Five anesthetized porcine subjects were exposed to blunt thoracic impact using a 21 kg mass with a flat contact surface traveling at 3.0 to 12.2 m/s. The experiments were conducted to assess the appropriateness of studying in vivo mechanical and physiological response to thoracic impact in a porcine animal model.A comprehensive review of comparative anatomy between the pig and man indicates that the cardiovascular, respiratory and thoracic skeletal systems of the pig are anatomically and functionally a good parallel of similar structures in man. Thoracic anthropometry measurements document that the chest of a 50 to 60 kg pig is similar to the 50th percentile adult male human, but is narrower and deeper. Peak applied force and chest deflection are in good agreement between the animal's responses and similar impact severity data on fresh cadavers. A thorough autopsy, performed at the completion of each test, revealed rib fracture injury patterns and thoracic organ hemorrhage levels which are similar to injuries produced in fresh cadavers. Other observations are that the living porcine model exhibits peak sternal accelerations, cardiovascular overpressures, resultant rib fractures and AIS ratings that are lower and spinal accelerations that are higher in amplitude than typical levels reported for pressurized fresh cadavers.