The long and short-term effects of head impacts in rugby league and union are becoming bigger talking points by the day. Brain injury is now beginning to be taken more seriously.

Red cards are on the rise as governing bodies try to reduce head-high tackles. This is in response to the increasing number of former players diagnosed with Chronic Traumatic Encephalopathy (CTE). Carl Hayman, Alix Popham, Michael Lipman, Steve Thompson, Neil Clarke, Tim Cowley, Jason Hobson, Neil Spence, Adam Hughes and Bobbie Goulding have all been diagnosed with CTE.

For a man in his 30s or early 40s, the odds of getting this diagnosis is around one in 10,000. And yet 75 former union players in England or Wales during the first 15 years of the professional era have now been diagnosed with CTE. This is roughly one in 20. And it is believed that up to one in two professional players will end up with some kind of neurological impairment.

Worryingly, the women’s players are beginning to echo the early years of men’s professionalism – bulking up and becoming fitter, faster and stronger. What does the future hold around brain injury in rugby?

This has all meant that contact load training, head injury assessment, concussion education, management and prevention are now key talking points across rugby. Is brain trauma in rugby a recent problem or has it simply been overlooked? It’s a combination of both.

In rugby, brain trauma has become overly focused on bigger impacts, concussion and contact load. However, it is the cumulative effect of smaller, sub-concussive impacts over time that contributes to neurogenerative disease.

These sub-concussions are caused by rotational force. So, there is a need to reduce rotational forces to the brain, as opposed to measuring and managing after an impact is received. Rotational forces occur from angled hits to the head, be it head-to-head, head-to-ball, or head-to-ground impacts. All of these cause the brain to rotate inside the skull, brain cells to shear, and tiny blood vessels around the brain cells to be torn in a twist-like movement. This sets up abnormal inflammatory processes, which become harmful and triggers CTE.

Another confusion in the debate around brain trauma in rugby is that former players have CTE with young-onset dementia, and not dementia as is understood in the context of ageing. Dementia is an umbrella term, not a specific condition, and refers to a number of cognitive symptoms. A lack of understanding between CTE and dementia by the media, governing bodies, coaches, players and fans means that CTE is not being properly understood, nor the risk factors appreciated.

The most significant mitigation to reduce brain injury in rugby is reducing the transmission of rotational forces to the brain from concussion and sub-concussive impacts. Halos® headbands for concussions and sub-concussions are uniquely designed to lessen the risk of rotational forces to the brain.

Headguards (scrum caps) protect against surface-level wounds. They are “not intended nor expected to protect against any form of mild traumatic brain injury or skull fractures”. However, given that sub-concussions are 500 times more likely than concussions and are symptomless, players need headgear that will protect from sub-concussions and neurological damage.

The risk of brain injury in rugby

In elite English rugby union, concussion rates have hit their highest levels since records began. The audit of the 2020-21 season showed that, for the 10th season running, concussion was the most reported injury, accounting for 28% of injuries [1].

The 2020-21 season had the highest incidence of concussion, with 22.2 concussions per 1000 hours of playing time. In total there were 131 concussions sustained in matches – resulting in an average of 17 days on the sidelines – and 17 sustained in training.

An audit into the women’s game showed that concussion was the most commonly reported injury, making up 26% of all match injuries. Again, measured against 1,000 hours, the rate was 12.6, more than double the previous season – a rise put down, in part, to more consistent reporting and better identification of concussion.

Rugby league is even more dangerous, largely because tacklers are instructed to hit the ball-carrier around the shoulder region to prevent them offloading the ball. As a result of this, concussion occurs frequently at a rate of 18 per 1000 hours of game time in league [2]. This is one of the highest concussion rates of any sport and that includes American football (15 per 1000 hours of play).

The governing bodies for both codes of rugby – the RFU and RFL – have introduced head injury protocols, but they focus on concussion. What they overlook is the number of repetitive, sub-concussive impacts which don’t produce overt signs or symptoms, but nonetheless cause damage to the brain.

Female rugby training session

How do head impacts injure our brain?

Concussion occurs when an impact to the head or body sends a strong force to the brain, resulting in significant, acute brain injury with symptoms including headache, mental fogginess, changes in memory, balance, coordination, behaviour, irritability, and slowed reaction time. Over 90% of concussions are not associated with a temporary loss of consciousness and more than 80% of concussions are diagnosed the next day or several days later.

Sub-concussions occur when the force of the impact damages brain cell function, but a player does not experience any symptoms and the impact is unnoticed. Repetitive, sub-concussive impacts cause injury to the tiny blood vessels around the  brain cells. This results in damage to the ‘blood brain’ barrier, a structure designed to protect the brain. When this structure is damaged by repetitive trauma, an abnormal mediated inflammatory response is triggered with the production of neurochemicals. The neurochemicals and inflammatory response should be protective. However, the problem arises when the brain is subjected to repetitive impacts before the protective neurochemicals and inflammatory changes from the initial head injury have had time to return to normal.

