If the pain relates to the coccyx, this should produce immediate relief.If the anesthetic test proves positive, then a dynamic (sit/stand) x-ray or MRI scan may show whether the coccyx dislocates when the patient sits.Use of dynamic x-rays on 208 patients who gave positive results with the anesthetic test showed:

31% Not possible to identify the cause of pain
27% Hypermobility (excessive flexing of the coccyx forwards and upwards when sitting)
22% Posterior luxation (partial dislocation of the coccyx backwards when sitting)
14% Spicule (bony spur) on the coccyx
5%  Anterior luxation (partial dislocation of the coccyx forwards when sitting)This study found that the pattern of lesions was different depending on the obesity of the patients: obese patients were most likely to have posterior luxation of the coccyx, while thin patients were most likely to have coccygeal spicules. Angle of incidence
Sagittal coccygeal movement is measured using the angle of incidence—or the angle at which the coccyx strikes the seat when an individual sits down. A smaller angle indicates the coccyx being more parallel to the seat, resulting in flexion (or “normal” movement) of the coccyx. A larger angle indicates the coccyx being more perpendicular to the seat, causing posterior subluxation (or “backward” movement) of the coccyx. Causes
One way of classifying coccydynia is whether the onset was traumatic versus non-traumatic. In many cases the exact cause is unknown and is referred to as idiopathic coccydynia. Coccydynia is a fairly common injury which can often result from falls, particularly in leisure activities such as cycling and skateboarding.
Pain in the coccyx can be caused from many incidents like falling, horseback riding, or even sitting on hard surfaces for a long period of time. The main focus is to prevent coccyx pain from occurring, by correcting everyday activities that contribute to tailbone pain. You can take hot or cold water baths. Have a stream of hot or cold water run down your back continuously if pain becomes unbearable. Use cold water if pain persists. Repeat the procedure in intervals of 5-6 minutes. Proper equipment used to preventing coccyx pain
There is no definite way to fully prevent coccyx pain because an accident can occur at any given time. However, people who are obese are at a higher risk for developing coccyx pain. Carrying excessive weight contributes to more stress on the coccyx while sitting down causing increased chances of pain. Prevention of carrying excessive weight gain can help reduce the tension and pressure on the coccyx. In other words, the coccyx for obese people may be more posteriorly outward when they are sitting down. Avoidance of contact sports like basketball, football, and or hockey can decrease the risks of coccyx pain, because it can help reduce the chances of falling. Another method is proper safety equipment for sports is to prevent coccyx pain. For example, there are hockey pants that provide extra cushion that protect the thigh, coccyx, and buttocks. These results will lead to less falls that can cause trauma to the coccyx.