@ocelot60- I have back pain too, and the more pressure you put on your back, the worse the pain becomes. The idea of the zero gravity chair is to relieve this type of pressure. Because these chairs are made to benefit an individual's back, legs, and posture, they are great for people with all kinds of pain issues.
Since you are new to zero gravity chairs you should purchase the least expensive model available in your area to make sure it works for you. Purchasing a zero gravity folding chair is a good start because they are typically not too costly.
If you find that you get some relief from your back pain, you can then invest in other types of chairs such as a zero gravity lounge chair.