Abstract A beam type finite element computer model is used to predict the natural frequency response of a human tibia with varying geometries, mass formulations and boundary conditions. Results are compared to analytic solutions and to published computer and experimental results. Variations between lumped and consistent mass formulations were found to be small, but significant. The effects of tibial twist and curvature were generally of the same order as the mass effects, with notable exceptions depending on boundary conditions. In fact, the major changes in predicted frequencies occurred with changes in boundary conditions. Variable springs at the boundaries were introduced to show a more continuous variation between free and fixed boundary conditions. Accuracy and repeatability of experimental and analytic results are examined in light of possible clinical applications.