That's true Sue. I had gotten my deep-contoured back after I had my total hip replacement surgery at the Mayo Clinic in your state. I don't know if these kinds of backs are fitted to the length of the wheelchair, but mine was originally fitted for my manual wheelchair, before it got swapped over to my power chair. It had to go through a few adjustments before it fitted well to my power chair.
The Jay Focus back seems to have much better side support than the traditional Jay backs do. I feel like my scoliosis has progressed, because I tend to lean over to the side, even with support (tray, chest posture belt). It has bigger (way bigger) side support pads than the others do. I'm looking at my other options for a wheelchair back, but I'm still leaning towards the Jay Focus.
Samantha