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The Interaction of Air Bags with Upper Extremities
ISSN: 0148-7191, e-ISSN: 2688-3627
Published November 12, 1997 by SAE International in United States
Annotation ability available
Recently there has been a greater awareness of the increased risk of certain injuries associated with air bag deployment, especially the risks to small occupants, often women. These injuries include serious eye and upper extremity injuries and even fatalities. This study investigates the interaction of a deploying air bag with cadaveric upper extremities in a typical driving posture; testing concentrates on female occupants. The goals of this investigation are to determine the risk of upper extremity injury caused by primary contact with a deploying air bag and to elucidate the mechanisms of these upper extremity injuries. Five air bags were used that are representative of a wide range of air bag ‘aggressivities’ in the current automobile fleet. This air bag ‘aggressivity’ was quantified using the response of a dummy forearm under air bag deployment.
For this study, sixteen excised cadaveric upper extremities were mounted to a four degree-of-freedom universal joint that functioned as a shoulder. The upper extremity position was a ‘natural’ driving posture in a one-hand turn crossover maneuver. In this posture, the forearm was pronated with the humerus normal to the plane of the steering wheel and the forearm positioned directly on the air bag module so that the distal third of the forearm was over the air bag tear seam. This position represents a ‘worst case’ for deployment of an air bag into a forearm.
Injuries sustained during testing included ulna nightstick fractures and multiple fractures. A nightstick fracture is a diaphaseal ulna fracture unaccompanied by a radius fracture . The results indicate that the air bag/flap interaction may be significant in the production of some injuries, but is not necessary to produce peak moments in the forearm. These primary contact injuries occurred within 13 ms of the deployment near the site of interaction with the flap. In addition, these results show that the risk of injury increases with increasing air bag aggressivity. The testing also suggests that there is an aggressivity among those air bags installed in the current automobile fleet below which the risk of forearm injury for occupants is low. Further, the results imply that there is a forearm bone strength above which the risk of injury is low even for an aggressive air bag deployment. Results also suggest that humerus position, forearm pronation angle. and forearm position relative to the air bag module affect the risk of injury from air bag deployment.
Comparison tests were performed with the SAE 5th Percentile Female Instrumented Arm using four of the air bags tested in the cadaveric series. These tests were performed using the SAE arm mounted on a Hybrid III dummy and the universal joint test fixture. Repeated tests revealed no significant difference between the forearm response on the fixture and on the dummy. Resulting forearm moments were used to develop logistic injury risk functions for ulna and ulndradius fractures of female forearms in the worst case position under air bag deployment. For 50% risk of ulna or ulndradius fractures, the dummy forearm moment is 61 N-m (+/- 13 N-m standard deviation). For 50% risk of fracture of both the ulna and the radius, the dummy forearm moment is 91 N-m (+/- 14 N-m standard deviation).
- C. R. Bass - University of Virginia
- S. M. Duma - University of Virginia
- J. R. Crandall - University of Virginia
- R. Morris - University of Virginia
- P. Martin - University of Virginia
- W. D. Pilkey - University of Virginia
- S. Hurwitz - University of Virginia
- N. Khaewpong - National Highway Traffic Safety Administration
- R. Eppinger - National Highway Traffic Safety Administration
- E. Sun
CitationBass, C., Duma, S., Crandall, J., Morris, R. et al., "The Interaction of Air Bags with Upper Extremities," SAE Technical Paper 973324, 1997, https://doi.org/10.4271/973324.
