EMPLOYEE FILLING IMPACTOR'S HYDRAULIC OIL RESERVOIR. ACCESS TO RESERVOIR GAINED USING A LADDER. EMPLOYEE CLIMBING DOWN LADDER UPON COMPLETION OF TASK AT A FAST RATE. SLIPPED ON THE SECOND RUNG FROM THE BOTTOM. EMPLOYEE FELL FROM LADDER, LANDING ON HIS FEET. UPON LANDING HE TWISTED HIS RIGHT KNEE, TORN ACL & MANISCUSS.