Over-exertion in lifting objects
3 EE'S WERE REPLACEING THE BELLYPAN ON A DUMP TRUCK. AFTER THE PAN WAS LOCKED IN PLACE, INJURED EE DROVE AWAY IN THE TRUCK. 30-45 MINUTES LATER, INJURED TOLD HIS FOREMAN THAT HIS BACK WAS HURTING. HE HAD NOT MENTIONED THIS TO THE OTHER TWO CO-WORKERS.