EMPLOYEE SLIPPED (AND FELL) ON ICE, CAUSING LOWER BACK STRAIN. RECIVED PRESCRIPTION MEDICATION AND HAD REPORTEDLY MISSED 1 DAY OF WORK BEFORE BEING OFF ON ROTATION. SUBSEQUENTLY LEARNED TREATING PHYSICIAN'S DOCUMENTATION REVEALED NO WORK RESTRICTIONS NOR TIME LOSS. RECLASSIFY THE INJURY AS MEDICAL ONLY, PER DISCUSSION WITH VACAVILLE MSHA REP.