The smell of meat pies mingles with that of liniment and freshly cut grass. Players take to the field, nervously anticipating the whistle that starts play. The scene plays out at thousands of community sports grounds across Australia each weekend as people (mostly men) from all walks of life congregate to contest their favourite football game; be it rugby union, rugby league, soccer or Australian Rules Football.

Injuries are inevitable: pulled hamstrings, or dislocated shoulders, grass burns, a sprained ankle or two, and maybe even the odd bloody nose that temporarily sidelines a player. No one grumbles. It's all part of the game.

But then there is the serious body crunching; the knock to the head, elbow to the ear, torsos and heads colliding at full tilt, and tackles that bring players thudding into the earth. The result, more often than recognised, is concussion, or mild traumatic brain injury (mTBI). It can occur without any actual contact to the head. It is the sudden acceleration or deceleration that can cause the brain to ricochet inside the skull. While the impact can seriously affect cognition, it is an injury that is far more difficult to see and diagnose than torn ligaments or an open cut. Even with a CAT scan there will usually be no visible bleeding or damage to the brain.

And here lies one of the greatest risks for players, particularly at a community level, says Monash University researcher Professor Mark Stevenson, who has been studying the incidence of concussion in rugby players over a three-year period. His findings show high numbers of concussions and relatively poor injury management.

Professor Stevenson’s concern is that the awareness of the potential long-term consequences of head injuries and the need for greater caution that exists at a professional level, has not flowed through to the amateur ranks.

Professor Stevenson says evidence is already mounting about the long-term impacts of concussions on professional athletes. Long recognised among the boxing community as ‘punch-drunk syndrome’ or dementia pugilistica, symptoms can include depression, memory loss, personality changes such as increased irritability, paranoia and aggression, and the early onset of dementia. Media reports in recent years have highlighted ongoing health problems in professional contact sports like rugby, gridiron, wrestling, ice hockey and even soccer (attributed to ‘heading’ the ball).

The effects of repeated mild brain injuries culminate in a condition known as chronic traumatic encephalopathy (CTE). Abnormal proteins accumulate in the brain, causing a degeneration of brain tissue and reduced cognitive functioning. CTE does not show up during brain scans and can only be diagnosed using specific identification techniques post mortem.

Professor Stevenson is director of the Monash University Accident Research Centre in the Monash Injury Research Institute but previously worked for the US Centers for Disease Control and Prevention (US CDC). In 2004, through the US CDC he received a grant to study the incidence and management of mTBI on a group of non-professional rugby union players in Australia. There is a substantial body of research examining the effects of mTBIs among professional athletes, but very little at the community sporting level, he says.

“The US does not have the same culture of community sport that is prevalent in Australia and also the United Kingdom. College and varsity sports such as gridiron are highly professional and have dedicated support staff. That’s not the case in community sport where most support staff are volunteers, and usually have little or no medical expertise.”

Professor Stevenson’s study followed almost 2000 Sydney school-grade and suburban rugby union players aged 15 to 48 for between one and three seasons to evaluate the frequency of concussions, injury management, and impact on player brain function in subsequent days and weeks. (He uses the terms concussion and mTBI interchangeably.)

“The symptoms that indicate you might have a concussion are dizziness, amnesia – you can’t recall what happened immediately prior to or immediately after the event. You may feel nauseous, you might have lost consciousness for a few seconds or maybe longer. It could just be that you end up with a headache from a knock, or blurred vision. It’s hard to predict, and similarly can be hard to diagnose,” he says.

Despite the uncertainties of diagnosis, the results of his study are alarming. They reveal a high incidence of concussion among players – seven per cent of players sustained a concussion within 10 hours of play. This is about half the length of an average adult rugby union season. The incidence doubled to 14 per cent with 20 hours of play. And players who sustained one concussion were twice as likely to sustain a second.

Players with a lower body mass index were 10 per cent more likely to sustain a concussion, and those who trained for less than three hours a week were 20 per cent more likely to be concussed than those who spent more time training.

Coaches, sports doctors and physiotherapists were among those who assisted the research, recording concussion incidents during games. According to their reports, 48 per cent of players who sustained a concussion returned to play in the same game, and 34 per cent did not leave the field at all.

