EE WAS HELPING INSTALL NEW ROLLERS ON A CRAWLER DRILL RIG. TO INSTALL THESE ROLLOERS YOU HAVE TO BEND OVER IN AN AWKWARD POSITION AND EXTEND YOUR ARMS. WHILE DOING SO EE FELT SOMETHING POP IN HIS BACK. HE WORKED THE REST OF THE DAY BUT THAT NIGHT BACK BEGAN TO STIFFEN UP AND HURT. CAME TO WORK THE NEXT MORNING AND WAS IN OBVIOUS PAIN AND WAS SENT TO THE DOCTOR.