A vehicle seat comprises a controllable deformable material and control apparatus is provided for controlling the state of a controllable deformable material. The control apparatus is configured to generate a signal to cause a control element in proximity to the controllable deformable material to change the characteristic of the controllable deformable material and thereby change the state of the controllable deformable material. The controllable deformable material is controllable to change state from a first state to at least a second state and is controllable to change state from at least the second state to the first state, the controllable deformable material being more deformable per unit force in the second state than in the first state.

A system includes a seat bottom having a seat bottom frame and a seatback having a seatback frame pivotably supported by the seat bottom frame. The system also includes a seat frame brace movable between a stowed configuration and a deployed configuration. The seat frame brace includes a back link having a first end portion and a second end portion coupled to the seatback frame. An actuator is coupled to the seat bottom frame and operative to move the first end portion in a seat rearward direction to position the seat frame brace in the deployed configuration.