Report FH-117608 IMPACT TOLERANCE - ABDOMINAL INJURY Prepared for: Federal Highway Administration Department of Transportation National Highway Safety Bureau Washington, D.C. 20591 June 30, 1971 Final Report for Period July 1 , 1970 - June 30, 1971 David 1. Beckman James H. McEl haney Verne L. Roberts Richard L. Stal naker Highway Safety Research Institute The University of Michigan Ann Arbor, Michigan 481 05 1 1. Report No. 2. Government Accession No. 3. Rcc~plent'sCatalog No. 4. Title and Subtitle 5. Report Date June 30, 1971 Impact To1 erance - Abdominal Injury 6. Perfornrllig Organization ~ot~e 7. Author(s) 8. Perforni~ngOrgani~at~on Kcport No. D.L. Beckman, J.H. McElhaney, V.L. Roberts and HSRI -71 -1 02 R.L. Stalnaker 9. Performing Organizat~onName and Address 10. Work Unit No. Highway Safety Research Institute The University of Michigan v11. Contract or Grant No. Huron Parkway and Baxter Road Ann Arbor, Michigan 48105 FH-11-7608 13. Type of lieport and Period Covered 12. Sponsoring Agency Name and Address Final Report National Highway Traffic Safety Administration July 1, 1970 to June 30, U.S. Department of Transportation I Nassif Building 14. Sponsor~ngAgency Code Washington, D.C. 20591 I 1 15. Supplementary Notes 16. Abstract In order to provide data on human to1 erance to blunt abdominal impact a literature study and laboratory tests were carried out to determine the major causes of abdominal injury, injury mechanisms, a quantitative re1 ationship between input and occurrence of trauma and to develop the criteria to recommend performance requirements for materials which often produce blunt abdominal injury. An extensive analysis of case reports indicated that the most frequent causes of blunt abdominal injury were the steering wheel, seat belt and various protruding objects in a vehicle; the organs most often injured were the liver, pancreas, spleen and intestine. However the results indicate that the vervet monkey (Cercopithecus er thrus) can survive (injury level of 3) blunt impacts to the upper abdomen Wl~riousimpactors used at velocities up to 22 mph, while in the midabdomen it can survive impacts of this type of approximately 26 mph and in the lopler abdomen of 34 mph. 19. Security Classil'.(of this rcport) 20. Sccurlty Classil,(of thlc page) 21. No. of I'agcs 22. Prl~e Form DOT F 1700.7 (8-69) TABLE OF CONTENTS Page Table of Contents ............................................... i Figures ......................................................... iii Tables ........................... ........................ iv Ac know1 edgments ................................................ v 1.0 Summary .................................................. 1 2.0 Introduction ................................................ 2 3.0 Definition and Analysis of Abdominal Injuries; Injury Types and Probability of Occurrence . Literature Review .......... 3 3.1 Injury Scale ............................................ 3 3.2 Injury Pattern and Mechanism ........................... 4 3.3 Summary and Conclusions of the Literature Review ........ 73 4.0 1.lechanisms of Injury - Literature Review .................... 76 4.1 Injury to the Pancreas ................................. 76 4.2 General Mechanism of Injury to the Small Bowel ......... 77 4.3 Duodenum ........*............. ...............*..... 78 4.4 Colon .................................................. 79 4.5 Ureter and Bladder ..................................... 79 4.6 Abdominal Wall Injuries ................................ 79 4.7 Liver .............................................. 80 4.8 Gall Bladder .......................................... 82 4.9 Kidney ................................................. 82 4.10 Spleen ............................................ 83 Table of Contents continued Page 5.0 Experimental Studies of Abdominal Trauma .................... 84 5.1 Introduction .......................... ............. 84 5.2 Test Methods ........................................... 84 5.2.1 Vervet Monkey Front Abdominal Impacts ........... 84 5.2.1.1 Sled Test with Lap Belt and Air Bag ...... 85 \ 5.2.1 .2 Abdominal Impacts ........................ 86 5.2.2 Iyli ni -Pi g Front Abdominal Impact ................. 87 5.2.3 Biomedical Data Collection ...................... 87 5.3 Results ................................................ 89 5.3.1 Results of Vervet Monkey Abdominal Impacts .......................................... 89 . 5.3.2 Sled Tests Vervet Monkey ........................ 90 5.3.3 Results of Mini -Pig Abdominal Impacts ........... 90 6.0 A Illathematical Iflode1 for Abdominal Impact .................. 111 6.1 Introduction ........................................ 111 6.2 Formulation of the Problem ............................ 