Abstract

Introduction
Sport-related concussions (SRC) have been a concern in all sports, including soccer. The long-term effects of soccer-related head injuries are a public health concern. The Concussion in Sport Group (CISG) released a consensus statement in 2017 and several soccer governing associations have published their own SRC guidelines while referring to it but it is unclear whether this has been universally adopted.

Research question
We aimed to investigate whether guidelines published by soccer associations have any discrepancies; and the extent to which they follow the CISG recommendations.

Materials and methods
A scoping review of available soccer-specific SRC guidelines was performed via databases PubMed, Google Scholar, and official soccer association websites via web browser Google. The inclusion criteria were soccer-specific SRC guidelines. Comparisons between guidelines were made concerning the following index items: initial (on-site) assessment, removal from play, re-evaluation with neuroimaging, return-to-sport protocol, special populations, and education.

Results
Nine soccer associations with available guidelines were included in this review. Guidelines obtained were from official associations in the United Kingdom, United States of America, Canada, Australia, and New Zealand. When compared to each other and the CISG recommendations, discrepancies were found within guidelines regarding the index items. Additionally, major soccer associations in some countries famous for soccer were found to have not published any publicly available guidelines.

Discussion and conclusion
SRC guidelines from different soccer associations contain discrepancies which may be detrimental to athletes, both short and long-term. We recommend that all major soccer governing associations publish guidelines that are standardised and accessible to all athletes.

Introduction

A concussion can be defined as a transient and sudden alteration of consciousness following traumatic biomechanical forces transmitted to the brain either directly or indirectly (Khurana and Kaye, 2012). Sport-related concussion (SRC) has been a growing concern over several years and has been attracting further attention amongst athletes and healthcare professionals due to recently publicised effects on both their immediate and long-term neurological health. Soccer is a sport with high concussion rates in comparison with others (Pierpoint and Collins, 2021). The injury rates amongst athletes of the National Collegiate Athletic Association (NCAA) being 0.28 and 0.41 per 1000 game exposures for male and female soccer athletes respectively. This is in comparison with other contact sports such as men’s wrestling (0.25), American football (0.37), basketball (0.16), ice hockey (0.41); and women’s basketball (0.22), gymnastics (0.16), and field hockey (0.18) (Hootman et al., 2007). High concussion rates were also seen in a 2020 study by Vedung et al., where the concussion incidence was 1.19 per 1000 game hours (Vedung et al., 2020).

Recent evidence from 2019 (Scotland) and 2023 (Sweden) showed that former elite soccer players are more likely to die from neurogenerative disease, which was attributed to the frequency of concussions and repetitive heading during their playing days (Mackay et al., 2019; Ueda et al., 2023). There has also been coverage from mainstream media reporting on former athletes that have developed neurodegenerative disease after sustaining SRC’s during their playing careers. For example, in an article from 2020, forty ex-soccer players were reported to take legal action against the English Football Association for dementia-related negligence due to brain injuries sustained (PA Media, 2020). Increasing attention has therefore been brought to this issue, which has raised questions on the effectiveness and utilisation of concussion protocols currently in place.

Conclusion

This scoping review identified discrepancies between soccer-specific SRC guidelines published by different official bodies. The major discrepancies identified were found in the timeframes for the return-to-sport protocol; the time recommended for the initial rest phase; and the decision to allow same day return-to-play after a suspected concussion. Possible implications of these discrepancies are that athletes could be managed in vastly different ways without any clarity on which guidelines would be best. This could lead to outcomes where, for example, athletes could be rested for too long or the opposite where athletes could be rushed back into play prematurely. Furthermore, the discrepancies could be putting certain populations at a higher risk of subsequently poorer neurocognitive outcomes after sustaining a concussion; for example, amateur athletes that do not have access to facilities like an individualised management plan with close monitoring of their progression through the different steps of the return-to-sport protocol. Due to the lack of studies in this area, it is unclear whether these discrepancies are detrimental to athletes and whether they may pose a risk, both at short-and long term. Soccer is one of the most popular sports in the world and SRCs continue to be a relevant issue. This is a field of growing interest amongst healthcare professionals and considerations for additional specific information about risk prevention and the use of neuroimaging should be made to include them within future guidelines.

It is fortunate that the most recent update from the CISG was concluded with the 6th International Conference on Concussion in Sport, held in 2022 (Patricios et al., 2023). This consensus statement was only just published in June 2023 and includes updated strategies for return-to-sport and material such as the Sport Concussion Assessment Tool-6 (SCAT-6), the Child SCAT-6, the Concussion Recognition Tool-6 (CRT-6), the Sport Concussion Office Assessment Tool-6 (SCOAT-6), and the Child SCOAT-6. These updates provide a fresh opportunity for soccer associations to update their guidelines in a consistent and collaborative manner.