India's Vithya Ramraj clinched a bronze medal in the women's 400m hurdles event at the Asian Games here on Monday, clocking a personal best of 54.75 seconds to break a more than four-decade-old national record created by the legendary P T Usha. The 28-year-old from Coimbatore finished behind UAE's Mariam Kareem, who won gold with a Games record 54.31 seconds, and Kazakhstan's Adelina Zems, who took silver with a personal best of 54.58sec. Ramraj bettered Usha's 55.42sec effort that came in the 1