The former rugby sevens' star suffered four concussions in only 12 months, putting an early end to his 2018 Super Rugby campaign.

Cusack's last head knock sidelined him for four months, which led to long stints in Melbourne with specialists undergoing cognitive and psychoanalysis tests.

The 25-year-old is fit and healthy again, chasing a spot in the Brumbies' starting XV for Friday night's opening-round clash with the Melbourne Rebels.

But after experiencing regular concussions during his career, Cusack has partnered with Sport Australia in releasing its new position statement on concussion protocol.

"It's a silent injury in the way you can't see it, so it is tough sitting out for long periods, not knowing when you'll return," Cusack said.

"It's an understanding amongst everyone in sport now that when someone's had an episode, they need to be treated correctly.

"Hard conversations need to happen and it's tough ... but it's important to realise there is life after footy and it's about mental health and longevity."

More than 40 sporting and medical organisations have endorsed Sport Australia's concussion stance and what should happen to recognise and treat an injury.

Australian Institute of Sport (AIS) chief medical officer David Hughes said sports needed to regularly update their position to keep up with new information.

"The evidence on concussion now is a lot different to what it was 10 years ago so we need to stay on top of it for the wellbeing of sportspeople at every level," Hughes said.

"Concussion usually results from a blow or knock to the head, but it can also occur from a knock or a blow to anywhere in the body when that force is transmitted to the head."

More information can be found at concussioninsport.gov.au.

Australian Associated Press