4. Pronounced curvature
Another way to diagnosis lumbar lordosis is to attempt to lay flat on the floor. If there is a sizeable gap between your lower back and the floor, you have lumbar lordosis. As a matter of fact, if you attempt to push your lower back to make contact with the floor, your back will probably go into spasm because those muscles are already overly-stressed holding your back in an unnaturally curved position.
While x-rays and other diagnostic tests are helpful. Visual cues are sometimes the easiest, least expensive and most accurate way of determining the cause of physical issues. Exaggerated curvature is easily seen by the trained eye.
Remember that some curvature is totally normal and does not need to be treated. Only very pronounced curvature needs to be medically addressed. Look at your body in the mirror from the side. Do you suspect your back pain arises from this condition? If so, a medical consultation might be in order.