Dynamic modeling approach to gymnastic coaching

The authors present a system for coaching novice gymnasts in performing the kip based on detailed body information. They study the kip using a pendulum and kinematically redundant 3-link model. Their simulations have shown that a variable length pendulum model is sufficient for modeling the dynamics of an expert gymnast´s center-of-mass without considering the complex parameters of the 3-link model. The authors optimize the dynamics equations of the pendulum using boundary conditions obtained from an expert gymnast´s center-of-mass trajectory. By varying these conditions they discover target and timing regions of success and other finds of basic coaching information. The authors input this information to the 3-link model to obtain detailed coaching information such as center-of-mass trajectories matched to the user´s body characteristics and corresponding torque data. This system improves on current coaching techniques for the kip