The HIA rugby concussion protocol, explained step by step

A player who has just been concussed will tell you he is fine. He will mean it. That is not bravado or a lie told to get back on the pitch, though rugby has plenty of both. It is the injury describing itself: the organ making the assessment is the organ that has been hit, and it will frequently report normal function while failing a memory test thirty seconds later.

Every part of the HIA rugby concussion protocol is built on that fact. The protocol does not ask the player how he feels, except as one input among several that a doctor weighs. It does not leave the decision with the coach, who wants his best openside on the field, or with the team doctor alone, who is employed by the club. It hands the final say to somebody with no stake in the result, gives him video the naked eye cannot supply, and stops the match clock so that nobody has to hurry.

Read the protocol as a medical document and it looks fussy. Read it as a document about incentives and it is unusually clear-eyed. Almost every clause is designed to take the decision away from a person who has a reason to get it wrong.

Two doors off the pitch, and only one of them has a test behind it

The first thing to understand about the head injury assessment is that most players who are removed for a head injury never take it.

The protocol splits head impact events into two groups. Criteria 1 signs mean the player is finished for the day, immediately and permanently, with no assessment and no discussion. Criteria 2 signs mean the player leaves the field for an off-field assessment and may come back if it is normal.

Criteria 1 covers the signs that are considered diagnostic on their own. Confirmed loss of consciousness, and suspected loss of consciousness, which is deliberately included so that ambiguity resolves against playing on. A convulsion. Tonic posturing, the stiffened, raised-arm response sometimes visible in the instant after impact. Balance disturbance or ataxia. A player who is clearly dazed. Then a second group identified in the on-field assessment rather than on video: disorientation in time, place or person, definite confusion, definite behavioural change, oculomotor signs such as spontaneous nystagmus, and any on-field identification of the signs or symptoms of concussion. A player who has been non-compliant with the protocol before the game is also treated as ineligible.

Those are not a scoring system. One of them is enough.

Criteria 2 covers everything suspicious but unresolved. A head impact event with no immediately apparent diagnosis. Possible confusion. Possible behavioural change. A subthreshold Criteria 1 sign, such as a balance disturbance that might have been a stumble. Any injury event with concussion potential. Another concerning motor response after head impact. And, in competitions that use them, an alert from an instrumented mouthguard indicating a head acceleration event above the threshold World Rugby has set.

That last one is worth pausing on, because it changes the character of the protocol. Every other entry criterion depends on somebody noticing something. A mouthguard sensor triggers on physics. It does not care whether the incident was in shot, whether the doctor was looking, or whether the player got up quickly to avoid attention, and it removes the most common failure mode in concussion management, which is not misdiagnosis but non-identification.

1. 1The impact is identifiedBy the referee, the touch judges, the team medical staff on the sideline, the independent match day doctor, the video review team, or an instrumented mouthguard alert. Identification is the step the whole protocol depends on, and it is the step most likely to fail.
2. 2The video is reviewedThe match day doctors review the incident on replay, with the ability to slow it and see angles nobody on the pitch had. The specific question is whether any Criteria 1 sign is present on the footage.
3. 3Criteria 1 present: the player is removed permanentlyConfirmed or suspected loss of consciousness, convulsion, tonic posturing, ataxia or a clearly dazed player. No assessment is offered, because the diagnosis is already made and a test could only muddy it.
4. 4Criteria 2 present: the player goes off for an assessmentA head impact event with concussion potential but no clear diagnosis. The player leaves the field and is temporarily replaced, so his team is not short while the assessment runs.
5. 5Twelve minutes of absolute time are allowedThe clock is non-playing time, so stoppages do not eat into it. The doctor is not racing the game, which is the point: a hurried cognitive test is a worthless one.
6. 6The off-field assessment is conductedImmediate memory, orientation questions, digits backwards, balance testing, a symptom checklist, clinical observation, and a delayed memory recall taken at least five minutes after the first.
7. 7The result is compared with the player's own baselineEvery player has pre-season baseline scores. The comparison is against himself where possible, and against normative rugby values where it is not, because absolute scores vary enormously between individuals.
8. 8An abnormal result ends the match for that playerAny abnormal finding supports a suspected concussion and the player does not return. A normal result allows return to play, with the independent match day doctor holding the final say.
9. 9Whatever the outcome, the protocol continuesEvery player who has an off-field assessment during a match must be assessed again after the match and again a day or two later, whether or not he passed at the ground.