- Schultz R.J. The Language of Fractures Williams and Wilkins Inc. Baltimore, Maryland 1990
- Marco F. Garcia-Lopez A. Leon C. Lopez-Duran L. Bilateral Smith Fracture of the Radius Caused by Air Bag Deployment Journal of Trauma 40 663 1996
- Freedman E.L. Safran M.R. Meals R.A. Automotive Air Bag-Related Upper Extremity Injuries: A Report of Three Cases Journal of Trauma 38 577 1995
- Huelke D.F. Moore J.L. Compton T.W. Samuels J. Levine R. Upper Extremity Injuries Related to Air Bag Deployments Journal of Trauma 38 482 1995
- Kirchhoff R. Rasmussen S.W. Forearm Fracture Due to the Release of an Automobile Air Bag Acta Orthopaedica Scandinavica 66 483 1995
- Roth T. Meredith P. Hand Injuries From Inflation of an Air Bag Security System Journal of Hand Surgery 18B 520 1993
- National Highway Traffic Safety Administration Third Report to Congress: Effectiveness of Occupant Protection Systems and Their Use U.S. Department of Transportation December 1996
- Kuppa S.M. Yeiser C.W. Oslon M.B. Taylor L. Morgan R. Eppinger R. RAID - An Investigation Tool to Study Air Bag/Upper Extremity Interactions SAE Paper SAE International Congress and Exposition Detroit, MI 1997
- Saul R.A. Backaitis S.H. Beebe M.S. Ore L. Hybrid III Dummy Instrumentation and Assessment of Arm Injuries During Air Bag Deployment SAE Paper 962417 40th Stapp Car Crash Conference Albuquerque. New Mexico 1996
- Kapandji I.A. The Physiology of the Joints, Volume One, Upper Limb Churchill Livingstone Edinburgh, United Kingdom 1982
- McConville J. Laubach L. Anthropometry Anthropometry Source Book Volume I Thornton W. Jackson J. 1978
- McBroon R. Hayes W. Edwards W. Goldberg R. White A. Prediction of Vertebral Body Compressive Fracture Using Quantitative Computed Tomography Journal of Bone and Joint Surgery 67A 1206 1985
- Schlenker R. VonSeggen W. The Distribution of Cortical and Trabecular Bone Mass Along the Lengths of the Radius and Ulna and the Implications for in vivo Bone Mass Measurements Calcified Tissue Research 20 41 1976
- Ruegsegger P. Durand E. Dambacher M. Differential Effects of Aging and Disease on Trabecular and Compact Bone Density of the Radius Bone 12 99 1991
- Weber C. Chirurgishe Erfahrungen und Untersuchungen Berlin 1859
- Messerer O. Uber Elasticitat und Festigkeit der Menschlichen Knochen Stuttgard 1880
- Yamada H. Strength of Biological Material Williams and Wilkins Baltimore, Maryland 1970
- Jurist J. Folitz A. Human Ulnar Bending Stiffness, Mineral Content, Geometry and Strength Journal of Biomechanics 10 455 1977
- Swanson E. Boyd J.B. Mulholland R.S. The Radial Forearm Flap: A Biomechanical Study of the Osteomized Radius Plastic and Reconstructive Surgery 85 267 1990
- Crandall J.R. Preservation of Human Surrogates for Biomechanical Studies PhD University of Virginia Charlottesville, Virginia January 1994
- Taylor L. Kuppa S. 1995
- Wapnairz M. Lehnamm R. Reincke M. Shonau E. Klein K. Allolio B. Determinants of Radial Bone Density as Measured by PQCT in Pre- and Postmenopausal Women: The Role of Bone Size Journal of Bone and Mineral Research 2 248 1997
- Myburgh K. Zhou L. Steele C. Amaud S. Marcus R. In Vivo Assessment of Forearm Bone Mass and Ulnar Bending Stiffness in Healthy Men Journal of Bone and Mineral Research 7 1345 1992
- Kirkish S. Proposed Provisional Reference Values for the Humerus for Evaluation of Injury Potential Proceedings of the 40 th Stapp Car Crash Conference Albequerque, New Mexico November 1996
- Carter D. Hayes W. Bone Compressive Strength: The Influence of Density and Strain Rate Science 194 1174 1976
- Melvin J. Evans F. Extremities: Experimental Aspects The Biomechanics of Trauma Nahum A. Melvin J. Appleton-Century-Crofts Norwalk, CT 1985
- Schreiber P. Crandall J. Micek T. Hurwitz S. Nusholtz G. Static and Dynamic Bending Strength of the Leg 1997 International Ircobi Conference on the Biomechanics of Impact Hanover, Germany September 1997