WORKING WITH ANOTHER EMPLOYEE PUTTING ROTEX BACK TOGETHER, WHILE LIFTING THE #4 MESH SCREEN HE FELT PAIN IN HIS SHOULDER. HE INFORMED THE SUPERVISOR THAT HE FELT IT WAS A BASIC SORE MUSCLE AND HE DID NOT WANT MEDICAL ATTENTION. SELF-TREATMENT WITH HOME MEASURES. IT PROGREESS TO VERY PAINFUL SO THAT IT EFFECTED HIS SLEEP. HE REPORTED WORSENED CONDITION ON NIGHT SHIFT 4/19.