Around the globe, concussion is well and truly on the public agenda, thanks to years of high-profile incidents in major sports leagues sidelining players and resulting in claims for injury compensation.
There is good cause to be concerned about concussion.
It’s a form of mild traumatic brain injury (a TBI), resulting from the brain twisting up against or striking the inside of the skull. Usually, concussion is accompanied by the telltale signs of disorientation, confusion and memory loss, accompanied by symptoms like nausea or vomiting, headaches, dizziness and fatigue.
Loss of consciousness isn’t necessary for a concussion to occur.
But while the media focus, at least in Australia, is honed sharply on sports-related concussions – which account for a fifth of head injury hospitalisations – science is also learning that the impact of repeated, seemingly mild blows to the head that don’t necessarily result in a concussion diagnosis, could also take their toll later in life.
Sydney Swans AFL star Paddy McCartin was shockingly taken out of the game against Port Adelaide in April after his head made what appeared to be the lightest of brushes against the grassy surface. That very same night, in the NRL, Canberra Raider Jordan Rapana was taken from the field bloodied (and in need of 18 stitches to his head) following a knee-on-head collision in his team’s game against the Broncos in Brisbane.
Head injuries are part and parcel of Australia’s two most lucrative sports, and have been since their inception. Sometimes, copping a blow to the head is seen as a rite of passage, of heroically putting one’s body on the line for the jumper.
But sporting codes – of all varieties – are now contending with what head injury management and prevention looks like at the top levels of their games, and how it trickles down to the community.
Already, reports have emerged of a 60% increase in concussion injuries in the NRL in the opening six rounds of the 2023 season compared to 2022. Running the rule over the first six weeks of AFL injury lists, the figure is– about eight percent higher – a headcount of just two more on last season.
And in Australia, sport is seeing its first legal claims for long-term brain injury: the AFL now has to deal with class actions claiming compensation for head injuries.
Globally, claims against a sporting body are nothing new. In Britain, rugby governing bodies are again being challenged by participants diagnosed with early-onset dementia and likely other neurodegenerative disease.
In Association football (that’s soccer for those living in non-British parts of the Anglosphere), the iconic act of ‘heading’ the ball in this sport might well be subjecting players to repeated mild trauma over the course of careers.
Recent Swedish and British studies have found the incidence of disorders like Alzheimer’s disease are significantly higher among former soccer players. But only, it seems, those who play in the infield – goalkeepers are much less likely to ‘head’ the ball.
Across the Atlantic, researchers at Boston University’s CTE Centre this year found 91% of 376 former NFL player brains assessed had CTE (chronic traumatic encephalopathy) – a condition similar to Alzheimer’s disease. Five years ago, it found just one case among 164 donated brains from among the general population (and that case was, again, a former NFL player).
The NFL paid out US$765 million to settle concussion lawsuits brought against it in 2013.
In 2017, a study published in the Journal of the American Medical Association, produced similar, and yet more startling figures. In a sample of 202 brains of deceased American Football players obtained through an organ donation program, CTE was found among 87% of them. Among those playing top-flight NFL, all except for onehad the disease.
And down under, where football generally means either Aussie Rules or either of the rugby codes, the nation’s sports brain bank last year presented deeply concerning results from its study of 21 donated brains, of which 80% were from ex-footballers (noting this could apply to several codes).
All except one brain showed signs of neurodegeneration. More than half had two or more neuropathologies, including CTE.
But even those that seem less obviously prone to head trauma, yes, even tennis, have been associated with concussion and head injury.
In the background of this, the Australian Senate opened an inquiry to hear from sports codes, practitioners, lobby groups, players and their advocates across hearings across Australia’s eastern seaboard.
Beneath it all, the science behind concussion and traumatic brain injury – or TBI – continues to grow, and it might pose some very difficult questions to sports across the globe.
And while concussion injuries may not be surprising in the roughest of sports – think Aussie Rules, American football, rugby and boxing – the emerging science shows it’s common in low-contact pursuits as well.
It seems likely that integral, even defining elements of the codes might be to blame.
Concussion matters but you don’t need a knockout blow
“What we’re seeing with a lot of these athletes, in particular, is a history of repetitive physical trauma to the brain,” Professor Alan Pearce, tells Cosmos.
