Injury and illness epidemiology in professional Asian football: lower general incidence and burden but higher ACL and hamstring injury burden compared with Europe

Is hip adductor or abductor strength in healthy athletes associated with future groin pain? A systematic review and meta-analysis

OBJECTIVE

To systematically review the association between hip adduction and abduction strength, and adduction-to-abduction strength ratio in healthy athletes with the occurrence of future groin pain and time-loss groin injuries.

DESIGN

Systematic review with meta-analysis.

DATA SOURCES

PubMed, Web of Science, SPORTDiscus, PEDro, Embase, and Scopus.

ELIGIBILITY CRITERIA

Studies included had to (1) measure hip adductor or abductor strength in healthy athletes, (2) conduct a follow-up period to assess the occurrence of groin pain, (3) present strength data separately for participants who remained uninjured and those who suffered an injury and (4) use a prospective design. Risk of bias was assessed according to the Quality in Prognosis Studies tool. The certainty in the evidence appraised was measured using the Grading of Recommendations Assessment Development and Evaluation approach.

RESULTS

Thirteen prospective cohort studies met the inclusion criteria. Overall study risk of bias was rated as low. Players who remained uninjured had stronger adduction strength compared with players who subsequently suffered groin pain (standardised mean differences with 95% CIs (SMD=-0.5, 95% CI -0.92 to -0.09)) and time-loss groin pain (SMD=-0.68, 95% CI -1.31 to -0.06). Trivial effects were observed for abduction strength (groin pain SMD=0.03, 95% CI -0.11 to 0.17; time-loss SMD=-0.07, 95% CI -0.25 to 0.11) and adduction-to-abduction strength ratio (groin pain SMD=-0.02, 95% CI -0.55 to 0.51; time-loss SMD=-0.11, 95% CI -1.11 to 0.89). Age and diagnostic criteria were not significant moderators of the relationship between adductor strength and groin pain (p=0.72 and p=0.12).

CONCLUSION

There is a moderate effect of hip adductor strength on the occurrence of groin pain, while there is no relationship between either abductor strength or the ratio of adductor-to-abductor strength with the occurrence of groin pain.

PROSPERO REGISTRATION NUMBER

CRD42024548630.

Epidemiology of Injury and Illness in North American Professional Men's Soccer: Comparing COVID-19 Lockdown With Previous Seasons

BACKGROUND

After COVID-19 lockdown, studies across Europe and Asia examined its effect on professional soccer injury rates and severity; however, COVID-19 lockdown influence on injuries in United States men's professional soccer has not been evaluated.

HYPOTHESIS

Injury and illness rates during the 2020 season were higher than the previous 2 seasons.

STUDY DESIGN

Retrospective observational cohort study.

LEVEL OF EVIDENCE

Level 3.

METHODS

Medical staff from participating Major League Soccer (MLS) clubs entered injuries and athletic exposures during the study period into a league-wide electronic medical record system. Injury rate and severity were analyzed to examine differentials between the 2020 COVID season and historical controls.

RESULTS

The injury incidence rate per 1000 hours in 2020 was 10.8, ie, higher than 2018 (5.4) and 2019 (5.0) (P < 0.05). Training injury incidence rate increased in 2020 (8.9) compared with 2018 (2.5) and 2019 (2.6) (P < 0.05), whereas match injury incidence decreased in 2020 (18.3) compared with 2018 (24.0) and 2019 (22.7) (P < 0.05). Incidence rates of lower extremity muscle injuries (6.04), anterior cruciate ligament (ACL) injuries (0.17), and concussions (0.49) were also higher in 2020 compared with 2018 (2.5, 0.07, 0.27) and 2019 (2.36, 0.05, 0.22) (P < 0.05). More injured players in 2020 missed >90 days (17.7%) than in 2018 (10.2%) and 2019 (10.1%) (P < 0.05). Incidence of all non-COVID-19 illness was higher in 2020 (3.93) than 2018 (1.53) and 2019 (1.32) (P < 0.05).

CONCLUSIONS

During 2020, there were significant increases in incidence rates of overall injuries, training injuries, lower extremity muscular injuries, ACL injuries, concussions, and non-COVID illness, along with a higher percentage of players missing >90 days compared with the 2 previous seasons.

CLINICAL RELEVANCE

These results may help clarify the effects of future MLS inseason work stoppages and periods of restricted training.

Epidemiology and clinical characteristics of football injuries among academy players in Ghana

ABSTRACT

Objective

To determine the epidemiology and clinical characteristics of match and training injuries among football players at an academy in Ghana.

Methods

In this prospective observational study, we followed 80 youth and adult football players at a Ghanaian academy over a season of 39 weeks. Medical attention and time-loss injuries, as well as exposure times of players, were recorded by resident physiotherapists using a standardised injury surveillance form. The average weekly injury prevalence was calculated. Injury incidence rates were calculated per 1000 exposure hours, with significance indicated as 95% CIs.

