Aggregation of Lumbar Loads in Rear Impact Crash Tests

An analysis of peak lumbar load data collected from the existing peer-reviewed literature on rear impact crash tests was performed. Values for peak lumbar tension/compression, peak lumbar sagittal forces, and peak lumbar flexion/extension moments were aggregated from each study. The trends in the accumulated data were analyzed as functions of the changes in velocity (delta-Vs) measured during the crash tests. The data were further analyzed to identify differences in trends found across variations in the testing conditions used across studies. These testing conditions included type of anthropometric test device (ATD) used, type of ATD pelvis used, ATD seating position, production year of seat used, type of seat used, and type of seat restraint used. Data were also aggregated from peer-reviewed research quantifying peak lumbar compression in human subjects performing various tasks, including activities of daily living (ADLs), tasks related to sports and exercise, and industrial tasks typical of manual labor. The peak lumbar compression data from rear impact tests with ATDs was compared with the corresponding peak load data from the studies with human subjects. Linear regressions of the aggregated data from rear impact crash tests with impact severities between 5-45 km/h indicated some relationships between peak lumbar loads and delta-V. However, the relatively low R2 values observed from these regressions suggest that other variables may contribute to the variance in peak lumbar loading with respect to delta-V. It appears that individuals performing ADLs may experience peak lumbar compression similar to the compression measured in ATDs in rear impact crash tests with impact severities between 5-45 km/h. Aggregated peak lumbar compressive loading values in tasks related to sports, exercise, and industry were largely greater than the aggregated peak loads from crash testing.