Method and arrangement for moving an underrun protection device for vehicles having a frame (3), an impact element (7) arranged on the vehicle at a location corresponding to an expected loading from a force during a possible collision, and at least one displaceable carrier element (6) connecting the frame (3) and the impact element (7). During displacement of the impact element (7) between at least one first, active position and at least one second, inactive position, at least a part of the displacement occurs in a direction that substantially coincides with a longitudinal axis of the carrier (6).