Comeback: Gloria Estefan says she's stronger than ever on stage after breaking her back in a bus accident last year. "I feel no limitations on stage," said Estefan, who kicked off the North American leg of her "Into the Light" world tour with the Miami Sound Machine in San Antonio over the weekend. "I'm working out six times a week. I probably overcompensated. Every time I do a show I feel better." Estefan broke her back in March, 1990, in an accident involving her tour bus in Pennsylvania.