EE WAS USING A PORTA POWER TO REMOVE BOLTS ON A SHOVEL HOIST DRUM. THE ALL-THREAD BROKE AND THE RAM STRUCK HIM ON THE HARDHAT. HE WAS CHECKED BY MINE RESCUE PERSONNEL AND RETURNED TO WORK. ON SEP 4 A PHYSICIAN EXAMINED HIM AND ALLOWED HIM TO CONTINUE TO WORK WITHOUT RESTRICTION. OVER TIME PAIN IN THE NECK AND ARMS INCREASED.