PERSON WAS GOING TO CHANGE A 60"" BOTTOM BELT ROLLER IN #6 BELT. PERSON CARRIED ROLLER TO AREA AND THEN SQUATED DOWN TO REMOVE WORN ROLLER. WHEN PERSON SQUATTED DOWN BENDING HIS KNEES FELT PAIN IN RIGHT KNEE. PERSON WENT TO DOCTOR ON 6/7/01. HAD SURGERY ON KNEE 7/12/01 RELEASED TO WORK 7/13/01.