Thanks for the Post , it was something I had not considered . I get tired shoulders and neck when I tie for any length of time .
I jury rigged a 1/2 inch piece of Plywood to 2 pieces of 2x4 to get 2" higher with my clamp on . Seems a lot better as my back is no longer bent over . The fly is now about chin high which seems to work for me . I'm going to get some better wood and make the change to my workbench . I'm going to experiment a bit with elbow rests . The cardiac specialist that put the little wire thingy in my heart uses padded elbow rests , He said it helped prevent fatigue .