The dangers of heading a football have been thrust back into the spotlight after a new study found that heading a ball can lead to an elevation in blood biomarkers of neural damage.

The study comes less than a month after a team at Loughborough University Sports Technology Institute identified a previously unreported mechanism of energy transfer to the brain from football headers – a finding that could prove significant in understanding the mechanics of headers and inform future research into long-term player health.

Commenting on the study which had found neural damage, Dr Peter Theobald, reader in Biomedical Engineering, Cardiff University, said: “This study adds to the emerging evidence that even modest head impacts elicit a negative response from brain tissue.  Even a small number of headers were found to correlate with a change in blood markers immediately post-match and again with 48-hours post-match.  This would indicate that heading is causing some brain trauma.  This finding is consistent with a recent study – ironically published from my lab – that also shows a modest (in this case 10) headers to cause a change in brain structure, with a 24-hour post-match period (reference below).  These findings were still evident 6-months after this single intervention.”

He continued: “The authors of the new study do not investigate whether these changes exist beyond 48 hours post-match, which is a limitation of the methodology and so limits their ability to infer any potential longer-term risks.  Equally, they do not use their presented data to infer what these changes may mean for longer-term brain health – and so the risk of brain disease, which is appropriate, as these correlations for such changes in blood markers are not fully understood. The study is limited but their inability to quantify the energy associated with the header – whilst they used a reasonable approximation, for such sensitive analyses this approach is an inherent limitation.

“Overall, in my opinion this is an incremental addition to the literature and so does not warrant significant media attention.  It also does have the potential for causing undue concern in the wider population. Arguably, our study has greater significance, given that the methodology was more robust in quantifying the intervention (i.e. the headers), and more specific in being able to identify the precise brain regions that were influenced, and over an extended period of time.  Whilst we had a smaller sample size, the results were still statistically significant, predominantly as we were using field-leading magnetic resonance imaging, which enabled far more detailed investigation.”

The study, led by Loughborough University Sports Technology Institute and philanthropically funded by The Football Association, saw researchers study ball-head impacts between a range of footballs from throughout the last century and an advanced surrogate head model, at match speeds. Using a specialist pressure sensor positioned within the brain model they observed, for the first time, a distinctive pressure wave that transfers energy into the frontal region.

The research showed the magnitude of this energy transfer varied by up to 55x across historical and modern ball types. Researchers hope that this new insight may help inform the development of new ball designs that will minimise pressure wave energy transfer.

Professor Andy Harland, professor of sports technology, Loughborough University said: “Having studied football impacts for two decades, I am pleased we have been able to find evidence of this pressure wave and quantify the energy that is being transferred into the brain during each header. There is still much work to do before we fully understand what this means for brain health, but this research allows us to provide a much more detailed description of how energy is transferred during heading.”

FA Chief Medical Officer, Charlotte Cowie, said: “We’re pleased to have funded Loughborough University’s study into the potential effects of pressure waves in footballs. This new independent research provides us with innovative and previously undiscovered insight – and it is part of our ongoing commitment to gain a greater understanding of this highly complex area. The results of the study have also been shared with FIFA and UEFA, and we continue to welcome a global approach to support further research in this important area.”