We can design footballs to reduce heading impact, say scientists

Scientists at Loughborough University believe footballs could be designed to significantly reduce the impact of heading, after a study found the energy transfer of some balls was 55 times greater than others that have been used in the professional game.

The research, which was led by Loughborough’s Sports Technology Institute and philanthropically funded by the FA, looked at “ball-head impacts” between a range of footballs used over the past century.

Repetitive headers through a player’s career have already been linked to an increased risk of neurodegenerative diseases in later life. The deaths of a number of ex-players, including Nobby Stiles, Jeff Astle and Gordon McQueen, have been caused by brain injuries which coroners have linked to repeated heading of footballs.

But until now, research has been targeted on the full head movements that can cause concussion rather than the previously unreported “pressure wave energy transfer” to the brain that occurs at the precise moment the ball strikes the forehead.

While Loughborough is not detailing the results of the different balls made by different brands, it concludes that differences in design and material use can have a significant impact on the level of that energy transfer.

Andy Harland, professor of sports technology at Loughborough, told The Times it would be wrong to assume that the old-fashioned leather balls produced consistently higher results than more modern footballs. Indeed, they found that in the balls being used in the modern game, some produced higher energy transfers than others. The FA has shared the research findings with Fifa and Uefa.

As the researchers say in a statement, their findings could influence future ball design and “could prove significant in understanding the mechanics of headers and inform future research into long-term player health”.

“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,” says the team at Loughborough.

“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.”

Harland suggested to The Times that Fifa could include a pressure wave energy test when accrediting future football designs. “They already have a suite of tests that a match ball has to meet,” he said. “This could potentially be another test.”

He added: “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.”

Lead researcher Dr Ieuan Phillips said: “These findings provide opportunities to work towards ball designs and testing specifications that minimise energy transfer into the brain. We look forward to collaborating with all stakeholders interested in taking this forward.”

The FA’s 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 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.”

The study has been published in the peer-reviewed Proceedings of the Institution of Mechanical Engineers: Journal of Sports Engineering and Technology.

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