I am 44 years old and I injured my tailbone 3 years ago, in March of 2005 from a driving accident with one of my horses. It was a runaway situation and when he ducked left just before heading straight into a fence he broke away from the shafts of the cart and upset the cart and I went flying. The onset of pain was not immediate. It showed up about 60 days later. I had excruciating pain while sitting, especially on hard surfaces and moving from a sitting to a standing position. I decided to stop riding for a while and started exercising, treadmill, crunches, squats etc. This helped a lot. The pain did go away from going from sitting to standing, but while sitting it still was painful. I put up with the pain and did not seek medical attention until July of 2006. I don't know why I waited so long.
The x-rays were negative for a fracture and my doctor prescribed Celebrex. I showed my x-rays to my Chiropractor husband and he commented that my tailbone was tilted toward the front a little more than it should be. He also noticed that it was sideways to the right.
After visiting your site I asked him to do a manual adjustment for me and he had never done it before for obvious reasons but he tried it. He got a slight release and I felt 80% better. I didn't feel that excruciating pinch anymore when rocking my pelvis back while sitting. I was able to start riding again. I also bought a Mayline ergonomic chair for my computer that has the depression in the tailbone area. I sit at the computer all day everyday and I never have pain from working at my desk.
I do still ride and I do still get sore but just ice afterwards and I am fine the next day. I found an orthopedic saddle that has a depression for the tail bone. Stubben makes it and you can read about it at stubbennorthamerica.com. I ordered one and will post back to let you know if it helps.
I still suffer from the pain after long car rides and stadium events so I have ordered some orthopedic cushions. That is what really exacerbates my condition, sitting on anything hard for long periods of time. Other than that I feel great. I still exercise and I still ride. I think I must have arthritis in that area and I may go visit a specialist, however, I have been able to manage my pain thus far without resorting to anything invasive.
I hope some of these suggestions will help.
Note from Jon Miles: See also Horse riding for people with coccyx pain