https://orcid.org/0000-0003-4308-901X
ABSTRACT
We used injury spotters and video footage review to establish the frequency of head impacts, their characteristics, and the subsequent medical assessment during the FIFA Arab Cup 2021TM. Six defined video signs of potential concussion based on an international consensus were used. A total of 88 head impacts were observed, with a median of 2 (IQR 1.5–4, range 0–7) head impacts per match, of which 44 (50%) resulted in on-pitch medical assessment. The median assessment duration was 51s (IQR 34–65s, range 19–262s). The most common mechanism was head-to-head contact (27% of all impacts and 43% of impacts with medical assessment). Seven head impacts showed video signs of potential concussion: six had one sign and one had two signs. The concussion substitution was used in three incidents. Head impacts during the FIFA Arab Cup were common and a median of 1 head impact per game required an on-pitch medical assessment. Only 8% of the head impacts showed any video sign of potential concussion, and only 3% resulted in a concussion substitution. The medical on-pitch assessments appeared too short (<1 min) to allow an appropriate assessment of all head impacts, indicating a need for further evaluation. Further standardisation of the injury spotter’s role in football is recommended.
Introduction
The diagnosis and management of suspected and actual sports-related concussions are prominent and contentious issues in football. Concussions are reported to account for about 1–3% of all injuries in football with an incidence around 0.1–0.5/1000 hours of exposure (training and match) (Prien et al. Citation2018; Mooney et al. Citation2020; Ekstrand et al. Citation2020; Van Pelt et al. Citation2021; Horan et al. Citation2022).
Diagnosing and determining the severity of a brain injury on the pitch can be a challenge because clinical signs may not develop immediately (Vos et al. Citation2012; Levin and Diaz-Arrastia Citation2015Citation; National Institute for Health and Care Excellence, Feddermann-Demont et al. Citation2020). An immediate decision on whether to substitute a player is nevertheless important because players who continue to play following a concussion have an increased risk of further injury, such as second impact syndrome, or subsequent musculoskeletal injury (Fuller et al. Citation2017; Stovitz et al. Citation2017; McPherson et al. Citation2019).
The Fédération Internationale de Football Association (FIFA), the world governing body of football, recommends that if a sports-related concussion is suspected or diagnosed, the player should be removed from play immediately. The referee is allowed to stop a match for three minutes for the team physician to perform an on-field assessment, a second team physician may access in-match video replays to assist with decision-making on player removal, and the injured player is only allowed to continue play after authorization by the team physician.
Studies of the 2014 and 2018 FIFA World Cups™, using reviews of match video footage, reported poor adherence by team physicians to general concussion assessment recommendations in terms of frequency and duration of assessments and player removal (Cusimano et al. Citation2017; Premkumar et al. Citation2019).
Since 2018, FIFA has introduced further initiatives to improve concussion management in football using the credo ‘Suspect and Protect’. An updated FIFA Medical Concussion Protocol is available along with updated online education modules through a free online resource (fifamedicalnetwork.com Citation2022). An independent Concussion Assessment and Rehabilitation Service is offered at FIFA-organized tournaments. FIFA has, in collaboration with The International Football Association Board (IFAB), initiated a trial of additional permanent substitutions for actual or suspected concussions during matches as of January 2021 (theifab.com Citation2022). A dedicated ‘injury spotter’ focused on concussions assists the FIFA Medical Coordinator and team medical staff during matches at FIFA-organized tournaments.
The aim of this study is to review the frequency of head impacts, their characteristics, and the subsequent medical assessment during the FIFA Arab Cup 2021 TM.
Methods
This study was performed at the FIFA Arab Cup 2021, a football tournament including national men’s senior football teams from across the Arab world. During the final tournament, 16 teams competed in 32 matches played in Qatar between November 30th and December 18th, 2021.
The tournament followed protocol A of the IFAB trial of additional permanent concussion substitutions, where each team is allowed to use one concussion substitute in a match in addition to their normal substitutions (https://www.theifab.comCitation2022).
