To calculate the overall star rating and percentage breakdown by star, we do not use a simple average. Instead, our system considers things like how recent a review is and if the reviewer bought the item on Amazon. It also analyses reviews to verify trustworthiness.
The cushion hugs your back perfectly. I have sciatica and this cushion has helped it improve so much it's almost gone. The pain relief was immediate. I like the memory foam and the spine cushion. I have so much more support and comfort sitting for hours a day now.
I think this is doing an okay job, but if you hare shorter/ have a shorter back it may be doing more damage than helping, as it may not be aligning with your back the way it should. I find that on the first day my back feels fine, and then a few days in it hurts pretty bad. Just make sure you have it in the correct place for your back!
The zipper is defective and you will never be able to zip the cloth cover back onto the cushion if you unzip it. It's a shame because the cushion itself is perfectly adequate for back support. 0 stars.