EE tried to pull a long length of 1"" rubber hose, stained his back and then asked for help moving the hose, moments later 2 more EE's arrived to help move hose, after hose was moved the EE felt pain in his back and reported the injury to his supervisor they filled out a C-1 report. EE did not want medical help at this time, worker had pain next morning, taken to hospital for exam.