Results

126 injuries were recorded during the season, with an average weekly injury prevalence of 4.1%. The overall injury incidence was 4.5 (95% CI 3.8 to 5.4) injuries per 1000 hours with under 14 (5.8 (3.3 to 10.2)/1000 hours) and under 18 players (5.7 (4.4 to 7.4)/1000 hours) recording a higher incidence than under 16 (5.1 (3.5 to 7.4)/1000 hours) and senior players (2.7 (1.9 to 3.9)/1000 hours). Match injury incidence was 13 times higher than training injury incidence (27.4 (21.5 to 34.9) vs 2.3 (1.8 to 3.0) injuries/1000 hours). Injuries to the lower extremities had the highest incidence (3.9 (2.1 to 7.2) injuries/1000 hours), with the knee being the most commonly injured site (n=30, 23.8%). The most common type of injury was a joint sprain (1.9 (1.5 to 2.5) injuries/1000 hours), and the most common injury mechanism was direct contact with another player (1.5 (1.1 to 2.0) injuries/1000 hours). Most injuries were moderately severe (2.0 (1.5 to 2.6) injuries/1000 hours).

Conclusion

Ghanaian academy football players have a substantial risk of sustaining injuries, especially among younger players. Further studies should focus on developing specific injury prevention programmes in under-researched football-playing populations.

Injury-inciting circumstances of sudden-onset hamstring injuries: video analyses of 63 match injuries in male professional football players in the Qatar Stars League (2013-2020)

OBJECTIVE

To describe and categorise the injury-inciting circumstances of sudden-onset hamstring match injuries in professional football players using systematic video analysis.

METHODS

Using a prospective injury surveillance database, all sudden-onset hamstring match injuries in male football players (18 years and older) from the Qatar Stars League between September 2013 and August 2020 were reviewed and cross-referenced with broadcasted match footage. Videos with a clear observable painful event (ie, a player grabbing their posterior thigh) were included. Nine investigators independently analysed all videos to describe and categorise injury-inciting circumstances. We used three main categories: playing situation (eg, time of injury), player action(s) (eg, running) and other considerations (eg, contact). Player action(s) and other considerations were not mutually exclusive.

RESULTS

We included 63 sudden-onset hamstring match injuries out of 295 registered injuries between 2013 and 2020. Running was involved in 86% of injuries. Hamstring injuries occurred primarily during acceleration of 0-10 m (24% of all injuries) and in general at different running distances (0-50 m) and speeds (slow to fast). At 0-10 m distance, indirect player-to-player contact and inadequate balance were involved in 53% and 67% of the cases, respectively. Pressing occurred in 46% of all injuries (injured player pressing opponent: 25%; being pressed by opponent: 21%) and frequently involved player-to-player contact (69% of the cases when the injured player was pressing vs 15% of the cases when the opponent was pressing) and inadequate balance (82% vs 50%, respectively). Other player actions that did not involve running (n=9, 14% of all injuries) were kicking (n=6) and jumping (n=3).

CONCLUSION

The injury-inciting circumstances of sudden-onset hamstring match injuries in football varied. The most common single-player action (24%) was acceleration over a distance of <10 m. Pressing, inadequate balance and indirect contact were frequently seen player actions. Injury prevention research in football should look beyond high-speed running as the leading risk factor for sudden-onset hamstring injuries.

Sports Injury Surveillance Systems: A Scoping Review of Practice and Methodologies

Background: Injury prevention/reduction strategies are driven by data collected through injury surveillance systems. The aim of this review was to describe injury surveillance systems that are used for ongoing surveillance in either a professional or amateur sporting environment. This was an update to a review done in 2015 to determine the gaps in injury surveillance. Methods: A systematic search process of five databases (MEDLINE, CINAHL, EMBASE, SCOPUS and ProQuest) was used to discover published research that presented methodological data about the injury surveillance systems implemented by clubs and organisations for ongoing surveillance. Inclusion criteria centred on the population under surveillance and the ongoing nature of that activity. Data extracted and summarised included the level of athlete under surveillance, the data collection mechanism and the personnel involved, the injury definitions applied and the date and country of origin to provide a comprehensive picture of the systems. Results: A total of 21 systems were documented as being used in ongoing injury surveillance, with 57% of these exclusively in the professional/elite landscapes and 33% at the amateur level. Surveillance systems cater for one sport per athlete entry so there is a gap in research for multi-sport athletes at the amateur level, especially where there is no early specialisation in a multi-sport participation environment. Conclusions: Research in this area will lead to a better understanding of subsequent injury risk for multi-sport athletes who have a higher athlete exposure than single-sport athletes.

