AERTS , P; Univ. of Antwerp (BE): Locomotor performance and strategies in frogs: a simple modelling approach

A simple mathematical model consisting of an ellipsoid body and telescopic limbs, driven by actuators with muscle-like properties, is used to assess locomotor performance and strategies in frogs. Fmax and Vmax of the actuators are tuned in such a way that, upon full activation, the model performs realistic jumps. These muscle characteristics are then used to mimic aquatic locomotion. The reliability of the approach is successfully tested by comparing maximal model performance (in terms of propulsive impulse) with the performance of animals stimulated to flee with maximal efforts. Obviously, the interaction between the physical properties of the environment and of the �muscles� suffices to explain the seemingly poor aquatic performance when compared to the jumping impulses. A sensitivity analysis indicates that adjusting intrinsic muscle speed offers the best option to improve maximal (aquatic) performance. Finally, the model is used to gain insight in coordination and control of submaximal swimming performance.