Career Highlights: Walker started riding BMX bikes in 1999; thirteen years later, she is again a top contender for a medal and will come to London looking for redemption. Four years ago, Walker represented New Zealand in Beijing and placed fourth - a disappointing finish after coming into the event ranked No. 1 in the world. She soon got back on track, finishing first at the 2009 world championships in both the elite and elite cruiser events. One year later, she placed second in the elite division but suffered a crash during the cruiser competition. Walker returned the following year to place second in the main event. She suffered a dislocated shoulder after crashing during the 2012 World Cup, but is confident the injury will be totally healed and won't impact her chances to finally stand on an Olympic podium.