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A finite element (FE) model of the THOR lower extremity (THOR-LX) was developed to enhance research using the THOR-LX. A three-dimensional representation of the physical THOR-LX was created with the same functionality: 3-axis ankle rotation, compliant tibia element, Achilles' cable, and deformable skin. The model outputs the same measurements as the THOR-LX hardware. The completed finite element model was correlated with the physical THOR-LX by simulating ten physical experiments and comparing the results. It was concluded that the FE model may be used to reasonably predict the results of physical tests performed with the THOR-LX.

NHTSA has recently released the documentation for manufacture and use of the Thor-Lx Hybrid III retrofit (Thor-Lx/HIIIr), an advanced lower extremity device that fits on the Hybrid III 50th percentile male dummy at the distal femur. In order to compare the response of the Thor-Lx/HIIIr and the Denton leg in the vehicle crash environment, NHTSA conducted a series of vehicle crash tests where 40 percent of the vehicle’s frontal structure along the driver’s side engaged the EU deformable barrier. The test series consisted of 4 pairs of crash tests using a belted Hybrid III 50th percentile adult male dummy in the driver’s position. Pairs of tests were conducted under identical crash conditions using the same vehicle make, model, and model year with the Denton legs on the dummy in one test and the Thor-Lx/HIIIr legs on the dummy in the other test. This paper presents a detailed analysis of the responses of the Hybrid III dummy and the two types of legs in the paired crash tests.

An analysis of the National Automotive Sampling System/ Crashworthiness Data System (NASS/CDS) for the years 1993–1999 was conducted to determine the risk of injury to different body regions in frontal crashes. Lower extremities were the leading injured body region. The risk of lower limb injuries was significant in all crash modes. A detailed examination of these lower extremity injuries was then conducted using the AIS-90 injury codes. The long term consequence of lower extremity injuries was estimated using the Functional Capacity Index (FCI) associated with each AIS-90 injury code. The effect of a particular injury on society was reported in terms of total Functional Life-years Lost to Injury (LLI) which is defined as the product of FCI and the injured person’s life expectancy.

A series of 26 human cadaver tests with chestband instrumentation and accelerometers were completed to assess side impact injury tolerance. A Heidelberg-type sled test system was used with thorax, abdomen, and pelvic load plates. Tests were conducted at the Medical College of Wisconsin and through the Ohio State University College of Medicine at the NHTSA Vehicle Research and Test Center at two different velocities: 24 kph and 32 kph. Test conditions included rigid wall, padded wall, and pelvic offset. Accelerations were recorded at rib 4, rib 8, and T12. Up to three chestbands were placed on each surrogate. Chest deflections were derived by computing chest contours at every millisecond throughout the event. The derived chest deflection-time curves were differentiated to obtain velocity of chest compression. Injury criteria including ASA15N, TTI, normalized chest deflection, and VC were computed. Resulting injuries ranged from AIS = 0 to AIS = 5.

The number of passenger vehicles with combined 3-point belt/driver air bag restraint systems is steadily increasing. To investigate the effectiveness of this restraint combination, 48 kph frontal collisions were performed with human cadavers. Each cadaver's thorax was instrumented with a 12-accelerometer array and two chest bands. The results show, that by using a combined standard 3-point belt (6% elongation)/driver air bag, the thoracic injury pattern remained located under the shoulder belt. The same observation was found when belts with 16% elongation were used in combination with the driver air bag. Chest contours derived from the chest bands showed high local compression and deformation of the chest along the shoulder belt path, and suggest the mechanism for the thoracic injuries.

The study reports on the results of frontal collisions with 16 cadavers and two Hybrid III dummies with impact velocities of 48 km/h to 55 km/h and a mean sled deceleration of 17 g; mounted to the sled was the front part of a passenger compartment. The cadavers were restrained in the driver position with either 3-point belts (6% and 16 % elongation) and/or air bag with knee bolster and one case was unrestrained. In most cases, both a 12-accelerometer thoracic array and 2 chest bands were employed. In some cases the acceleration at Th6 was measured. The cadavers were autopsied and the injury severity was rated according to the AIS 90. Maximum resultant Th1, Th6, and Th12 accelerations or sternum accelerations in x-direction ranged from 35g to 78g when using 3-point belts and produced injuries ranging from a few rib fractures to unstable chest wall (flail chest).