Heading in football: a systematic review of descriptors, definitions, and reporting methods used in heading incidence studies.

The primary objective of this systematic review was to describe the number and type of heading descriptors used in all published studies which report on heading incidence in football. The secondary objective was to detail the data collection and reporting methods used in the included studies to present heading incidence data. Eligible studies were identified through searches of five electronic databases: Ovid MEDLINE, CINAHL, EMBASE, SPORTDiscus, and Web of Science, using a combination of free-text keywords (inception to 12th September 2023). Manual searching of reference lists and retrieved systematic reviews was also performed. A descriptive overview and synthesis of the results is presented. From 1620 potentially eligible studies, 71 studies were included, with the following key findings: 1) only 61% of studies defined a header with even fewer (23%) providing an operational definition of a header within the methods; 2) important study and player demographic data including year and country were often not reported; 3) reported heading descriptors and their coding options varied greatly; 4) visual identification of headers was essential when inertial measurement units were used to collect heading incidence data; and 5) there was a lack of standardisation in the reporting methods used in heading incidence studies making comparison between studies challenging. To address these findings, the development of a standardised, internationally supported, operational definition of a header and related heading descriptors should be prioritised. Further recommendations include the development of minimum reporting criteria for heading incidence research.

Time-loss injuries and illnesses at the FIFA world cup Qatar 2022.

The study aimed to analyse incidence and characteristics of time-loss injuries and illnesses during the FIFA World Cup Qatar 2022. Of 838 male football players, 705 consented to participate. Team medical staff reported 82 time-loss injuries, corresponding to an injury event incidence of 5.6 injuries/1000 h of total exposure (95%CI 4.5 to 7.0 injuries/1000 h), with a median of 2 time-loss injury events per team (IQR, 1 to 4.5, range 0-7). The total injury burden was 103 (95% CI 61 to 152) days per 1000 h. Muscle/tendon injuries had the highest incidence of tissue types (48 cases, 3.3/1000 h (95% CI 2.5 to 4.4), and hamstring muscle injuries were the most frequent diagnosis (16 cases, incidence 1.1/1000 h, 95% CI 0.6 to 1.8). Match injury event incidence was 20.6/1000 h (15.0 to 27.7) and training injury event incidence was 2.1/1000 h (1.4 to 3.1). The majority (52%) of sudden-onset injuries were non-contact injuries, 40% direct contact and 8% indirect contact. We recorded 15 time-loss illnesses, corresponding to an illness event incidence of 1.1 per 1000 competition days, (95% CI: 0.6 to 1.8), and illness burden of 2.1 (1.0 to 3.4) days lost per 1000 competition days. The most common illness was respiratory infection (12 cases, 80%). Match injury event incidence was the lowest in any FIFA World Cup since injuries have been monitored.

Broadening our understanding of injury mechanisms to include at-risk situations: an overview of potential injuries at the FIFA men's World Cup Qatar 2022TM.

This study aims to examine and describe the characteristics of potential injury situations during a men's professional international tournament quantified using the FIFA Football Language Medical Coding. A prospective study was conducted during the 64 matches of the FIFA World Cup Qatar 2022™, during which five analysts recorded potential injury situations from video analysis. "Potential injuries" were recorded when players stayed down > 5 s and/or requested medical attention. Characteristics were further recorded for variables such as opponent's action and body location. In total, 720 potential injury situations were recorded of which 139 required medical assessment. The actions which resulted in most potential injuries were running while receiving a pass (74; 10%), while passing the ball (59; 8%), and while progressing with the ball (48; 7%). Duels and ball progression led to a potential injury in 3.0% and 2.1% of all similar actions in total. Both aerial duels and ball progression led to an potential injury that required medical assessment on 0.4% of occasions. Most potential injuries involved the head (149; 21%), foot (120; 17%), or lower leg (110; 15%) with most medical assessments of the head (35; 25%), lower leg (17; 12%), and knee (15; 11%) with a median duration of 47 seconds (IQR 28-61). This study provides a detailed overview of match circumstances that may have a higher injury risk. Although some variables within the coding system need improvement to increase reliability, its use will allow a more detailed comparison of differences between high-risk player actions leading to injury and those that do not, which can improve future prevention strategies.

Knee Cartilage Injuries in Football Players: Clinical Outcomes and Return to Sport After Surgical Treatment: A Systematic Review of the Literature.

