@nysister - thank you for the post!! I don't want to scare you or anyone else, but be careful with this type of device . After I had my first knee surgery I placed a fold up (bleacher chair in a bag) chair underneath my desk to elevate my leg. When I told my surgeon"about my great idea" he warned me that if the "back of my leg, where it bends" (directly behind the knee) is not supported, I would be right back in surgery. Using the little plastic knee model in his office, showed me what could happen due to the stress placed on that area.