Soccer injuries: a review on incidence and prevention

Apophyseal injuries in soccer players

Soccer is the most popular sport worldwide, and it is associated with high injury rates, with most of these injuries occurring in the lower extremities. Particularly, in youth soccer players with immature skeleton, the physeal plate is two to five times weaker than the surrounding fibrous structures, and therefore more vulnerable to injury. The physeal plate consists of epiphyses and apophyses, with the former serving as tendon attachment sites and being subject to traction forces. There are two types of apophyseal injury: (i) apophyseal avulsion, which consists of an acute separation across the physeal plate; and (ii) apophysitis, an injury caused by chronic and repetitive contraction of musculotendon unit, leading to inflammation of the growth plate cartilage. Apophyses of the hip and pelvis are the most commonly injured in youth soccer players, due to vigorous contractions during sports activities and the fact that they tend to fuse later compared to other epiphyseal centers, making them more susceptible to injury. In this review, we will discuss the anatomy of lower limb apophyses and clinical and imaging findings of apophyseal injuries in youth soccer players, as well as briefly review treatment options and complications.

Shoulder, arm, and elbow injuries in soccer players

Soccer is a global widespread sport with a high injury rate, mostly to the lower limbs. Even though upper limb injuries are much less common among soccer players, their prevalence has increased in recent years. This is due to several reasons/factors, including new and more aggressive tactics, a rise in the number of younger players with different levels of skeletal maturation, and due to the growth of women's participation in sports, which is in line with the fast progression in the degree of professionalism in women's soccer. This review paper aims to (a) describe the most common injuries in the shoulder, arm, and elbow in soccer players and (b) to show the role of different imaging modalities in diagnosing upper extremity injuries that can occur in this sport. Familiarity with these injuries and their mechanisms will lead to a quicker diagnosis and correct reporting of imaging of soccer players.

The role of playing position in soccer injury characteristics: evidence from sub-elite athletes

This study examines the association between playing position and injury characteristics among sub-elite male soccer players in South Africa. Using a cross-sectional survey, 223 players from four universities were assessed for injury prevalence, type, mechanism, and severity during the 2023 soccer season. Midfielders experienced the highest injury frequency (43.6%), followed by defenders (30.0%), forwards (17.9%), and goalkeepers (8.6%). Lower limb injuries were predominant across all positions (89.6%), with defenders (94.6%) and midfielders (95.1%) at greatest risk, while goalkeepers sustained a significant proportion of upper limb injuries (44.4%) due to their specialized role. Soft tissue injuries were most common among midfielders (78.0%) and defenders (67.6%), whereas goalkeepers reported higher rates of bone-related injuries (66.7%). Defensive actions, such as tackling, accounted for most injuries among defenders (56.8%), while aerial play contributed substantially to goalkeeper injuries. No statistically significant differences in injury severity were found across positions. These findings highlight the influence of playing position on injury characteristics and underscore the need for position-specific injury prevention strategies tailored to sub-elite soccer players.

Breaking new grounds in injury risk screening in soccer by deploying unsupervised learning with a special focus on sex and fatigue effects

In injury prevention, a vertical drop jump (DJ) is often used for screening athletes at risk for injury; however, the large variation in individual movement patterns might mask potentially relevant strategies when analysed on a group-based level. Two movement strategies are commonly discussed as predisposing athletes to ACL injuries: a deficient leg axis and increased leg stiffness during landing. This study investigated the individual movement pattern of 39 female and male competitive soccer players performing DJs at rest and after being fatigued. The joint angles were used to train a Kohonen self-organising map. Out of 19,596 input vectors, the SOM identified 700 unique postures. Visualising the movement trajectories and adding the latent parameters contact time, medial knee displacement (MKD) and knee abduction moment allow identification of zones with presumably increased injury risk and whether the individual movement patterns pass these zones. This information can be used, e.g., for individual screening and for feedback purposes. Additionally, an athlete's reaction to fatigue can be explored by comparing the rested and fatigued movement trajectories. The results highlight the ability of unsupervised learning to visualise movement patterns and to give further insight into an individual athlete's status without the necessity of a priori assumptions.

The FIFA 11+ injury prevention program reduces the incidence of lower extremity injuries in football players: a systematic review and meta-analysis

INTRODUCTION

The FIFA 11+ preventive program is designed to reduce the incidence of injury in sports. However, to gain a better understanding of its effect a systematic review and meta-analysis is needed. The current review aims to investigate the effect of the FIFA 11+ preventive program on injury incidence among male and female football players.

EVIDENCE ACQUISITION

This study used Scopus, PEDro, SPORTDiscus, and ProQuest as data sources. The initial selection of the studies, thorough assessment of the tile, and abstract. Extraction of the necessary study data was conducted by two independent researchers. Another two independent researchers assessed the quality of each included study against 39 used criteria. These criteria were combined from several popular quality assessment scales. The incidence of injuries measured in the lower extremities in football players after addressing the FIFA11+ was the outcome of interest.

EVIDENCE SYNTHESIS

This review included 12 trials of variable methodological quality from which 10 trials were selected for the meta-analysis. In general, the FIFA11+ program showed a significant reduction (P<0.1) in lower limb injury incidence for male young and adults in comparison to other programs. However, evidence of its effectiveness in females is lacking and more studies are needed.

CONCLUSIONS

The FIFA 11+ program is recommended to be used and implemented as a preventive strategy in males. Although, the result showed a significant reduction in injury incidence in adult males, heterogeneity between studies is high which may reduce the generalizability of the results. More studies are needed to investigate the effect of the FIFA 11+ program on females.

Acceleration profile of high-impact movements during young football games: a cross-sectional study involving healthy children

Repetitive high-impact movements cause growth-related injuries in children. This study aimed to identify which movements during junior football games require >6 G and >8 G acceleration and the frequency at which they occur. Additionally, we compared the components of acceleration among movements with >8 G resultant acceleration. Eleven young male footballers (10.7 ± 0.4 years) played 8-a-side games while wearing a tri-axial accelerometer on their upper back. The number and frequency of the movements that generated >6 G and >8 G were calculated, and each directive acceleration of the top five items was compared using two-way ANOVA to examine the effect of movements. The frequency of movements that generated >6 G and >8 G acceleration during junior football games was 8.70 case/min and 2.62 case/min, respectively. The top five >8 G movements were braking and pre-braking in shuffle, slowdown, stop, and run/jog items. The vertical acceleration was significantly greater during braking in shuffle than during slowdown, stop, and run/jog and also greater during stop and pre-braking in shuffle than during run/jog movement. This pilot study suggests that decelerated movements mainly provoked high-impact situations and may be key actions for preventing overuse injury in young footballers.

Kinesiology taping improves balance in football players with chronic ankle instability

INTRODUCTION

There appears to be no consensus on the usefulness of kinesiological tape in athletes with chronic ankle instability, therefore the aim of this study was to examine the effects of kinesiological tape on dynamic balance in football players with chronic ankle instability.

