EE was working on a CH4 monitor on a Joy miner (3rd shift). While kneeling down next to the miner, a rock fell hitting EE's left shoulder. This caused EE's face to hit the pan on the side of the miner which caused a small cut just above the left eyebrow. EE was taken to the hospital where EE received 4 stitches to close the wound. EE returned to work on the next scheduled shift.