CHARACTERIZATION OF LEG INJURIES FROM MOTOR VEHICLE IMPACTS

The objective of this investigation was to understand relationships among loading characteristics as they affect the kinematics and injury of a pedestrian’s lower extremity. Real-life pedestrian and motor vehicle collision scenarios were modeled by impacting 604 human cadaver intact legs and long bones with a cart/guide rail impacting system designed to simulate the front end of an automobile. A parametric study was conducted that varied the boundary conditions on the foot as well as test parameters such as loading direction, impact velocity, and impactor geometry. The series of tests can be categorized as follows: (1) Fracture Characterization, (2) Threshold Velocity, (3) Friction versus Inertial Constraint, (4) Anterior and Lateral Thigh Impacts, and (5) Embalmed vs. Unembalmed. Documented data for various specimens include, but are not limited to, specimen anthropometrics, fracture patterns, failure force levels, and calculated bending moments. Representative values include averages as follows: Failure forces for the tibia ranged from 1.19 to 7.07 kN. Failure forces for the femur ranged 1.31 to 8.37 kN. Bending moments averaged from approximately 100 to 500 Nm. These values varied depending on the speed of impact, impactor geometry, direction of impact, gender of specimen, etc. The results and observations may be helpful as an aid for evaluating the effectiveness of any protective or mitigative devices or strategies.