The in-match sequence set out in World Rugby's published HIA protocol. Which branch a player takes is decided by the criteria, not by how he says he feels.

What the twelve minutes actually contain

The off-field assessment is not a doctor asking how many fingers he is holding up. It is a structured battery, and each component is chosen because it fails in a different way.

Immediate memory. The player is read a list of five words, at roughly one-second intervals, and asked to repeat them back. This is done three times, and the version used in the protocol draws on a set of six different five-word lists so that a player cannot learn one. The best possible score is thirty.

Orientation questions. A short, standardised set about the match itself: which ground, which half, who scored last. These are asked because a concussed player very often knows his own name and address perfectly well while having no idea what has happened in the last twenty minutes.

Digits backwards. Strings of numbers repeated in reverse. This tests working memory and attention rather than recall, and it is sensitive to exactly the kind of processing disruption that a knock produces.

Balance. Tandem stance and single-leg stance, each held for twenty seconds. Balance is controlled by systems that are disturbed by concussion and that a player cannot consciously compensate for the way he can compensate for a memory question.

Symptom checklist. The player is asked to identify symptoms aloud from a set of nine. This is the self-reported component, and everyone involved knows it is the weakest one, which is why it is not the deciding component.

Clinical observation. The doctor's own assessment, structured around a short set of questions rather than left as a general impression.

Delayed memory. The word list again, at least five minutes after the immediate recall, which is what makes the five-minute gap in the middle of the assessment necessary rather than an accident of timing.

Two design features hold the whole thing together. The first is the baseline: every elite player is tested in pre-season so that his in-match scores are compared with his own normal performance rather than with an average. A player who scores twenty-four out of thirty on immediate memory may be perfectly normal or badly concussed depending entirely on what he scores in July. The second is the twelve minutes of absolute, non-playing time. Stoppages do not count, so a scrum reset or a lengthy television match official review does not silently shorten the assessment.

The protocol does not end at the final whistle

This is the part casual viewers miss entirely, because it happens after the broadcast ends. Passing the pitch-side assessment does not clear a player. It gets him back onto the field for the rest of that afternoon, and nothing more.

Every player who has an off-field assessment during a match, whatever its result, must be assessed again within a few hours of the final whistle, using a fuller diagnostic tool supported by his baseline or by normative values. Then again roughly a day and a half to two days later, after two nights of sleep, with a clinical assessment, a symptom checklist, balance testing including tandem gait, and a cognitive assessment.

The staging exists because concussion is not a state that is either present or absent at a single moment. Symptoms can be absent immediately after impact and unmistakable the following morning. A player who is genuinely fine twelve minutes after a collision may be photophobic and unable to concentrate by Sunday lunchtime, and a protocol that stopped at the pitch-side test would have declared him uninjured and let him train on Monday.

So the second and third assessments are not appeals against the first. They are separate examinations of a moving target, and a player can be cleared at the ground and diagnosed two days later. That is the protocol working, not failing, which is a distinction almost nobody makes when a player passes an assessment on television and is ruled out of the next match.

• 12Minutes of absolute time for the off-field assessment
• 3Assessments in the full protocol, match day to follow-up
• 7Minimum days out, no history and every assessment normal
• 12Minimum days out, concussion history or obvious symptoms

Periods set by the published World Rugby protocols. The stand-down minimums apply in the elite game; community periods are set by each national union and are longer.

Why an independent doctor is standing on the touchline

A team doctor is a good doctor with a bad position. He is employed by the club, he travels with the squad, he has a professional relationship with the coach who selects, and he is being asked to make a judgement that may cost his employer a match. Nobody serious suggests team doctors routinely wave concussed players back on. The point is structural: a system that relies on one person resisting a pressure is weaker than a system that removes the pressure.

Elite competitions appoint an independent match day doctor, whose relationship is with the competition rather than the club. The team doctor usually conducts the assessment, but the independent doctor holds oversight and the ultimate decision on return to play. Both review the video together before any final decision is taken.

The independent doctor also has an identification role that no team doctor can perform, because he is watching everything rather than watching his own players. He can initiate a removal for an incident the team's staff did not see, and he can overrule a return.

Alongside him sits a video review capability that has quietly become the most important diagnostic tool in the protocol. Concussion signs are brief. Tonic posturing lasts a second or two. A stumble on standing is visible only from certain angles. A player whose eyes are not tracking properly cannot be seen from thirty metres away. Replay, slowed and repeated, converts a fleeting sign into evidence, and it does so within the window in which the decision has to be made.

