Risk of head injury in football due to heading duels − A video analysis of 11.514 headings in elite football

Introduction: Heading is an integral part of football and frequent media reports and previous studies about potential danger of heading and head trauma in football fuelled discussions. Epidemiological data and video analyses regarding the frequency of headings and associated head injuries are still missing in adult elite football. Methods: In a prospective cohort study in the fourth German football league, 100 official matches of the 2015-2016 season were assessed by means of video analysis and a standardized protocol. Head injuries were documented and confirmed by standardised epidemiological injury reports of the teams. Results: Overall, 11,514 headings were analysed in detail. Video analysis yielded a mean of 5.7 headings per player and match (SD: 1.2; min: 0; max: 15). Heading was predominantly performed with the frontal part of the head (76.8%), and nearly two thirds of all headings occurred during defending (65.8%). 71.0% of all headings occured during tacklings, of which 71.9% involved body contact with the opponent player. Video analysis yielded 31 critical incidents (CI) on the head due to heading (incidence: 1.02 per 1000 h match exposure and player). 29 CIs occurred during heading duels (Odds ratio: 5.91), 30 CIs with body contact (odds ratio: 28.8) and 6 CIs with elbow contact (odds ratio: 6.13). Conclusion: Heading duels, especially with body contact and high elbow, are important risk factors for head injuries and key factor for prevention strategies. The impact of 5.7 headings per match on players` brain should be investigated in further research.