To release the obturator, have the patient in sidelying (I would recommend right sidelying as it is easier to get to the lower side for me, but you will probably need to release both sides). With the patient in right sidelying, keep the right leg straight (in neutral) and flex the left hip and knee to 90 degrees and rest on a pillow in front of patient. Now, you'll have to palpate the length of the coccyx, and place your hand (fingers extended, using the tips of digits 2-5 to apply pressure) between the most inferior prominent portion of the coccyx and the anal opening. If the muscle is severely spasmed, it may be hard to tell the difference between the bone and tissue. So, to verify, ask your patient to roll his right knee and press into the mat (external rotation) and you should feel the contraction (or an increased hardness). Move to where the contraction is, again between the coccyx and anus. To help in your biomechanics and safety, keep you elbow/wrist/hand in a straight line, angling down at 45 degrees in relation to the mat or table your patient is on. Then, apply pressure to the muscle. This is what I mentioned as being a "Barnes style" but I know it is not exclusive to him. The main thing is to not do any "stroking" massage here. So, apply sustained, direct pressure, and wait for the muscle to release (time, not pressure or frequency of stroking, is the factor here). You will feel the muscle release (like sticking your hand through jell-o). This can take anywhere from 2-10 minutes, so don't worry if it seems too long, it's probably not, just focus on how the muscle feels. Once you have released this side, repeat on the left. Have the patient remain in right sidelying, and resist external rotation done by your hand at his knee. Once you find the left muscle, sit and drop your elbow to the mat, so this time your arm is angling up from the mat, at 45 degrees.

Sometimes pelvic floor tension can be felt externally when doing this release (once the obturator is relaxed) and a little closer to the anus. I find that this can be felt and released a little externally, but is not as efficient or beneficial as an internal release. However, a hypertonic obturator does not guarantee a hypertonic pelvic floor, so I'll keep my fingers crossed for this guy.

Of course, you will want to wear gloves when doing this.

It seems from everything you have written that so musch has been ruled out. That is typically the case with this. In fact, I have a new client who, as I found out today, has had all these tests and they of course were negative. I know his injuries are extensive, but he also has an ideal mechanism for coccygodynia. Have you found any information specific to this condition? I don't believe there is much unless you have attended or study courses specific to the pelvic floor. Internet is limited on this and discusses surgical removal of the coccyx (not recommended, usually ends up causing more problems).

Please keep me posted! Good luck with this and let me know how the release goes!