2005 GMC Sierra 1500 Pickup Owner's Manual - Page 14

Head Restraints Seatback Latches {CAUTION: If the seatback is not locked, it could move forward in a sudden stop or crash. That could cause injury to the person sitting there. Always press rearward on the seatback to be sure it is locked. The seatbacks fold forward to let you access the rear of the cab. To fold a front seatback forward, lift the lever at the base of the seat to release the seatback. The lever is located on the outboard side of the seat cushion. Adjust your head restraint so that the top of the restraint is closest to the top of your head. This position reduces the chance of a neck injury in a crash. To raise the head restraint pull up on the head restraint. Your vehicle may have rear seat head restraints that can be adjusted up and down. To return the seatback to the upright position, push the seatback rearward until it latches. After returning the seatback to its upright position, push and pull on the seatback to make sure it is locked. 1-8