Several years ago, my wife slipped in the bathroom and fractured her tailbone. The result is recurring pain and at those times she likes to use a heating pad. I got her a basic one, but she says that it is hard to keep it closely molded to the right part of her body (lower back and top curve of rear end), because that part of her body is especially curvy (lucky me!), and it’s even harder when she’s sleeping, because, of course, it’s hard to stay in one position while asleep. Does anyone know of a heating pad that can be made to stay put in a particular spot, perhaps with straps or something?
Some heating pads have straps sewn into the bottom. K-Mart, Target, Walgreens has them. If your crafty or SO is you can make your own. I use the extra large ones and sometimes I use a towel to tie it where I want it. I hope she feels better. 
You don’t mention whether or not she’s tried the single-use style heat pads–Thermacare is the only brand that comes to mind right now, but they advertise that the heat lasts up to 8 hours and the pads have adhesive to hold them in place. As for making a standard pad stay put, I’d go with badkittypriestess’s suggestion.
Good luck.
I use a heating pad a lot and generally just get the plug in kind that you can prop up on a pillow. I don’t think you’re supposed to use those all night or anything though. I love the Thermacare Heat Wraps
http://www.thermacare.com/lowerbackwraps.jsp
and I find they stay on close with no real problem.
Another thought: if she has health insurance and decent coverage, maybe her doctor can send her for some physical therapy? I’ve gone a lot over the years and I swear THEY have the ultra heating pads- HOT HOT HOT moist pads the sink in so deep that they’re heavenly. You can’t buy them commercially- they require a big machine to heat them up and all. Just something to check on- she may find some relief from that.
One more thought- I saw these in Walgreens and I think they have potential.
http://www.walgreens.com/store/product.jsp?CATID=100071&navAction=jump&navCount=0&id=prod2124742
you can get hot or cold packs for it and it looks like it probably holds tighter then a Thermacare.
Thanks for the suggestions, guys!
We do have pretty good health insurance, but my wife is one of those people who is incredibly resistant to seeing doctors or therapists. For regular dental/gynae checkups I basically have to tackle her and drag her to the doc. Plus she has very crappy vacation/sick leave policy at her job (3 sick days a year!?) and it would be a struggle to find times for appointments
FWIW, it would probably really be to her benefit. I have long term ongoing back problems due to disease, but my sister has a similar issue to your wife. She fell on some stairs and sustained a tailbone wack and years later she still has a lot of trouble with it. Some kind of treatment would probably really help her.
Most PT offices realize that people work and can take patients after normal work hours and weekends. I’ve never been to one that wasn’t open long hours- one I used to go to was open at 6am and closed at something like 8pm. If she tries the uberhot PT heating pads she’ll probably weep with joy at the relief (if she gets some relief from a regular pad, she’ll probably get LOTS of relief from them.)
Did her doctor tell her to put heat on it, btw? I"m only asking because I know in the past I’ve had both heat AND ice treatments depending on the nature of my pain. If she hasn’t had a good recent check on it, it’s probably worth it just to make sure she’s treating it the way it needs to be done. They may also be able to give her some stretching exercises that will strenghten her back and relieve the pain when it does flare.
This isn’t much help for the staying-put issue, but for overnight use (which personally, I’m nervous using an electric pad for), or for use out of reach of a plug, a rice bag is awesome. Pop it in the microwave for about two minutes, and it stays hot for at least half an hour, and warm for considerably longer. It’s also nice and moldable.
You can buy them for ridiculous prices, but they’re easy to make with a sewing machine. It’s just fabric and plain old white rice. I have two, and they are in daily use for my physical therapy maintenance.
And yeah, PT is worth it. I’ve had it three times, for different problems, and have gone from figuring they couldn’t really do me much good to being a True Believer in PT. Some things, doctors don’t really know jack about, while a good therapist can fix you right up.