Background: Video analysis is one of the most commonly applied methods for analysing football injuries.
Purpose: The objective of this study was to assess the accuracy of video analysis for recording head injuries in professional football from official matches in the four highest men's professional football leagues in Germany.
Methods: In this cohort study, head injuries detected by means of video analysis of all official matches over one season (2017-18) were compared to head injuries registered with the German statutory accident insurance.
Results: Our video analysis yielded 359 head injuries of 287 players. The comparison of head injuries found in our video analysis to those registered with the accident insurance only yielded a match in 23.1% (n = 83), which presents a rather low verification rate. The verification rates varied between the leagues (7.0-30.8%). All injuries documented in the accident insurance registry were found in the video analysis (100%). The types of head injury most often verified by the accident insurance registry (n = 83) were contusion (43.4%), bone fractures (19.3%) and skin lacerations (18.1%). Only 66 of the 359 head injuries (18.4%) resulted in absence from at least one training session and involved a mean time loss of 18.5 days (1-87 days).
Conclusion: The mismatch between the number of head injuries found in the video analysis and head injuries registered with the accident insurance is an important methodological issue in scientific research. The low verification rate seems to be due to the unclear correlation between injury severity and clinical consequences of head injuries detected by means of video analysis and the failure of football clubs to register minor head injuries with the accident insurance.