Injury surveillance of head and neck injuries with a special focus on sport-related concussions: Eight seasons observational study in professional football in Qatar

OBJECTIVES

To describe the head and neck injuries with a focus on Sport-Related Concussion (SRC) in professional football in Qatar (PFQ) during eight consecutive seasons.

DESIGN

Prospective observational study.

METHODS

Seventeen PFQ teams were included over eight seasons (2013/14-2020/21) study. The injury data were collected by the respective clubs' medical staff using standardized (time-loss injuries) protocols.

RESULTS

Data were obtained from 119 teams' seasons resulting in a total of 87 head and neck injuries (1.8 % of the 4736 time-loss injuries). Head and neck injury rate was of 0.57 injury/squad-season (95%CI: 0.56-0.59), representing 0.12 injury/1000 h (95%CI: 0.09-0.14). Thirty-three concussions were recorded. The concussion rate was 0.25 injury/squad-season (95%CI: 0.23-0.26), representing 0.04 injury/1000 h (95%CI: 0.03-0.06). The concussion proportion of all head injuries was 31.7 % during the four initial seasons and 43.5 % during the following four seasons with a non-significant increase of 11.8 % (X2 = 1267, p = 0.26).

CONCLUSIONS

Injury rates in this cohort remain lower than comparable leagues elsewhere. Even though the incidence rate of SRC did not change significantly over the eight seasons, seasonal variations' trend may indicate that the medical staff are more aware of diagnosing head and neck injuries, including concussion.

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.

Impact of COVID-19 lockdown on injury risk in Qatar's professional football

OBJECTIVES

To compare injury incidence, burden and characteristics between the pre- and post-COVID-19 lockdown periods in Qatari professional football.

DESIGN

Prospective cohort study.

METHODS

Injury and exposure data for two post-COVID-19 lockdown periods [early post-lockdown period: short-term ~2 months (54 matches) and late post-lockdown period: long-term 8-months (183 matches)] were compared to the benchmark of the same periods from the three previous seasons (2017/18-2019/20).

RESULTS

We observed no difference in overall, training or match incidence between early post-lockdown period and the benchmark reference. However, this short-term period resulted in lower burden for overall- (RR 0.80, P < 0.0001), training- (RR 0.73, P < 0.0001) and match-injuries (RR 0.40, P < 0.0001) compared to the benchmark. During late post-lockdown period match injury incidence (RR 0.72, P = 0.0010) and match injury burden (RR 0.69, P < 0.001) were lower than the benchmark. In contrast, both overall- (RR 1.30, P < 0.001) and training-injury burden (RR 1.65, P < 0.001) were higher. A significant increase in adductor strains in both post-lockdown periods was observed.

CONCLUSIONS

Immediately after the COVID-19 lockdown (short-term effect), there was no difference in injury incidence but a lower injury burden compared to benchmark. Moreover, the rapid return to competition for the successive season (long-term effect) was associated with a higher overall- and training-injury burden, but a lower match-injury burden compared to the benchmark.

Epidemiology of Injuries in Professional and Amateur Football Men (Part II)

Background (1): Men's football is a physically demanding contact sport that involves intermittent bouts of sprinting, jogging, walking, jumping and changes of direction. The physical demands of the game vary by level of play (amateur club, sub-elite and open club or international), but injury rates at all levels of the men's football game remain the highest of all sports. Objective: The aim of this study is to conduct a systematic review of data from the epidemiological literature regarding the profile, severity and mechanisms of injuries and the frequency of recurrent injuries in professional and amateur football players. Methods (2): A systematic review, according to PRISMA guidelines, was performed up to June 2023 in the databases of PubMed, Web of Science, Google academic, Google scholar and the Diva portal. Twenty-seven studies that reported data on the type, severity, recurrence and mechanisms of injury in professional and amateur men's football were selected and analyzed. Two reviewers independently audited data and assessed the study quality using the additional and adapted version of the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement and the Newcastle Ottawa Scale (NOS) to assess risk of bias for the quality of external validity. Results (3): In professional male football players, the mean prevalence of muscle/tendon injuries was 39.78%, followed by joint and ligament injuries-21.13%, contusions-17.86%, and fractures-3.27%, and for amateur football players, the prevalence's were 44.56% (muscle/tendon injuries), 27.62% (joint and ligament injuries), 15.0% (contusions) and 3.05% (fracture), respectively. The frequency of traumatic injuries was higher in amateur football players (76.88%) compared to professional football players (64.16%), the situation being reversed in the case of overuse injuries: 27.62% in professional football players and 21.13% in amateur football players. Most contact injuries were found in professional footballers (50.70%), with non-contact injuries predominating in amateur footballers (54.04%). The analysis of the severity of injuries showed that moderate injuries dominated in the two categories of footballers; the severe injuries in amateur footballers exceeded the severe injuries recorded in professional footballers by 9.60%. Recurrence proportions showed an inverse relationship with the level of play, being higher in amateur footballers (16.66%) compared to professional footballers (15.25%). Conclusions (4): Football-related injuries have a significant impact on professional and amateur football players and their short- and long-term health status. Knowing the frequency of severe diagnoses, such as strains, tears and cramps of the thigh muscles, ankle ligament sprains and hip/groin muscle strain requires the establishment of adequate programs to prevent them, especially in amateur football players, who are more prone to serious injuries.

