The 25-year-old came off his bike and landed on his back and required surgery overnight with his mother traveling from Adelaide to the USA to be by his side.

The multiple world champion received treatment at the track by medical staff USA Cycling.

Officials said he was conscious and able to move his arms but further details are yet to be known.

Willoughby finished sixth in the men’s final at the Rio Olympics last month.

He is currently contesting the world cups and preparing for the US season.