Influence of seat back angle on occupant dynamics in simulated rear-end impacts.

This study directly associates the ability of the seat to adequately retain an occupant surrogate in rear-end impacts with the severity of deceleration. Although the seat back may dynamically deform 20-30 degrees during occupant loading, the tangential acceleration of the occupant is not sufficient to overcome the normal compression of the occupant into the seat at a seat back angle less than 60 degrees. However, in those simulations where the seat back angle was greater than 60 degrees, there was enough tangential acceleration of the occupant to permit riding up the seat back with the potential for secondary impacts of the occupant with the automotive interior.