EE WAS TIGHTENING THE HOSE ON THE HEAD JACK. AS HE WAS TIGHTENING THE HOSE, HE SLIPPED ON A ROCK AND TWISTED HIS LEFT KNEE. EE FINISHED HIS SHIFT AND THEN WENT TO HOSPITAL. HE WAS DIAGNOSED WI TH A SPRAINED KNEE. EE RETURNED TO WORK THE NEXT DAY, 8-25-00.