Contact modeling and inverse dynamics identification of the handspring front somersault in pike position

摘要

Handspring front somersaults are explosive and exciting events consisting of several distinct ballistic motion and support phases, in which the gymnast contacts the springboard/mat and the table, respectively, with his feet and hands. The purpose of this article is to develop an effective formulation for the inverse dynamics simulation of all the vaults that are suitable for analyses in two dimensions. A planar model of a jumper composed of 16 rigid segments connected by 15 hinge joints is used in the computations. The determinate inverse dynamics formulation, developed in Cartesian coordinates of the segments, allows for the explicit estimation of the resultant muscle torques in the joints and external reactions (up to three components) during the analyzed vaults. By using a projection method, the analysis is then confined to the lower limbs. A computational scheme for the indeterminate inverse dynamics is proposed to distribute the previously assessed net torques in the limbs into the respective muscle forces based on static optimization solution. The reaction forces in the lower limb joints are finally determined following the projection-based formulation. Some numerical results of the inverse dynamics simulation of the handspring front somersault in pike position are reported.