EE WAS OPENING A FIRE HYDRANT TO FILL A WATER TANK. THE VALVE WAS TIGHTLY CLOSED AND WHEN HE APPLIED MORE PRESSURE TO THE HYDRANT WRENCH, IT BROKE. THIS RESULTED IN HIM FALLING TO THE GROUND A ND CAUSED PAIN IN THE BACK, NECK AND ELBOW. EMPLOYEE SOUGHT NO MEDIAL TREATMENT UNTIL 2-9-00, WHEN HE BEGAN CHIROPRATIC TREATMENT FOR HIS DISCOMFORT. MINE OPERATOR NOTIFIED OF TREATMENT 2-14-