Hi, I t is not very unusual to have such an experience after childbirth. This srises from pressure at the joint between the sacral bone and the lumbar vertebrae. Treatment involves rest, analgesics like paracetamol, anti inflammatory drugs and at times injections of steroids, resting on flat surfaces is very important and immobilizing the back is important. For now, avoid standing for long and lifting heavy loads. failure with these measures and drugs should prompt a review and possible X rays with your primary care physician. Kind regards. Rogers. MD