Prior to the tournament, all teams received a circular related to medical matters. Regarding concussions, the following was stated: ‘A player who experiences a suspected concussion during a match must undergo an examination by the team doctor. The referee may temporarily suspend play for up to three minutes whenever an incident of a suspected concussion occurs. The referee may only allow the player to continue playing with the authorisation of the team doctor, who must have evaluated the player and concluded that there is no suspicion of a concussive injury (using all available resources as deemed necessary, such as video replays and the assistance of the pitch-side medical teams). The team doctor will have the final decision based on their clinical examination, and it is expressly forbidden to allow a player to continue if a concussion is suspected.’
Recording of head impacts
We used injury spotters and subsequent video footage review to study head impacts. All matches were attended by one of six independent ‘injury spotters’, who registered head impacts on a standardized scoring form (Appendix 1). All injury spotters (AB, IB, JA, LG, MB, SHB) were qualified medical doctors with experience in football medicine and were also FIFA Medical Coordinators in other matches. The injury spotters were positioned on the tribune above the midline of the pitch with visibility of the entire pitch. If the injury spotter observed a head impact, they could review video footage on a large computer screen. The injury spotter could select one or more angles for review at the same time (up to four close views and four wide views) and rewind and forward at different speeds, including frame-to-frame views. The injury spotter was instructed to inform the Medical Coordinator at the pitch-side of all potential concussion incidents via radio. If deemed appropriate, the Medical Coordinator informed the respective team physician and offered them to review the video footage.
The definition of a head impact was modified from that used in a previous study (Abraham et al. Citation2019) to: ‘a direct or indirect head impact where a player is unable to immediately resume play following impact or subsequently shows potential concussion-related symptoms.’
Six video signs of potential concussion were used based on an international consensus of video signs of sports-related concussions (Davis et al. Citation2019): 1. Lying motionless, 2. Motor incoordination, 3. Impact seizure, 4. Tonic posturing, 5. No protective action – floppy, 6. Blank/vacant look. It was emphasised that ‘the presence of any one sign does not necessarily indicate that concussion has occurred, but rather, the presence of any of these signs indicates the need to remove the athlete from the playing arena for formal assessment and evaluation from a suitably qualified health practitioner.’ (Davis et al. Citation2019) If it was unclear whether a sign was present, it was scored as absent.
We recorded the observed injury mechanism, location of the head impact (Lawrence et al. Citation2014), presence and timing of the assessment, whether there was foul play and sanction, and if the player was substituted.
Medical assessment was defined as any apparent clinical examination, direct talk, or visual inspection while the medical person was in close range of the player. Referee actions and other assessments (teammates or opponents) were described in absence of a medical assessment. Stoppage time was registered from when the ball was out of play, or the game was halted by the referee, following the head impact until the match was restarted. Any communication between the injury spotter and the FIFA Medical Coordinator and between the Medical Coordinator and the team physician was noted.
After the tournament, broadcasted video footage of all matches was reviewed by a medical researcher (AS) who registered all head impacts, including potential head impacts missed by the injury spotters. Video footage of each head impact was cut into shorter clips and rescored, using the same standardized scoring that the injury spotter had used. Each head impact was then additionally scored by one injury spotter who had not been involved in that particular match and was blinded to the initial injury spotter’s and the researcher’s scoring. Any discrepancies between the video assessments were discussed between the researcher and the re-scorers. If there was no agreement, the case would be discussed by the whole group to decide on a final scoring. Official match reports were used to check whether a concussion substitution was used.
Ethics
Given no health-related personal data was included, and ethics exception was granted by the Swiss Association of Research Ethics Committees, Kanton Zürich (BASEC nr.: req-2022–00801).
Statistics
Simple descriptive statistics were applied using IBM SPSS Statistics for Windows (Version 27.0. Armonk, NY: IBM Corp) and presented according to distribution of the data.
Sample size estimation
No a priori sample size calculation was performed. All head impacts were included. Based on previous studies during football tournaments (Cusimano et al. Citation2017; Premkumar et al. Citation2019; Abraham et al. Citation2019) and the lower number of matches in the Arab Cup, we expected around 50–60 head impacts during the tournament, with around 10–20 receiving on-pitch assessment by team medical staff.
