On 6-8-15 Employee was coming back from the miner with a load of coal employee hit two holes and jarred his back. On 7-16-15 Employee was going up #6 entry to the miner he hit a hole in the intersection causing his lower back to slam into the shuttle car seat. The safety department was notified on 8-17-15 Employee was under doctors care. Employee began missing work on 8-20-15.