OBJECTIVE: To systematically review the literature and analyze clinical outcomes and return-to-sport after surgical management of cartilage injuries in football players. DESIGN: A systematic literature review was performed in August 2023 on PubMed, WebOfScience, and Cochrane Library to collect studies on surgical strategies for cartilage lesions in football players. Methodological quality and risk of bias were assessed with the modified Coleman Methodology score and RoB2 and RoBANS2 tools. RESULTS: Fifteen studies on 409 football players (86% men, 14% women) were included: nine prospective and two retrospective case series, one randomized controlled trial, one prospective comparative study, one case report, and one survey. Bone marrow stimulation (BMS) techniques were the most documented. The lesion size influenced the treatment choice: debridement was used for small lesions (1.1 cm2), BMS, osteochondral autograft transplantation (OAT), matrix-assisted autologous chondrocytes transplantation (MACT), and scaffold-augmented BMS for small/mid-size lesions (2.2-3.0 cm2), and autologous chondrocytes implantation (ACI) for larger lesions (5.8 cm2). The surgical options yielded different results in terms of clinical outcome and return-to-sport, with fastest recovery for debridement and scaffold-augmented BMS. The current evidence is limited with large methodological quality variation (modified Coleman Methodology score 43.5/100) and a high risk of bias. CONCLUSIONS: Decision-making in cartilage injuries seems to privilege early return-to-sport, making debridement and microfractures the most used techniques. The lesion size influences the treatment choice. However, the current evidence is limited. Further studies are needed to confirm these findings and establish a case-based approach to treat cartilage injuries in football players based on the specific patient and lesion characteristics and the treatments' potential in terms of both return-to-sport and long-term results. LEVEL OF EVIDENCE: Systematic review, level IV.

The incidence and characteristics of heading in the 2019 FIFA Women's World Cup™.

INTRODUCTION: To quantify the incidence and characteristics of purposeful heading and other head impacts in professional women's football at the 2019 FIFA Women's World Cup™. METHODS: This cross-sectional cohort study analysed purposeful headers (uncontested and contested) and their characteristics (e.g. playing position, match situation, field location, and distance ball travelled), and other head impact events using video analysis. Total headers and head impact events, and incidence rate (IR) per 1000 match-hours were calculated for countries, positions, and other characteristics, such as location on the pitch. RESULTS: Purposeful headers accounted for 76% of all coded events (uncontested: 71%; contested: 29%), followed by attempted headers (21%), unintentional ball-head impacts (2%), and other head impacts (1%). Headers ranged from 0 to 22 per player, per match with a mean of 4.8 [±1.2]. Of all field positions, centrebacks had the highest heading rates and wingers the lowest. Strikers performed significantly more contested headers than any other position, and significantly less uncontested headers. Most headers occurred in the middle third (48%), from free game play (72%) and from long balls (>20 m) (68%). CONCLUSION: The findings of this study could assist the development of player heading risk profiles, sex-specific heading guidelines, and coaching practices.

Clinical examination tests for adductor- and pubic-related groin pain in athletes with longstanding groin pain: Inter-examiner reliability and prevalence of positive tests.

OBJECTIVES: Evaluate the inter-examiner reliability of pain provocation tests for hip adductors (palpation, stretch and resistance) and for pubic symphysis (palpation) in athletes with longstanding groin pain, and to determine the prevalence of positive tests. DESIGN: Inter-examiner reliability. SETTING: Orthopaedic and sports medicine hospital. PARTICIPANTS: Male athletes with longstanding groin pain. MAIN OUTCOME MEASURES: Inter-examiner reliability, absolute/positive/negative agreement, and the mean prevalence of positive tests for athletes classified with adductor- and pubic-related groin pain were calculated. RESULTS: We included 44 male athletes with longstanding groin pain (61 symptomatic sides). The mean age was 29 years (±6) and 70% were soccer players. Inter-examiner reliability was slight to moderate for adductor palpation (Cohen's Kappa statistic(κ)) = 0.02-0.54) and pubic palpation (κ = 0.37-0.45); moderate for the adductor stretch test (κ = 0.50), and fair to substantial for adductor resistance tests (κ = 0.22-0.74). Palpation pain was most prevalent at the adductor longus origin (94%) in athletes classified with adductor-related groin pain. CONCLUSION: The inter-examiner reliability of palpation tests varied from slight to moderate. The adductor stretch test had a moderate reliability, and adductor resistance tests a fair to substantial reliability. Adductor longus origin is the main site for palpation pain. Adductor palpation tests not related to the adductor longus have limited inter-examiner reliability. The adductor stretch test did not assist in classifying adductor-related groin pain.

Radiographic assessment of the pubic symphysis in elite male adolescent football players: Development and reliability of the Maturing Adolescent Pubic Symphysis (MAPS) classification.

