The objective of this study was to determine the dynamic force-deflection characteristics of the human lower thoracic region. Five unembalmed cadavers with vascular pressurization were subjected to impact on the right lower anterior region of the thorax at a velocity of 4.3 m/s. A pendulum (23.5 kg, 150 mm diameter face) delivered the impact. The force-time history was obtained from the load cell attached to the pendulum impactor. Deflections at the impact site were obtained using the chest band signals. Force-deflection curves were obtained by eliminating the time variable between the force and deflection time histories. Peak impact forces ranged from 1.9 to 2.7 kN (mean: 2.29 kN ± 0.38). Peak deflections ranged from 34 to 85 mm (mean: 59.3 mm ± 18.1). Detailed autopsy revealed rib and liver trauma. The nonlinear force-deformation curves presented in this study provide fundamental data for the design of anthropomorphic test devices with improved biofidelity so that injury can be predicted in realworld crash environments.