Epidemiology of Injuries in Men's Professional and Amateur Football (Part I)

Background (1): Football is the most popular sport among men, associated with a certain risk of injury, which leads to short- and long-term health consequences. While the injury profile of professional footballers is known, little is known about the injury profile of amateur footballers; amateur football is a major and diverse area, the development of which should be a priority for football associations around the world and UEFA. The aim of this study was to perform a systematic review of epidemiological literature data on injuries in professional and amateur football players belonging to certain leagues. Methods (2): A systematic review according to the PRISMA guidelines was performed until June 2023 in the databases PubMed, Web of Science, Google Academic, Google Scholar, and Diva portal. Forty-six studies reporting injury incidence in professional and amateur men's football were selected and analyzed. Two reviewers independently extracted data and assessed study quality using an adapted version of the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement and the Newcastle Ottawa Scale (NOS) to assess risk of bias for the quality of external validity. Results (3): The overall incidence of injuries in professional male football players was 7.75 ± 2.28, 95% confidence interval, injuries/1000 h of exposure and that of amateur football players was 7.98 ± 2.95, 95% confidence interval, injuries/1000 h of exposure. The incidence of match injuries (30.64 ± 10.28, 95% confidence interval, injuries/1000 exposure hours) was 7.71 times higher than the training injury incidence rate (3.97 ± 1.35, 95% confidence interval, injuries/1000 h) in professional football players and 5.45 times higher in amateurs (17.56 ± 6.15 vs. 3.22 ± 1.4, 95% confidence interval, injuries/1000 h). Aggregate lower extremity injuries had the highest prevalence in both categories of footballers, being 83.32 ± 4.85% in professional footballers and 80.4 ± 7.04% in amateur footballers: thigh, ankle, and knee injuries predominated. Conclusions (4): Professional and amateur football players are at substantial risk of injury, especially during matches that require the highest level of performance. Injury rates have implications for players, coaches, and sports medicine practitioners. Therefore, information on football injuries can help develop personalized injury risk mitigation strategies that could make football safer for both categories of football players. The current findings have implications for the management, monitoring, and design of training, competition, injury prevention, especially severe injury, and education programs for amateur football players.

Difference Asymmetry between Preferred Dominant and Non-Dominant Legs in Muscular Power and Balance among Sub-Elite Soccer Players in Qatar

The objective of this study was to determine and compare leg asymmetry between preferred dominant and non-dominant legs in muscular power and balance among sub-elite soccer (football) players in Qatar. Thirty-two professional local soccer players from the Qatar Stars League (Second Division) participated in the study (23.1 ± 6.1 years). They were classified according to their preferred dominant leg (preferred leg to kick the ball). Twenty-two players had a right dominant leg, and the remaining ten had a left dominant leg. Countermovement jump (CMJ) was used to measure unilateral and bilateral vertical jump performances. The Y-balance test (YBT) was used to assess dynamic balance. No significant differences were found between the dominant and non-dominant leg for CMJ flight height (p > 0.05; asymmetry index (AI) = 1.83 ± 11.46) or the relative and absolute reach distance derived from the YBT (p > 0.05; AI (relative) = −0.45 ± 9.68, AI (absolute) = −0.60 ± 12.3). Bilateral asymmetry in dynamic balance was not significant for any of the anterior, posteromedial, or the posterolateral reaching directions (p > 0.05). The selected football players demonstrated an acceptable level of leg symmetry for power and dynamic balance. These findings may prove helpful for the assessment and evaluation of talents and should help to develop and optimize training regimes.

Effectiveness of Conservative Interventions After Acute Hamstrings Injuries in Athletes: A Living Systematic Review

BACKGROUND

Hamstrings injuries are common in sports and the reinjury risk is high. Despite the extensive literature on hamstrings injuries, the effectiveness of the different conservative (i.e., non-surgical) interventions (i.e., modalities and doses) for the rehabilitation of athletes with acute hamstrings injuries is unclear.

OBJECTIVE

We aimed to compare the effects of different conservative interventions in time to return to sport (TRTS) and/or time to return to full training (TRFT) and reinjury-related outcomes after acute hamstrings injuries in athletes.

DATA SOURCES

We searched CINAHL, Cochrane Library, EMBASE, PubMed, Scopus, SPORTDiscus, and Web of Science databases up to 1 January, 2022, complemented with manual searches, prospective citation tracking, and consultation of external experts.

