Trauma Biomechanics. Third Edition

Transcription

1 Trauma Biomechanics Third Edition

2 Kai-Uwe Schmitt Peter F. Niederer Markus H. Muser Felix Walz Trauma Biomechanics Accidental Injury in Traffic and Sports Third Edition 123

3 PD Dr. Kai-Uwe Schmitt Prof. Dr. Peter F. Niederer (emeritiert) Institute for Biomedical Engineering University and ETH Zurich ETZ F90 Gloriastrasse 35 CH-8092 Zurich Dr. Markus H. Muser Prof. Dr. med. Felix Walz AGU Winkelriedstrasse 27 CH-8006 Zurich ISBN e-isbn DOI / Springer Heidelberg Dordrecht London New York Library of Congress Control Number: c Springer-Verlag Berlin Heidelberg 2010 This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilm or in any other way, and storage in data banks. Duplication of this publication or parts thereof is permitted only under the provisions of the German Copyright Law of September 9, 1965, in its current version, and permission for use must always be obtained from Springer. Violations are liable to prosecution under the German Copyright Law. The use of general descriptive names, registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. Cover design: deblik, Berlin Printed on acid-free paper Springer is part of Springer Science+Business Media (

4 Preface Injury is a leading cause of death, hospitalisation and disability world-wide. The World Health Organization predicts that unintentional injuries arising from road traffic incidents will rise to take third place in the rank order of international disease burden by the year Although these statistics and the associated economic costs are staggering, the effect of unintentional injury and death from trauma is more apparent, and more disturbing, when seen personally. By a young age, nearly everyone in the world, regardless of region, wealth or education, has had a relative or someone that they know killed or disabled in an "accident". The quality of life and financial effects on the injured person and their families and friends are plainly evident and clearly devastating. Many unintentional injuries are in reality not accidents; they could be prevented with changes in policy, education, or through improved safety devices. Arrayed against these preventable injuries, a diverse group of injury prevention researchers and practitioners work to decrease the incidence of unintentional injury. In trauma biomechanics, the principles of mechanics are used to understand how injuries happen at the level of the bones, joints, organs and tissues of the body. This knowledge is central in the development, characterization and improvement of safety devices such as helmets and seat belts and in the safe design of vehicles and equipment used for transportation, occupation and recreation. The field of trauma biomechanics is highly interdisciplinary, with engineers and physicists being centrally involved with medical practitioners and many other experts. This book, Trauma Biomechanics, is organized as a short primer of this subject and it provides a logical overview of the field. It is written to be accessible to a range of students or practitioners, while still providing considerable detail in each section. Each chapter contains plentiful and up-to-date references to guide readers who require more information on a particular topic. In contrast to the relative abundance of texts that describe basic biomechanics, sports biomechanics, gait analysis and orthopaedic biomechanics this is one of only two or three texts focused on trauma

5 VI Preface biomechanics that I am aware of. I have used a previous version of the book as a required text for a combined senior undergraduate- and graduate- level Mechanical Engineering class called the "Fundamentals of Injury Biomechanics" at the University of British Columbia. The students commented positively on the layout and accessibility of the book and they used it as a key reference in the assigned problems and project work in the class. I think the short primer structure of the book helped to make it accessible to the students. It is possible to start reading at the beginning of any chapter and quickly come up to speed with the most important basic knowledge about the anatomy, tolerance and injury prevention techniques for that region of the body. This is of great utility for students but also for people working in injury research contexts were they can be asked to rapidly switch their focus from injury in one area of the body or from one mechanism to another. This can occur not only while studying in university but also in many industrial and academic research contexts. For example, this is frequently required of people working on government-sponsored injury reconstruction teams or who are engaged in reconstructing injuries in the litigation context. I recommend this book as a key basic resource for anyone interested in injury prevention. Everyone, from graduate students working in an academic injury biomechanics setting to engineers, physicists, clinicians, surgeons, kinesiologists, biologists, statisticians and social scientists working in the broad field of injury prevention, frequently has questions about how injuries happen in various parts of the body. This book is an essential and accessible resource to anyone with these questions. Peter A. Cripton Associate Professor of Mechanical Engineering and Associate Faculty Member of the Department of Orthopaedics The University of British Columbia