DESIGN, SETTING AND PARTICIPANTS

Football players who were eligible for this randomized controlled study were randomly assigned (allocation ratio 1:1:1) to one of three groups: experimental group, placebo group or control.

INTERVENTIONS

The experimental group received kinesiological tape bands applied to the peroneal and tibialis anterior muscles. The tape was applied for 48 h. The placebo group received a sham kinesiological tape application for the same duration, while the control group did not receive any tape.

OUTCOME MEASURES

Balance was assessed using the Y-Balance Test at baseline and 48 h later, with the kinesiological tape still in place, either sham or control.

RESULTS

A total of 69 (23 per group) semi-professional, male, players (22.1 ± 4.3 years) completed the study. There was a significant change in test performance over time (F1,66 = 9.425; P = 0.003; ηp2 = 0.125), with a significant interaction for group × time (F2,66 = 11.154; P < 0.001; ηp2 = 0.253). The kinesiological tape group improved the overall performance in the Y-balance test (85.2 ± 8.7% to 90.3 ± 8.4%, P < 0.001), while no differences were observed for the placebo and control groups.

CONCLUSION

The application of kinesiological tape for 48 h improved overall dynamic balance performance on the Y-balance test. These findings suggest that kinesiological tape could be a beneficial strategy for addressing the consequences of chronic ankle instability.

Mitigating the Risks of Lower Extremity Injuries in Soccer: A Comprehensive Analysis of Lower Extremity Injury Rates in Soccer Between 2014 and 2023

Objective

With events such as the Copa America 2024, the 2026 World Cup, and the arrival of European stars in Major League Soccer (MLS), the already observed and forecasted rise of soccer in the United States (US) seems to be an inevitable outcome. Although regular participation in soccer features several benefits, including increasing cardiovascular health, decreasing stress, and promoting interpersonal relationships, the risk of injury, as is the case in any sport, is ever present. Although many sports that are popular in America feature high rates of concussion, rotator cuff injuries, and general upper extremity injuries, soccer, being more strenuous on the lower-half of the body, features a disproportionate rate of lower extremity injuries. An analysis of the frequencies of these injuries, relative to factors such as year of injury, age, gender, location of injury, and diagnosis of injury, may help organizational bodies and soccer leagues implement new regulations regarding the usage of protective equipment and rules regarding gameplay. This study aims to illuminate these takeaways in an effort to better patient care outcomes in soccer-related injuries.

Method

This paper utilized the National Electronic Injury Surveillance System Database (NEISS) to compile data on lower extremity soccer-related injuries within the defined study period, 2014-2023. Inclusion criteria for the study involved all patients presenting to the emergency department (ED) within the study period and within the defined age range of 0 to 69 years old, with injuries sustained from or related to soccer. Using NEISS, trends were elucidated discriminating based on year of injury, sex, age group, location of injury, and diagnosis group of injury.

Results

Within the defined study period of 10 years, from 2014-2023, there were approximately 843,063 total soccer-related lower extremity injuries which presented to various EDs across the US. Regarding majorities, the most injuries were sustained in 2014 (12.84% of total injuries), most patients sustaining injuries were male (66.6% of all patients), and within the age range of 10-19 years old (63.24% of all patients), with the most instances occurring at age 15. Lower extremity injuries were most reported to be affecting the ankle with 306,797 incidences (36.39% of total injuries seen) and the most frequent diagnosis group was reported to be strains/sprains with 396,420 (47.02% of total injuries seen) total occurrences.

Conclusion

This study analyzes the incidents of lower extremity injuries while participating in soccer for the last 10 years, 2014-2023. The study provides new data regarding the frequency of injuries and their relative rate with respect to year of injury, age group, sex, location of injury, and diagnosis. The results of this study show injury majorities and trends which can be used to dictate changes in regulation regarding gameplay and the utilization of protective equipment in order to mitigate injuries related to the lower extremities in soccer.

Return to Play and Performance After Anterior Cruciate Ligament Reconstruction in Soccer Players: A Systematic Review of Recent Evidence

BACKGROUND

The available literature referring to the return to play (RTP) and performance after anterior cruciate ligament reconstruction (ACLR) has already been comprehensively summarized in team sports such as basketball or American Football. Therefore, in this sense, it is necessary to synthesize evidence relating to the mentioned parameters in soccer players who underwent ACLR.

OBJECTIVE

The aim of this systematic review was to examine RTP and the performance of soccer players after ACLR.

METHODS

Three electronic databases, Web of Science, Scopus, and PubMed, have been comprehensively searched to identify relevant articles. The following inclusion criteria were applied: (1) the sample of respondents consisted of soccer players irrespective of their age, sex, or level of competition; (2) athletes experienced anterior cruciate ligament injury and underwent ACLR; (3) outcomes estimated referred to the RTP, RTP at the preinjury level of competition, RTP time, performance, and career duration of soccer players; (4) studies were written in the English language. The methodological quality of the research was evaluated using the Methodological Index for Non-Randomized Studies (MINORS).

RESULTS

Databases searched yielded a total of 694 studies, of which 17 fulfilled the eligibility criteria and were included in the final analysis. These included 3657 soccer players, 2845 males and 812 females, who underwent ACLR and most commonly competed at the elite, national, amateur, and recreational levels. The results obtained indicated that 72% of soccer players successfully RTP and 53% RTP at the preinjury level of participation after ACLR. In addition, recent evidence provided in this literature review demonstrated that mean RTP time was 264 days or 8.7 months. Moreover, the majority of the studies unambiguously suggested that performance related to statistical aspects noticeably deteriorated compared with both the preinjury period and noninjured athletes. The mean career length of soccer players following ACL surgery was approximately between 4 and 5 years.

CONCLUSION

Although a high percentage of athletes RTP after a relatively short period of absence from the sports field compared with other sports closely related to soccer, ACLR negatively impacts soccer players' performance and career duration.

Knee osteoarthritis in the former elite football players and the ordinary population: a comparative cross-sectional study

A cross-sectional case-control study compared subjective knee function, quality of life and radiographic knee osteoarthritis (OA) between 45 former elite football players and an age-matched general male population. Participants completed the Knee OA Outcome Score (KOOS), a quality-of-life assessment (EQ-5D-3 L) and standing knee radiographs. Among the players, 24 (53%) sustained at least one moderate or severe knee injury, while 21 (47%) did not recall any injury. Players with previous knee injuries reported significantly lower knee-specific and general quality-of-life scores (KOOS 69; EQ-5D-3 L 0.69 (0.2)) compared to the non-injured players (KOOS 92; EQ-5D-3 L 0.81 (0.2)) or the control population (KOOS 90; EQ-5D-3 L 0.83 (0.2)). The injured knees had higher radiographic OA Kellgren-Lawrence (KL) scale grades 1.7 (1.3) than the knees of the non-injured players 0.8 (1.0) or the control knees 0.8 (1.0)Former elite football players who had previously sustained a moderate or severe knee injury reported inferior knee function and lower quality of life. Injured knees had higher levels of radiographic OA. Non-injured players reported similar knee and general function and their knees had similar grades of OA to those in the control group. The defining moment for long-term knee preservation in football should be injury prevention protocols.