ELIGIBILITY CRITERIA

The eligibility criteria were multi-arm studies (randomized and non-randomized) that compared conservative treatments of acute hamstrings injuries in athletes.

DATA ANALYSIS

We summarized the characteristics of included studies and conservative interventions and analyzed data for main outcomes (TRTS, TRFT, and rate of reinjuries). The risk of bias was judged using the Cochrane tools. Quality and completeness of reporting of therapeutic exercise programs were appraised with the i-CONTENT tool and the certainty of evidence was judged using the GRADE framework. TRTS and TRFT were analyzed using mean differences and the risk of reinjury with relative risks.

RESULTS

Fourteen studies (12 randomized and two non-randomized) comprising 730 athletes (mostly men with ages between 14 and 49 years) from different sports were included. Nine randomized studies were judged at high risk and three at low risk of bias, and the two non-randomized studies were judged at critical risk of bias. Seven randomized studies compared exercise-based interventions (e.g., L-protocol vs C-protocol), one randomized study compared the use of low-level laser therapy, and three randomized and two non-randomized studies compared injections of platelet-rich plasma to placebo or no injection. These low-level laser therapy and platelet-rich plasma studies complemented their interventions with an exercise program. Only three studies were judged at low overall risk of ineffectiveness (i-CONTENT). No single intervention or combination of interventions proved superior in achieving a faster TRTS/TRFT or reducing the risk of reinjury. Only eccentric lengthening exercises showed limited evidence in allowing a shorter TRFT. The platelet-rich plasma treatment did not consistently reduce the TRFT or have any effect on the risk of new hamstrings injuries. The certainty of evidence was very low for all outcomes and comparisons.

CONCLUSIONS

Available evidence precludes the prioritization of a particular exercise-based intervention for athletes with acute hamstrings injuries, as different exercise-based interventions showed comparable effects on TRTS/TRFT and the risk of reinjuries. Available evidence also does not support the use of platelet-rich plasma or low-level laser therapy in clinical practice. The currently available literature is limited because of the risk of bias, risk of ineffectiveness of exercise protocols (as assessed with the i-CONTENT), and the lack of comparability across existing studies.

CLINICAL TRIAL REGISTRATION

PROSPERO CRD42021268499 and OSF ( https://osf.io/3k4u2/ ).

The Effects of Fixture Congestion on Injury in Professional Male Soccer: A Systematic Review

BACKGROUND

Professional soccer teams are often required to compete with ≤ 4 days recovery between matches. Since congested schedules reduce recovery time between matches, players are possibly at an increased injury risk. To date, there are no published systematic reviews on the impact of match congestion on injuries during professional male soccer.

OBJECTIVE

The aim of this systematic review was to assess the effects of fixture congestion on injuries during professional soccer.

METHODS

Following pre-registration on the Open Science Framework ( https://osf.io/86m25/ ) and conforming with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, systematic searches of four electronic databases (PubMed, Scopus, SPORTDiscus, and Web of Science) were conducted by independent researchers from inception until February 2022. Articles were included if they were original articles written in English and contained relevant time-loss injury data (injury that results in unavailability for training and/or match-play) for male professional soccer players regarding periods of fixture congestion (a minimum of two matches with ≤ 4 days recovery).

RESULTS

A total of eight articles were included in the review. Five studies identified that congested fixture schedules expose players to increased match injury incidence, although layoff duration was typically lower during congested periods. Two studies identified that training and overall injury incidence were higher during congested periods, with another study identifying a lower training injury incidence during congested periods.

CONCLUSION

Injury risk is, overall, increased during fixture-congested periods; however, the layoff duration is typically shorter. The current findings have implications for practitioners regarding the management, periodisation, monitoring, and design of training and competition schedules.

Impact of the COVID-19 Pandemic on Injury Incidence in Japanese Male Professional Soccer Players

Background

The outbreak of the 2019 novel coronavirus disease (COVID-19) led to an enforced quarantine period and limited training and match activities for athletes.

Purpose

To report the influence of the COVID-19 pandemic on the occurrence of injury in Japanese male professional soccer players.

Study Design

Descriptive epidemiology study.

Methods

In total, 21 clubs in the 2019 season and 28 clubs in the 2020 season from the Japan Professional Football League were prospectively followed, and 16 clubs in 2019 and 24 clubs in 2020 were analyzed in this study. Individual training, match exposure, and time-loss injuries were recorded using an electronic data capture system. The influence of COVID-19-related suspension during the 2020 season was retrospectively investigated via comparisons with the 2019 season.