Results
A total of 81 head impacts were registered in 32 matches. Following video review, eight head impacts were removed: in five incidents, the player immediately continued playing following the head impact, and three incidents were determined to not include head impact, although the player behaved as if there was head impact. Fifteen head impacts were added during the video review of all the matches after the tournament. Thus, a total of 88 head impacts were included, with a median of 2 (IQR 1.5–4, range 0–7) head impacts per match. Medical assessment on-pitch was performed in 44 (50%) cases and at least once in 24 (75%) matches (median 1, IQR 0.5–2, range 0–6). Twelve players received a side-line medical assessment, and two players received further on-pitch medical assessments after returning to play (3 min 45s and 7 min 51s after the first head impact).
Communication and review
The FIFA Medical Coordinator was notified by the injury spotter in 97% of the registered head impacts (71 out of 73 initially recorded cases). In 32% of these (23 out of 71), the Medical Coordinator notified the respective team physician, and in 17% of these cases (4 of 23) the team physician chose to review the video footage.
Assessment duration
The median on-pitch medical assessment duration was 51 seconds (IQR 34–65s, range 19–262s). In total, 27 (64%) of the on-pitch assessments lasted less than 1 min, 12 (29%) between 1–2 mins, and 3 (7%) more than 2 mins. Two assessment times could not be visualised on the video footage. In 12 head impacts, there was an additional side-line assessment with a median assessment duration of 17s (IQR 10–33s, range 7–196s). One side-line assessment time was not visible on the video footage. In the 44 head impacts without a medical assessment, there appeared to be an assessment by the referee in 24 (55%) cases, with a median duration of 3.5s (IQR 3–7.5s, range 1–52s), and in 8 (18%) cases, there was a brief assessment by a teammate, in 7 (16%) cases by an opponent, and 1 (2%) case by both. In 16 (18%) head impacts, there was no assessment at all. The 88 head impacts resulted in a total of 6784 s (1 h 53 min 4s) stoppage time, with a median duration of 64.5s (IQR 32.5–101s, range 0–316s).
Video signs of concussion
The video review found seven head impacts with signs of potential concussion, although the injury spotters had initially only registered three head impacts with video signs. Six incidents showed one sign: three players were lying motionless (5–11s), two showed no protective action, and one showed motor incoordination. The player with two signs of potential concussion showed no protective action and was lying motionless.
Substitutions
The concussion substitution was used in 3 of 88 head impacts: one immediately following the head impact and two following initial return to play (one 6 min after the head impact and one at half time, 35 min after the head impact). Additionally, five players with a head impact were substituted in the same match following the normal procedure (one immediately and four later in the match). It is uncertain whether these substitutions were related to the head impact. Of the seven players who showed video signs of potential concussion, two were substituted using the concussion substitution (one immediately and one later), and two were substituted later in the match using normal substitutions.
Contact and foul play
The most common contact mechanism was head-to-head contact (), and the most common location of impact was the temporal region (). In 34 (40%) head impacts, the referee called foul play. In 22 cases, the foul was committed by the opponent, but no card was given, in 7 cases a yellow card was given, and in 2 cases a red card. In three cases, the foul was committed by the player suffering a head impact with no cards given.
Table 1. Overview of contact mechanisms of the head impacts.
Table 2. Overview of the location of the head impacts.
Discussion
In this study of 32 matches during the FIFA Arab Cup, the median number of head impacts was 2 per match. Half of these (n = 44) received medical on-pitch assessment and less than 10% showed video signs of concussion.
Head impacts
The frequency of head impacts per match in this study is slightly higher than that reported in other studies at international tournaments, which vary between 1.1 and 1.8 incidents per match (Cusimano et al. Citation2017; Premkumar et al. Citation2019; Abraham et al. Citation2019; Tarzi et al. Citation2020, Citation2020), but lower than what is reported at the league level with up to 4.5 per match (Beaudouin et al. Citation2021). These differences may not be related to the actual incidence, but instead to the head impact definitions that vary from relatively narrow definitions, such as ‘any event in which a player is unable to immediately resume play within 5 s after direct head contact’ (Tarzi et al. Citation2020), to more broad definitions, such as ‘any external contact with a player’s head (except regular heading) and consequently a visible biomechanical force transmitted to the brain.’ (Beaudouin et al. Citation2021) We modified a previously used definition (Abraham et al. Citation2019) to ensure the inclusion of cases with indirect head impact.
