Employee was getting off of Coal stockpile truck unit number 1146 (HD 325 Komatsu) when he slipped on rough ground. He said it felt like something pulled in his right hip. He went to doctor on 04/09/2014. He worked on 04/10/2014. Went back to the doctor on 04/11/2014 and was off till 04/16/2014. Lumbar strain.