INTRODUCTION: The pubic symphysis is susceptible to growth related injuries long after the adolescent growth spurt. Our study describes the radiographic maturation of the pubic symphysis on pelvic radiographs in adolescent football players and introduces the Maturing Adolescent Pubic Symphysis classification (MAPS classification). METHODS: Anteroposterior pelvic radiographs of 105 healthy adolescent male football players between 12 and 24 years old were used to develop the classification system. The radiological scoring of the symphyseal joint was developed over five rounds. The final MAPS classification items were scored in random order by two experienced readers, blinded to the age of the participant and to each other's scoring. The inter- and intra-rater reliability were examined using weighted kappa (κ). RESULTS: We developed a classification system with descriptive definitions and an accompanying pictorial atlas. The symphyseal joint was divided into three regions: the superior corners, and the upper and lower regions of the joint line. Inter-rater reliability was substantial to almost perfect: superior region: κ = 0.70 (95% CI 0.60---0.79), upper region of the joint line: κ = 0.89 (95% CI 0.86---0.92), lower region of the joint line: κ = 0.65 (95% CI 0.55---0.75). The intra-observer reliability showed similar results. CONCLUSION: The Maturing Adolescent Pubic Symphysis classification (MAPS classification) is a reliable descriptive classification of the radiographic maturation of the pubic symphysis joint in athletic males. The stages can provide a basis for understanding in clinical practice and will allow future research in this field.

Imaging-detected sports injuries and imaging-guided interventions in athletes during the 2022 FIFA football (soccer) World Cup.

OBJECTIVE: To describe imaging-detected musculoskeletal injuries and image-guided interventional procedures during the 2022 FIFA football (soccer) World Cup. MATERIALS AND METHODS: Retrospective analysis of all radiologic examinations performed in a central medical facility for athletes was performed by two board certified musculoskeletal radiologists. Data on muscle, tendon, ligament, cartilage, and bone injuries were collected according to imaging modality and body part. RESULTS: A total of 143 radiology examinations in 94 athletes were evaluated at the central medical facility. Magnetic resonance imaging (MRI) was the most utilized modality (67%), followed by radiography (12%), ultrasonography (9%), and computed tomography (4%). Image-guided interventions corresponded to 8% of all radiological examinations. There were 112 injuries described, affecting muscles and tendons (42%), ligaments (25%), cartilage (21%), and bone (12%). Most injured body parts were thigh (27%), foot and ankle (23%), knee (23%), and hip/groin (8%). Most injured players were within the age range of 24-35 years old (71%). CONCLUSION: Imaging was utilized in 11% of players who participated in the 2022 FIFA World Cup in Qatar. MRI was the most utilized modality, and acute muscle tears were the most diagnosed type of injury. Diagnostic imaging played an important role in diagnosing sports-related injuries during the 2022 FIFA World Cup.

Development of a Standardised System to Classify Injury-Inciting Circumstances in Football: the Football Injury Inciting Circumstances Classification System (FIICCS).

BACKGROUND: A comprehensive examination of the sport-specific activities and circumstances being performed at the time of injury is important to hypothesise mechanisms, develop prevention strategies and inform future investigations. Results reported in the literature are inconsistent because inciting activities are reported using different classifications. Hence the aim was to develop a standardised system for the reporting of inciting circumstances. METHODS: The system was developed using a modified Nominal Group Technique. The initial panel included 12 sports practitioners and researchers from four continents with respectively ≥ 5 years of experience working in professional football and/or conducting injury research. The process consisted of six phases: idea generation, two surveys, one online meeting and two confirmations. For answers to the closed questions, consensus was deemed achieved if ≥ 70% of respondents agreed. Open-ended answers were qualitatively analysed and then introduced in subsequent phases. RESULTS: Ten panellists completed the study. The risk of attrition bias was low. The developed system includes a comprehensive range of inciting circumstances across five domains: contact type, ball situation, physical activity, session details, contextual information. The system also distinguishes between a core set (essential reporting) and an optional set. The panel deemed all the domains to be important and easy to use both in football and in research environments. CONCLUSION: A system to classify inciting circumstances in football was developed. Given the extent of reporting inconsistency of inciting circumstances in the available literature, this can be used while further studies evaluate its reliability.

Clinical examination for athletes with inguinal-related groin pain: interexaminer reliability and prevalence of positive tests.

