INJURED STATED THAT HE WAS ATTEMPTING TO STAND UP AFTER INSTALLING A ROOF BOLT. AS HE WENT TO MOVE HE TWISTED HIS RIGHT KNEE. IT HAD SWELLING & DISCOMFORT. INJURED DID NOT FILL OUT AN ACCIDENT REPORT UNTIL 4/24/01. ON 5/1 HE TOLD US THAT HE WAS GOING TO HAVE AN MRI. IT DID NOT BECOME REPORTABLE UNTIL THEN.