Results

Total activity time included 114,001 hours in training and 16,339 hours in matches in 2019 and 170,798 hours in training and 25,411 hours in matches in 2020. The mean training interruption period caused by COVID-19 in 2020 was 39.9 days (range, 3-65 days), and the mean game-interruption period was 70.1 days (range, 58-79 days). The total number of injuries was 1495 in 2019 and 1701 in 2020. The overall injury incidence per 1000 hours of exposure was 5.7 in 2019 and 5.8 in 2020. The overall injury burden per 1000 hours of exposure was 155.5 days in 2019 and 130.2 days in 2020. The muscle injury incidence was highest in May 2020, immediately after the suspension period.

Conclusion

The overall injury incidence did not differ between 2019 and 2020. However, muscle injury incidence notably increased in the 2 months after the COVID-19 pandemic suspension period.

Pre-COVID-19 pandemic health-related behaviours in children (2018-2020) and association with being tested for SARS-CoV-2 and testing positive for SARS-CoV-2 (2020-2021): a retrospective cohort study using survey data linked with routine health data in Wales, UK

OBJECTIVES

Examine if pre-COVID-19 pandemic (prior March 2020) health-related behaviours during primary school are associated with (1) being tested for SARS-CoV-2 and (2) testing positive between 1 March 2020 and 31 August 2021.

DESIGN

Retrospective cohort study using an online cohort survey (January 2018 to February 2020) linked with routine PCR SARS-CoV-2 test results.

SETTING

Children attending primary schools in Wales (2018-2020), UK, who were part of the Health and Attainment of Pupils in a Primary Education Network (HAPPEN)_school network.

PARTICIPANTS

Complete linked records of eligible participants were obtained for n=7062 individuals. 39.1% (n=2764) were tested (age 10.6±0.9; 48.9% girls) and 8.1% (n=569) tested positive for SARS-CoV-2 (age 10.6±1.0; 54.5% girls).

MAIN OUTCOME MEASURES

Logistic regression of health-related behaviours and demographics were used to determine the ORs of factors associated with (1) being tested for SARS-CoV-2 and (2) testing positive for SARS-CoV-2.

RESULTS

Consuming sugary snacks (1-2 days/week OR=1.24, 95% CI 1.04 to 1.49; 5-6 days/week OR=1.31, 95% CI 1.07 to 1.61; reference 0 days), can swim 25 m (OR=1.21, 95% CI 1.06 to 1.39) and age (OR=1.25, 95% CI 1.16 to 1.35) were associated with an increased likelihood of being tested for SARS-CoV-2. Eating breakfast (OR=1.52, 95% CI 1.01 to 2.27), weekly physical activity ≥60 min (1-2 days OR=1.69, 95% CI 1.04 to 2.74; 3-4 days OR=1.76, 95% CI 1.10 to 2.82; reference 0 days), out-of-school club participation (OR=1.06, 95% CI 1.02 to 1.10), can ride a bike (OR=1.39, 95% CI 1.00 to 1.93), age (OR=1.16, 95% CI 1.05 to 1.28) and girls (OR=1.21, 95% CI 1.00 to 1.46) were associated with an increased likelihood of testing positive for SARS-CoV-2. Living in least deprived areas (quintile 4 OR=0.64, 95% CI 0.46 to 0.90; quintile 5 OR=0.64, 95% CI 0.46 to 0.89) compared with the most deprived (quintile 1) was associated with a decreased likelihood.

CONCLUSIONS

Associations may be related to parental health literacy and monitoring behaviours. Physically active behaviours may include coparticipation with others and exposure to SARS-CoV-2. A risk-versus-benefit approach must be considered in relation to promoting these health behaviours, given the importance of health-related behaviours such as childhood physical activity for development.

Recommencement of football competition with spectators during the active phase of the COVID-19 pandemic in a Middle Eastern country

BACKGROUND

With the global spread of COVID-19 infection caused by the severe acute respiratory syndrome coronavirus-2 virus (SARS-CoV-2), all the national and international sports events were ceased early in 2020. The sport activities have been reinstated since then, albeit without spectators. However, several governments have established a variety of risk-mitigation measures to gradually reintroduce the spectators to stadiums.

OBJECTIVES

We aimed to evaluate the implementation of a strict health protocol to ensure the resumption of professional football with spectators and to access its effectiveness in limiting the spread of COVID-19 infections within the community.

METHODS

This was a retrospective, observational study involving football players, match officials, local organizing committee members, working in close coordination, and over 16,000 spectators in the state of Qatar. We examined data from the Amir Cup final (December 18th, 2020), which was played under a strict protocol that included extensive reverse transcription-Polymerase chain reaction (RT-PCR) testing for players and match officials, as well as the utility of COVID-19 rapid antigen and antibody testings as screening tools for spectators to ensure their safe return to the stadiums. In addition, we reviewed the guidelines and protocols that were put in place to organize Qatar's Amir Cup Football Final, which drew over 16,000 spectators in the stadium.

