The response of the head to impact was investigated using live anesthetized and postmortem Rhesus monkeys and repressurized cadavers. The stationary test subject was struck by a guided moving impactor of 10 kg for monkeys; 25 or 65 kg for cadavers. The impactor striking surface was fitted with padding to vary the contact force-time characteristics. The experimental technique used a nine-accelerometer system rigidly mounted on the head to measure head motion, transducers placed at specific points below the skull to record epidural pressure, repressurization of both the vascular and cerebral spinal systems of the cadaver model, and high-speed cineradiography (at 400 or 1000 frames per second) of selected test subjects. The results of the tests demonstrate the potential importance of skull deformation and angular acceleration on the injury produced in the live Rhesus and the damage produced in both the post-mortem Rhesus and the cadaver as a result of impact.