Concussion research can make our athletes safer

Here at QBI, we are researching the impact of concussions on the brain. We aim to answer questions like:

  • How does concussion affect the brain’s ability to function?
  • Is there a better way to diagnose concussions?
  • How long does it take the brain to recover from a concussion?
  • Do concussions put sports players at a greater risk of diseases like dementia?

In a pilot study conducted in 2021, our researchers worked with volunteers from a variety of contact sports, including AFL, rugby league, and boxing, to study concussions using:

The study confirmed that brain changes are ongoing after a concussion, even when behavioural symptoms have stopped. They also found these brain changes differ between people and injuries. 

Associate Professor Fatima Nasrallah and her colleagues are now building on this data with the next research phase. They’ve teamed up with:

  • World Rugby
  • Rugby Australia
  • Qscan
  • Trajan
  • Sonic Health
  • South-East Queensland High Schools 

Together, they’re working to identify a blood biomarker that can accurately reflect concussion-induced changes to the brain. This biomarker knowledge will help determine whether there is a brain injury and when the brain has fully recovered. Ultimately, this new evidence will help improve the diagnosis and treatment of concussions and inform return-to-play decisions.

Volunteer for the school concussion study

Hear from some of our sporting ambassadors who are helping to raise awareness about concussion and their widespread impacts on people’s lives. Their stories and experiences show why research is important and how it will help athletes at all levels keep their heads in the game.

Let’s keep enjoying sport and make players safer.

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"In the end it is just a game.

You only get one brain."







Jude Bolton

Former AFL player and now commentator

During a career spanning 15 years, including more than a decade playing with the Sydney Swans, retired Australian Football League (AFL) star Jude Bolton experienced around six concussions.

One of those was in the late stages of the 2012 Grand Final. He knocked his head on the ground during a tackle and quickly found himself confused and groggy, thinking it was still the third quarter. With such big stakes, he ran to the boundary for some quiet recovery time rather than alerting the coaching or medical staff. After the match, he couldn't recall if he finished on the bench or the field, but does remember the celebrations of the win.

"You’re taught as a young kid to put on these layers of armour to get out there and into the fray. I remember my grandfather always saying, ‘It's better to wake up in an ambulance than to duck out of a contest.'"  

But concern about the long-term consequences has since made him an advocate for player welfare. “It was actually my same grandfather who then said to me after I sustained two concussions in one game – and played the following week – ‘You don't want to be a dribbling mess when you're an old man’,” Bolton explains. “His words hit me between the eyes. A brain injury is not like any other injury. Each head knock is different and sometimes the innocuous ones can be the worst.

“I look back now and I feel I was pretty foolish to get back out on the field. I know that having sustained multiple concussions puts me in a high-risk category. I would hate to think that the way I played may contribute towards potentially having something like dementia, CTE or depression later in my life.”

Bolton emphasises, however, that he doesn’t want the sport to change. “AFL is a tough and sometimes brutal sport that I love,” he says. “I never want to see the physicality taken from the game, nor do I ever want families to not allow their kids to play sport.”

He believes science is the key to improving player safety: “I would love to see the research to be at a point where we have absolute certainty on the protocols and that kids, families and all sporting clubs know what to do if a concussion is sustained, and have an ability to limit any long-term effects.”




"There were many times
I thought I wouldn’t
play again...

I just felt like I was
never the same."





Casey Dellacqua

Tennis champion, dual Olympian

Tennis is not usually a sport you'd associate with concussion, but for Casey Dellacqua the injury is all too real.

The former dual Olympian, World No. 26 singles and World No. 3 doubles player suffered a concussion late in a match in Beijing in October 2015 that put her out of action for almost a year. In her desperation to reach a ball, she tumbled back, unable to get her hands down in time to stop the momentum of her head hitting the hard concrete court. 

"I remember thinking, I'll be ok. I'll play a couple more points," she says. "Afterwards I walked off the courts and was throwing up." Now, more than two years later, she still doesn't remember those points, nor the ambulance ride to the hospital. The days and weeks after are "still very vague", she says.  

Not having experienced concussion before and not playing a sport where concussion is common, Dellacqua expected she'd be back on the court fairly quickly. "I thought, in a few days, I'll be right." Unfortunately, she was in for a long recovery. Her symptoms worsened over those initial days and weeks.

"I couldn't open my eyes and was sleeping a lot," she says. "I had to stay in a dark room and was really sensitive to light – I couldn't watch TV or use my phone. I felt like my head weighed a thousand kilograms."

The most difficult part, she says, was the uncertainty around the length of the recovery. "There was no time frame on it – it was just a long, slow process," she says. "As that drew out and got longer and longer, I became a bit more anxious. It was an emotional rollercoaster."  

After a few months the physical symptoms went away, but she was not where she needed to be, mentally, to return to such an elite level in such a mentally tough sport. Having time off when she was playing so well, perhaps at the peak of her career, was hard, she says. "There were many times I thought I wouldn’t play again."

In the end, the concussion hastened her decision to retire from singles tennis. "I just felt like I was never the same," she says.

But Dellacqua was determined not to end her career on that note – she wanted to go out on her own terms. She made a return to doubles tennis in 2017, climbing back up into the World Top 10 ranking. In April 2018, she retired completely from the sport.

