Major changes to the way the world’s most popular sport is played may be drawing closer, after a new study revealed the act of heading the ball is more likely to result in a concussion than other head impacts sustained during play, including collisions with elbows, heads and even goalposts.
The Einstein Soccer Study recruited experienced and active amateur adult footballers in the New York area, screening out any with existing psychological or neurological disorders. The players were then asked to self-report any impacts to the head – both intentional and accidental – and any subsequent symptoms through a validated questionnaire known as HeadCount, providing a set of results covering two weeks of activity.
The results are published in the journal Frontiers in Neurology.
Read: Cosmos Q&A: Concussion
To support the data gathered through the questionnaire, each participant also completed an in-person neuropsychological assessment during the same two-week period. The assessment used a variety of tests to measure recall, verbal learning, psychomotor speed and attention span.
Many participants repeated this protocol at three- to six-month intervals across a 37-month period, yielding 741 complete sets of data from more than 300 participants, four-fifths of whom were male. The study concluded that heading incidence was a significant factor in reduced performance in the areas of psychomotor speed and attention, and to a lesser extent on working memory.
Players headed the ball an average of 50 times during each two-week study period for men, and 26 for women, and those who reported the most headings demonstrated poorest performance on cognitive tasks. Unintentional knocks to the head, however, were shown to have no significant effects on any area of neuropsychological testing.
The lead author of the study, Michael Lipton of Albert Einstein College of Medicine in New York, US, noted that while no obvious impairment could be seen as a result of the changes in cognitive function, further research is needed to assess potential long-term effects.
“What we’re really looking at here is something that is a subclinical effect and the open question, which remains to be answered by more research, is how much of this does it take to cause a permanent effect?” he says. “And that’s not known yet.”
Lipton’s group had already concluded in an earlier study that frequent heading of the ball is more likely to result in concussion symptoms.
The new study also notes that soccer is the only sport where participants “deliberately engage in repeated head impacts”. The United States has taken a lead in concussion prevention in the sport, making worldwide headlines in 2015 when the US Soccer Federation recommended a ban on heading for all children aged 10 and under as part of its Recognise to Recover program. This recommendation was implemented in 2016.
Another recent development in concussion research from the United States has come from the Virginia Tech Helmet Lab, which has released a set of ratings on a range of safety equipment designed for soccer players. Though they found a wide variance in performance, the researchers awarded the maximum five star rating to three models, which translates to a minimum reduction in concussion risk of 70%.
Questions concerning brain trauma in soccer have grown louder since the death of Hilderaldo Bellini, the captain of Brazil’s 1958 World Cup-winning team. Bellini’s cause of death in 2014 at the age of 83 was originally attributed to complications related to Alzheimer’s Disease, but this was soon revised after the former Vasco da Gama and São Paulo defender was diagnosed with an advanced case of chronic traumatic encephalopathy (CTE) during an autopsy. CTE had previously been associated chiefly with boxing and American football.
Andrew Patterson is a freelance science writer from Newcastle, UK.
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