The Effects of Motor Imagery on Static and Dynamic Balance and on the Fear of Re-Injury in Professional Football Players with Grade II Ankle Sprains

Lateral ankle sprains are one of the most frequent athletic injuries in football, causing deficits in balance. Motor Imagery (MI) has been successively included in sports rehabilitation as a complementary therapeutic intervention. The aim of the present study was to explore the effects of MI on static and dynamic balance and on the fear of re-injury in professional football players with Grade II ankle sprains. Fifty-eight participants were randomly allocated into two groups: First-MI group (n = 29) and second-Placebo group (n = 29), and they each received six intervention sessions. The first MI group received MI guidance in addition to the balance training program, while the second Placebo group received only relaxation guidance. One-way ANOVA showed statistically significant results for all variables, both before and 4 weeks after the interventions for both groups. The t-test showed statistically significant differences between the two groups for static balance for the right lower extremity (t = 3.25, S (two-tailed) = 0.002, p < 0.05) and also for heart rate (final value) in all time phases. Further research is needed in order to establish MI interventions in sports trauma recovery using stronger MI treatments in combination with psychophysiological factors associated with sports rehabilitation.

Towards a more individualised assessment of post-training fatigue in young footballers

Despite improvements in training load and fatigue monitoring, fatigue status may adversely affect intrinsic risk factors, particularly in young footballers. This study aimed to better individualise the fatigue effects of a 75-min football training session in young elite male players. Eighteen players (15.6 ± 1.7 years) completed a test battery before and after a football training session. Assessments included capillary blood samples (HCO3 -, lactate, pH), subjective ratings of muscle soreness and fatigue. Functional tests included 30 m field sprint, laboratory drop jump (DJ) and horizontal force-velocity (H-FvP). The k-means method was applied to the first two dimensions of principal component analysis of changes in the H-FvP and DJ tests. Football training resulted in significant physiological changes and functional impairments, in particular an increase in interlimb asymmetry in the DJ test. No significant fatigue effect was found on the H-FvP test data. However, confirming the interest of combining the two tests, cluster analysis revealed two subgroups: In the H-FvP test, Cluster 1 decreased inV ‾ 0 (p < 0.001) andP ‾ max (p < 0.01), while Cluster 2 decreased inF ‾ 0 (p < 0.001). In the DJ test, Cluster 1 decreased in mean velocity (p < 0.01), relative mean and maximum power (p < 0.01) during push-off, while Cluster 2 decreased in relative mean push-off force (p < 0.01) and increased in interlimb asymmetry during braking (p < 0.01). This study highlights the contribution and complementarity of the H-FvP and DJ tests to improve individual screening for fatigue-related functional changes in footballers. Extrapolated values from the H-FvP test led to the identification of two subgroups with opposite fatigue profiles. One subgroup showed increased interlimb asymmetry in DJ, indicating an increased risk of injury with fatigue. These findings highlight the need for individualised fatigue assessment in young footballers.

Exploring Injury Prevention Strategies for Futsal Players: A Systematic Review

Futsal carries a high risk of injury for players. This systematic review aimed to assess the existing literature on injury prevention strategies for futsal players. The literature was searched using PubMed, Web of Science, and Scopus databases from inception to 20 March 2024. Relevant articles were searched using the terms "futsal" AND "injury" AND "prevention". Fourteen studies were included in the review. The review identified several injury prevention strategies with potential benefits for futsal players. Structured warm-up routines were shown to improve balance and eccentric strength and to reduce total, acute, and lower limb injuries. Proprioceptive training methods were suggested to improve joint stability and landing mechanics, which may reduce the risk of injury. Furthermore, multicomponent methods that include components such as core stability and flexibility have shown potential for reducing injury rates in futsal players. Finally, by reducing fatigue and improving movement control, strength training procedures designed to correct muscular imbalances may improve performance, which may ultimately minimize the risk of injury. This systematic review demonstrates the potential benefits of different injury prevention strategies for futsal players. The combination of several strategies, such as proprioceptive training, multicomponent programs, warm-up routines, and strength training specifically designed to address muscular imbalances, appears promising.

Interpersonal Coordination between Female Soccer Players: Leader-Follower Roles within a Collision-Avoidance Task

Background/Purpose

Return to sport decision-making may be improved by assessing an athlete's ability to coordinate movement with opponents in sport. The purpose was to investigate whether previous injuries associated with female soccer players' interpersonal coordination during a collision avoidance task. The authors hypothesized that external perturbations would disrupt the strength and stability of coordinated movement, and that individuals with a history of injury would be less likely to recover coordinated movement.

Study Design

Cross-Sectional.

Methods

Nine female athletes with a history of lower extremity injuries and nine without injuries were paired into dyads. Each dyad completed twenty trials of an externally paced collision-avoidance agility task with an unanticipated perturbation. Participant trajectories were digitized and analyzed using cross-recurrence quantification analysis (CRQA) to determine the strength and stability of interpersonal coordination dynamics. Trials in which participants with injury history assumed leader or follower roles within each dyad were then used to study how dyadic coordination varied across task stages (early, perturbation, and late) using linear mixed effect models. Cohen's d effect sizes were calculated to demonstrate magnitude of differences. In exploratory analysis, psychological readiness (i.e., self-reported knee functioning, fear of injury, and risk-taking propensity) was evaluated for their association with leader-follower status.

Results

Perturbation disrupted the strength (R2=0.65, p<0.001, early=49.7±1.7, perturbation=41.1±1.7, d=0.39) and stability (R2=0.71, p < 0.001, early=65.0±1.6, perturbation=58.0±1.7, d=0.38) of interpersonal coordination regardless of leader-follower status. Individuals with injury history failed to restore coordination after the perturbation compared to control participants (injury=44.2.0±2.1, control=50.8±2.6, d=0.39). Neither demographic nor psychological measures were associated with leader-follower roles (B=0.039, p=0.224).

Conclusion

Individuals with a history of lower extremity injury may have a diminished ability to adapt interpersonal coordination to perturbations, possibly contributing to a higher risk of re-injury.

Level of Evidence

3.

Ultrasound Imaging in Football Players with Previous Multiple Ankle Sprains: Keeping a Close Eye on Superior Ankle Retinaculum

The superior extensor ankle retinaculum (SEAR), a transversely fascial thickening positioned above the tibia-talar joint, serves as a crucial anatomical structure in ankle stability. The purpose of this study was to measure and compare by ultrasound (US) imaging the bilateral thickness and echogenicity of SEAR in football players with previous multiple ankle sprains (group 1) and healthy volunteers (group 2). A cross-sectional study was performed using ultrasound imaging to measure longitudinal and transversal axes using a new protocol in a sample of 50 subjects: 25 football players with previous multiple ankle sprains and 25 healthy subjects. The findings for SEAR thickness revealed statistically significant differences for both axes (p = 0.0011 and p = 0.0032) between the healthy side and the previously sprained side, and with the corresponding side of group 2 (p = 0.003 and p = 0.004). Moreover, in group 1, regarding the ROI echogenicity, a statistically significant difference was found between the sides (p = 0.0378). These findings suggest that the football players with previous ankle sprains showed a thicker and inhomogeneous SEAR on the sprain side, unveiling a remodeling of this structure compared to the other side and to the healthy volunteers. In these athletes, during US examination, one needs to keep "a US eye" on side-to-side SEAR comparisons.

