UMTRI Project

Knee-Thigh-Hip (KTH) Response and Injury in Frontal Crashes

Sponsor: National Highway Traffic Safety Administration
Investigator: Jonathan Rupp
04/20/2005 - 04/19/2006

UMTRI has been conducting biomechanical research on KTH injuries in motor-vehicle crashes for the past decade under the sponsorship of the National Highway Traffic Safety Administration (NHTSA). This research has demonstrated that the hip is the weakest part of the KTH complex under loading of the anterior surface of the 90˚ flexed cadaver knee. Using this finding, UMTRI developed computational models that can predict human injury response and used these models to establish new injury assessment reference values (IARVs) for the Hybrid III and THOR-NT midsize male ATDs.

Current research on KTH injuries in frontal crashes aims to improve these IARVs. FE modeling is currently being conducted to characterize the effects of tension in the thigh and pelvis musculature on KTH injury response and tolerance. Additional biomechanical testing is being performed to quantify the effect of knee posture on knee injury tolerance and fracture pattern and how femur tolerance is affected by combined compression-bending. Both these modeling and test results may be used to modify the IARVs.

UMTRI is also actively working with NHTSA and an SAE Task Group to develop response specifications and improved designs for the THOR-NT KTH complex and pelvis. UMTRI is collaborating with NHTSA and vehicle restraint system designers to evaluate the potential of inflatable knee bolsters to mitigate the risk of KTH injury in crashes. UMTRI is also working to develop design guidelines for optimal knee bolsters, i.e., knee bolsters that absorb the maximum amount of occupant energy possible without producing knee impact force histories that are capable of exceeding an acceptable risk of KTH injury.

Associated publications:

Rupp, J., Schneider, L. 2004. Injuries to the Hip Joint in Frontal Motor-Vehicle Crashes: Biomechanical and Real-World Perspectives. The Orthopedic Clinics of North America. Vol. 35 p. 493-504.  

Rupp, J., Reed, M., Madura, N., Miller, C.S., Kuppa, S., Schneider, L. 2005. Comparison of the Inertial Response of the THOR-NT, Hybrid III, and Unembalmed Cadaver to Simulated Knee-to-Knee Bolster Impacts. ESV: 19th International Technical Conference on the Enhanced Safety of Vehicles..  05-0086-O
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