EE WAS DESCENDING THE SOUTH LOWER STAIRWAY FROM THE PRIMARY CRUSHER DECK. ABOUT THE THIRD STEP DOWN, BOTH FEET SLIPPED ON THE STEPS, LEAVING CONTACT WITH HIS HANDS ONLY. EE TIGHTENED HIS GRIP ON THE HANDRAILS TO PREVENT BODY CONTACT WITH THE STAIRS. IN DOING THIS, EE CLAIMS TO HAVE TWISTED HIS LOWER BACK.