Objectives: To evaluate the interexaminer reliability of abdominal palpation and resistance tests in athletes with longstanding groin pain, and to identify the prevalence of positive clinical tests in athletes classified with inguinal-related groin pain. Methods: Male athletes (18-40 years) with longstanding groin pain were prospectively recruited between March 2019 and October 2020 at a sports medicine hospital. Two examiners performed history taking and standardised clinical examination (including abdominal palpation, scrotal invagination and abdominal resistance tests) blinded to each other's findings. Interexaminer reliability was calculated using Cohen's Kappa statistic (κ). Examiners classified groin pain using the Doha agreement meeting terminology. A differentiation was made between 'defined inguinal-related groin pain' (according to recommended definition criteria) and 'likely inguinal-related groin pain' (expert-based application of the Doha agreement classification when not all recommended criteria were present). Results: Overall, 44 athletes were included (61 symptomatic sides). Interexaminer reliability of inguinal palpation pain provocation tests varied from fair to moderate (κ=0.35-0.49). Reliability of posterior wall structure palpation (firm/soft) was slight (κ=0.01), and posterior wall bulging (yes/no) fair (κ=0.29). Reliability for abdominal resistance tests varied from fair to substantial (κ=0.35-0.72). In athletes classified with defined inguinal-related groin pain, recognisable injury pain on palpation during scrotal invagination when athletes performed a Valsalva manoeuvre was the most prevalent positive palpation test (79%). Abdominal resistance tests were positive in 21%-49% of these cases. Conclusion: The interexaminer reliability for clinical examination tests used to classify inguinal-related groin pain in athletes varies from slight to substantial. There is no single perfect clinical examination test. Trial registration number: NCT03842826.

Football-specific extension of the IOC consensus statement: methods for recording and reporting of epidemiological data on injury and illness in sport 2020.

Several sports have published consensus statements on methods and reporting of epidemiological studies concerning injuries and illnesses with football (soccer) producing one of the first guidelines. This football-specific consensus statement was published in 2006 and required an update to align with scientific developments in the field. The International Olympic Committee (IOC) recently released a sports-generic consensus statement outlining methods for recording and reporting epidemiological data on injury and illness in sport and encouraged the development of sport-specific extensions.The Fédération Internationale de Football Association Medical Scientific Advisory Board established a panel of 16 football medicine and/or science experts, two players and one coach. With a foundation in the IOC consensus statement, the panel performed literature reviews on each included subtopic and performed two rounds of voting prior to and during a 2-day consensus meeting. The panel agreed on 40 of 75 pre-meeting and 21 of 44 meeting voting statements, respectively. The methodology and definitions presented in this comprehensive football-specific extension should ensure more consistent study designs, data collection procedures and use of nomenclature in future epidemiological studies of football injuries and illnesses regardless of setting. It should facilitate comparisons across studies and pooling of data.

Inter-examiner reliability of the Doha agreement meeting classification system of groin pain in male athletes.

The Doha agreement classification is used to classify groin pain in athletes. We evaluated the inter-examiner reliability of this classification system. We prospectively recruited 48 male athletes (66 symptomatic sides) with groin pain between 10-2017 and 03-2020 at a sports medicine hospital in Qatar. Two examiners (23 and 10 years of clinical experience) performed history taking, and a standardized clinical examination blinded to each other's findings. Examiners classified groin pain using the Doha agreement terminology (adductor-, inguinal-, iliopsoas-, pubic-, hip-related groin pain, or other causes of groin pain). Multiple entities were ranked in order of perceived clinical importance. Each side was classified separately for bilateral groin pain. Inter-examiner reliability was calculated using Cohen's Kappa statistic (κ). Inter-examiner reliability was slight to moderate for adductor- (κ = 0.40), inguinal- (κ = 0.44), iliopsoas- (κ = 0.57), and pubic-related groin pain (κ = 0.12), substantial for hip-related groin pain (κ = 0.62), and slight for "other causes of groin pain" (κ = 0.13). Ranking entities in order of perceived clinical importance improved inter-examiner reliability for adductor-, inguinal-, and iliopsoas-related groin pain (κ = 0.52-0.65), but not for pubic (κ = 0.12), hip (κ = 0.51), and "other causes of groin pain" (κ = 0.03). For participants with unilateral groin pain classified with a single entity (n = 7), there was 100% agreement between the two examiners. Inter-examiner reliability of the Doha agreement meeting classification system varied from slight to substantial, depending on the clinical entity. Agreement between examiners was perfect when athletes were classified with a single clinical entity of groin pain, but lower when athletes were classified with multiple clinical entities.

Video review of the frequency and assessment of head impacts during the FIFA Arab Cup 2021TM.

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.

Injury-Inciting Activities in Male and Female Football Players: A Systematic Review.

