WHEN Simone Biles headed to the Tokyo 2020 Olympic Games in July, a slew of headline-grabbing feats of greatness were predicted.

Feats of greatness did happen, but rather than Biles leaving Japan with a clutch of gold medals, she instead carried a new mantle: global mental health hero.

A quick recap?

Simone Biles is a once in a lifetime talent. The 24-year-old from Texas burst onto the gymnastics scene in 2013, winning her debut world all-around title in Antwerp (her running tally of golds is 19, alongside a clutch of silver and bronze medals).

READ MORE: Time to bust myth of gymnastics as a sport for tiny little girls

At the Rio 2016 Olympic Games, she claimed four golds and a bronze. Heading into Japan, it was largely expected that Biles would sweep the board again. But then, in the women's team final, the sporting gods ripped up the script.

What happened?

After performing her opening vault, a stricken-looking Biles immediately left the arena with the team doctor. Word filtered through that she was withdrawing from the competition.

To the untrained eye, it looked like Biles had merely taken a big step on landing. But what unfolded was far graver and dangerous. While rotating high off the vault in a tricky and complicated skill, she had become completely disorientated.

HeraldScotland: USA's Simone Biles at Ariake Gymnastics Centre during the Tokyo 2020 Olympic Games in Japan. Picture: Mike Egerton/PAUSA's Simone Biles at Ariake Gymnastics Centre during the Tokyo 2020 Olympic Games in Japan. Picture: Mike Egerton/PA

"It looks like I got shot out of the air," said Biles afterwards. It was something that every gymnast fears: the dreaded "twisties".

What are the "twisties"?

Put simply, you don't know up from down, left from right, or even where you are in the air. When performing complex and high-risk gymnastics moves, pinpoint accuracy is crucial to avoid injury. That ability had deserted Biles. Her mind and body weren't in sync, she said.

The upshot?

Biles withdrew from four of her five remaining finals. A handful of critics, such as Piers Morgan, lambasted her for "quitting." But around the world, she was hailed as a hero for standing up for her mental health.

Prior to this Olympics, Biles was already an outspoken advocate for athletes' rights after confirming she was among the 300 girls and women that former USA Gymnastics physician Larry Nassar had sexually assaulted under the guise of medical treatment.

READ MORE: Time to bust myth of gymnastics as a sport for tiny little girls

In Tokyo, Biles again made a powerful statement: mental health is more important than the pursuit of medals. She humanised elite sport. The crux of her stance: it's OK to not be OK.

And now?

This month saw Biles named Time magazine's Athlete of the Year for her role in sparking a vital global conversation on mental health. She also received a Lifetime Achievement Award from BBC Sports Personality of the Year.