High-Impact Heading: New Analytics FC Research Reveals That More Has To Be Done In The Fight Against Brain Injury

We use TransferLab to assess the FA’s recommendation regarding high-impact heading to assess the extent of protection being offered to players.

The spectre of long-term head injuries continues to haunt contact sports and football is no different. As tragedies continue to emerge that confirm the seriousness of the issue, it is good to see a growing desire to tackle these problems by the football authorities.

Earlier this year, the Football Association released new guidance ahead of the 21/22 season, recommending players across the English football pyramid should be limited to 10 “higher-force” headers per week in training in order to reduce the risk of brain injuries. 

In the statement put out by the FA, the Premier League, the English Football League, the Women’s Super League, the League Managers Association, and the Professional Footballers Association, “higher-force” headers were defined as “headers following a long pass (more than 35 meters) or from crosses, corners and free kicks.”

The guidance itself focused on heading in training. “It will be recommended that a maximum of 10 higher force headers are carried out in any training week,” the statement read. “This recommendation is provided to protect player welfare and will be reviewed regularly as further research is undertaken to understand more regarding the impact of heading in football.”

At Analytics FC, we don’t have access to the training data on higher-force headers. But using the FA’s definition, we were able to assess the number of these high-impact heading actions that take place on the football field during competitive matches. 

Taking these numbers against the FA’s recommendation for high-impact headers in training, it is clear that football does have a high-impact heading problem. The question is: are we taking it seriously enough?

How did the FA arrive at its recommendation?

Before digging into the on-field data, it is worth looking at the process by which the FA arrived at its recommendation.

In July 2021, the FA published a study that it had carried out in the wake of an earlier study that came out in 2019 that concluded that, “mortality from neurodegenerative disease was higher and prescriptions of dementia-related medications were more common among former professional soccer players than among controls from the Scottish population.”

The 2021 study focused on four pieces of research: a formal systematic review of existing academic publications researching the quantification of heading in football carried out by the University of Central Lancashire’s Football Performance Hub; an analysis of Opta data; an original study carried out by Second Spectrum looking at force exposure in high-impact heading; and another piece of original research into the impact exposure attributable to heading activities in training sessions carried out by Sport and Wellbeing Analytics Limited.

The recommendation itself emerges from the analysis of the Opta data. Section 4.3 of the study states that: 

Based on the findings of preliminary studies a recommended maximum number of 10 higher force headers per training week has been calculated. This recommendation applies to headers categorised as resulting in the highest forces, namely:

a) Headers following a long pass (those in excess of 35m), for example, returning a goal kick.

b) Headers from crosses, corners and free kicks.

The recommended limit has been calculated using the maximum mean number of headers occurring for any position group across competitions as set out in table one. The recommendation follows the principle of preparing players adequately for match-play. 

Here is table one as referenced in Section 4.3:

The principle, then, appears to be “train as you play” and the figure selected seems to be based on the maximum mean numbers of headers occurring for League Two defenders: a figure of 10.10 rounded down to 10 high-impact headers.

What does our data show?

Taking the definition of high-impact headers in the FA’s recommendation, Analytics FC have been able to conduct our own research into high-impact headers. To reiterate, the FA’s definition is:

a) Headers following a long pass (those in excess of 35m), for example, returning a goal kick.

b) Headers from crosses, corners and free kicks.

Based on this definition, here are the average numbers of high-impact headers on average in matches across the English football pyramid from last season:

As you can see from the numbers, the average gradually increases down the pyramid with a 0.4 difference between the Premier League and the National League. 

Of course, there should be no surprise to hear this given the style of football played in each league respectively. But this does highlight the fact that future injury as a result of high-impact heading frequency is disproportionately skewed towards players in the lower leagues of English football. 

This poses a deeper issue. Given the relative inequalities between the top and the bottom of the English pyramid, those people most likely to suffer the long-term consequences of high-impact heading are playing in leagues that do not enjoy the same sorts of provision or resources that the top leagues have available to them.

Leaving this aside for the time being, though, these numbers do suggest that a recommendation of fewer than 10 high-impact headers per week is an achievable target for clubs to attain.

However, digging into the data a little deeper, things become complexified somewhat. Here are the top twenty-five players for high-impact headers per 90 in the Premier League last season for players with over 1000 minutes:

It should come as no surprise that this list is populated with centre backs and the odd striker. 

At the top of the list, we find Sheffield United striker Oliver McBurnie coming in at 4.44 high-impact headers per 90 mins. This is obviously within the FA’s recommendations. But assuming that McBurnie plays a midweek game, then his high-impact header quotient would already be at around 9 headers. Given the recommendation is “a maximum of 10 higher force headers are carried out in any training week”, McBurnie is already close to the limit of what is suggested for training simply by playing two-90 minute games.