This is despite a recommendation from the International Rugby Union Board, supported by the Australian Rugby Union, that players who suffer a concussion take a three-week break from training and play. This regulation is mandatory for all international age-graded players under 19 years. Other players may return to play within three weeks if found to be symptom free and declared fit to play by a recognised neurological specialist.

Players who suffer some loss of cognitive function and who return to the play without fully recovering may increase their risks of further injury.

Alarmingly, only 22 per cent of players identified as receiving a concussion in the study reported receiving any return-to-play advice. And 75 per cent of those players did not comply with the three-week stand-down period. No player in the study who received the recommended post-concussion advice complied. Professor Stevenson says 87 per cent of concussed players returned to either training or competition within one week and 95 per cent had returned within three weeks of injury.

He says while it appears there was a relatively low level of awareness of the international concussion regulations, the failure of players to follow advice presented a serious barrier to identifying and better managing mild brain injuries.

Professor Stevenson says that the third and most crucial aspect of the study – the evaluation of cognitive skills post concussion – is still to be completed. Participants in the research undertook a computer-based cognitive test prior to the playing season to establish baseline function. Of the 187 who suffered a concussion during the study period, 60 per cent consented to follow-up assessments 72 hours after the injury. Further assessments were also undertaken seven days and 21 days after the injury.

“These findings will be critical in identifying the impact of concussion on players during the post-game period when they are making decisions about returning to training or to competition. But even without these results, it’s clear that return-to-play decisions and the management of sport-related concussion is a challenge for players, support staff and the sporting community in general,” he says. “There is a real urgency to take these findings to sporting organisations and their regulatory bodies to ensure adequate management, particularly as there is limited information on the long-term impact of mild traumatic brain injuries.”

The Monash Institute for Brain Development and Repair and the Australian Centre for Research into Injury in Sport and its Prevention, both at Monash, are interested in the translational aspects of Professor Stevenson's work and ensuring his recommendations for action reach the organisations.

High profile cases of concussion-related sports injuries have highlighted the potential consequences of unseen damage and resulted in improved management practices in professional contact sports. The potential for legal action by players in both the US and Australia related to the management of head injuries is a major driver behind improved injury management and heightened awareness of the potential dangers that are expected to flow through from professional to community sport. Some recent high-profile cases include:

Rugby Union
Australian Wallabies player Elton Flatley retired prematurely on medical advice in 2006, aged 28, suffering continued blurred vision attributed to concussion-related injuries. A national and state representative player for a decade, he is reported to have suffered seven concussions in the two years prior to his retirement.

Rugby League
Shaun Valentine (North Queensland Cowboys) was cut from his team in the National Rugby League after the 2002 season, aged 26, on medical grounds after seven severe concussions during a 36-game career. He continues to suffer vomiting, nausea, dizziness and confusion and in 2011 he became the first Australian to commit to donating his brain to the Sports Legacy Institute based at Boston University for study as part of its ongoing research into sports-related concussion.

Australian Rules Football
Daniel Bell (Melbourne Football Club) was delisted from his club in 2010 and retired from the game on medical grounds, aged 26. He was diagnosed with brain damage after suffering eight to 10 concussions during his 66-game career with Melbourne. He reports ongoing memory loss and concentration problems and in 2011 he lodged an application for compensation from the Australian Football League Players' Association.

In 2010 US high-school football player Nathan Stiles died, aged 17, after suffering a second impact brain injury during the final game of the season with the Spring Hill Broncos in Kansas. He had suffered a concussion during a match several weeks earlier that had not fully healed, although medical advice had cleared him to play. An autopsy revealed him to be the youngest reported case of chronic traumatic encephalopathy (CTE).

English soccer player Jeff Astle (West Bromwich Albion) died in 2002, aged 59. He retired from soccer in 1977, aged 35, after an 18-year professional career that included national representative selection five times; his skill as a header of the ball was widely recognised. He was reported to have suffered cognitive issues dating back five years before his death. The coroner ruled his death was the result of a degenerative brain disease caused by heading heavy leather soccer balls.