A seat assembly including a seat stroking device for a vehicle and methods of use include a seat adjustment mechanism comprising a stationary rail fixedly attached to a vehicle floor and a movable rail slidably engaged with the stationary rail, wherein the seat adjustment mechanism is adapted to position a seat; an active material based stroking device having one end fixedly attached to a non-movable portion and an other end in operative communication with the movable rail; and a controller in operative communication with the active material, wherein the controller is operable to selectively apply an activation signal to the active material and effect a change in an attribute of the active material, wherein the change in the attribute results in force and acceleration adjusting energy absorption.