KY massage and lubricant oil(as long as your not allergic)
Step1
First you want your partner to warm you up and relax your back muscles at the same time. A little back massage before you get sexual is great. Alot of foreplay while he rubs your back on and off feels great!
Step2
when you begin sex a good one is to be on top and have him also hold onto your back and rub while you move up and down on his penis. your pleasing him and yourself and pampering your back too!
Step3
Also lying side by side with him behind you with you leg elevated. If it helps, have him hold your leg up for you. Make sure when he enters you that he should do so gently and none of that hard thrusting. It actually feels better gentler, because i have a bad back myself and when i told my husband to be gentler it felt even hotter!
Tips & Warnings
if you take pain meds for your back, you may want to do so before sex as well to make it even more comfortable.
Of course you always want to follow any of your physicians orders that may not coincide with my position recommendations, because all back problems are not the same. if you feel discomfort that is too intense to continue intercourse, you can always please each other orally or use sex toys as well!