Helpful for Back Pain, But Cuts off Leg Circulation
I have been using this cushion for about 6 weeks on my leather office chair, to give more support. I got it because of disk degeneration at L5-S1, which was causing pain after sitting at the computer. I can assure you that this cushion would not pass the egg test.  While it adds cushioning to the chair, it is thicker at the edges and thinner in the center. As a result, it cuts into my thighs and tends to cut off circulation. Also, the width, which at first seemed excessive, is not really adequate-- and I am not a large person (5'6&#34; and 130 lbs). On the positive side, and discomfort of the edges aside, it does enable me to sit for longer periods at the computer. I'll continue to use it, but suspect that it might be more useful and more comfortable when used on an unupholstered chair.
Rating: 4 stars