EMPLOYEE WAS WORKING ON A GEARBOX TIGHTENING NUTS WITH A 2 3/8 BOX ENDED WRENCH. HE SPRAINED RIGHT SHOULDER BY PULLING AND PUSHING WRENCH. HE WAS TREATED FOR FIRST AID AND CAME BACK TO WORK. H E WENT FOR SURGERY ON SAME SHOULDER ON 5/17/02 AND MISSED WORK UNTIL NOW.