Detailed experimental investigations are being conducted at the University of Virginia to obtain data for determining mechanisms of injury and response for lower extremities in automotive crashes. To be specific, conduct 12 dummy and 17 human cadaver frontal sled tests per year to study lower extremity trauma. Thus, in a five year period (FY93-FY97), 60 dummy and 85 cadaver sled tests will be conducted.

With the introduction of air bags and the increased survivability of crashes, hospital and trauma centers are seeing increasing numbers of lower extremity injuries. Ankle injuries constitute nearly 10% of all AIS 2 injuries sustained by occupants in frontal motor vehicle crashes. Although ankle injuries are not usually life-threatening, they are costly to treat and involve lengthy rehabilitation and loss of earning for patient.

Various accident surveys have suggested numerous mechanisms of ankle/foot injuries including the following:

• Forced dorsiflexion of the foot,
• Forced inversion/eversion of the foot,
• Forced internal/external rotation of the foot,
• Axial load due to entrapment, and
• Intrusion into the vehicle.

In an automobile crash, one single mechanism of the injury rarely occurs. However, combinations of these mechanisms are common. High axial loads combined with foot rotation are common causes of ankle foot injuries. Crashes with large toepan intrusion in conjunction with the initial orientation of the foot may cause severe foot rotation.

Twelve dummy and 17 cadaver sled tests per year will be conducted to study lower extremity injury. The upper part of the torso will be restrained by a variety of air bag and belt restraint systems. Over five years (FY93-FY97), 60 dummy and 85 cadaver sled tests will be conducted. In addition sixty human cadaver lower legs will be impact to establish ankle/foot tolerance level with regard to 4 injury mechanisms mentioned above.

By better understanding injury mechanisms, the project will point to further design approaches and research testing devices (such as HYBRID III, SID etc.) which can contribute to reduced injury severity and cost of lower extremity injury.

• To establish foot/ankle injury criteria by September 1997

• Kennett, K. B.; Crandall, J. R.; Bass, C. R.; Klopp, G. S.; "In Situ Measurement of Loads in the Tibia", Proc. 24th International Workshop on Human Subjects for Biomechanical Research, Albuquerque, NM, Nov. 1996.

• Sieveka, Edwin M.; Crandall, Jeff R.; Pilkey, Walter D.; "Lumped Mass Model of the Lower Extremity Using the Articulated Total Body Program", Proc. Intl. Conference on Pelvic and Lower Extremity Injuries, Washington, D. C. , Dec. 1995.



• Klopp, G. S.; Crandall, J. R.; Bass, C. R.; Pilkey, W. D. "Sensitivity of Ankle Impact Injuries to Initial Foot Orientation", Proc. Intl. Conference on Pelvic and Lower Extremity Injuries, Washington, D. C. , Dec. 1995.

• Klopp, G. S.; Hall, G. W.; Crandall, J. R.; Pilkey, W. D. "Measurement of Rotational Kinematics using Magnetohydrodynamic Angular Rate Sensors" Proc. 23rd International Workshop on Human Subjects for Biomechanical Research, San Diego, CA, Nov. 1995.

• Bass, C.R.; Dekel, E.; Crandall, J. R.; Lange, M.; Pilkey, W. D.; "Experimental devices to simulate toepan and floorpan intrusion", SAE International Congress, 1997.

• Crandall, J. R.; Bass, C.R.; Klopp, G. S.; Pilkey, W. D.; Morgan, R. M.; Eppinger, R. H., "Sled Tests with Toepan Intrusion using Post-Mortem Human Surrogates and the Hybrid III Dummy"; Proc. IRCOBI Conference on the Biomechanics of Impacts, Dublin, Ireland Sept. 1996.

• Crandall, J. R.; Portier, L.; Petit, P.; Hall, G. W.; Klopp, G.S.; Bass, C. R.; Hurwitz, S.; Trosseille, X.; Tarriere, C., Pilkey, W. D.; Lavaste, F.; Lassau, M.; "Biomechanical Response and Physcial Properties of the Leg, Foot, and Ankle" Proc. of 39th Stapp Car Crash Conference, Society of Automotive Engineers, Warrendale, PA; Nov. 1996.

• Schreiber, P.; Crandall, J. R.; Dekel, E.; Hall, G. W.; Pilkey, W. D. "The Effects of Lower Extremity Boundary Conditions on Ankle Response during Joint Rotation Tests" Proc. 23rd International Workshop on Human Subjects for Biomechanical Research, San Diego, CA, Nov. 1995.

• Bass, C.R.; Crandall, J. R.; Dekel, E.; Jordan, A.; Pilkey, W. D.; "A System for Simulating Structural Intrusion in Automobile Full-Frontal and Frontal Offset Crashes in the Laboratory Sled Test Environment", J. Automobile Engineering (submitted 10/95)

• Klopp, G.S.; Crandall, J. R.; Sieveka, E. M.; Pilkey, W. D.; "Simulation of Muscle Tensing in Pre-Impact Bracing", Proc. IRCOBI Conference on the Biomechanics of Impacts, Sept. 1995.

• Crandall, J. R., Jordan, A., Bass, C.R., Klopp, G. S., Pilkey, W. D., "Reproducing the Structural Intrusion of Frontal Offset Crashes in the Laboratory Sled Test Environment" in Issues in Automotive Safety Technology, Society of Automotive Engineers, 1995.

• Pilkey, W. D., Sieveka, E., Crandall, J. R., Klopp, G. S., "The Influence of Vehicular Intrusion and Rotation on Occupant Protection in Full Frontal and Frontal Offset Crashes", Proc. 14th International Technical Conference on the Enhanced Safety of Vehicles, Munich, Germany, May 1994.




• Morgan, R.M., Eppinger, R.H., Haffner, M.P., Yoganandran, N., Pintar, F.A., Sances, A., Crandall, J. R., Pilkey, W.D., Klopp, G.S., Kallieris, D., Miltner, E., Mattern, R., Kuppa, S., Sharpless, C., "Thoracic Trauma Assessment Formulations for Restrained Occupants in Frontal Impacts", Proc. of 37th Stapp Car Crash Conference, Society of Automotive Engineers, October 1994.

• Crandall, J. R., Kuhlmann, T.P., Pilkey, W.D., "Air Bag and Knee Bolster Restraint System: Laboratory Sled Tests with Human Cadavers and the Hybrid III Dummy", J. Trauma, Vol. 38, No. 4, April 1995.




• Crandall, J. R., Pilkey, W. D., Klopp, G. S., Sieveka, E., Morgan, R., Eppinger, R., Kuppa, S., Grove, C., "A Comparison of Two and Three Point Restraint Systems", Joint Session of AAAM and International Research Council on the Biomechanics of Impact Conference, Lyon, France; Sept. 1994.