The subsequent, repetitive head injuries can then result in an abnormally exaggerated further production of neurochemicals and an exaggerated inflammatory response which is harmful to the brain, rather than protective. This response damages the brain tissue and eventually leads to the irreversible death of brain cells. Over time, this abnormal inflammatory pathway, triggered by repeated head injuries in contact sports, leads to changes in a brain protein called tau.

The tau protein found within cognitive brain cells normally stabilises brain cells so they can work and communicate effectively with other cognitive brain cells. This allows an individual to think and behave normally. When the tau protein becomes damaged, it can no longer stabilise the brain cells and they lose their ability to function effectively. As the tau protein spreads around the brain, more and more brain cells, needed for thought and control of emotions and behaviour, are killed.

Limiting contact in training

The governing bodies for both codes of rugby – the RFU and RFL – have introduced head injury protocols, but they focus on concussion and not sub-concussions. World Rugby has introduced a framework which sets out non-mandatory contact guidelines for training sessions. It aims to inform coaches and players of the best practices for reducing injury risk and optimising match preparation.

Rugby logos

These guidelines have been developed because training environments are much easier to control than competitive matches. They advise reducing the cumulative contact loads and time spent tackling in training to the lowest possible levels, reducing injury risk while still allowing for adequate player conditioning and technical preparation.

Reducing contact loading and the levels of physicality away from match days is one of the changes demanded by The Rugby Players Association (RPA). The group is made up of former players, and they are also in favour of incorporating data analysis into full-contact training.

In rugby league, contact loading is also a focal point. The league is preparing to launch a game-wide, three-year research project to quantify head impact and acceleration exposures. Rather than impose arbitrary restrictions, the data gleaned will be used to reduce elements of contact training that are of particular risk and protect players from repeated impacts to the head.

Female rugby player - Blaydon Rugby

The limits of measuring contact load

Repetitive head impacts during gameplay and training cause damage to the brain from concussion and sub-concussive impacts. The risk and severity of CTE is caused primarily by multiple smaller, sub-concussive impacts, and not by one-hit concussions. Sub-concussive impacts are those which are of sufficient force to adversely affect the function of the brain cells but do not cause symptoms of concussion. Players and those around them are not aware of these impacts. 20% of people with CTE diagnosed after life were recorded as never having sustained a single concussion.

There is no known safe threshold tolerance for rotational forces to the brain from concussion and sub-concussive impacts, or evidence if a certain number of impacts leads to later-life brain degeneration, or if there is a safe threshold of repetitive impacts in a game, season and career. Meaning, the focus should be on what level of brain trauma is too much, and why reducing rotational forces and protecting the brain from rotational forces from concussive and sub-concussive impacts is a smarter focus.

How are head injuries assessed during and after a match?

The Head Injury Assessments (HIA) Protocol has been developed for the elite level of rugby union to improve the pitch-side management of head injuries and concussion. HIA does not diagnose a concussion, it is a tool to help identify a suspected concussion.

HIAs take place when the referee, another match official or a pitch-side doctor sees a player take an impact to the head which may have caused a concussion, even if there are no immediately obvious symptoms. It allows doctors to temporarily remove a player following a head injury, where the diagnosis is unclear, to undertake an off-field assessment.

HIA is a three-stage process that consists of the following:

  • Stage 1 – Game day, off-field assessment (when not showing clear on-pitch symptoms or signs, players must undergo an off-field assessment consisting of a clinical evaluation by an attending doctor who is aided by screening tools and video reviews. Players cannot return before ten minutes to allow assessment to elapse. Players taken off for HIA can be replaced, and any replacement can take a kick).
  • Stage 2 – Post-game, sameday assessment (after the match, every player entered into the HIA protocol must undergo another evaluation within three hours. This is done using a check of symptoms, memory assessment and balance evaluation – compared with previous player baselines).
  • Stage 3 – 36-48-hour post-injury assessment (the player will be assessed again, going through a symptoms checklist, studying a player’s balance and using a cognitive assessment tool).

Players displaying obvious, on-pitch signs of concussion must be immediately and permanently removed from play, without further assessment.

HIAs in rugby league have free interchanges which allows for a HIA in place to allow clubs to deliver the medical attention required for possible concussive injuries, without having to use an interchange.

The pitfalls of HIA and amateur rugby

HIAs have little utility because they are after-the-event interventions when brain trauma has already been incurred and the injury will continue to unfold.

There are no HIAs in amateur rugby union. If there is a suspicion that the player is confused or disorientated, they should be safely removed from the field for further assessment and should not return to play that day. If at any point during a match or training, a player is concussed or has a suspected concussion, that player must be immediately and permanently removed from the field of play. This is known as “recognise and remove”. Whether this is enforced in amateur rugby specifically is another question.

Physios in the professional and amateur game are relied upon to check the physical wellbeing of players. Unfortunately, there is not always one present in amateur rugby, just like there is not always trained medical staff and ambulance crews on hand in case of emergency. The responsibility for safeguarding players then falls on each individual club, while rugby’s governing bodies are seen more so as the overseers of the professional game.

This oversight means that amateur players, both in league and union, are much more likely to remain on the field after sustaining head trauma. In the absence of medical practitioners, and a higher likelihood of having fewer substitutes to replace them, players continue to put themselves in danger, unaware of the potential consequences.

