Effectiveness of physical therapy interventions for coccydynia: a systematic review with a narrative synthesis.

Only ten trials and 563 patients in total, and several techniques were tested in a single small trial each. Four of the ten trials were at high risk of bias, mostly because the person measuring the outcome was not blinded or measured it poorly; the review states that no area of bias was entirely free of concerns, and pain-free sitting duration was at high risk of bias in every study that used it. The interventions were too varied to combine, so the review produces no single estimate of how well these treatments work. Most treatments were passive, and no trial tested active exercise on its own. Where techniques were combined, the contribution of any one of them cannot be separated. Only one trial reported anything beyond six months, so there is almost nothing here about long-term benefit. Three trials had incomplete data that could not be retrieved, which prevented the authors from calculating how large the treatment effects were. Only studies published in English were included.

The authors declare no competing interests and say the review received no specific funding from any public, commercial or not-for-profit agency. The protocol was registered on PROSPERO before the searches were run.

Do not take this review as proof that any single technique works for tailbone pain. Most interventions were tested in one small trial each, several were given alongside other treatments so their own contribution cannot be separated, and the authors themselves say the findings should be interpreted cautiously because four of the ten trials were at high risk of bias.