Abstract: A safety arrangement for use in a motor vehicle includes a blocking unit (6) and a drive (7, 8, 9, 10) to drive the blocking unit (6) from a position where it is flush with the dashboard (4) to a forward position where it will block movement of the knees of an occupant of a seat (1). A timing arrangement (17) is provided which controls the drive to return the blocking unit to an initial position after a predetermined period of time. An energy-absorbing element, which may be an air-bag (12) absorbs energy as the blocking unit (6) is moved from the operative position by a force applied to the blocking unit by the knees of a seat occupant.