Dalilah Muhammad’s world 400m hurdles record of 52.20 and Brittany Anderson’s world U20 100m hurdles records of 12.79 and 12.71 have been ratified.
Muhammad, the Olympic champion, broke the 400m hurdles world record at the US Championships in Des Moines on 28 July, taking 0.14 off the previous mark set by Russia’s Yuliya Pechonkina in Tula on 8 August 2003.
It was Muhammad’s third foray into sub-53-second territory, her other two coming when winning the 2016 and 2017 US titles. And as was the case on those occasions, Muhammad was once again pushed all the way by strong domestic opposition.
After the race, the 29-year-old revealed she had suffered minor concussion just a few weeks prior. “I had a crazy fall and got a little injured,” she said. “I just trusted in what we had been working on at this point.”
Anderson, the 2017 world U18 champion, twice broke the world U20 hurdles record at the Motonet Grand Prix in Joensuu on 24 July.
The 18-year-old Jamaican, who is young enough to be an U20 athlete next year, clocked 12.79 (1.4m/s) in her heat before winning the final in 12.71 (1.3m/s).
The previous world U20 record of 12.84 was set by Cuba’s Aliuska Lopez in Zagreb on 16 July 1987. Three athletes had bettered Lopez’s mark in recent years – Tobi Amusan (12.83), Chanel Brissett (12.75) and Dior Hall (12.74) – but their marks did not fulfil the ratification criteria.