up to a biological level. In order to address this challenge we invited an interdisciplinary community of researchers from robotics biomechanics control engineering and applied mathematics to come together in Heidelberg at the Symposium “Fast Motions in Biomechanics and Robotics – Optimization & Feedback Control” which was held at the International Science Forum (IWH) on September 7–9 2005. The number of participants in this symposium was kept small in order to promote discussions and enable a fruitful exchange of ideas. Re injecting the Structure in NMPC Schemes Application to the Constrained Stabilization of a Snakeboard Recent Advances on the Algorithmic Optimization of Robot Motion A Spring Assisted One Degree of Freedom Climbing Model Fast Direct Multiple Shooting Algorithms for Optimal Robot Control Stability Analysis of Bipedal Walking with Control or Monitoring of the Center of Pressure Multi Locomotion Control of Biped Locomotion and Brachiation Robot On the Determination of the Basin of Attraction for Stationary and Periodic Movements Task Level Control of the Lateral Leg Spring Model of Cockroach Locomotion Investigating the Use of Iterative Learning Control and Repetitive Control to Implement Periodic Gaits Actuation System and Control Concept for a Running Biped Dynamical Synthesis of a Walking Cyclic Gait for a Biped with Point Feet Performing Open Loop Stable Flip Flops — An Example for Stability Optimization and Robustness Analysis of Fast Periodic Motions Achieving Bipedal Running with RABBIT: Six Steps Toward Infinity Velocity Based Stability Margins for Fast Bipedal Walking Nonlinear Model Predictive Control and Sum of Squares Techniques Comparison of Two Measures of Dynamic Stability During Treadmill Walking Simple Feedback Control of Cockroach Running Running and Walking with Compliant Legs Self stability in Biological Systems — Studies based on Biomechanical Models Holonomy and Nonholonomy in the Dynamics of Articulated Motion Dynamic Stability of a Simple Biped Walking System with Swing Leg Retraction.