Emulation of the human torso dynamic effects during walking gait

An approach consisting of the identification of a minimal mechanical system which is capable to emulate the dynamic effects of the human torso during walking gait is presented. A 3D dynamic simulation of a virtual manikin with 27 degrees of freedom (DOFs) is carried out in order to identify the effort wrench exerted by the torso on the lower limbs. An analysis of the six components of this wrench shows that some components are dependant. A systemic study of two, three and four DOFs mechanisms based on general state equation formalism leads to an interesting result. Indeed, four DOFs are necessary and sufficient to emulate the dynamic effects. We also show the efficiency and generality of the proposed approach.