Abstract: In bio-inspired design activities, nature is a basis of knowledge. Over the last twenty years, many solutions to measure and analyze human or animal gaits have been developed (VICON system, X-ray radiography...). Although, these methods are becoming more and more accurate, they are quite expensive, long to set up and not easily portable. In this paper, a method called the bio-inspired topological skel-eton is proposed in order to complement the classic videography process and to enable animal gait analysis. A new predictive kinematic model with closed-loops of an unguligrade quadruped is suggested. This kinematic model includes three segments per leg and takes into account the scapula movements. The proposed method allows us to improve the accuracy of the kinematic input data measured from a single video including an additional artefact. To show the benefits of this method, joint parameters that are difficult to measure are derived symbolically from the kinematic model and compared with experimental data.

Key words: quadruped locomotion, motion analysis, topological skeleton, closed-form solutions, Multibody Systems (MBS)