The Role of MRI in Groin Pain Syndrome in Athletes

Groin pain syndrome (GPS) is one of the most frequent injuries in competitive sports. Stresses generated in the lower limbs by quick turns and accelerations, such as in soccer, basketball or hockey, can produce localized regions of increased forces, resulting in anatomical lesions. The differential diagnoses are numerous and comprise articular, extra-articular, muscular, tendinous and visceral clinical conditions and a correct diagnosis is crucial if treatment is to be efficient. MRI is the gold standard of diagnostic techniques, especially when an alternative pathology needs to be excluded and/or other imaging techniques such as ultrasound or radiography do not lead to a diagnosis. This paper, based on the current literature, gives a comprehensive review of the anatomy of the pubic region and of the typical MRI findings in those affected by GPS. Many clinical conditions causing GPS can be investigated by MRI within appropriate protocols. However, MRI shows limits in reliability in the investigation of inguinal and femoral hernias and therefore is not the imaging technique of choice for studying these clinical conditions.

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.

Development and Predictive Validation of the Brazilian Adductor Performance Test for Estimating the Chance of Hip Adductor Injuries in Elite Soccer Athletes

PURPOSE

To develop and validate the Brazilian Adductor Performance Test (BAPT) for predicting hip adductor muscle injuries in elite soccer athletes.

METHODS

A total of 108 soccer athletes were assessed, followed up for 3 months, and evaluated for a history of adductor injury 6 months before BAPT evaluation. The Shapiro-Wilk test was used as the normality test. The Mann-Whitney U test was used to compare BAPT scores between injured and uninjured athletes. Binary logistic regression was performed to identify the athletes' chances of injury based on their BAPT scores. A receiver operating characteristic curve was used to determine the cutoff point for the number of repetitions in the BAPT and Spearman bivariate correlation and identify factors potentially related to the test score. Furthermore, the intraclass correlation coefficient was used to determine interexaminer agreement. The level of significance was set at 95%.

RESULTS

The BAPT scores for hip adductor injury history did not differ significantly (P = .08). A significant deficit was identified in the BAPT scores of the injured athletes at the 3-month follow-up (P = .001). The cutoff point identified was 33 repetitions. Low BAPT scores increased the chance of injury by 20% (odds ratio, 1.20%; P = .001). The interexaminer agreement was .96 (P = .001).

CONCLUSION

BAPT can be used to identify athletes most likely to sustain hip adductor muscle injuries, indirectly reducing the rate of this injury in soccer clubs.

Efficacy of Electromyographic Biofeedback in Muscle Recovery after Meniscectomy in Soccer Players

Electromyographic biofeedback (EMG-BF) is a therapeutic technique that has been used successfully in the rehabilitation of injuries. Although it has been applied to athletes, its use in this field is not very widespread. The objective of this study is to analyze its effectiveness in the recovery of electromyographic activity of the quadriceps after meniscectomy, evaluated through isometric contraction of the vastus lateralis. The sample comprised ten professional footballers in the Spanish League (2nd Division A) who had previously suffered a meniscus injury in their knee and had undergone a meniscectomy. The intervention consisted of EMG-BF treatment lasting between 6 and 10 sessions. The electromyographic signal was recorded using a Thought Technology ProComp Infiniti 8-channel biofeedback unit with a sampling rate of 2048 samples/second. For each session, a within-subject ABA design of 6 or 10 trials per session was used, with three pre- and three post-measures, which determined the gain for each session. The results indicated (1) improvements in all cases, (2) EMG-BF was effective, (3) the working model was statistically significant with an explained variance of between 67% and 75%, and (4) the generalizability analysis showed that the results are reliable and generalizable. The results indicate that EMG-BF is effective in neuromuscular rehabilitation after this type of intervention.

Epidemiology of Campus Football Injuries in Ningxia, China: Occurrence, Causes, and Management

Objective

By 2022, the Chinese government intends to have more than 30 million primary-, middle- and high-school children and adolescents regularly participate in campus football. In contrast, epidemiology of campus football injuries is completely missing. The goal of this descriptive epidemiological study was to determine the current state of campus football injuries and then to recommend appropriate prevention and management strategies.

Methods

This retrospective epidemiological study conducted a survey of students, physical education and football teachers in primary, middle and high schools in the Ningxia Autonomous Region to determine the campus football injuries that occurred throughout the preceding 12-month period. The survey comprised questions on demographic characteristics, the occurrence, causes, and management of campus football injuries.

Results

A total of 1,285 students and 200 teachers returned eligible surveys. 25.7% of students had encountered injury accidents while participating in campus football activities. 31.3% of high school students, 23.8% of middle school students, and 19.2% of primary school students have sustained injuries. Football competition, accounting for 45.4% of all injuries, is the leading cause of injury. Football class teaching, which accounted for 3.0% of all injuries, had the lowest injury rate of any campus football activity. Students and teachers reported that a lack of safety awareness and injury prevention education were the primary causes of injuries. Only 18.7% and 11.4% of students are familiar with first aid basics and cardiopulmonary resuscitation, respectively. 10.6% and 7.5% of students lack any first aid basics and skills, respectively. 43.9% of students lack insurance coverage for athletic injuries. 62.5% and 38.5% of teachers reported that schools lack first aid training and an emergency plan for injuries, respectively.

Conclusion

Students in Ningxia's campus football programs have a high injury risk. Injury prevention and management strategies lag significantly behind the mainstream nationwide promotion of campus football in China.

Epidemiology of soccer injuries in Korea women national team for 5 years

The purpose of this study was to analyze the characteristics of injuries in female national soccer players. The injuries data were recorded by Korea Football Association medical staff using the Daily Medical Report provided by the Asian Football Confederation during a total 21 training camps and friendly and official matches from January 2014 to December 2018. A total of 483 players in the national team training camps and matches participated in the study, of which 377 players experienced more than one injury. Sports injuries accounted for 89% of the total 1,019 injuries; general diseases accounted for the remaining 11%. The number of injuries per 1,000 exposure hours was higher in matches than in training sessions. Most injuries that occurred during training and matches involved the lower extremities (79%). The most common injury diagnosed during training and matches was muscle rigidity (45%), followed by contusions/hematomas/bruises (22%) and sprain (15%). The largest proportions of injuries in terms of absence from soccer play were minimal injury (67%), followed by mild (29%), moderate (3.5%), and severe (1%). As conclusion, the characteristics of injuries during training sessions and matches were different. Rehabilitation and injury prevention programs need to developed for female soccer players to improve the players’ performance.

