For the purpose of increasing available knowledge of human dynamic response and tolerance to thoracic impact, and experimental investigation of both blunt and localized impacts to embalmed and unembalmed human cadavers is being carried out. This is a progress report to date.Force and deflection time histories resulting from midsternal A-P impacts over a six inch diameter area and from blows localized near the costo-chrondral junctions were measured and cross plotted to provide dynamic force-deflection characteristics. The extent of skeletal damage was assessed by both radiological examination and thoracic dissection and is presented in relation to the impact parameters.X-ray assessment of rib fracture damage was found to be inadequate, revealing on the average less than half of the fractures confirmed by dissection.When compared with existing data for embalmed cadavers from a different source, the new results for embalmed specimens demonstrate similar skeletal damage characteristics on a deflection basis but somewhat lower associated forces and thoracic stiffness values. It is suspected that differences in embalming and subsequent storage practice relate to these findings. From the current study the stiffness of unembalmed specimens is somewhat less than that of the embalmed.Many questions concerning human thoracic stiffness and tolerance to dynamic loading remain unanswered at this time, and the work reported here is being continued.