Dalilah Muhammad (born February 7, 1990) is an American track and field athlete who specializes in the 400 meters hurdles. A 2016 Rio Olympics champion and 2020 Tokyo Olympics silver medalist, she won a gold medal at the 2019 World Championships, setting the former world record with a time of 52.16 seconds. Muhammad is only the second female 400 m hurdler in history, after Sally Gunnell, to have won the Olympic, World titles and broken the world record. In 2019, she added a gold in the 4×400 m relay, having won silver medals in her signature event at the 2013 and 2017 World Championships.

The 400 meters hurdles is a track and field hurdling event. The event has been on the Olympic athletics programme since 1900 for men and since 1984 for women.

On a standard outdoor track, 400 meters is the length of the inside lane, once around the stadium. Runners stay in their lanes the entire way after starting out of the blocks and must clear ten hurdles that are evenly spaced around the track. The hurdles are positioned and weighted so that they fall forward if bumped into with sufficient force, to prevent injury to the runners. Although there is no longer any penalty for knocking hurdles over, runners prefer to clear them cleanly, as touching them during the race slows runners down.

More Info: en.wikipedia.org