EMPLOYEE WAS PREPARING THE PARKER PRIMARY PLANT TO BE MOVED TO ANOTHER LOCATION AND BENT OVER TO LIFT A TIMEBER (BLOCKING). HE EXPERIENCED PAIN AND WENT TO THE GROUND IN PAIN. HE HAS HAD BAC K RELATED INJURIES IN THE PAST AND IT JUST SNAPPED. DR TOLD HIM HE HAS A TORN MUSCLE ON LEFT SIDE OF HIS BACK.