Neuromuscular control of the lower extremities can be better enhanced by applying ankle taping and kinesiological taping rather than elastic bandaging: a randomized control study in amateur soccer players

[Purpose] This study evaluated the effects of ankle elastic bandaging, taping, and kinesiology taping on the neuromuscular control of the lower extremities before and after their application and after exercise in soccer athletes. [Participants and Methods] Fifty-five amateur soccer players were randomly divided into four research sub-groups either receiving bandaging (n=15), taping (n=15), and kinesiology taping (n=15) on their ankle or serving as controls (n=10). The dynamic stability of the non-dominant limb was assessed through the star excursion balance test (SEBT) in three research conditions: a) before sports taping application, b) after the application, and c) after a 15 min laboratory simulation of soccer activities. [Results] Taping and kinesiology taping improved the dynamic stabilization of the lower limb more statistically significantly than bandaging. The addition of exercise significantly improved the SEBT results in the taping and kinesiology taping more than the bandaging and control groups. [Conclusion] Exercise activates the proprioceptive mechanisms of the lower limb and improves its neuromuscular control. This functional improvement of the lower limb appears to be enhanced after ankle taping and kinesiology taping compared with elastic bandaging and controls.

Anterior ankle impingment syndrome is less frequent, but associated with a longer absence and higher re-injury rate compared to posterior syndrome: a prospective cohort study of 6754 male professional soccer players

PURPOSE

To study the epidemiology and return to play characteristics of anterior and posterior ankle impingement syndromes (AAIS and PAIS) over 18 consecutive seasons in male professional soccer players.

METHODS

Between the 2001-2002 and 2018-2019 seasons, 120 European soccer teams were followed prospectively for various seasons. Time loss injuries and player exposures were recorded individually in 6754 unique players. Injury incidence and burden were reported as the number of injuries and days absence per 1000 h with 95% confidence intervals (CIs). Injury severity was reported as median absence in days with the interquartile range (IQR).

RESULTS

Out of 25,462 reported injuries, 93 (0.4%) were diagnosed as AAIS (38%) or PAIS (62%) in 77 players. AAIS and PAIS were similar regarding injury characteristics except for a greater proportion of AAIS having a gradual onset (69% vs.47%; P = 0.03) and being re-injuries (31% vs. 9%; P = 0.01). Impingement syndromes resulted in an overall incidence of 0.03 injuries (95% CI 0.02-0.03) per 1000 h and an injury burden of 0.4 absence days per 1000 h. PAIS incidence was significantly higher than that for AAIS [0.02 (95% CI 0.002-0.03) vs. 0.01 (95% CI 0.005-0.01) injuries per 1000 h (RR = 1.7). The absence was significantly longer in AAIS than in PAIS [10 (22) vs. 6 (11) days; P = 0.023]. Impingement syndromes that presented with a gradual onset had longer absences in comparison to impingement with an acute onset [8 (22) vs. 5 (11) days; P = 0.014]. Match play was associated with a higher incidence and greater injury burden than training: 0.08 vs. 0.02 injuries per 1000 h (RR 4.7), respectively, and 0.9 vs. 0.3 days absence per 1000 h (RR 2.5).

CONCLUSION

Ankle injuries are frequent in men's professional soccer and ankle impingement is increasingly recognized as a common source of pain, limited range of motion, and potential time loss. In our study, ankle impingement was the cause of time loss in less than 0.5% of all injuries. PAIS was more frequently reported than AAIS, but AAIS was associated with more absence days and a higher re-injury rate than PAIS. The findings in this study can assist the physician in best practice management on ankle impingment syndromes in professional football.

LEVEL OF EVIDENCE

II.

Elite Badminton Is Getting Older: Ages of the Top 100 Ranked Badminton Players from 1994 to 2020

The purpose of this study was to determine the evolution of the age of badminton players in the top 100 of the World Ranking for men and women from 1994 to 2020. Data were collected from badminton players participating in the top 100 World Rankings (4800 entries: 1233 players; 595 men and 638 women) from 1994 to 2020. The mean age of the top 100 and the average highest ranking of the players were analysed for both genders. The mean age of the male players in the World Ranking increased from 23.7 ± 3.2 years in 1994 to 26.3 ± 4.4 years in 2020 (p < 0.001) and in female players, from 22.8 ± 3.8 years in 1994 to 24.7 ± 3.3 years in 2020 (p < 0.001). In addition, women recorded a younger age at entry into the top 100 and when reaching their best ranking. Additionally, there has been a clear increase in Asian players in the top 100 of the World Ranking in recent years, reaching over 60%. These data could be used to develop and organise training plans in this sport, optimising and maximising players’ performance.

Medial Meniscus Repair in Major League Soccer Players Results in Decreased Performance Metrics for One Year and Shortened Career Longevity

Background

The rate of medial meniscus tear (MMT) in professional soccer players is high. There are no studies on objective performance metrics following medial meniscus repair in these athletes.

Purpose

Examine the impact of MMT treated with surgical repair on performance metrics and career longevity in Major League Soccer (MLS) players.

Methods

MLS players who sustained an MMT between 1993 and 2019 were identified via publicly available databases. These players were each matched to 2 uninjured controls by debut date, experience, position, race, ethnicity, height, weight, and body mass index (BMI). Demographic data and performance metrics were then collected for both groups. Matches, minutes, goals, assists, shots, shots on target, duels, and duel percentage won are collectively referred to as performance metrics. Statistical analysis compared demographic distributions and performance metrics between the MMT and control groups.

Results

Thirty-three MLS players who had undergone medial meniscus repair were identified and matched to 66 controls. All performance metrics decreased in the MMT group when compared to their controls in the first year after injury. This difference remained significant even when the performance metrics were normalized with respect to time, indicating that the injured players both played less and were not as productive. At 2 years after injury, performance metrics returned to pre-injury levels and were equivalent to those of the healthy controls. Career length was found to be significantly different between the two groups at 8.81 ± 3.9 years for the MMT group and 12.63 ± 3.51 years for the control group (P < 0.001).

Conclusion

MLS players undergoing medial meniscus repair had decreased performance metrics in the first year after injury but returned to baseline levels of play at the second year after injury. Their careers were also shorter than those of their uninjured controls.

