This is one of four backrests I bought from Amazon in hopes of getting one or two that help support my lower back, providing a natural curve to the lower spine. The ridges on each side of this support are way to close together for my back to fit into so what I feel is my back resting on the ridges which in not comfortable at all. Now, I am 6' tall and weigh 165lbs so I should be able to fit into a support built for the normal- sized adult male. This cushion would appear to fit a petite woman's back.I don't recommend this support for most adults.