A 3-Link Model of a Human for Simulating a Fall in Forward Direction

In this study we consider a 3-link biomechanical model of a human for simulating a forward fall. Individual segments of the human body are modelled as rigid bodies connected by the rotary elements which correspond to the human joints. The model implemented in Mathematica is constructed based on a planar mechanical system with a non-linear impact law modelling the hand-ground contact. Due to kinematic excitation in the joints corresponding to the hip and the shoulder, the presented fall model is reduced to a single-degree-of-freedom system. Parameters of the model are obtained based on the three-dimensional scanned human body model created in Inventor, while its kinematics (time histories of the angles in hip and shoulder joints) are obtained from the experimental observation with the optoelectronic motion analysis system. Validation of the model is conducted by means of comparing the simulation of impact force with experimental data obtained from the force plate. Finally, the obtained ground reaction forces can be useful in further studies, as a load conditions, for finite element analysis of the numerical model of the human upper extremity.