I had a coccyx problem a month ago. It happened while I was sleeping and my friend accidentally kicked me to my buttocks. I woke up in the morning and I could not stand up anymore. The pain was awfully strong. I had never had a problem with this so I couldn't even think what has happened. Since I had to fly 10 h to get home, it got worse.
I was recommended to see Dr. Robert Griffiths in Sayer Clinics in London (see Doctors and specialists in the UK, London). I went there straight away. He did an awesome job. After 4 treatments I'm feeling 99% well already. Of course I did everything what he suggested me to do as well. So I wasn't really doing any sports or sitting while I had that problem.
I'm very thankful and I would definitely recommend him!