She's grateful the WTA (Women's Tennis Association) had good concussion protocols in place, even though concussion is a rare occurrence in tennis. "It was very smooth sailing for me," she says of her concussion management.

Dellacqua also wants so see more research into concussion. "As the years go by there's so much more knowledge about the long-term damage of concussion," she says. "Research is going to benefit sport and especially athletes, which is really the priority."


Read Casey Dellacqua's full story      Listen to the podcast




"It’s such an important thing that we increase concussion awareness and research, so people can keep on playing the sports they love.”




Justin Clarke

Retired Brisbane Lions player

Justin Clarke has no memory of the head knock that ended his promising Australian Football League (AFL) career at the age of just 22. Nor can the former Brisbane Lions defender recall the three weeks following that concussion in January 2016.

“That period was a tough time because I wasn’t able to do much,” Clarke says, explaining that he had severe headaches, and spent most of that time in the dark, because his symptoms became worse in the light. “Every little thing sort of set me off, and I struggled to get outside much.”

Clarke sustained the concussion during a routine training session, and footage of the collision appears innocuous. “I just got a little shove in the back and that propelled me into a bloke who was running in the opposite direction, into his knee,” he says. The impact knocked Clarke unconscious for about 30 seconds. He had sustained concussions in the past, but soon realised this one was different. One month later, his symptoms still hadn’t improved. His brother had gone through a similar experience and Clarke “had an inkling that things might not turn out for the best.”

He was assessed separately by three doctors and each urged that he avoid future contact sport – a heavy recommendation for a young athlete with his entire football career ahead. Although his decision to retire, in March 2016 after four years playing with the Lions, was heartbreaking, it wasn’t difficult. “When you have three specialists all tell you that you’d be mad to play footy again, then you’d be a stupid man to go against that advice,” Clarke says.

The road to recovery has been long. Even now, he can't remember the preceding two months, nor much of the three months after the concussion. He struggled with headaches, mood swings, slurred speech and difficulty concentrating; he'd have to sleep after briefly exerting himself physically or mentally. Six months later, he still had symptoms and could barely manage to jog, but those gradually improved. More than two years later, he's thriving in his aeronautical engineering degree at The University of Queensland – though he can only handle moderate lengths of intense concentration before his brain needs to rest. And he still keeps the exercise intensity in check.

"It’s just accepting what I have, knowing that I have my limits, working within those limits," he says.

Clarke believes that managing how concussed athletes are diagnosed and treated is crucial. Objective protocols can help override a player’s often-skewed self-assessment. “A player in that moment—whether it’s for the best or not—they’ll want to be back out there. I wanted to be back out there,” Clarke explains. “It’s about being able to control how much say that player has in that moment and being able to ensure their safety first and foremost.”


Read Justin Clarke's full story

  Listen to the podcast





"It’s just accepting what I have, knowing that I have my limits, and working within those limits,"

Charlotte Caslick

Rugby sevens Olympic gold medallist

Olympic gold medallist, Commonwealth Games silver medallist and professional rugby sevens player Charlotte Caslick is at the top of her game.

Head knocks are not uncommon in rugby and 23-year-old Caslick estimates that during each contact session she'd have at least one hit that "hurt a little bit," she says. "It’s probably more often than you’d like."

She's had one concussion and that was enough to show her how serious a head injury could be. In a quarter-final against the US, Caslick's head collided with a knee of an opposing player when she went in for a tackle.

"I think immediately after I was just lying on the ground; I was just a bit out of it. Once I got off I just felt a little bit rattled and emotional about it," she says.

After assessment, she was ruled out from playing the rest of the game. Caslick had a week off any activity and a slow return to full training after two weeks. She praises the way the medical team handled her injury.

Caslick says the guidelines implemented for concussion during play help coaches, medical staff and athletes with the decision of whether or not to return to the field. "It’s pretty black and white, whether you’re in or you're out," she says. 

She recognises the importance of good concussion management. "As much as sometimes you’d love to go back out there, it’s obviously best for your health and wellbeing to make sure you do take the right time to get it right," she says.

Early education about the best ways to move your body during contact can go a long way, Caslick says. "If you go about contact the right way and if you’re taught from a young age the right technique, it can be safe."

And while she doesn't worry about concussion day-to-day, she still considers life after rugby. "I enjoy playing so much, but obviously in the back of my mind I do think about [head] injury every now and then, and hope I don’t have long-term effects when I do finish."


Read Charlotte Caslick's full story

More ambassadors

Former Wallabies and Queensland Reds player
Captain of the Greater Western Sydney AFL Giants
Sunshine Coast Lightning netball captain
AFL Greater Western Sydney Giants defender
Former NRL, State of Origin player
Former Wallabies player and now assistant coach
ABC sports reporter and presenter
AFL Melbourne player
Hockeyroos squad member
FOX Sports journalist and commentator
Former Brisbane Broncos player
Chief Executive of Brain Injury Australia


Andrea Markey
Deputy Director - Advancement


Telephone: +61 7 3346 6300

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Queensland Brain Institute
The University of Queensland
QBI Building (#79)
St Lucia, QLD 4072 Australia