Book excerpt: The 2004 World Health Day is dedicated to the theme of road safety by the World Health Organization (WHO) due mostly to the enormous socio economic costs attributed to trafik accidents. More than 140,000 people are injured, 3,000 killed, and 15,000 disabled for life everyday on the world's roads. The field of trauma biomechanics, or injury biomechanics, uses the principles of mechanics to study the response and tolerance level of biological tissues under extreme loading conditions. Through an understanding of mechanical factors that influence the function and structure of human tissues, countermeasures can be developed to alleviate or even eliminate such injuries. This book, Trauma-Biomechanics, surveys a wide variety of topics in injury biomechanics including anatomy, injury c1assification, injury mechanism, and injury criteria. It is the first collection I am aware of that lists regional injury reference values, or injury criterion, either currently in use or proposed by both U. S. and European communities. Although the book is meant to be an introduction for medical doctors and engineers who are beginners in the field of injury biomechanics, sufficient references are provided for those who wish to conduct further research, and even established researchers will find it useful as a reference for finding the biomechanical background of each proposed injury mechanism and injury criterion.