Employee had walked the main belt-line and came outside. He was at the drift mouth at A-1 belt. Employee bent over to pick up a piece of chain link wt. about 20 lb. He developed a sharp pain in his low back. Dr. at the E.R. examined him and said he had acute muscle strain, told follow up with family Dr., he saw family Dr. 8-5-09, and was taken off work. (Mine Closed 2-10-10)