THE EE WAS PICKING UP A CRATE FILLED WITH USED OIL FILTERS. HE STATED THAT IT WEIGHTED APPROXIMETELY 50 LBS. WHEN HE ATTEMPTED TO LIFT THE CRATE HE FELT A POP IN HIS BACK, AND HAD IMMEDIATE PA IN. LATER WHEN HE BENT OVER TO CHECK THE OIL, HE FELT INTENSE PAIN AGAIN. HE NOTIFIED HIS SUPERVISOR, AND WAS TRANSPORTED TO NNRT ER FOR EVALUATION AND TREATMENT. HE WAS DISGNOSED WITH AN ACU