Pearce is based at Latrobe University in Melbourne, Australia’s self-styled home of sport and site of the biggest stadium in the southern hemisphere (the MCG); the Australian Formula One and MotoGP grands prix, the Australian tennis open, plus a swathe of one-off international soccer, rugby, netball and cycling fixtures.
Most of these sports don’t usually feature massive whacks to the head which result in concussion.
“It’s not the big concussive hits that you see in highlight reels, but rather it’s the tackles, the collisions, going to ground, it’s the change [of direction] from a whiplash-type action when they get bumped hard,” Pearce says.
He’s referring to injuries caused by what the Concussion in Sport Group describes as being “induced by biomechanical forces”.
“There’s a biomechanical force that’s going through to the brain tissue, and the brain tissue is very delicate, so it doesn’t take much for stretching and shearing strain to put some tension – and possibly cause damage – from that trauma [on the brain],” Pearce says.
This is the physics of concussion and head trauma – the force of physical impact that might manifest in traumatic injury.
For many people, it might defy expectations of what concussion or head injuries are: it doesn’t require a hit to the head, merely the influence of forces on it. A tackle around the waist might not necessarily end with any contact occurring higher up, but if such a tackle causes the movement of the head and neck, the action could have concussive effects.
This head trauma can lead to disease later in life, and even the most seemingly innocuous of impacts – like heading a soccer ball – might be enough to do damage.
“There’s a biomechanical force that’s going through to the brain tissue, and the brain tissue is very delicate, so it doesn’t take much for stretching and shearing strain to put some tension – and possibly cause damage.”
Professor Alan Pearce
The science of head injury is emerging, sports will watch closely.
It’s impossible to say whether a single hit to the head or repeated knocks over the course of a lifetime will give a person a serious neurological problem in the short or long term.
While research around the globe in the field hunts for clearer answers, authorities are mobilising to better manage recovery from concussion.
On the eve of the 2023 season, Australia’s premier football codes – the AFL and NRL – released altered concussion management policies. For Rugby League, concussed players would be stood down for 11 days. The AFL sets a 12-day stand-down period as part of an 11-step return to play program.
Emeritus Professor Robert Vink, a brain injury specialist at University of South Australia, says appropriate education and management is likely to be the way forward for athletes, but that not every player will ‘fit the policy’.
“Eighty percent of people will recover in two to four weeks, but the other twenty percent can be going a longer time,” Vink says.
“Having a guideline that everybody will stay out of sport for 12 days, that’s going to work most of the time, but doesn’t work for everybody. What about the person who still has a headache on day 14, but wants to play and doesn’t tell anybody?
“Those people have to be followed.”
In the absence of a biomarker – a molecular deviation from normal physiology – that can indicate a person has a brain injury, sporting codes, doctors and athletes will need to lean on judgement, available science and education to avert the consequences of brain injury, he says.
“Everybody needs to be educated – managers, players, parents, coaches – everyone needs to be educated about concussion: how to recognise it, how to manage it, and knowing that everyone’s different.”
Scientists are pushing – hard – to learn how these injuries manifest in players.
They’re also seeking answers to questions like: why do some, and not others, develop neurodegenerative illness?
“Everyone needs to be educated about concussion: how to recognise it, how to manage it, and knowing that everyone’s different.”
Emeritus Professor Robert Vink
We know there’s unlikely to be a ‘magic number’ of head knocks or concussion injuries that will apply to all athletes. So how can those with a duty-of-care – like the coaches, managers, and even medical professionals Vink says need to be educated on the issue – or even players themselves, know the likelihood of injury?
Does a full and proper recovery from a concussion act as an effective ‘reset button’?
While scientists pursue definitive answers to these questions, sports and society are pushing ahead: professional athletes are seeking compensation for sustained injuries, sports bodies are responding with new protocols and politicians are seeking to understand what they’re doing to mitigate and prevent disaster.
Next up, Cosmos dives into the brain and what happens when trauma is sustained.
Editor’s note: We have updated the position titles for Professor Alan Pearce.
More on the Science of Concussion in Sport
Originally published by Cosmos as Brain Games: Everyone talks about concussion in sport, but there’s more to it than that
Matthew Ward Agius
Matthew Agius is a science writer for Cosmos Magazine.
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