EE WAS LOOSENING THE BOLTS ON A D11 FINAL DRIVE WITH AN AIR WRENCH WHEN HE EXPERIENCED PAIN IN HIS LEFT HAND. DR DETERMINED HE HAD A SPRAIN AND CARPAL TUNNEL WHICH IS RELATIVE TO HIS JOB AS A MECHANIC WHICH INVOLVES REPETETIVE MOTION. HE RETURNED TO WORK 8/29/00. OPERATION WAS SCHEDULED 11/22/00 & HE WORKED HIS SHIFTS UNTIL THIS DATE. THIS MATTER BROUGHT TO MY ATTENTION 12/20/00.