The objective of this paper is to identify the parameters of a new plane biodynamic model of a man jumping down on a hard base. In the modelling of this kind of dynamic phenomena, with dominant directions of human body motion and reactions, many simple and complex models have already been applied. Some of them were lumped parameter and unidirectional [Książek, 1999], [Fritz, 2001] or plane [Pandy, 1990], [Farley, 1998]. There are also spatial models, applied in the sport and medical investigations of the kinematics and dynamics of the human body [Morecki, 1990], [A. Nagano and col., 2005]. The presented approach has been founded on the results of experiments described in [Nosiadek, 2006] where body motions of 40 men volunteers were registered during drop jumping and landing from several assumed heights. By means of video cameras in 3D space and a dynamic platform linear and angular displacements of participants’ bodies and three mutually perpendicular components of the dynamical reactions between the feet and platform were measured. The numerical results of the displacements were numerically remodelled by the authors of the present paper and used for synthesis of models of muscles of a man during drop landing. Similar investigations can be found in [Pain and Challis, 2006].