 Complete the following phrase:  Michelle Johnson Skog born April 12, 1974 is an American female former track and field hurdler who specialized in the 400-meter hurdles. She set personal records of 54.15 seconds for the 400 m hurldes in 1999 and 12.88 seconds for the 100-meter hurdles in 1998. She was a bronze medalist at the 1999 Pan American Games and represented her country at the 1999 World Championships in Athletics and 