High injury rates and weak injury prevention strategies in football referees at all levels of play

Football referees need other physiological requirements on field than football players and are affected by different types of injury. The absence of referees may result in canceled matches, so special focus should be placed on injury prevention through specific training programs for referees. This study retrospectively analyzed injury occurrence and prevention strategies for German football referees at the different levels of play over one season. Data were collected by means of seasonal injury reports based on the consensus statement of injury definition and data collection. Of the 923 participating referees, 91 (9.9%) played at the professional level, 151 (16.3%) at the semi-professional, and 681 (73.8%) at the amateur level. 86.2% (n = 796) were men and 13.8% (n = 127) women. Referees at the amateur level showed the highest injury incidence (3.14/1000 h football) compared to referees at the semi-professional (1.92/1000 h; p < 0.001) and professional level (1.01/1000 h; p < 0.001). Most referees at the amateur (n = 372; 56.4%) and semi-professional level (n = 46; 31.3%) conducted warm-up programs of <10 min, whereas the mean warm-up duration of professional referees was >11 min (n = 75; 82.4%). Although running and stretching exercises were common among referees during warm-up, preventive exercises focusing on coordination and trunk muscles were less frequent, especially among amateur referees (jumping: 15.9%; strengthening: 9.7%; balance exercises: 7.9%). Injury incidence was highest at lower amateur levels, which thus has specific need for injury prevention. Appropriate training exercises to prevent injuries of referees were weak at all levels of play, especially the lack of strength, plyometric, and balance exercises in training and warm-up programs.

Sprint Variables Are Associated with the Odds Ratios of Non-Contact Injuries in Professional Soccer Players

Significant evidence has emerged that a high volume of sprinting during training is associated with an increased risk of non-contact injuries in professional soccer players. Training load has been reported as a modifiable risk factor for successive injury in soccer. Sprint workload measures and non-contact injuries were recorded weekly in twenty-one professional soccer players over a one season period. Odds ratio (OR) and relative risk (RR) were calculated based on the weeks of high and low load of total distance (TD), high-speed distance (HSD), sprint distance (SPD). and repeated sprints (RS). The Poisson distribution estimated the interval time between the last injury and the new injury. The weeks with high-load levels increased the risk of non-contact injury associated with TD (OR: 4.1; RR: 2.4), HSD (OR: 4.6; RR: 2.6), SPD (OR: 6.9; RR: 3.7), and RS (OR: 4.3; RR: 2.7). The time between injuries was significantly longer in weeks of low-load in TD (rate ratio time (RRT) 1.5 vs. 4.2), HSD (RRT: 1.6 vs. 4.6), and SPD (RRT: 1.7 vs. 7.7) compared to weeks of high-load. The findings highlight an increased risk of non-contact injuries during high weekly sprint workloads. Possibly, TD, HSD, and SPD measured via a wearable inertial measurement unit could be modeled to track training and to reduce non-contact injuries. Finally, the interval time between the last injury and the new injury at the high-load is shorter than the low-load.

A multidisciplinary assessment of 320 athletes with long-standing groin pain syndrome in keeping with the Italian consensus agreement: the high incidence and the multiple causes of inguinal and hip pathologies and pubic osteopathy

BACKGROUND

Groin pain syndrome is an important and increasing problem in numerous sports (e.g. soccer, football, ice hockey, handball and rugby). Long-standing groin pain syndrome is a form of groin pain syndrome in which the cohort of symptoms reported by the patient is experienced for a long period, typically for over 12 weeks, and is recalcitrant to any conservative therapy. Long-standing groin pain syndrome is potentially career-ending for elite athletes.

METHODS

A descriptive epidemiological study was carried out on 320 athletes (290 men and 30 women) affected by long-standing groin pain syndrome, following the Guidelines issued by the Groin Pain Syndrome Italian Consensus Conference on terminology, clinical evaluation and imaging assessment of groin pain in athlete.

RESULTS

Amongst the clinical tests for inguinal pathologies, only the External Inguinal Ring Exploration proved conclusive (sensitivity: 0.97; specificity: 0.95; positive predictive value: 0.98; negative predictive value: 0.90; likelihood ratio: 19.4). In testing for adductor tendinopathies, only the Isometric Squeeze with flexed knee and distal resistance (sensitivity: 0.86; specificity: 0.45; positive predictive value: 0.48; negative predictive value: 0.85; likelihood ratio: 5.7) and the Palpatory Test at the pubic insertion of the adductor longus (sensitivity: 0.93; specificity: 0.89; positive predictive value: 0.96; negative predictive value: 0.79; likelihood ratio: 8.5) proved, respectively, useful at times and moderately useful. Among the tests for hip pathologies, only the Flexion Abduction External Rotation Test was seen to be conclusive (sensitivity: 0.90; specificity: 0.93; positive predictive value: 0.98; negative predictive value: 0.72; likelihood ratio: 12.9). In the male population on average, long-standing groin syndrome presents either a single cause or multiple causes in respectively 74% and 26% of cases. Furthermore, almost 58% of all cases traced to a single clinical cause can be attributed to inguinal pathologies alone. Long-standing groin syndrome in the female population shows only one pathological cause with inguinal pathologies, and acetabular labrum tear representing the most frequent etiologies.

CONCLUSIONS

Men and women exhibit different causes for long-standing groin pain syndrome. Several routine tests used in the clinical evaluation of this condition furnish a low likelihood ratio. Consequently, in order to optimize clinical evaluation and minimize patient discomfort, clinical evaluation should be based on tests with a greater likelihood ratio.

Determinants of lower-extremity injury severity and recovery in U.S. High School Soccer Players

Lower-extremity injuries are common among soccer players, yet few studies have attempted to identify determinants of lower-extremity injury severity and recovery within this group. We aim to identify determinants of lower-extremity injury severity and recovery among high school (HS) soccer players in the US. We used soccer-related injury observations recorded within the NATION-SP during 2011/12-2013/14. Odds of a season-ending game-related injury were higher than a season-ending practice-related injury (Adj. OR = 2.64, 95% CI = [1.39, 5.01]). Gender, setting, and playing surface emerged as significant determinants of any time loss following lower-extremity injuries in multivariable logistic regression models, and multivariable random effects Poisson regression models also revealed significant differences in recovery durations across levels of these variables for "similarly severe" injuries. Findings suggest that gender, injury setting, playing surface contribute to injury corollaries differently. Similar multi-method approaches are needed to identify determinants of injury severity and recovery in this group.

Injuries on the Youth Soccer (Football) Field: Do Additional Referees Reduce Risk? Randomized Crossover Trial

OBJECTIVE

Youth soccer injury can be prevented through various means, but few studies consider the role of referees. Following previous research suggesting children take fewer risks when supervised intensely, this randomized crossover trial evaluated whether risky play and injuries decrease under supervision from three referees instead of one referee.

METHODS

Youth soccer clubs serving a metropolitan U.S. area participated. Boys' and girls' clubs at under age 10 (U10) and under age 11 (U11) levels were randomly assigned such that when the same clubs played each other twice in the same season, they played once with one referee and once with three referees. A total of 98 games were videotaped and subsequently coded to obtain four outcomes: collisions between players, aggressive fouls (involving physical player-to-player contact) called by the referee(s) on the field, aggressive fouls judged by trained coders, and injuries requiring adult attention or play stoppage.

RESULTS

Poisson mixed model results suggest players in the 98 games committed fewer aggressive fouls, as identified independently by referees (rate ratio [RR] 0.58; 95% confidence interval [CI] 0.35-0.96) and by researchers (RR 0.67; 95% CI 0.50-0.90), when there were three referees versus one referee. Collisions (RR 0.98; 95% CI 0.86-1.12) and injury rates (RR 1.15; 95% CI 0.60-2.19) were similar across conditions.

