This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Effect of Hybrid III Leg Geometry on Upper Tibia Bending Moments
ISSN: 0148-7191, e-ISSN: 2688-3627
Published March 05, 2001 by SAE International in United States
Annotation ability available
Event: SAE 2001 World Congress
The knee and ankle joint pivots of the Hybrid III dummy's leg are positioned in approximately the same orientation as the knee and ankle joint rotation centers of a human in a normal driving posture. However, the dummy's leg assembly is not simply a straight member between these two pivots. It is a zigzag-shaped solid link composed of one long straight section in the middle and short angled sections at either end, which form the pivots. The upper and lower tibia load cells are mounted on the straight middle section, making the upper tibia load cell location anterior to the line between the ankle and knee pivots and the lower tibia load cell location slightly posterior to the line between the pivots. Hence, an approximately vertical force on the foot can act along the line behind the upper tibia load cell and in front of the lower tibia load cell, creating bending moments. The upper tibia moment would bow the leg forward (negative Y moment by SAE J211 convention), and the lower tibia moment generated would bow the leg rearward (positive Y moment). Such spurious bending moments, particularly at the upper tibia, can be large enough to suggest a significant risk of proximal tibia fracture that likely would not exist in humans subjected to the same forces. Several instances of forward bending of the proximal tibia coincident with axial loading on the lower tibia have been identified among the data recorded in 64 km/h (40 mi/h) frontal offset crash tests conducted by the Insurance Institute for Highway Safety. The ratio of upper tibia bending moment to measured tibia axial force was approximately equal to the distance between the center of the upper tibia load cell and the line connecting the knee and ankle pivots. In addition, other measures recorded on the same leg indicated the proximal tibia bending was due predominantly to an upward force on the foot. This paper describes how the potentially erroneous indications of proximal tibia fracture risk were identified and suggests a method for estimating more realistic moments at the upper and lower load cell locations.
CitationZuby, D., Nolan, J., and Sherwood, C., "Effect of Hybrid III Leg Geometry on Upper Tibia Bending Moments," SAE Technical Paper 2001-01-0169, 2001, https://doi.org/10.4271/2001-01-0169.
SAE 2001 Transactions Journal of Passenger Cars - Mechanical Systems
Number: V110-6; Published: 2002-09-15
Number: V110-6; Published: 2002-09-15
- Fildes, B.N. Lenard, J.C. Lane, J. Vulcan, A.P. Wenzel, J. 1994 Lower limb injuries to passenger car occupants (CR 137) Canberra, Australia Federal Office of Road Safety
- Association for the Advancement of Automotive Medicine 1990 The Abbreviated Injury Scale, 1990 Revision Des Plaines, IL
- Jibril et al. 1998 Logistic regression analysis of lower limb injuries in frontal crashes Proceedings of the 16th International Technical Conference on the Enhanced Safety of Vehicles 1473 81 Washington, DC National Highway Traffic Safety Administration
- Karlson, T.A. Bigelow, W.E. Beutel, P. 1998 Serious lower extremity injuries in motor vehicle crashes Wisconsin, 1991-1994 Proceedings of the 16th International Technical Conference on the Enhanced Safety of Vehicles 1328 36 Washington, DC National Highway Traffic Safety Administration
- State Farm Insurance 1999 Private communication. National estimate based on distribution of claim costs Injuries in Auto Accidents: An Analysis of Auto Insurance Claims Insurance Research Council 1999
- Ore, L.S. Tanner, C.B. States, J.D. 1993 Accident investigation and impairment study of lower extremity injury (SAE 930096) Human Surrogates: Design, Development, and Side Impact Protection (SAE SP-945) 17 28 Warrendale, PA Society of Automotive Engineers
- Pattimore, D. Ward, E. Thomas, P. Bradford, M. 1991 The nature and cause of lower limb injuries in car crashes Proceedings of the 35th Stapp Car Crash Conference (P-251) 177 88 Warrendale, PA Society of Automotive Engineers
- Dischinger, P.C. et al. 1994 Lower extremity trauma in vehicular front-seat occupants: patients admitted to a level 1 trauma center (SAE 940710) In-depth Accident Investigation: Trauma Team Findings in Late Model Vehicle Collisions (SP-1042) 11 18 Warrendale, PA Society of Automotive Engineers
- Sherwood, C. O'Neill, B. Hurwitz, S. 1999 Lower extremity injury causation in frontal crashes Proceedings of the 1999 IRCBOI Conference on the Biomechanics of Impact 513 526 Bron, France International Research Council on the Biokinetics of Impacts
- Crandall, J.R. et al. 1998 Injury mechanisms for the human foot and ankle under axial impacts to the foot International Journal of Crashworthiness 3 2 147 61 Cambridge, England Woodhead Publishing Ltd.
- Mertz, H.J. Injury assessment values used to evaluate Hybrid III response measurements NHTSA Docket 74-14 March 22 1984
- Crandall, J. 2000 Personal communication November 16
- Backaitis, S.H. Mertz, H.J. 1994 Hybrid III: The First Human-Like Crash Test Dummy Warrendale, PA Society of Automotive Engineers
- Nyquist, G. Denton, R. 1978 Crash test dummy lower leg instrumentation for axial force and bending moment Instrument Society of America Transactions 18 3
- Parenteau, C.S. 1996 Foot-ankle joint responses: epidemiology, biomechanics and mathematical modeling (thesis) Göteborg, Sweden Chalmers University of Technology
- Williams, D.A. McDonough, P.J. 1999 European New Car Assessment Programme Testing Protocol May 1999
- Insurance Institute for Highway Safety 1999 Crashworthiness evaluation offset barrier crash test protocol Arlington, VA
- Wellbourne, E.R. Shewchenko, N. 1998 Improved measures of foot ankle injury risk from the Hybrid III tibia Proceedings of the 16th International Technical Conference on the Enhanced Safety of Vehicles 1618 26 Washington, DC National Highway Traffic Safety Administration
- Shams, T. et al. 1999 Development and design of the THOR-LX: The THOR lower extremity Proceedings of the 43rd Stapp Car Crash Conference (P-350) 141 60 Warrendale, PA Society of Automotive Engineers
- Rudd, R. Crandall, J. Butcher, J. 1999 Biofidelity evaluation of the dynamic and static response characteristics of the THOR LX dummy lower extremity Proceedings of the 1999 International Conference on the Biomechanics of Impact 485 97 Bron, France International Research Council on the Biokinetics of Impacts
- Society of Automotive Engineers SAE Handbook Warrendale, PA