As unfortunate as it may be sometimes you suffer from back problems. I just recently purchased something I hope to get help from and that is an Inversion table. If you haven't seen or don't know about them you lock your ankles in, lean back and invert to 20, 40, 60 ,or 90 degrees. You can wind up partially or fully suspended upside down. Self bondage may be hard because I fear that if handcuffs are used the keys may be dropped and you may not be able to get yourself out, resulting in an embarrasing situation, or worse. Not only can this machine be used for tie up fun but in the 2 weeks I've had it my back problems have slowly improved. I would suggest this to everyone to prevent back pain if nothing else but please, if you end up with one of these machines use it safely if tie ups are done and have someone else present. you can buy them at most sporting goods stores for anywhere from 100-400 dollars, but I believe it's a great investment to stay in shape if nothing else.