Shone, a 22-year-old former heptathlete, was preparing for her first competition as a member of the British squad, which she joined last month, when her two-woman sled crashed on turn 13 towards the bottom of a track which is not renowned for being dangerous.

Driver Fiona Harrison (pictured), 29, who was a member of the British squad at the 2010 Winter Olympics, suffered a head injury and concussion and remained in hospital overnight for observation.

Gary Anderson, the performance director of British Bobsleigh, flew to Germany and visited Shone, who had to be airlifted to Margurg University Hospital.

"She underwent surgery in the morning and the surgeons are extremely happy that they have been able to stabilise her lower spine because there was a fracture of the spine," he said.

"I've spoken to her and she's communicating but she's in intensive care and she is likely to undergo further surgery in the next three or four days.

"We've asked what the prognosis is and the doctors aren't prepared to give that prognosis until after the next operation but they are positive after today's operation.

"She has feeling in her limbs but she's still quite heavily sedated.

"She's talking, but it doesn't make much sense."

Nicola Minichiello, the 2009 world champion who retired last year, and is now head of development for the International Bobsleigh Federation, predicted that Stone would soon be back involved in the sport.

"I understand that Serita is serious but not critical, so fingers crossed that everything's fine and that she'll be back in a sled soon," she said.

Anderson added that Harrison's condition was less serious. 

"She's very, very groggy," he said.

"She's got a head injury and concussion but we're hopeful she can come home in the next 24 hours."

Earlier this week, Shone had posted a message on Twitter describing her experiences on the Winterberg track: "Day two of sliding great confidence day and some great skills being developed few crashes but still alive."

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