Rugby got there before most sports because it had already built the apparatus for something else. The infrastructure that lets an official review incidents on replay before a decision is made was installed to adjudicate tries and foul play, and the medical use of it is a by-product. It is a rare case of a technology introduced for one purpose turning out to matter far more for another.

Temporary replacement is the law change that made all of this possible

None of the medical protocol would function without a change to the laws of the game, and it is the piece most often left out of explanations.

If a player leaving the field for an assessment meant his team played a man short for twelve minutes, or meant burning a substitution he would not get back, every incentive in the stadium would point at deciding he was fine. Coaches would lean on doctors. Doctors would feel it. Players would hide symptoms to avoid costing the team.

So the law permits a temporary replacement for a head injury assessment. The player goes off, a replacement comes on, and if the assessed player returns, the replacement goes off again and the substitution is not consumed. If he does not return, the replacement becomes permanent. The competitive cost of taking a player off for assessment is set as close to zero as the laws can manage.

The mechanism borrows its shape from the blood replacement rule, which had already established that a player could leave and return without his team being punished for it, and it sits inside the wider framework governing who may come on and when. The front row is the awkward case, as it always is, because a team without a qualified replacement cannot simply plug the gap, and the laws carry specific provisions for what happens when a front-row player is removed for assessment and no qualified cover remains.

There is a further subtlety that matters more than it sounds. Because the replacement is temporary, the assessment can be initiated on suspicion rather than on certainty. A doctor who is unsure whether what he saw was a stumble or an ataxia can send the player off and find out, at almost no cost. A protocol where removal was irreversible would push every borderline case towards leaving the player on, which is precisely the wrong direction for the cases where the answer is uncertain.

Coming back: the graduated return, and who signs it off

A diagnosed concussion is not resolved by feeling better. The return is staged, each stage is a defined level of exertion, and progression depends on remaining symptom-free through the previous one.

1. 1Rest and relative inactivityAn initial period of physical and cognitive rest. The cognitive half is the part players and clubs most often skip, and it covers screen time, study and the mental load of work as well as training.
2. 2Light aerobic exerciseWalking, stationary cycling or similar at low intensity, with heart rate kept well below maximum. The purpose is to test whether mild exertion provokes symptoms, not to maintain fitness.
3. 3Sport-specific exerciseRunning and change of direction, still without any impact or head-loading. This is the first stage that resembles training rather than rehabilitation.
4. 4Non-contact training drillsFull training intensity with passing, kicking and skills work, but no contact of any kind. Progressive resistance training may be introduced here.
5. 5Full contact practiceOnly after medical clearance. The player returns to normal training including contact, which is the first time since the injury he has been exposed to the mechanism that caused it.
6. 6Return to playAvailable only once every earlier stage has been completed without symptoms and the return has been approved, in the elite game, by an independent concussion consultant rather than by the club's own staff.

The structure of the graduated return to play pathway. Progression to the next stage requires the player to remain free of symptoms at the current one, and a return of symptoms sends the player back a stage.

In the elite game the minimums are firm. A player with no concussion history whose later assessments are all normal is not eligible before the seventh day. A player with a concussion history, or one removed from the field with obvious symptoms, faces a minimum of twelve days, which in a weekly competition means missing at least one match. Return is approved by an independent concussion consultant, not by the club.

The logic of the two-tier minimum is that repeated concussion is the risk the protocols are actually managing. A single event is a problem. A second event before the brain has recovered from the first is a different and much more serious problem, and a player with a history is treated as a player whose threshold has moved.

Community rugby works on the opposite principle, and deliberately. There is no HIA in the community game, because there is no independent doctor, no video review team, no baseline testing and no possibility of a valid twelve-minute assessment on a Saturday afternoon in a park. The instruction is simply to recognise and remove: any player with a suspected concussion comes off and does not return to play or train that day, full stop. The stand-down that follows is set by each national union and is measured in weeks rather than days, with longer periods for age-grade players. The elite game gets shorter minimums because it can watch the player every day. The club game gets longer ones because nobody can.

Elite, no history, all assessments normal7

Elite, history or removal with obvious symptoms12

Community adult, England21

Elite minimums are set by World Rugby's return to play protocols. The community figure shown is the minimum period applied to adult players in England; other unions set their own, and age-grade minimums are longer everywhere.

