Hello. I m Dr. Christensen. I m sorry you re having back problems. Even people with anatomically normal tailbones can develop back pain while sitting at a desk all day; for someone with a tailbone deformity, back pain is even more likely to occur. For one thing, you re probably altering your posture to compensate for your tailbone deformity, and this is undoubtedly straining your back. For another, if your tailbone has some anatomical anomalies, it s possible your lumbar or thoracic spines aren t quite right, either. X-rays or MRI might be needed to determine if that s the case, but it s something to keep in mind. You might benefit from using a chair that s more ergonomically appropriate for you. Physical therapists can be helpful in this regard. (Some employers retain physical therapists who offer ergonomic evaluations to employees, so you might ask your boss if he/she has any suggestions.) At the very least, a doughnut pillow might allow you to sit more comfortably in your chair and take the strain off your back. However, if your problems persist, see your doctor for an evaluation. I hope that answers your question. Good luck!