WHILE ACCOMPANYING AN MSHA INSPECTOR ON A ROUTE INSPECTION OF AREA, I SLIPPED ON GROUND COVER AND FELL, STRIKING MY LEFT SHOULDER/ARM ON THE GROUND. NO INJURY NOTED AT THAT TIME. IN JULY I HAD AN M.R.I. AND IT WAS DISCOVERED THAT I HAD A TORN ROTATOR CUFF. THIS AFTER 3 MONTHS HAD PASSED.