INJURED WAS EXITING A 988 END LOADER WHEN HIS RIGHT FOOT SLIPPED OFF THE NEXT TO LAST STEP. THIS CAUSED HIM TO LAND AWKWARDLY ON HIS RIGHT LEG. HE CONTINUED TO WORK BUT HIS KNEE DIDN'T GET ANY BETTER. HE STARTED TO MISS 12/15/03 AFTER SCHEDULED DAYS OFF. HE THOUGHT HIS KNEE WOULD GET BETTER.