The seat and back move as a unit so that your support and posture is not compromised. The pivot is on the front edge of the cushion, so butt goes down, and the knees come up slightly. Some call this a knee tilt. The tilt goes back to 16 degrees and can be locked at 0 or 6 degrees. You can leave the tilt unlocked and adjust the tension to your desired "free floating" position.