As I sit in this office chair with a blown out back today. We have all heard how we should lift with our legs. I do not know about others but I have yet to master the art of setting a toilet with my leg muscles. Or, a Cast Iron kitchen sink. I am thinking that he guy that came up with lift with your legs is not a plumber, does not know a plumber, and would not lift in text book fashion if he was a plumber. I have accepted a bad back as part of my life in the trade I chose.