EMPLOYEE WAS TRAMMING A FEEDER ON #2 SECTION WHEN HE WAS STRUCK IN THE BACK FROM A FALLING BROW. THE PORTION OF THE RIB THAT FELL MEASURED 4' W X 4' L X 2' THICK. HE WAS TRANSPORTED TO HOSPI TAL WHERE X-RAYS SHOWED NO ABNORMALITIES. HIS FAMILY DOCTOR ADVISED HIM TO REMAIN OFF WORK UNTIL AN MRI WAS PERFORMED.