Sideline testing and HIAs have flaws, false negatives and little utility. This is why reducing rotational forces and protecting the brain from rotational forces from concussive and sub-concussive impacts through Halos® is a smarter focus.

Graduated return-to-play (GRTP) – how long is needed for the brain to recover?

When a player sustains a concussion, they enter into what is known as the graduated return to play (GRTP) protocol. GRTP is a progressive program that brings an individual back to sport in a step-wise fashion. Under the GRTP protocol, the player can advance to the next stage only if there are no symptoms of concussion at rest and at the level of physical activity achieved in the current GRTP stage.

GRTP is really an informed guess on how long it takes the brain to recover postinjury. Damage to the brain cells from an impact can be both immediate (damage to the brain cell structure) and delayed (blood flow changes or neural inflammation). Research and opinion from medical literature reviews suggest that 30 days is the minimum period before returning to play post a concussion event.

Under current GRTP Guidelines

  • A player in elite rugby union can complete the six stages of the GRTP no earlier than the seventh day after injury, with the player’s return approved by an independent concussion consultant. Players with a history of concussion or who are removed from a match with obvious concussion symptoms will sit out from play for a minimum of 12 days.
  • A player in amateur rugby union can complete the six stages of the GRTP in a minimum of 19 days for adults and 23 days for children.
  • A player in rugby league can complete the six stages of the GRTP in a minimum of 11 days.

Rugby has focused on evaluating brain recovery based on the level of play. However, there is no precise answer to how long it takes the brain to recover post-injury.

Returning to play too soon can increase the risk of sustaining further injury and subsequent symptoms, requiring a prolonged period of recovery. Changes in white matter, brain connections and blood flow can persist a year or more after a concussion. Research [3] provides a significant association between a history of concussion and lower extremity injury, especially lateral ankle sprain, knee injuries and muscle strains. Athletes of all levels in sport have a greater risk of lower-body injury issues for more than a year following a sport-related concussion. In some cases, this risk is as high as 67%.

Technological solutions

Instrumented Mouthguards

Instrumented mouthguards are increasingly being introduced into rugby to help detect whether or not a player is at risk of a concussion or head trauma. Instrumented mouthguards are mouthguards with in-built hardware to allow for the accurate measurement and reporting of head impacts in real-time. They calculate the force, location, direction and number of head impacts, while effectively filtering out false-positive non-head impact events. This data is fed to an online reporting portal to report by player the linear and rotational force, location, direction and number of head impact(s) received.

This data is intended to provide a greater understanding of when a player is in danger, by measuring the force of every collision they experience during a match. However, as there is no known safe threshold for head impact, it is difficult to draw conclusions from this data.

More than 700 male and female amateur rugby union players, from adults to under-13 level, have taken part in the largest instrumented mouthguard study in New Zealand. The Rugby Football League has approved the game-wide introduction of instrumented mouthguards across the professional game, Women’s Super League, academy rugby and the community game.

Instrumented mouthguards are a measurement tool of head impact exposure, but do not protect against brain trauma occurring.

Eye-tracking technology

Eye-tracking technology is also being introduced to help with the detection and management of concussion. Studies have suggested that oculomotor function – eye movement – alters at the time of a concussion or shortly afterwards. This technology is being piloted in matches alongside HIA process and the return-to-play protocols. This technology does not reduce brain trauma or protect against concussion or sub-concussion . It is a measurement and management tool to identify concussion and is irrelevant to sub-concussion.

Measuring brain patterns

Measuring brain patterns through an electroencephalogram (EEG) is also being introduced to better spot and manage concussion. An EEG tracks and records brain wave patterns. Localised brain activity is recorded via a number of metal electrodes. The EEG brain test is typically used for tracking and observing brain state changes. This technology measures and identifies concussions, but does not support preventative care.

All of these technologies focus on measuring and managing brain injury after it has happened. Whilst removing a player with concussion is becoming accepted, removing a player based on cumulative sub-concussions is unlikely to be popular or practical when the player has no symptoms, and the numeric threshold has not been proven.

Rezon’s answer to brain trauma in rugby

The brain is at risk, not just to a single or high-force impact, but also to the multiple sub-concussive impacts which are invariably unnoticed and undetected in rugby. Every single impact on the head in training and playing has the potential to be career-ending and life-changing.

Whilst the effects of brain injury may be instantly visible, repetitive brain injury over many years may not be recognised until later, meaning it is never too early to protect the brain in sport. The way head injuries are dealt with in rugby is now an overwhelming priority. World Rugby, the Rugby Football Union, Welsh Rugby Union, Rugby League are all facing a lawsuit from retired players who have been diagnosed with CTE.

The most significant mitigation to reduce brain injury in rugby is reducing the transmission of rotational forces to the brain from concussion and sub-concussive impacts. Halos® is uniquely and intentionally designed to lessen the risk of rotational brain injury due to the reduction in the transmission of rotational forces to the brain from concussive and sub-concussive impacts.

Youth rugby players wearing Halos