CONCLUSION

When the same youth soccer clubs played with three referees rather than one, they committed fewer aggressive fouls. More intense supervision created better rule adherence. Injury rates were unchanged with increased supervision. Results raise questions concerning whether financial investment in additional referees on youth soccer fields yields safety benefits.

Asymptomatic Foot and Ankle Abnormalities in Elite Professional Soccer Players

Background

Professional soccer players are often evaluated with asymptomatic lesions of the ankle and foot, and such abnormalities may eventually become clinically relevant.

Purpose

To ascertain the prevalence of foot and ankle abnormalities in elite professional adult soccer players.

Study Design

Case series; Level of evidence, 4.

Methods

Professional adult male elite soccer players (n = 37) underwent magnetic resonance imaging (MRI) scans of both their feet and ankles. All competed for their respective national junior or adult soccer teams. MRI scans were performed with 1.5-T scanners and analyzed independently by 2 experienced radiologists.

Results

The MRI scans of 86.5% of the players showed degenerative joint disease (DJD) in at least 1 of the joints of the foot and ankle. Articular cartilage lesions in the joints of the foot and ankle were evident in 42% of the scans. Of all lesions, 17% were grade 3 or 4 (Noyes and Stabler classification) cartilage lesions and accompanied by subchondral bone marrow edema. The greater the age, weight, and height of the players, the greater was the odds ratio of DJD of the ankle joint. Synovitis in at least 1 of the joints of the foot was detected in 64% of the MRI scans. Leg dominance significantly correlated with bone marrow edema of the talus.

Conclusion

Elite professional soccer players are often evaluated with a high prevalence of asymptomatic osteochondral lesions with subchondral bone marrow edema in the foot and ankle. These osteochondral lesions may remain asymptomatic or, with the continuing high-intensity stresses that modern professional soccer demands of its athletes, may evolve and cause foot and ankle pain. It is unclear whether and which interventions can be implemented to prevent the occurrence of these abnormalities in the first place.

Injury prevention effects of stretching exercise intervention by physical therapists in male high school soccer players

We aimed to examine the prevalence of injury after physical therapy intervention for muscle tightness and injury prevention in male high school soccer players. A randomized controlled trial was conducted. Participants comprised 124 players from two high schools who competed in national tournament soccer games held from April 2018 to March 2019. Players were randomly divided into intervention (with a 12-week stretching intervention by physical therapists) and control groups (without the intervention). Players and coaches provided written information regarding injuries and daily training and match times; physical therapists visited each team weekly to collect data and review documentation. Muscle tightness and injury incidence, number, type, location, circumstances, situations, severity, and contents during the 12-week intervention period and a subsequent 40-week observation period were compared between groups. Injuries were significantly lower with intervention during the 40-week observation period (P < .01) but not during the 12-week intervention period (P = .44). Injury types mainly included disorder, non-contact, lower-limb/trunk, and muscle/tendon injuries. Significant interactions were observed for all tightness-test measurement items. The intervention group showed significant improvements in heel-buttock distance, and straight leg-raise and hip rotation angles (pre-intervention < 12 weeks < 52 weeks), as well as significant improvements in ankle dorsiflexion angles at 12 and 52 weeks (relative to pre-intervention values). Instructed stretching exercises, personally designed by physical therapists to address muscle tightness, improved the range of motion and trunk flexibility, with a positive effect on the injury rate in male high school soccer players, especially for non-contact disorder injuries during training.

Magnetic resonance imaging of midtarsal sprain: Prevalence and impact on the time of return to play in professional soccer players

BACKGROUND

Ankle sprain is a common injury in professional soccer, but to date midtarsal sprain has not been investigated in this context. The purpose of this study was to determine the prevalence of midtarsal sprain by MRI and to assess its impact on the time of return to play in professional soccer players.

METHODS

We included 52 professional soccer players who underwent 59 MRI examinations after acute ankle trauma between January 2012 and September 2019. Images were retrospectively reviewed in consensus by two radiologists for assessment of midtarsal sprain and ankle sprain. Ligaments were graded as i) normal, ii) partial tear, or iii) complete tear. Time to return to play (RTP) for each athlete was retrieved from team medical records. A Kruskal-Wallis test and Dunn's pairwise tests were used to calculate differences in RTP time between groups with i) isolated midtarsal sprain, ii) isolated lateral ankle sprain, and iii) combined midtarsal and lateral ankle sprain.

RESULTS

MRI revealed isolated ankle sprain in 24 of 59 MRI examinations (40.6 %). Acute midtarsal ligament injury was present in 15 examinations (25.4 %). Four of the 15 examinations (26.7 %) had isolated midtarsal injuries and eleven of the 15 examinations (73.3 %) had concomitant ankle sprain. RTP time was 39 days (range 9-70 days) for isolated midtarsal sprain. RTP time was significantly higher for athletes with combined ankle and midtarsal sprain (47 days, range 15-74 days) when compared to athletes with isolated ankle sprain (24 days, range 2-59 days) (p = .019).

CONCLUSION

Our MRI study reveals that midtarsal sprain is a frequent injury in professional soccer players with ankle sprain. Midtarsal ligament findings on MRI combined with evidence of lateral ankle sprain is associated with a longer time of return to play compared to isolated lateral ligament injuries.

LEVEL OF EVIDENCE

Retrospective study, observational study.

Reducing Injuries in Soccer (Football): an Umbrella Review of Best Evidence Across the Epidemiological Framework for Prevention

Soccer is the most popular sport in the world. Expectedly, the incidence of soccer-related injuries is high and these injuries exert a significant burden on individuals and families, including health and financial burdens, and on the socioeconomic and healthcare systems. Using established injury prevention frameworks, we present a concise synthesis of the most recent scientific evidence regarding injury rates, characteristics, mechanisms, risk and protective factors, interventions for prevention, and implementation of interventions in soccer. In this umbrella review, we elucidate the most recent available evidence gleaned primarily from systematic reviews and meta-analyses. Further, we express the exigent need to move current soccer injury prevention research evidence into action for improved player outcomes and widespread impact through increased attention to dissemination and implementation research. Additionally, we highlight the importance of an enabling context and effective implementation strategies for the successful integration of evidence-based injury prevention programs into real-world soccer settings. This narrative umbrella review provides guidance to inform future research, practice, and policy towards reducing injuries among soccer players.

