Sports on Instagram: "The 4x100m relay finals at the London 2012 Olympics were a historic display of speed that saw world records shattered in both the men’s and women’s events. On August 10, the American women’s quartet of Tianna Madison, Allyson Felix, Bianca Knight, and Carmelita Jeter delivered a flawless performance to clock a staggering 40.82 seconds, obliterating a 27-year-old world record previously held by East Germany. The following night, the men's final reached a fever pitch as the J