A seat supports an occupant of a vehicle. The seat comprises a seating frame member for providing a surface to support the occupant and a back frame member extending away from the seating frame member. The back frame member has a first side member and a second side member. A first cross member and a second cross member extend horizontally between the first and second side members. Each of the first and second cross members have a central region flanked on both sides by bent portions with the first and second cross members folded back upon themselves within the bent portions. The bent portions straighten out when a force above a predetermined value is applied to the first and second cross members. The central region plastically deforms once the bent portions straighten out for reducing an impact force transferred from the seat to the occupant.