When a lever is pulled, the second row seat can move freely back and forth on a track until the back of the seat is returned to the upright position. I was driving at highway speeds and had to brake suddenly. The seat was at the back of the track with the lever pulled, and it slammed into the back of the driver seat, hurting my back. It stuck there putting pressure on the seat (which could be felt) until I stopped and had to use force to make it slide back.