An employee was in the LV712 transport van traveling to 12 shovel. When van hit a pot hole, employee experienced lower back pain. Employee traveled 1.5 miles to EE's assigned equipment at the 5150 before EE called HS3. On the evening of 7/4/2017, the employee returned to the clinic and was prescribed pain medication. Employee was scheduled off 7/6, 7/7, and 7/8.