That normally happens when you have less than 2” of remaining foam density in your cushion. For example: a 4” cushion height with a 3” sag measurement while siting. The remaining foam is only 1”… so there is nothing left to compress. (OR) a 6” cushion with a 5” sag measurement while sitting… leaving only 1” of remaining seat foam – that won’t work either.
This solution needs at least 2 inches to be effective. Your cushion height and sag measurement while sitting are so important and determine your results. Also, be sure and sit as you normally do when taking your sag measurement. Our case studies show how sitting with one leg under you can change results.