STEP TO GET OFF PEDISTAL IS NARROWER THAN A NORMAL STEP. EE WAS PACKING A PUMP. HE STEPPED FROM THE BEARING PEDESTAL TO A STEP ON SIDE OF PEDESTAL TO MOVE DOWN OFF PUMP. HIS RT. FOOT SLIPPED FROM THE STEP AS HE SWUNG HIS LT. FOOT DOWN TO DISMOUNT PUMP. THIS RESULTED IN A 6"" TWISTING FALL THAT EFFECTED HIS LOWER BACK.