EE WAS USING A 1-1/2 TON HOIST TO LIFT A 5-1/2 STD CRUSHER DISTRIBUTION PLATE FROM THE CRUSHER DECK FLOOR & BACK UP INTO THE CRUSHER. AS THE PLATE TRAVELED UP THE SIDE OF CRUSHER, IT GOT CAUGH T ON A LOCKING POST. EE & CO-WORKER GRABBED A SIDE OF THE PLATE & PUSHED IT AWAY FROM POST. EE FELT PAIN IN LOWER BACK & LEFT SIDE. REPORTED INJURY TO SUPERVISOR 10/18/02. WENT TO CLINIC.