At ERWR - While dragging a trolley to job site , suddenly a part of trolley stuck in grating hole. He tried to pull it up by himself, he stood above the trolley and bent his body. He caught the trolley and finally pulled it up. After that he felt painful in his lower back. He informed his college, so another worker came to him and provided him a pain killer balm. After took a rest, he felt more painful and waited for crew boat to pick him back. Crew boat arrived and pick him and team back LQ. He informed his supervisor and went to consult Medic.