Friends and family are rallying around a young freestyle rider after she severed her spinal cord in a training accident.

Christina Vithoulkas, 23, has been left paralysed from the ribs down after mistiming a jump and crashing her motorbike in Barmera in the South Australian Riverland region on Saturday.

Ms Vithoulkas was knocked unconscious after she fell from her bike, her fiancé James Wild, who is also a freestyle rider, told nine.com.au.

Ms Vithoulkas with her fiance James Wild in hospital.

“I was screaming at her to wake up. She was unconscious for a while. She wasn’t alert and to watch everything that unfolded was just horrific. It’s a massive scar that’s going to be in my brain for the rest of my life,” he said.

Paramedics rushed Ms Vithoulkas to the Royal Adelaide Hospital where it was discovered that she had severed her spinal cord, broken several vertebrae, lacerated her spleen and torn several ligaments in her neck.

Mr Wild said his finacee was still trying to come to terms with her injuries, but was a relentlessly positive person who tackled all of life’s challenges head on.

“Christina is an absolute soldier. She is incredible, she honestly is. Obviously, deep down she is hurting a lot, but she is one in a billion, she just has this amazing strength and drive.”

“She said to me and the rest of her family if anyone is going to get through this I will. She is one tough cookie.”

Ms Vithoulkas and her fiance James were working towards their dream of putting freestyle shows for the public. (Supplied)

Friends and family have been raising money online for Ms Vithoulkas's medical costs. (Supplied)

Ms Vithoulkas and Mr Wild had just gotten engaged to be married last month and were in the process of buying their first home.

“Christina Wild... I think I could get used to that name. I love you James Wild,” Ms Vithoulkas wrote in a Facebook post after Mr Wild surprised her by popping the question at his 25th birthday party.

The couple met on the freestyle riding circuit three years ago and had been inseparable ever since, Mr Wild said.

Family and friends say Ms Vithoulkas is a vibrant and positive person.

Freestyle riding was Ms Vithoulkas's passion.

In recent years, they had been training hard together and were close to realising their dream of performing in their own motorbike stunt show, Mr Wild said.

“We bought our own freestyle truck and we wanted to go around and do our own public events. It’s been a big goal of ours for the last couple of years.”

Riding motorbikes was Ms Vithoulkas’s greatest passion, Mr Wild said.

“She got into riding five years ago but it was her dream ever since she was a child to ride motorbikes. It was her passion, her everything,” he said.

Mr Wild said he was now preparing to sell his motorbikes and give up freestyle riding so he could look after fiancée.

“At the end of world Christina is my world and she is what means the most to me in my life.

“I can’t afford to break a finger and sprain an ankle or break my wrist, or even worst-case-scenario, sever my spine. I’ve got to be there for my girl and push through the punches too,” he said.

Christina Vithoulkas and James Wild got engaged last month.

Christina Vithoulkas, 23, severed her spinal cord in the accident.

Mr Wild said he had feared the worst when he saw his fiancée crash her bike, and he was just thankful that she was still alive.

“We could have lost her. At the end of the day we still have each other and that’s what matters,” he said.

“It’s frigging hard but we will push through and we’ll tackle it the way Christina tackles every situation in life and that’s head on.”

An online fundraising page set up by Ms Vithoulkas’s sister-in-law Stephanie Wild to help with her medical costs has so far raised $35,000.