Have been doing some research on the coccyx because I have been suffering often-excruciating pain with mine. I seem to remember that it's always been this way - however, very seldom did I experience a 'twinge'. I fell flat on my back about 15 years ago, and then again three years ago. I don't recall feeling any great pain, until now. I have been blaming my so-called orthopaedic chair at work for the trouble I have sitting down (it send a hideous pain from my tailbone through the small of my back every time!) - so now I am assuming the 'condition' is being exacerbated by it, as opposed to being caused by it.
I finally went to the doctor the other day, and had x-rays taken. The technician said that the tailbone is usually supposed to end off straight - and that mine looked 'strange', as it curves inwards. Actually, it too seems to be bent inwards at a 90 angle - a bit of a shock to look at!
I am seeing him again in two weeks and will e-mail with his advice, etc. I am hoping he has a solution for me (other than sitting on a rubber ring!) and will be sure to let you know what he says.
Thank you for putting together such an informative website!