Who started it: LL Cool J
Circa: 1995 

This mid-90s trend was first spotted in LL Cool J's"Hey Lover" music video in 1995, and it's become one of the ridiculous trends that personified that era of hip-hop style. Whitney Houston claimed that LL jacked it from Bobby Brown, although the rapper insists it was the other way around. However, if The New York Times has anything to say on the matter, the trend actually came from mid-90s bike messengers, who hiked one leg up to avoid getting their pants caught in their bike chains.