In the discrete modeling of bone it is common practice to assume that bone behaves as an isotropic material. Bone can exhibit directionally different material properties. A rate-dependent transversely isotropic material model has been developed in order to better represent the actual behavior of bone. This m aterial model is incorporated into the DYNA3D family of nonlinear, explicit finite elem ent codes. A model of a thick walled hollow cylinder was created to simulate the bending behavior long bones. Using this analogue model, sensitivity studies were conducted to determine the effects of using this newly developed directionally dependent material model on the bending strength of bone. A finite element model of a female upper extremity was created using data from computed tomography of a cadaveric upper extremity. To properly describe the bone mechanics, a new constitutive law was applied to the model. The radius was tested to fracture in tension, compression, torsion and three-point bending. The fracture patterns predicted in these sim ulations using the newly developed material model were consistent with the patterns observed in the literature. Quasi-static simulations of the radius and ulna predicted bending failure moments that were correlated with data from the literature. The finite element upper extremity model was also verified against drop tests conducted at the University of Virginia Automobile Safety Laboratory.