Show the numbers

Minimum stand-down before a return to competitive play

Item	Value
Elite, no history, all assessments normal	7
Elite, history or removal with obvious symptoms	12
Community adult, England	21

Refereeing the cause: the head contact process

Assessing concussion after it happens is treatment. The other half of rugby's response is an attempt to reduce how often the impact occurs at all, and that runs through the laws rather than the medical protocol.

The head contact process gives referees a structured sequence for any incident involving contact with the head. It asks four questions in order.

Has head contact occurred? If not, the process stops.

Was there foul play? Accidental contact in a legal tackle is not automatically an offence, and the process is explicit that some head contact is not foul play at all.

What was the degree of danger? High danger means direct contact, high force, high speed, a leading head, shoulder, forearm or swinging arm, and it reaches the red card threshold. Low danger, meaning indirect contact, low force, low speed and no leading limb, reaches the penalty or yellow card threshold.

Is there mitigation? A sudden drop in height by the ball carrier, a change of direction, contact from a second tackler, or an obvious attempt by the tackler to change his height can reduce the sanction by one level. The guidelines also state where mitigation is not available, most importantly where tackler and ball carrier are in open space and the tackler had a clear line of sight and time to adjust. That exclusion is the whole framework in miniature: mitigation exists for the situations a player could not control, not for the ones he chose.

The framework's real purpose is not fairness in individual cases, though that is what the arguments are about. It is behaviour change. A sanction applied consistently to a class of action shifts coaching, and coaching shifts technique, and technique is what determines how many head impacts a season contains. The full mechanics of how the sanction levels interact, and why the same-looking tackle can produce different cards, are worked through in the framework refereeing head contact.

The 20-minute red card sits awkwardly alongside all of this and is the most contested piece of the apparatus. A player who commits an act of foul play judged not to be deliberate is permanently removed, but his team may restore its numbers after twenty minutes. The argument for it is that referees hesitate to end a contest as a spectacle, and a sanction they are willing to apply is worth more than a harsher one they avoid. The argument against it is that reducing the team's punishment reduces the deterrent that was supposed to change behaviour in the first place, and the debate over whether a twenty-minute red card protects players or protects matches has run since it was first trialled.

Tackle height is the other lever. Lowering the legal height reduces the proportion of tackles that involve the head, because the most common concussion mechanism in rugby is contact between the tackler's head and the ball carrier's head, shoulder or knee. Community trials across a number of unions have run for several seasons, and World Rugby has reported encouraging changes in player behaviour, along with reductions in concussion rates in some of the participating unions. The elite game has been slower, and the extension of a lower tackle height trial to age-grade international rugby is the first time the change has been tested at that level of speed and force. The obvious risk, and the one coaches raise, is that lowering the tackle target moves the tackler's head closer to the ball carrier's knees and hips, which trades one mechanism for another rather than removing it. That is an empirical question, and the trials exist to answer it.

The criticisms, and which of them land

The protocol attracts three distinct complaints, and they are not equally good.

Inconsistency. The most common criticism, and it is aimed less at the medical protocol than at the identification step in front of it. Two similar incidents in two matches produce different responses because one was seen and one was not, or because one broadcaster had the angle and the other did not. The protocol is only as good as the moment somebody decides an event has occurred, and that moment is still substantially human. Instrumented mouthguards are the most serious attempt to fix this, because they remove the need for anyone to notice.

The assessment can be beaten, or can simply miss. A cognitive test administered under time pressure to a professional athlete who wants to stay on the field has obvious limitations. A player who deliberately underperforms his pre-season baseline gives himself room. A player with a high baseline can be meaningfully impaired and still score within normal limits. And concussion genuinely can present with a normal assessment at twelve minutes and an abnormal one at forty-eight hours. World Rugby's answer to all three is the multi-stage structure: the pitch-side test is not treated as diagnostic on its own, which is why the second and third assessments are mandatory regardless of the first result.

The stand-downs are too short. This is the criticism made most forcefully by player welfare campaigners and by some former players, who argue that the elite minimums are set by what a competition calendar can absorb rather than by what a brain requires, and that a considerably longer minimum should apply. The counter-argument from the governing body is that elite players are monitored daily by specialist staff and cleared individually by an independent consultant, so a blanket period would be both over-restrictive for some and under-restrictive for others. Both positions are coherent. The disagreement is about how much weight to give individualised medical judgement in a sport where the incentives have historically pointed one way.

