Sky Brown is expected to make a full recovery ©Getty Images

Britain's 11-year-old skateboarder Sky Brown has said she is "lucky to be alive" after a catastrophic fall while training in California.

Brown, who is hoping to become her country's youngest Summer Olympian at Tokyo 2020, suffered skull fractures and broke her left wrist and hand.

According to the BBC, she was unresponsive on arrival after being airlifted to hospital, but her family has now said she should make a full recovery.

Her father Stewart said: "Sky landed head-first off a ramp on her hand.

"When she first came to hospital, everyone was fearful for her life.

"Sky had the gnarliest fall she's ever had and is lucky to be alive.

"Sky remains positive and strong, the whole medical team is shocked to see her positivity."

Born in Japan to a Japanese mother and a British father, Brown became the youngest person to take part in the Vans US Open in 2016 when she was just eight-years-old.

She is also an avid surfer.

Last year, she won bronze at the World Skateboarding Championship in São Paulo in Brazil.

Skateboarding is scheduled to make its Olympic debut at Tokyo 2020, which has been pushed back to next year because of COVID-19.

In a video on Instagram, Brown said: "I'm going to push boundaries for girls with skating and surfing.

"I'm going for gold in 2021 and nothing will stop me."