Originally posted by Lauren Hill on April 28, 2014 at redefiningpostureblog.com
Try this experiment—this works best if you have two identical chairs. If you only have one you can work with that. The chair should have a relatively firm seat—a typical kitchen chair works well. Determine if the chair seat (a) slopes backward (the front of the seat is higher than the back), (b) is level or (c) slopes forward (the front of the seat is lower than the back). You will create two different seats so you can contrast them—one that slopes backward and one that is level or slopes forward a bit. You will need several same sized books to adjust the chair seats. If your chair is level put two same sized books under the front legs so that the seat slopes backward. If your chair slopes backward put two same sized books under the back legs so that the seat is level or slopes slightly forward.
Sit on both chairs. Sit toward the front of the chair seat and don’t lean back. This is called active or task sitting (as contrasted with restive sitting, when you lean against the back of a chair). Don’t think too much. See if your body prefers one seat over the other.
Picture credit: Change Your Posture Change Your Life by Richard Brennan