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The former BMX world champion dislocated her shoulder at the UCI World Cup in Norway in April but showed remarkable recovery to get back on the bike in mid-May, nursing her way to Olympic qualification at the world championship in Birmingham.
Walker managed the injury throughout her Olympic campaign and, while it caused no significant issues on the way to her outstanding silver medal in London, her medical team believe there is a strong chance her shoulder will dislocate again.
"I have been told there is a 75-90 per cent chance it will go out again as it is but that with surgery it will reduce that down to about 3 per cent," Walker said. "With the nature of BMX, I know I will not go another four years without crashing so there is too much at risk.
"In the big picture of the next four years, now is the best time and it will give me at least three months of time on my bike before the world championships in Auckland next July."
Walker will have the surgery in Hamilton today under Dr Chris O'Meeghan. Full recovery will take up to six months, although she will be able to move the shoulder in a few weeks.
"I'm a quick healer so hopefully it will take less than the six months."
Three months on from London, Walker is still busy with school visits and events resulting from the Olympics.