THE EE REPORTED A KNOT IN A BACK MUSCLE, ACCOMPANIED BY MINOR PAIN, UPON COMING TO WORK ON 8-29-01. HE REPORTED THE ONSET OF THE CONDITION AFTER GOING HOME FOLLOWING COMPLETION OF A 10-HOUR SH IFT THE PREVIOUS DAY, 8-28-01. NO SPECIFIC INCIDENT IWAS IDENTIFIED BY THE INJURED EE. THE EE SOUGHT MEDICAL ATTENTION/DIAGNOSITC TESTING AND WAS PLACED ON RESTRICTED DUTY 9-3-01.