EMPLOYEE STATED THAT HE WAS OPERATING A DOZER PUSHING SHOT ROCK TO THE LOADER. HE BACKED UP TO AVOID A ROCK WHICH WAS GOING TO FALL FROM THE MATERIAL BEING PUSHED. WHEN HE DID, HE BACKED THE D OZER UP AND INTO A LARGE BOULDER WHICH CAUSED THE DOZER TO JAR THE EMPLOYEE. WENT TO DOCTOR ON 1-15-04 AND INCURRED LOST TIME ON THAT DATE.