I went to Dr Ruff for advice about chronic back pain stemming from a herniated L5/S1 disk resulting in inability to sit or do vigorous exercise. Needless to say, inability to sit results in having to completely change every aspect of one's lifestyle and amounts to a severe disability. Dr Ruff barely listened to me and dismissed me, saying casually that I needed to strengthen my core by doing as many sit-ups as possible. This was disastrous advice that led to worsened pain. It is well known that sit-ups are harmful to those with lumbar issues and may in fact even cause them.