Last season, Sheffield United played 11 double game weeks in the course of their season, which ran from September to May: a rate of around 1.4 double fixtures per month. This doesn’t include international fixtures or European fixtures.

For someone like West Ham’s Tomas Soucek, then, who is both an established footballer internationally and is playing in Europe this season, the scope for high-impact headers is much greater. Across all formats in 20/21, Soucek played a total of 5,072 minutes without playing in Europe. This season, assuming he played in all of West Ham’s Europa League group stage fixtures, you’re adding another 560 minutes to be squeezed into midweek fixtures, bringing the potential total to around 19 double game weeks in a schedule. This isn’t even taking into account a long domestic cup run in either of the two cups.

Soucek is a high-volume header of the ball for West Ham, picking up 3.51 high-impact headers per 90 in the Premier League last season. This is still three below the FA’s recommendation for training in a double game week. But 7 high-impact headers per double game week is much higher than the league average of 1.8 headers per double game week.

Moving down the English leagues, this worrying trend becomes even more stark. Here are the top 25 players for high-impact headers in the Championship last season for players with over 1000 minutes:

As you can see, not only are the outliers even higher—Adebayo Akinfenwa putting up 5.65 high-impact headers per 90—but the numbers start plateauing out at a much higher level than the Premier League. Where the Premier League top 25 drop below 3 high-impact headers per 90 within the first six players, the Championship sees 21 of its top 25 above that level.

And this trend continues down the Football Leagues. Here is League One last season for players with over 1000 minutes:

Again, notice how the outliers would already be outside (or very close to) the parameters recommended by the FA report should a double game week occur in the schedule. In the Championship, Akinfenwa would be at 11.3 high-impact headers per double game week. In League One, Gary Madine would be expected to make an even 10 high-impact headers if he played a double gameweek in the division. On top of this, all 25 of the top players for high-impact headers are over 3 per 90.

So while the FA’s recommendation matched against the league averages for high-impact headers across the English football pyramid seems achievable, when you compare it against the outlier cases in each league, it does seem as though some players are going to be disproportionately affected by high-impact headers than others. 

If this is the case, a blanket recommendation may not be enough. Instead, recommendations might need to be tailored to be position or league-specific to ensure that the welfare of players is being protected across the board.

Where does this leave us?

It should be noted at this point that the FA’s recommendation is clear that high-impact heading quotas should be “means-tested”. Table one from the report shows a broad spread of mean high-impact headers across the positional spectrum. 

On top of this, Section 4.2 clarifies that high-impact heading should be evaluated across a number of parameters:

Given the factors listed above [age and gender, position, quantity of headers, type of header by preceding event] it is clear that all headers are not equal. Further research is required to increase understanding and inform future iterations of this guidance so that it reflects differences in position, age and sex.

And Section 5 advises that:

During training sessions it is essential that club staff monitor each player’s heading practice in real time, ensuring that the quantity of headers resulting in higher accelerations is minimised and is commensurate with each player’s individualised match play heading profile.

However, it remains the case that the burden of high-impact heading is being borne by a select group of people, namely strikers or defenders in the lower leagues of English football. 

Per the Analytics FC research, in a double game week, the average Premier League player would be expected to make 1.8 high-impact headers during competitive play plus another 10 in training. For a player like Gary Madine, that number is almost doubled to 20 high-impact headers during a double gameweek.

To produce a one-size-fits-all recommendation runs the risk of presenting the problem as a one-size-fits-all issue. But this is simply not the case. The argument will be made that limiting headers in training is limiting the number of headers that outlier players are making. This is true, of course, and as such, the recommendation should be welcomed. However, at this point, the emphasis seems to be on limitation rather than mitigation.

Throughout the recommendation, the onus is placed on the training staff at clubs to make decisions for the benefit of their players’ future health. For instance, Section 4.2 of the recommendation contains the following lines:

To aid the development of player centric guidance it is recommended that clubs

develop player profiles that consider the following:

– Gender

– Age

– Playing position

– The number of headers per match

– The nature of these headers

By placing the responsibility for specific mitigation in the hands of clubs, the FA runs the risk of only having their recommendation about the base limitation of headers in training implemented. While clubs will take the recommendation seriously, it may only be the clubs towards the top of the pyramid who have the resources or time to track high-impact heading effectively or have individualised plans for players.

Of course, the FA’s recommendation should be commended. It begins a process and it is good to see these positive steps being followed up with proactive moves this season. For instance, this week, the FA, Premier League, EFL and PFA have announced a new joint action plan on understanding, promoting and protecting brain health.

However, this is only the first step in what will be a long journey. Not only does there need to be more research carried out into the effect and mitigation of high-impact headers. There needs to be clearer guidelines as to the specifics of what clubs must do to prevent the future incidence of long-term neurodegenerative disease amongst players. 

At Analytics FC, we provide software and data services to entities within football looking to realise the gains possible from analytical thinking.

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