If where you work allows it, try Sven clogs. They are made by a Swedish orthopedist and are the absolute best for working long hours. I could do 12 hour shifts running up and down the hall all night and my legs would never, ever get tired. They have a website, can't think what it is, but if you Goggle Sven clogs, it should come up with some. They also sell them on Ebay.