Whether sex is used a means of pleasure and excitement, or one of those "necessary evils" to keep the relationship going, sex and back pain are generally not good friends, unless you follow some of these simple techniques to make it all work great, and who knows, you might have fun doing it.

Emotional Control
Physical pain, chronic disease and generally things that you cannot control are all negative stress factors that obviously affect our emotional well being. One of the most important aspects to have any chance of overcoming or living with the condition, is the best possible attitude and emotional state towards your state. If you feel depressed, frustrated, angry, or preoccupied you are unlikely to enjoy a sexual experience no matter what your physical state is. First and foremost, you must accept the condition that you have and look beyond it. In fact, as silly as it may sound, use your existing condition as an advantage to do things or ask for things (sexually) that otherwise might not be well received by the opposite party (more on that later). Generally, most of the emotional issues can be resolved with common sense approach, and good support from your partner. If not, don't hesitate to contact a licensed physician or a mental specialist for assistance. Once you get your attitude in check, the rest is easy.

Physical Limits
To first attack any problem, you must first understand the extent of it. To that effect, you need first to determine the extent of the back pain that you are experiencing. That is, what exactly are the limits of the range of motion after which the pain becomes unbearable? Similarly, what are the positions or movements of your back that feel good? What you find is what I call "movement zones", essentially areas that you know you can create some comfort in within your body. Once you mapped out your inner limits of comfort zones you can begin investigating how to maximize the pleasures in the movement zones that feel good.

Set your expectations
As you and your partner embark on this journey to make sex more enjoyable, keep in mind that things may not necessarily happen perfectly all at once. It will take time; it requires some patience and understanding from your partner. Take your time, go slow. Frustration, at times, is expected; just keep in mind that the reward is worth it. One of the easiest things to "start with" is for you and your partner to start with a hot bath or shower together. It's predictable, easy and warm. Add a little warm oil massage to decrease overall pain, and relax the muscles and mind. Make sure that you enjoy it; remember this isn't work, its pleasure that you are after.

Positions
There are many resources that go into a lot of depth and detail as to the various positions that are available to choose from. I have links to these on my site. I will not do that here, as I will not be able to do justice to all of the variations, details and sketches of these positions. Here, we will only highlight the basic key categories that may serve as areas for you to research further.

Standard Group
These are your basic man on top, woman on the bottom (or reverse) in missionary position situations. These are ok if the one on the bottom is the one with the back pain problem, as he/she can comfortably rest on a flat surface. Pillows can be used to prop-up the pelvic area to maximize the thrusting motion of the penis. Research this category a bit more as there are minor variations to this theme.

Backwards Group
The second group is what I call the "backwards" group for one simple reason; most of the positions are such that you are not facing your partner directly, but rather their back side. These positions are best used when the back pain doesn't ease by lying down, but rather subsides as you either stand, crouch or sit. With certain non-disc spine problems sitting may often be more comfortable during sex. Again, experiment with your partner what works for both of you. These positions often lead to enhanced pleasure situations as they promote fantasies of having relations with other than your partner to occur because of the fact that you are not directly seeing your partner's face.

Manual / Risky Group
This is a group, which many criticize, is the group that you can take advantage of your situation to ask for things (sexually) that would normally be not easy to get. Again, there is criticism to this group as it takes advantage of your disability, but on the other hand if both partners agree then what's the harm? Here ask for manual stimulation, such as hand masturbation, or oral sex. In the later, do ask for extremes, such as ejaculations into the face, mouth or swallowing. Again, since your pain may prevent you from "normal excursions", these options may be available. Remember, the key is to make sure that you feel no pain in the position that you are in.

Conclusion
In lovemaking as a rule, the partner with lower back pain should take a passive role, with the other partner introducing stimulation in a gradual, relaxed manner. Remember to take it slow. From onset, define what movements or positions hurt and should be avoided and which ones feel good and encouraged. Remember to experiment. Trying something new can be extremely rewarding physically and emotionally as it leads to more intimacy between partners. Just because back pain limits one's physical abilities, it doesn't have to limit sensuality.