A vehicle seat assembly having a seatback frame, an upper armature that is movable relative to the seatback frame and a head restraint mounted on the upper armature. A linkage assembly operatively interconnects the upper armature and an impact body such that movement of the impact body relative to the seatback frame acts on the linkage assembly to move the upper armature relative to the seatback frame to cause the head restraint to move toward the occupant. The linkage assembly includes a linkage and a coupler movably connected to the linkage. The coupler includes a first member movably connected to the seatback frame and a second member movably connected to the first member at a location below the upper end of the impact body.