EE REPORTED SORENESS IN RIGHT ELBOW WHICH BEGAN ABOUT 9 A.M. & CONTINUED TO WORSEN THROUGHOUT THE DAY. EARLIER THAT MORNING HE WAS WORKING ON THE EAST OUTSIDE ELEVATOR TRYING TO TIGHTEN BELT & HAD PROBLEM TIGHTENING FROZEN TAKE UP SLIDES. HE HAD BEEN USING AN IMPACT WRENCH AND RATCHET. DOCTOR DIAGNOSED TENNIS ELBOW ON 12/31 & THOUGHT HIGH IMPACT WRENCH MAY HAVE CONTRIBUTED.