A restraint system for a vehicle is disclosed. The restraint system includes a seat shaped to accommodate an occupant, wherein the seat includes a seat back and an energy absorption member that expands from a stowed position and into a deployed position. The energy absorption member fills a volume of space behind the seat back when in the deployed position to absorb energy that would otherwise be imparted towards an occupant of the seat during an impact involving the vehicle. The restraint system also includes an impact sensing device generating an impact signal in response to detecting the impact involving the vehicle is imminent. The impact signal indicates an orientation and magnitude of the impact involving the vehicle. The restraint system includes a control module in electronic communication with the energy absorption member and the impact sensing device.