Muhammad won the 400 m hurdles at the 2007 World Youth Championships, and placed 2nd in the event at the 2009 Pan American Junior Championships. Collegiately, she ran for the USC Trojans, for whom she was a four-time All-American at the NCAA Outdoor Championships. She was also the 2013, 2016, and 2017 American national champion. and two time Diamond League champion. With a personal best of 51.58, she is the second fastest woman of all time in the 400 m hurdles.