BACKGROUND: A comprehensive examination of the sport-specific activities performed around the time of injury is important to hypothesise injury mechanisms, develop prevention strategies, improve management, and inform future investigations. The aim of this systematic review is to summarise the current literature describing the activities performed around the time of injury in football (soccer). METHODS: A systematic search was carried out in PubMed, Web of Science, SPORTDiscus, and OpenGrey. Studies were included if participants were football players aged > 13 years old and the activities performed at the time of injury were reported together with the total number of injuries. Risk of bias was assessed using an adapted version of checklists developed for prevalence studies. The activities reported by the studies were grouped to account for inconsistent reporting, and the proportion of each injury activity was calculated. Data were not meta-analysed due to high heterogeneity of methods and classification criteria. RESULTS: We included 64 studies reporting on 56,740 injuries in total. ACL injures were analysed by 12 studies, ankle/foot and knee injuries were analysed by five studies, thigh injuries were analysed by four studies, hip/groin injuries were analysed by three studies, and hamstring injuries were analysed by two studies. Five studies analysed more than one type of injury and 38 studies did not specify the type of injuries analysed. Running and kicking were the predominant activities leading to thigh and hamstring injuries. Changing direction and kicking were the predominant activities leading to hip and groin injuries and duels were the predominant activities leading to ankle injuries. Duels and pressing seem the predominant activities leading to ACL injuries, while results for other knee and general injuries were inconsistent. CONCLUSIONS: A qualitative summary of the activities performed at the time of injury has been reported. The results need to be interpreted carefully due to the risk of bias observed in the included studies. If we are to meaningfully progress our knowledge in this area, it is paramount that future research uses consistent methods to record and classify injuries and activities leading up to and performed at the time of injury. REGISTRATION: The protocol of this systematic review was registered at the Open Science Framework ( https://doi.org/10.17605/OSF.IO/U96KV ).

Digital body mapping of pain quality and distribution in athletes with longstanding groin pain.

Groin pain is common in athletes, but remains a challenge to diagnose. Self-reported pain quality distribution may facilitate differential diagnoses. We included 167 athletes with groin pain (≥ 4 weeks). All athletes received a standardized clinical examination. Athletes could choose multiple quality descriptors and intensity, and drew these on a digital body map. Overlay images were created to assess distribution and area visually. Intensity, duration, and qualities were compared between each clinical entity and multiple entities. Top three quality descriptors were electric (22%), pain (19%), and dull/aching (15%). There were no differences in the frequencies of quality descriptors (p = 0.893) between clinical entities. Areas of the mapped qualities were similar between the single clinical entities (χ2(3) = 0.143, p = 0.986) and independent of symptom duration (ρ = 0.004, p = 0.958). Despite a considerable overlap, the mapped pain qualities' distributions appear to differ visually between single clinical entities and align with the defined clinical entities of adductor-related, inguinal-related, and pubic-related groin. In iliopsoas-related groin pain, pain extended more medially. The overlap between the drawn areas underscores a challenge in differentiating groin pain classifications based only on self-reported pain. The prevalence of pain quality descriptors varied and individually do not associate with one particular clinical entity of groin pain.

A Delphi survey and international e-survey evaluating the Doha agreement meeting classification system in groin pain: Where are we 5 years later?

OBJECTIVES: To evaluate the adoption of and opinions on the Doha agreement meeting classification in groin pain in athletes. DESIGN: Delphi survey and e-survey. METHODS: A 2-round Delphi survey among the Doha agreement meeting expert group, and a separate international e-survey among clinicians who regularly assess athletes with groin pain. Clinical cases were presented, and participants provided their preferred terms for the diagnoses. All participants reported if they had adopted the Doha agreement meeting classification system in their practice. The Doha agreement meeting experts also shared opinions on amendments to the classification system, and reported their level of agreement with suggested statements. RESULTS: In the Delphi survey, the Doha agreement meeting experts (n = 21) reported 8-11 different terms for their primary diagnosis of each presented case. The Doha agreement meeting terminology was used by 50-67% of these experts. In the international e-survey (n = 51), 12-15 different diagnostic terms were reported in each clinical case, and 43-55% of clinicians used the Doha agreement meeting terminology. Adoption of the Doha agreement classification system in practice was reported by 73-82% of the Doha agreement meeting experts and 57-69% of the clinicians in the international e-survey. The experts suggested 49 statements regarding amendments to the classification system. Seven of these reached >75% agreement or disagreement. CONCLUSIONS: Five years after publication, the majority of the Doha agreement expert group and independent international clinicians report adopting the Doha agreement meeting classification system. There is still considerable heterogeneity in diagnostic terminology when clinical cases are presented, and disagreement on statements related to amendments of the current classification system.