Miner was lifting 12'x8"" channel overhead to be welded in place. Miner reported to the employer on May 23, 2013 that he had pain in the lower back. Employer offered medical treatment but miner refused. on 5/24/13 miner requested medical treatment and was placed on restricted duty. The project was 100% complete on 5/24/13 and the miner was laid off at the end of shift.