A latch secures an element such as a motor-vehicle headrest for movement relative to a support between a rest position and an advanced position. A pivotal lever can hold the element in the rest position. A spring pushes the element into the advanced position and presses it against the lever so as to apply a torque to the lever that presses a latch formation on the lever against a retractile latch part of an actuator. If the actuator retracts the part, the lever is released and the lever can pivot to allow the spring to move the element into the advanced position.