6 Preface - 2nd edition Everyday, more than people are injured, 3000 killed, and disabled for life everyday on the world's roads. Likewise, sports related injuries are numerous and have a significant socio-economic impact. 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 classification, 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. As more people become aware of and understand this subject, it will someday lead to better mitigation and prevention of automotive and sports related injuries. I like this book very much and believe that you will find the same. King H. Yang Professor of Biomedical Engineering and Mechanical Engineering Director of Bioengineering Center Wayne State University

7 Acknowledgements The positive feedback that we have obtained from students and colleagues and in particular from our readers of the previous editions was the major source of motivation to tackle this third edition. Thank you! We highly appreciate the various suggestions which were of great help to further develop the book. In the present third edition the contents were updated with the latest knowledge and references and known mistakes and typos were corrected (surely adding a few new ones). As a particularly important addition for students, exercises of various levels of complexity were added. Nevertheless, we kept the original focus of the book. It primarily offers an introductory overview on different aspects of trauma biomechanics, but also serves as a quick reference for experts. Thus we hope to provide a suitable starting point for sharing our excitement and enthusiasm about this field of biomechanics research. Kai-Uwe Schmitt, Peter Niederer, Markus Muser, Felix Walz

8 Contents 1 Introduction About the contents of this book Historical remarks References Methods in Trauma Biomechanics Statistics, field studies, databases Basic concepts of biomechanics Injury criteria, injury scales and injury risk Accident reconstruction Experimental models Standardised test procedures Anthropomorphic test devices Numerical methods Summary Exercises References Head Injuries Anatomy of the head Injuries and injury mechanisms Mechanical response of the head Injury criteria for head injuries Head Injury Criterion (HIC) Head Protection Criterion (HPC) ms criterion (a 3ms ) Generalized Acceleration Model for Brain Injury Threshold Head injuries in sports Head injury prevention Head injury prevention in pedestrians Summary...88

9 X Contents 3.8 Exercises References Spinal Injuries Anatomy of the spine Injury mechanisms Biomechanical response and tolerances Injury criteria Neck injury criterion NIC N ij neck injury criterion Neck protection criterion N km Lower Neck Load Index (LNL) Neck injury criteria in ECE and FMVSS Further neck injury criteria Correlating neck injury criteria to the injury risk Spinal injuries in sports Prevention of soft tissue neck injury Head restraint geometry and padding material Controlling head restraint position Controlling seat back motion Summary Exercises References Thoracic Injuries Anatomy of the thorax Injury mechanisms Rib fractures Lung injuries Injuries to other thoracic organs Biomechanical response Frontal loading Lateral loading Injury tolerances and criteria Acceleration and force Thoracic Trauma Index (TTI) Compression Criterion (C) Viscous Criterion (VC) Combined Thoracic Index (CTI) Other criteria Thoracic injuries in sports...163

10 Contents XI 5.6 Summary Exercises References Abdominal Injuries Anatomy of the abdomen Injury mechanisms Testing the biomechanical response Injury tolerance Injury criteria Influence of seat belt use Abdominal injuries in sports Summary Exercises References Injuries of the Pelvis and the Lower Extremities Anatomy of the lower limbs Injury mechanisms Injuries of the pelvis and the proximal femur Leg, knee and foot injury Impact tolerance of the pelvis and the lower extremities Injury criteria Compression force Femur Force Criterion (FFC) Tibia Index (TI) Other criteria Pelvic and lower extremity injuries in sports Prevention of lower extremity injuries Pedestrian injury conuntermeasures Summary Exercises References Injuries of the Upper Extremities Anatomy of the upper limbs Injury incidences and mechanisms Impact tolerance Injury criteria and evaluation of injury risk from airbags Upper extremity injuries in sports Summary...226

11 XII Contents 8.7 Exercises References Impairment and injuries resulting from chronic mechanical exposure Occupational health Sports Non contact sports Contact sports Household work Summary References Solutions to exercises Subject index...247