Dynamic Response Properties of Lower Extremity Subjected to Side Impact Loading

摘要

References(14) Aging of population is a problem that is perceived globally. An increase in the elderly population causes a corresponding increase in the number of traffic accidents and injured pedestrians. In general, the most common injured body region of a pedestrian involved in a traffic accident is the lower extremity. In order to reduce the severity of pedestrian injuries, we need to experimentally predict the risk of bone fracture using biological specimens. In this study, we constructed an experimental setup for impact measurement. We utilized a torsion spring as the energy source and used porcine hind legs to replicate the human lower extremity while performing side impact tests. Strain gages were used to directly measure the dynamic responses of the cortical bone. From the results of the measurement of the strain distributions in the femoral diaphysis, we observed that higher strain occurred in the region nearer to the proximal. The maximum value of the strains in the lateral side of the femur was less than that in the medial side. Using the strain values, we quantitatively predicted the risk of femoral fracture in each region. Hence, our method, which is used for directly measuring the dynamic responses of the cortical bone, can be effectively used in biological tests to elucidate the nature of the injuries sustained by an accident victim.