There is a fourth issue that is less an argument than a limitation. The protocol manages diagnosed concussion. It does not manage repetitive head impacts that never produce a diagnosis, which is the exposure that the long-term concern is actually about. A forward who takes hundreds of sub-diagnostic impacts across a season never enters the protocol at all, because nothing about any single one of them meets any criterion. That gap is the reason the head contact process, tackle height, contact training limits and impact monitoring exist alongside the HIA rather than as afterthoughts to it: the assessment protocol was never designed to address cumulative load, and it cannot be adapted to.

The litigation that changed the urgency

Rugby's approach to head injury changed sharply in pace when a large group of former players, from both codes and across several countries, began legal action against the governing bodies, alleging a failure to protect them from the consequences of repeated head impacts. The claims cover neurological conditions including early-onset dementia. The governing bodies have denied liability, arguing among other things that injury is a foreseeable and inherent risk of the sport.

The case's outcome is not the interesting part for anyone trying to understand the protocol. The interesting part is what it did to the calculus. Before it, player welfare measures competed against tradition, entertainment and the calendar, and often lost. After it, the cost of being seen to have known about a risk and done too little became the dominant consideration in a way it had never been.

That is visible in the substance of the changes. The stand-down minimums were lengthened. The independent consultant sign-off was added. Mouthguard technology moved from research project to competition tool. The tackle height trials were expanded. Contact training loads came under governance rather than being left entirely to clubs. Almost every one of those was proposed years before it was adopted, and adopted after litigation made inaction expensive.

That is an uncomfortable thing to say about a sport that genuinely does care about its players, and it is also the honest reading. Sports change their safety rules when the cost of not changing them exceeds the cost of changing them. Rugby is not unusual in this. It is simply further along the process than most, and considerably more transparent about the protocols it has ended up with, which is why the documents are public and the criteria are specific enough to argue about.

Who is allowed to use the protocol at all

One detail gets almost no attention and explains a great deal about why the HIA is confined to the top of the game. The protocol is not a document any competition can pick up and adopt. Its use has to be approved, and approval depends on the competition demonstrating that it has the resources the protocol assumes: qualified match day medical staff, an independent doctor, a video review capability with the angles and the replay control to identify a Criteria 1 sign, and a baseline testing programme covering every player who might be assessed.

Take any one of those away and the protocol degrades into something worse than useless, because it produces a formal-looking clearance with nothing behind it. A twelve-minute assessment with no baseline to compare it against is a doctor guessing whether a tired forward's score is normal for him. A video review with two camera angles and no slow motion cannot reliably show tonic posturing. A competition that ran the paperwork without the infrastructure would be manufacturing false reassurance, which is the specific harm the whole apparatus exists to prevent.

That is why the community game does not get a watered-down version. Recognise and remove is not a lesser protocol for people who could not afford the real one. It is a different instrument built for a different environment, and it errs in the only direction it safely can, which is towards taking the player off and keeping him off for weeks. Compliance is then a matter of clubs policing themselves, which is a much weaker guarantee than an independent doctor and the honest limit of what the community game can offer.

Watching a match and knowing what you are seeing

The protocol becomes legible once you know what the pieces are, and there are four things to look for.

Whether the player leaves with the doctor or with the physio. A player walking off with a medic and a replacement immediately entering is likely to be in the protocol. A player who trots off and straight back on is not.

Whether a replacement follows him. A temporary replacement means an assessment is running, and there is a defined window. If the assessed player has not returned by the time the window closes, he is not coming back.

Whether he returns at all, and how quickly. A player who returns after two minutes was not assessed. A player who never returns either failed the assessment or never got one, and the distinction between those two matters: the second means a Criteria 1 sign was present on video, which is a more serious finding than an abnormal test.

What the club says on Monday. A player who passed at the ground and is subsequently ruled out has been caught by the second or third assessment. That is not a contradiction and it is not a cover-up. It is the protocol doing the thing it was built to do, which is to keep asking the question after the game has stopped being the reason for asking it.

The whole apparatus rests on one judgement, made by people who were prepared to say it out loud: a rugby player is not qualified to decide whether he has a brain injury, and neither is anybody who wants him on the field. Everything else, the criteria lists, the twelve minutes, the video, the independent doctor, the temporary replacement, the staged return, is engineering built around that single conclusion. The same instinct runs through the rest of the laws, from the way contact is policed at the tackle and the ruck to the sanctions collected across the wider rugby section: where a decision can be taken away from someone with a reason to get it wrong, it has been.