I bounced down the stairs and did the same thing grannya. Yes, it’s horribly painful. A cushion and a Tens machine were my friends , also arnica for the bruise which did seem to help initially. I found heat helped relax my spine, tension made it a whole lot worse. Dining chairs were avoided like the plague, even with a cushion I needed something softer with more give. My most comfortable chair was one of those office chairs that has the fine mesh seat and back. Totally adjustable and moved with me. Not pretty in our living room but at least I could sit. Lying on my side eased the pressure, I did a lot of resting. Good wishes to your daughter, I hope the pain eases soon.