On March 10, 2010 EE was rock dusting w/scoop and duster. To get out of the dust, he backed-up the scoop and ran over a rock resulting in pain in his lower back. He completed his shift and went to have it checked. He was released and returned to work on his next scheduled shift. He returned to Dr on 4/19/10 due to continued pain & was placed off work. An MRI was performed.