Medical assessment
Half of the players with head impacts received an on-pitch medical assessment, including all seven players with video signs of concussion. This is more than what has been reported for previous international tournaments (Premkumar et al. Citation2019; Abraham et al. Citation2019), indicating that referees at the Arab Cup might have had a lower threshold for allowing the medical team on the pitch or that the impacts possibly appeared more serious. The median medical assessment duration on-pitch was less than a minute, which appears to be consistent with previously reported assessment durations at FIFA World Cups (Cusimano et al. Citation2017; Premkumar et al. Citation2019). Side-line assessment duration was even shorter and resulted in a substitution in only 1 of 12 cases. It has been advocated that the 3-min allowance for on-pitch head injury assessments, which is widely used in football leagues internationally, should be increased as more time is needed for a thorough concussion assessment (Gouttebarge et al. Citation2022). An increase in the allowance may be unlikely to affect the assessment duration, as currently the medical staff use much less than three minutes, with 93% of the assessments in this study lasting less than 2 min. Even in the seven cases with video signs of potential concussion, the median assessment duration was less than 1 min. This indicates a need to explore the reasons for these fast assessments further and potentially initiate further education for team physicians on head injury assessment.
Video signs of concussion
Only 8% of the players with head impacts showed video signs of a potential concussion, and in six of these seven incidents there was only one sign. It is difficult to compare this finding with previous research as the number and choice of possible video signs vary between studies and between sports (Davis et al. Citation2019). Prior studies in football have reported that most head impacts had two or more video signs of concussions, although these studies used different signs, such as the player being slow to get up and clutching of the head (Abraham et al. Citation2019; Tarzi et al. Citation2020). We used the recent consensus on the most useful video signs for the identification of a possible sports-related concussion across sports, which recommends six video signs (Davis et al. Citation2019). It is uncertain whether the head impacts in this study were less severe or whether the fewer observed signs were a result of the difference in specific video signs used. For a direct comparison, the same video signs should therefore be used for future comparison. The most frequent sign seen in this study was lying motionless. This may be considered the least specific sign of the six concussion signs, as the player may just be resting in an attempt to recover from a head injury without a concussion. It is uncertain whether these players had lost consciousness.
Substitutions
The concussion substitution was only used once immediately following a head impact. This is less than expected and may represent either a hesitance by the medical staff to substitute a player or too high a threshold for suspecting a concussion. The latter seems more likely since two players were substituted using the concussion substitution shortly after returning to play, and only four of the seven players with video signs were substituted. The use of the additional permanent concussion substitute should be further investigated in a larger population. In general, the substitution of 9% of all players with a head impact and 14% of players who underwent medical assessment is higher than previously reported in men’s football, where the rate varies from 2–6% (Cusimano et al. Citation2017; Premkumar et al. Citation2019; Tarzi et al. Citation2020; Beaudouin et al. Citation2021).
Contact and foul play
Head-to-head contact was the most frequent mechanism overall, and accounted for almost half of the head impacts that led to an on-pitch assessment. This is consistent with a recent report of concussion injuries in French professional men’s football, where head-to-head contact also accounted for almost half of head impacts resulting in diagnosed concussions (Cassoudesalle et al. Citation2021). In German professional men’s football, arm-to-head contact was the most frequent head impact overall, whereas head-to-head contact was the most frequent when looking at head impacts leading to head injuries only (Beaudouin et al. Citation2021). Rules changes can be an effective way of preventing dangerous player actions. Following the introduction in 2006 of a red card with direct and intentional elbow to head impact, a considerable reduction of this head injury mechanism was shown (Beaudouin et al. Citation2019). Head-to-head impacts are potentially more challenging to influence through rule changes, and will instead likely require a higher focus on technical aspects for prevention. We encourage further research, focusing on situations leading to head-to-head contact, with a purpose of improving prevention strategies.
Head-to-ground contact following an initial head contact (double head impact) was not very common, but it was the most frequent contact leading to video signs of potential concussion in this study and may warrant further assessment.
There was no clear pattern of the location of head impact, although temporal and frontal head contact accounted for a higher proportion of head impacts leading to on-pitch assessment than other locations. A previous study in football used slightly different head locations and found the face in general to be the most frequent location (Beaudouin et al. Citation2021). The proportion of head impacts resulting in a foul play call was slightly higher than in other studies reporting on concussions and head injuries (Beaudouin et al. Citation2020; Cassoudesalle et al. Citation2021), whereas the rate of yellow cards was similar (Beaudouin et al. Citation2020).
