EMPLOYEE HAS BEEN AWARE OF HIS WEAK BACK, AND HAS PERFORMED HIS DUTIES WHILE TRYING TO PROTECT HIS BACK FROM FURTHER INJURY. PRIOR TO THE INCIDENT HE COMPLAINED OF BACK PAIN AND STIFFNESS. WE THINK THAT THIS INCIDENT WAS CAUSED PRIMARILYFROM PRE-EXISTING DEGENERATIVE DISK DISORDER THAT HE HAS SUFFERED WITH THE LAST TWELVE YEARS.