"A half century of heading in #soccer"
@EmmaRosalyn11, @KatyStewart4 & @WillStewNeuro

@GlasgowTBI @UofGMVLS

#football #heading #dementiainfootball
1/

Neurodegenerative disease mortality among former professional #soccer players is higher than in matched population controls, ranging from a doubling of Parkinson’s disease to a 5 fold increase in deaths with Alzhemier’s disease

https://www.nejm.org/doi/full/10.1056/NEJMoa1908483

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Neuropathology studies of former #soccer players with #dementia reveal a majority with chronic traumatic encephalopathy ( #CTE), a pathology virtually exclusive to patients with prior exposure to traumatic brain injury ( #TBI)

https://link.springer.com/article/10.1007/s00401-019-02030-y

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#TBI including #concussion are infrequent in #soccer,* however, repetitive head impacts in the form of soccer ball #heading are part of routine training and match play.

A concern is that heading represents a risk for neurodegenerative disease

* https://bjsm.bmj.com/content/53/21/1332
4/

There have been calls for measures to reduce #heading in #soccer to mitigate against #dementia risk.

Meanwhile there are suggestions current risk is lower than in past for various reasons, including ‘there is less heading in the modern game’ (hereafter @BBCMOTD hypothesis)

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To test the @BBCMOTD hypothesis we reviewed #heading data from all @FIFAWorldCup #soccer competitions spanning 1966 to 2018

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Raw data for heading in @FIFAWorldCup competitions were provided by @StatsPerform.

Video for each match was reviewed by @StatsPerform analysts and all heading events recorded and categorised as either: defensive header; headed pass; headed shot

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There has been an increase in total #headers/ match over 1966 to 2018 competitions, though with competition to competition variability

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Adjusting for competition variability #headers/ match was compared early competitions 1966-1990 to ‘modern’ competitions 1994-2018.

There were fewer headers/match @FIFAWorldCup soccer competitions 1966-1990 than in more recent World Cups 1994-2018 (71 versus 93; p=0.002)

9/

Looking at #header type, headed passes have increased over time, while clearances and shots have remained stable

Headed passes/match in @FIFAWorldCup 1966-1990 were around two thirds those of World Cups 1994-2018 (43 versus 64; p=0.001)

10/

These data demonstrate that, contrary to the @BBCMOTD hypothesis, at the highest level of global #soccer competition, #headers are increasing in match play, reflecting an increase in headed passes.

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As such, there is no evidence from these data that so called modern day #soccer players playing at the highest international level might be at lower risk of neurodegenerative disease through reduced exposure to head impacts via #heading in match play

#football #dementia

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