WHILE CLOSING A VALVE ON AN L5 PUMP, EE LOST HIS BALANCE AND FELL. CONTRIBUTING TO THE FALL WAS A SUDDEN CHANGE IN RESISTANCE IN OPENING THE VALVE AND THE WRENCH SLIPPING. WHEN HE FELL, HIS RI GHT LITTLE FINGER WAS PIKNCHED BETWEEN THE WHEEL WRENCH AND THE CONCRETE FLOOR CAUSING A LACERATION. MEDICAL DEPT. REFERRED HIM TO ER WHERE HIS FINGER WAS XRAYED AND HE RECEIVED 4 SUTURES.