RESULTS

A total of 16,171 spectators undertook rapid antigen and antibody tests for the Amir cup final (from December16-December18, 2020). Fifteen Spectators (n = 15) returned with a positive result for COVID-19 infection during the final event (positivity rate = 0.12%). All players underwent RT-PCR testing 48 h before the match. None of the players tested positive for COVID-19 infections. 1311 individuals reported having symptoms related to COVID-19 post final of Amir Cup. These spectators were tested for COVID-19 RT-PCR with an overall positivity rate (positive/reactive) to be 0.42% (69/16171).

CONCLUSION

This report shows a meagre incidence rate of COVID-19 infections during and post-Amir Cup football final. Based on the low infectivity rate reported during and post the Amir Cup, we propose that supervised and controlled resumption of football matches with spectators can be carried out safely following a strict testing and tracing protocol. Similar infection control policies can be replicated with a higher number of spectators.

Higher risk of ACL rupture in amateur football compared to professional football: 5-year results of the 'Anterior cruciate ligament-registry in German football'

PURPOSE

Anterior cruciate ligament (ACL) injuries are a common severe type of football injury at all levels of play. A football-specific ACL registry providing both prospective ACL injury data according to the skill level and risk factors for ACL injury is lacking in the literature.

METHODS

This study is based on the prospective 'ACL registry in German Football' implemented in the 2014-15 season. Professional (1st-3rd league), semi-professional (4th-6th league) and amateur leagues (7th league) were analysed regarding the incidence and risk factors for ACL injuries. Injuries were registered according to the direct reports of the injured players to the study office and double-checked via media analysis. After injury registration, the players received a standardised questionnaire. Data were analysed from the 2014-15 to the 2018-19 football season.

RESULTS

Overall, 958 ACL injuries were registered during the 5-year study period. The incidence of ACL injuries was highest in amateur football (0.074/1000 h football exposure) compared to professional (0.058/1000 h; p < 0.0001) and semi-professional football (0.043/1000 h; p < 0.0001). At all skill levels, match incidence (professional: 0.343; semi-professional: 0.249; amateur: 0.319) was significantly higher than training incidence (professional: 0.015; semi-professional: 0.004; amateur: 0.005). Major risk factors were previous ACL injury (mean: 23.3%), other knee injuries (mean: 19.3%) and move to a higher league (mean: 24.2%).

CONCLUSION

This sports-specific ACL registry provides detailed information on the incidence and risk factors for ACL injuries in football over five years. Risk factors are skill level, match exposure, move to a higher league and previous knee injury. These factors offer potential starting points for screening at-risk players and applying targeted prevention.

LEVEL OF EVIDENCE

II.

Motor Imagery and Action Observation as Appropriate Strategies for Home-Based Rehabilitation: A Mini-Review Focusing on Improving Physical Function in Orthopedic Patients

Dynamic stability of the knee and weakness of the extensor muscles are considered to be the most important functional limitations after anterior cruciate ligament (ACL) injury, probably due to changes at the central (cortical and corticospinal) level of motor control rather than at the peripheral level. Despite general technological advances, fewer contraindicative surgical procedures, and extensive postoperative rehabilitation, up to 65% of patients fail to return to their preinjury level of sports, and only half were able to return to competitive sport. Later, it becomes clear that current rehabilitation after knee surgery is not sufficient to address the functional limitations after ACL reconstruction even years after surgery. Therefore, new therapeutic tools targeting the central neural system, i.e., the higher centers of motor control, should be investigated and integrated into current rehabilitation practice. To improve motor performance when overt movement cannot be fully performed (e.g., due to pain, impaired motor control, and/or joint immobilization), several techniques have been developed to increase physical and mental activation without the need to perform overt movements. Among the most popular cognitive techniques used to increase physical performance are motor imagery and action observation practices. This review, which examines the available evidence, presents the underlying mechanisms of the efficacy of cognitive interventions and provides guidelines for their use at home.

Organising football matches with spectators during the COVID-19 pandemic: What can we learn from the Amir Cup Football Final of Qatar 2020? A call for action

The COVID-19 pandemic is a potential threat to professional sporting events when they eventually return to their usual calendar with spectators’ capacity of football stadiums usually exceeding 40,000 seats for important events. Hence, a strategy for safe return to sporting events is needed in the COVID-19 pandemic to pave the way towards a new normalcy. We reviewed the guidelines and policies implemented in organising the Amir Cup Football Final of Qatar, which hosted about 20,000 fans. The authors evaluated the publicly available information on the official websites of the various organizations involved and highlight the importance and usefulness of the Covid-19 Rapid Antigen Assay-Kit as a tool for screening sports spectators as well as the importance of a rigorous spectator pathway, including their accurate traceability thanks to a specific mobile phone application. Despite the surging of COVID-19 all over the world, a big football event with around 20,000 spectators in the same stadium has been hosted under strongly controlled preventative measures. These preventative measures show that it is possible to organize a major football match held outdoors, with the presence of thousands of supporters. This article is a call for action for the organisers of such events where the supporters’ health status is traceable to provide the scientific community with actual data of post-event infection rates. Therefore, it is suggested to consider using procedures like the ones described in the present article as a potential model in the process of organizing big sporting events with spectators in times of COVID-19.