The injury spotter
This is the first study in football including injury spotters. There were 15 (17%) head impacts added following video review of the full matches that were not registered by the injury spotters during the matches. None of these head impacts showed video signs of potential concussion in the subsequent review, but five underwent medical assessment on the pitch. The reasons for these omissions are unclear. Following reflection from the injury spotters, it may be that these head impacts were considered minor or indicate insufficient familiarity with the video system initially. The injury spotter role was new for most of the spotters, and they reported increased confidence with both the role and technical aspects at the venues as the tournament progressed. In comparison, a study in rugby union, where the injury spotter role is more established, has shown that 27% of head impacts had been missed in the side-line video review during matches when reviewing match footage again post-season (Gardner et al. Citation2018).
As recommended, communication between the injury spotter and the FIFA Medical Coordinator took place in almost all registered head impacts, whereas the Medical Coordinator notified the team physician in one-third of these cases. In four of the seven head impacts with video signs of potential concussion, the injury spotter did not register any signs. The video review is the main function of the injury spotter, so further training might be required to ensure signs of potential concussions are not missed during matches.
In the remaining three incidents, one player was immediately substituted, whereas two were not. The team physician reviewed the video footage in one of these incidents. The limited use of video review by the team physicians could suggest that further standardisation of the communication between the FIFA Medical Coordinator and the team physician is needed, including when a video review is recommended or required. In comparison, World Rugby, the governing body of Rugby Union, has a clear protocol for video reviews, with suspicious potential concussion incidents being reviewed by both the match-day doctor and the team doctor present (worldrugby.org Citation2022). With obvious signs of concussion, the player is permanently removed, whereas without clear video signs, an off-field assessment is required and has to be followed by an additional video review of the incident before allowing a player back into the match. In American Football (NFL), the injury spotters have the ability to call a mandatory medical timeout to stop the match and remove a player for a medical examination in specific cases, for example, where a player displays obvious signs of disorientation or is clearly unstable, or if the player is clearly avoiding medical assessment to stay in the match (nfl.com, Citation2022).
Similar approaches to defining required actions following obvious signs of concussion noticed by the injury spotter may also be appropriate in football. This would require further standardisation, training, and potential certification of the injury spotter role and closer cooperation with team doctors and referees.
Limitations
The generalisability of these findings is limited due to the relatively small sample size of one regional men’s senior tournament only. It has previously been shown that women have a higher risk of sports-related concussions (Van Pelt et al. Citation2021), but also that their management may be more thorough than in men (Tarzi et al. Citation2020). Further studies should focus on both men and women and extend across age groups, regions, and levels of play.
In this study, we did not have any medical information related to the head impacts, including diagnosis and subsequent management. Therefore, the severity of the head impacts is only indicated by the occurrence of medical assessment and presence of video signs. The presence of video signs does not necessarily indicate a concussion (Davis et al. Citation2019). More detailed medical information would be required to improve the understanding of the appropriateness of the assessments.
Conclusion
Head impacts were common during the FIFA Arab Cup. In general, two head impacts per match occurred with one resulting in an on-pitch medical assessment. The most common head impact mechanism was head-to-head contact. Only 8% of the head impacts had a video sign of potential concussion, and only 3% resulted in a concussion substitution. In general, the on-pitch medical assessments appeared too short (most <1 min) to allow an appropriate assessment of all head impacts, indicating a need for further evaluation of this important aspect of player safety. Further standardisation of the injury spotter’s role in football is recommended.
Contributorship
AS: Conceptualization, Methodology, Project Administration, Resources, Investigation, Data Curation, Formal Analysis, Validation, Writing – Original Draft Preparation. AB, IB, JA, LG, MB, SHB: Methodology, Investigation, Writing – Review & Editing. AM, KG: Methodology, Supervision, Writing – Review & Editing.
Supplemental Material
Download MS Word (121.6 KB)Disclosure statement
Three authors (AS, AM, KG) declare full time employment by FIFA, and 6 authors (AB, IB, JA, LG, MB, SHB) declare freelance employment by FIFA. All authors declare no other relevant financial or non-financial competing interests.
Supplementary Material
Supplemental data for this article can be accessed online at https://doi.org/10.1080/24733938.2022.2120629.
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