pillows and positioner aids...

Though honestly I don't really notice pain during, but there are times I REALLY feel it afterwards.

I pull out my lower back on occasion...sometimes it is honestly to painful for me to do anything but simply lay on my back - takes out some of the fun but it works. My fiance will rub my back or help my stretch as a type of foreplay - use some massage oil.

I fold a pillow in half and put under me.

I have been trying the pillows there is a million in our bed.. and last night i bought a sex sling so i hope that helps

It might be better to think of fixing it outside of sex. So exercising (especially your abdomen, that often helps back pain). Massaging it prior to sex maybe. Stretching it out.