US golfer Jason Dufner's laid-back lounging at a charity youth center visit sparked a Twitter trend on Friday as his fellow pros -- and a host of others -- posted pictures of themselves "Dufnering". "What can I say, I was tired, my back hurt from sitting on the floor, and we were talking about relaxation and focusing," Dufner tweeted after the picture of him lolling on the floor with a group of children became a social media sensation. Northern Ireland's Rory McIlroy was among the many to tweet a picture of himself sprawled in a "Dufnering" pose.