113 6.3 Selected References .................................. 126 6.4 Nomenclature .......................................... 127 7.0 Recommendations and Conclusions ....................... .... 129 8.0 References Cited .......................................... 130 Appendix A Bi bl iography ....................................... A1 . Appendix B Representative Data Sheets ......................... B1 Appendix C Cases of Abdominal Injury from Review of the Literature .................................... C1 FIGURES Page Figure 1 . Over-a1 1 View of Impacting Facility .................. 98 Figure 2 . Block Diagram of Head Impact Facil i ty ................. Figure 3 . Block Diagram of High Acceleration Test Facility ............................. .............. Figure 4 . Typical Set-Up for Lap Belt Sled Test with Air Bag ... Figure 5 . Air Bag Pressure Re1 i ef Val ve ....................... Figure 6 . Rigid Impactor ...................................... Figure 7 . Flexible Impactor ................................... Figure 8 . Typical Set-Up for Test with Rigid Impactor .......... Figure 9 . Typical Set-Up for Test with Flexible Impactor ....... Figure 10 . Typical Mini-Pig Impact Set-Up ....................... Figure 11. Typical Spleen Injury from Rigid Impactor ............ Figure 12 . Stomach Injury from Flexible Impactor ............... Figure 13. Typical Liver Injury from Round Rigid Impactor ....... Figure 14 . Geometry of a Shell of Revolution Showing Various Coordinates ......: ......................... Figure 15. Side View of an Element of Shell in Undeformed and in Deformed State .................................. TABLES Page Table I . Seat Belt ...................................... 8 Table I1 . Steering Wheel .................................. 16 Table I11 . Pedestrian ...................................... 24 Table IV . Detailed Reports ................................ 35 Table V . Bicycle Accidents ................................ 39 Tab1 e VI . Cbtorcycl e ...................................... 43 Table VII . Ejection ........................................ 46 Table VI I1 . Bl unt Abdominal Compression Trauma ............... 49 Table IX . Unspecified Blunt Abdominal 'Trauma ............... 51 . Table X . Mi scell aneous Vehicular Bl unt Abdominal Trauma ................................... 70 Table XI . Injury Count .................................... 71 Table XI1 . Summary Injury Patterns ......................... 75 Table XI11 . Test Data ....................................... 92 Table XIV . Injury Patterns from Tests ...................... 93 Table XV . Post Mortem Examination Data .................... 94 Table XVI . Additional Test Data ............................ 97 ACKNOWLEDGEMENTS This research program was carried out by the staff of the Biosciences Division of the Highway Safety Research Institute, The University of Michigan. The program was under the direction of Dr. D. L. Beckman with significant inputs by Drs. R. L. Stalnaker, J. H. McEl haney and V. L. Roberts. The data for the literature review was completed by Peter Van Eck through many hours of research. The authors would like to thank Mr, Arthur Hirsch for his speci a1 quidance, suggestions, cooperation, and support. Special thanks are due to Dr. Charles Frey for medical guidance for this program. We are also indebted to Lauretta MacColman and Donald Baslock for their assistance in the animal preparations and autopsies. 1.0 SUMMARY In order to provide data on human tolerance to blunt abdominal impact a literature study and laboratory tests were carried out to determine the major causes of abdominal injury, injury mechanisms, a quantitative relation- ship between input and occurrence of trauma and to develop the criteria to recommend performance requirements for materials which often produce blunt abdominal injury. An extensive analysis of case reports indicated that the most frequent causes of blunt abdominal injury were the steering heel, seat belt and various protruding objects in a vehicle; the organs most often injured were the 1iver, pancreas, spleen and intestine. However the results indicate that the vervet monkey (Cercopithecus pvaerythrus) can survive (injury level of 3) blunt impacts to the upper abdomen with the various impactors used at velocities up to 22 mph,- while in the midabdo~iien it can survive impacts of this type of approximately 26 mph and in the lovrer abdomen of 34 mph, 2.0 INTRODUCTION This study was conducted to define and analyze abdominal injuries to restrained and unrestrained vehicle occupants and pedestrians during crashes. Injury types were associated with the trauma producing agent and ranked according to the probability of occurrence. This aspect of the study was based on a careful review of over 43,000