Exercise-Based Training Strategies to Reduce the Incidence or Mitigate the Risk Factors of Anterior Cruciate Ligament Injury in Adult Football (Soccer) Players: A Systematic Review

Anterior cruciate ligament (ACL) is one of the most concerning injuries for football players. The aim of this review is to investigate the effects of exercise-based interventions targeting at reducing ACL injury rate or mitigating risk factors of ACL injury in adult football players. Following PRISMA guidelines, a systematic search was conducted in CINAHL, Cochrane Library, PubMed, Scopus, SPORTDiscus and Web of Science. Studies assessing the effect of exercise-based interventions in ACL injury incidence or modifiable risk factors in adult football players were included. 29 studies evaluating 4502 male and 1589 female players were included (15 RCT, 8 NRCT, 6 single-arm): 14 included warm-up, 7 resistance training, 4 mixed training, 3 balance, 1 core stability and 1 technique modification interventions. 6 out of 29 studies investigated the effect of interventions on ACL injury incidence, while the remaining 23 investigated their effect on risk factors. Only 21% and 13% studies evaluating risk of injury variables reported reliability measures and/or smallest worthwhile change data. Warm-up, core stability, balance and technique modification appear effective and feasible interventions to be included in football teams. However, the use of more ecologically valid tests and individually tailored interventions targeting specific ACL injury mechanisms are required.

The Effects of Ramadan Intermittent Fasting on Football Players and Implications for Domestic Football Leagues Over the Next Decade: A Systematic Review

BACKGROUND

The month of Ramadan will intersect with many football leagues' schedules over the next decade. Understanding the effects of Ramadan intermittent fasting (RIF) on physical performance is necessary to guide considerations for football players.

OBJECTIVE

The aim of this systematic review was to investigate the effects of RIF on physical factors in football players, and secondarily to consider the impact this may have on domestic club football leagues.

DESIGN

We conducted a systematic review using PRISMA guidelines.

DATA SOURCES

The online literature search utilized CINAHL (EBSCO), Cochrane Library, Embase.com, PubMed, and Scopus databases, and grey literature (all from database inception to May 2020).

STUDY SELECTION CRITERIA

Inclusion criteria consisted of studies of football (soccer) players, data collected during and/or around Ramadan, with injury and/or performance data provided.

RESULTS

The search yielded 11,226 studies. Twenty-two studies were included following a review of titles, abstracts, and full texts. Studies included some iteration of before-Ramadan, during-Ramadan, and after-Ramadan data. Common measures observed included ratings of perceived exertion (n = 8), sprinting (n = 7), sleep (n = 7), peak heart rate (n = 6), jumping (n = 5), Yo-Yo intermittent recovery tests (n = 4), Wingate anaerobic test (n = 3), field-specific tests (n = 3), and injury rates (n = 2). Decreased physical performance was commonly observed during late afternoon/evening testing (before breaking the fast) and with high-intensity exercise.

CONCLUSION

There appears to be a performance deficit related to RIF in Muslim football players. Studies should explore the effects of RIF on actual match demands. Due to the month of Ramadan emerging into league calendars, considerations should be made to accommodate Muslim football players who are intermittently fasting.

Impact of COVID-19 lockdown on the epidemiology of soccer muscle injuries in Italian Serie A professional football players

OBJECTIVE

To evaluate the influence that COVID-19 lockdown had on the epidemiology of soccer musculoskeletal injuries during 2019/2020 Italian First Football League Serie A in professional football players.

METHODS

In this retrospective study we analyzed records from media-based platform (Trasfermarkt, https://www.transfermarkt.com), describing the epidemiology of muscle injuries before and after the first COVID-19 lockdown phases in Italian professional football players. We also classified the severity of the injury as the number of missing days from participation.

RESULTS

We assessed a lower prevalence of post-lockdown injuries, albeit showing a similar injury rate at 1000 game-hours (pre-lockdown: 16.9 [13.0-20.7], post-lockdown: 15.5 [9.9-21.1]; RR: 0.92 [0.46-1.8]). All risk ratios for injury rate were not significantly different (p> .05) between pre- and post-lockdown.

CONCLUSIONS

The incidence of muscle injuries has not significantly changed after the first COVID-19 lockdown in Italian professional soccer players. Recognizing injury rates might be crucial for physician to evaluate adequate preventive measures.