EMPLOYEE WAS BOLTING TOP AND A PIECE OF ROCK FELL OUT AND WENT AROUND THE CANOPY AND HIT EMPLOYEE ON LOWER BACK. EMPLOYEE WORKED THE REST OF THE SHIFT AND WENT TO THE DOCTOR ON 2/9/05 AND WAS GIVEN A RETURN TO WORK(OUTSIDE SEATED JOB) FOR 2/9/05. HE RETURNED ON 2/10/05 AND WORKED OUTSIDE UNTIL 2/24/05 WHEN HE WAS RETURNED TO WORK BY DOCTOR TO FULL DUTY NO RESTRICTIONS.