A vehicle seat adjustment system for adjusting the position of a portion of a vehicle seat. The system comprises a hydraulic actuator, a primary activation system for operating the hydraulic actuator and adjusting the seat position, and a secondary activation system for the hydraulic actuator. The secondary activation system is arranged to be activated in the event of a detected crash, to provide for movement of the hydraulic actuator to automatically adjust the position of a portion of the seat towards a predetermined position. The secondary activation system comprises a chamber to allow fluid to be displaced from the hydraulic actuator into the chamber. The secondary activation system may additionally comprise a fluid injection unit which supplies a quantity of fluid, preferably gas, to the actuator.