Government recommendations have been made to place children into the rear seating areas of motor vehicles in order to alleviate airbag hazards in frontal impact. In most moderate to severe rear impacts, however, the adult occupied front seats will “yield” or “collapse” into the rear seat area and thus pose another potential head and chest injury hazard to the rear seated children. Numerous factors or variables, each with a wide parameter range, influence whether or not an occupied collapsing front seat will result in engagement with the rear occupant, and whether that engagement is likely to cause injury to the rear-seated occupant. A combined experimental and analytical method, employing instrumented surrogates in a sled-buck test set-up, has been utilized to study the multivariable potential injury problem of the rear-seated child in rear impact. A 3 year-old H-III surrogate, seated in the built-in booster seat of a minivan, was used as the rear seat passenger in this study. Five tests were utilized. The experimental surrogate data from the test method is combined into a “polynomial response function” that expresses “injury levels” (i.e. HIC and chest G) as a function of the many variables, and allows for analytical “interpolation and extrapolation” at variable combinations and ranges not tested. Actual accident cases were compared with the biomechanical injury measures. The present study presents a methodology to delineate the biomechanics of injuries using multivariate analysis.
Rear seating position is associated with a higher risk of mortality in motor vehicle crashes: analysis of Japanese Trauma Data Bank