A Fraction of Recommended Practices: Implementation of the FIFA 11+ in NCAA Soccer Programs

Background and Objectives: National Collegiate Athletic Association (NCAA) soccer coaches implement numerous warm-up and flexibility strategies to prepare athletes for training and competition. The Fédération Internationale de Football Association (FIFA) developed the 11+ injury prevention program to reduce non-contact injuries. This study aimed to analyze the level of familiarity with and implementation of the evidence-based FIFA 11+ amongst NCAA Division I (DI) and Division III (DIII) men’s and women’s soccer coaches. Materials and Methods: NCAA soccer coaches in the United States received an Institutional Review Board—approved survey hyperlink. A total of 240 coaches completed the survey. The respondents represented 47.5% men’s and 52.5% women’s teams distributed within DI and DIII programs. Descriptive statistics are reported as frequency counts and mean ± standard deviation where applicable. Pearson’s chi-square tests were performed to assess potential differences with a significance level set at α < 0.05. Results: The results indicated that approximately 62% of the respondents reported being familiar with the FIFA 11+ program. Of those coaches familiar with the program, 15.0% reported full implementation, 57.5% reported partial implementation, and 27.5% reported no implementation. Chi-square analyses revealed significant differences in FIFA 11+ implementation based upon division level (χ² = 4.56, p = 0.033) and coaching certification levels (χ² = 13.11, p = 0.011). Conclusions: This study indicates that there is a gap between FIFA 11+ knowledge and actual implementation. To reduce the risk of non-contact injury, there is a need to educate coaches and athletic trainers on the purpose of the FIFA 11+ program and how to perform the exercises correctly.

The conservative treatment of longstanding adductor-related groin pain syndrome: a critical and systematic review

Longstanding (chronic) adductor-related groin pain syndrome is a widely common problem for athletes in many sports activities which often drastically reduces player activity and performance. The first choice in therapeutic treatment is conservative therapy. The objective of this study is to provide a systematic review regarding conservative treatment for longstanding adductor-related groin pain syndrome present in literature today. Furthermore, this study aims to give a critical vision of the current state of the art of the considered topic. After screening 234 articles, 19 studies following the inclusion criteria were included and summarized in this current systematic review and seven different types of therapeutic interventions were described. Compression clothing therapy, manual therapy together with strengthening exercise and prolotherapy were the therapeutic interventions which showed both the greatest level of strength of evidence (Moderate) and grade of recommendation (D). The remaining four types of therapeutic interventions i.e.: corticoid injection, platelet rich plasma therapy, intra-tissue percutaneous electrolysis and pulse-dose radiofrequency, showed both lower levels of strength of evidence (Conflicting) and grade of recommendation (C). In conclusion the literature available on the conservative treatment for longstanding adductor-related groin pain syndrome is limited and characterized by a low level of evidence. Therefore, our recommendation is to refer only to the few studies with higher level of evidence and at the same time to encourage further research in this area. The intervention showing the greater level of strength of evidence, and the greater grade of recommendation are compression clothing therapy, manual therapy and strengthening exercise, and prolotherapy. Other therapeutic interventions such as intra-tissue percutaneous electrolysis and pulse-dose radiofrequency seem promising but require further studies to confirm their efficacy.

Injury Profiles in Korean Youth Soccer

We aimed to analyze injury profiles and injury severity in Korean youth soccer players. Data on all injuries that occurred in U-15 youth soccer players during the 2019 season were collected from 681 players of 22 teams through a medical questionnaire. The questionnaire was based on injury surveillance procedures of the Federation International de Football Association Medical and Research Centre and International Olympic Committee, and it comprised questions on demographic characteristics, training conditions, and injury information. Among all players, defenders accounted for 33.0%, followed by attackers (30.7%), midfielders (26.8%), and goalkeepers (7.9%). Most players played soccer on artificial grounds (97.4%). Injuries occurred more frequently during training (56.3%) than during matches (43.7%). Recurrent injury rate was 4.4% and average days to return to full activities were 22.58. The ankle (26.6%) and knee joints (14.1%) were the most common injury locations, and ligament sprains (21.0%), contusions (15.6%), and fractures (13.9%) were the most frequent injury types. In conclusion, Korean youth soccer players have a high injury risk. Therefore, researchers and coaching staff need to consider these results as a key to prevent injuries in youth soccer players and injury prevention programs may help decrease injury rate by providing injury management.

Injuries and functional performance status in young elite football players: a prospective 2-year monitoring

BACKGROUND

Motor function, such as strength asymmetries of the lower extremities and impaired dynamic stability, have a predictive value for the risk of injury. The present study aimed to reveal potential associations between injury and motor performance.

METHODS

Two hundred and five male youth elite (association) football (soccer) players (mean: 13.5±4.5 years, 57.2±30.2 kg, 168±35 cm) were included. A test battery was conducted twice per season, over two consecutive seasons (four times). Mobility (Sit and Reach Test, SnR), dynamic stability (Single Leg Hop for Distance, SLHD), linear sprinting speed (10 m, 30 m [s]), agility (Zig-Zag test with and without dribbling a ball [s]), jump performance (countermovement jump (CMJ) and drop jump (DJ), in cm) and maximal isometric voluntary force (MIVF, in N) of the knee extensors and flexors were assessed. All injuries occurring over the two-year period, as well as training and competition exposure time, were collected and used as grouping variables for statistical difference testing.

RESULTS

One hundred and twenty-five injuries in 93 players occurred (an injury incidence of 2.7/1000 hours of exposure). Age was associated with injury incidence (r=0.191; P=0.006). Neither DJ, CMJ, SnR nor agility performance were statistically different between injured and non-injured participants (P>0.05). Group differences did occur for sprint and strength (P=0.011; P=0.016), but these lapsed after the inclusion of age as a covariate. Only for SLHD symmetry was a non-significant trend evident after the correction for age (P=0.08).

CONCLUSIONS

The occurrence of musculoskeletal injuries in junior football players are, probably, not related to baseline motor function. Group differences between injured and non-injured youth elite football players are mostly explained by age. Only the symmetry in SLHD could be a potential risk factor for injuries and merits further investigation.

Sports Injuries in the Australian Regular Army

Sports participation in the military is important for physical fitness and building morale and camaraderie. However, injuries caused by sports are detrimental to military capability. The purpose of this study was to investigate patterns of injury from sports participation in Australian Regular Army personnel. Injury data spanning a two-year period were obtained from the Department of Defence Workplace Health, Safety, Compensation, and Reporting (WHSCAR) database. Data were extracted for the top five sporting activities causing injuries. The most common body sites, natures, and mechanisms of injuries across these five sports were then determined. Sports participation accounted for 11% (n = 1092) of reported injuries (n = 9828). Soccer presented with the greatest number of injuries (23.3%), followed by rugby union/league (22.9%), touch football (18.6%), Australian rules football (12.0%), and basketball/netball (11.9%). The ankle, knee, and shoulder were the most injured body sites (21.9%; 17.2%; 11.6% respectively) across these five sports, with soft tissue injury, dislocation, and fractures being the most common natures of injury (55.1%; 12.7%; 11.9% respectively). The most common mechanisms of injuries were contact with objects (35.1%) and falls (27.4%). The current injury rates, locations, and mechanisms are similar to historical rates suggesting little impact by injury mitigation strategies.

Improving predictor selection for injury modelling methods in male footballers

Objectives

This objective of this study was to evaluate whether combining existing methods of elastic net for zero-inflated Poisson and zero-inflated Poisson regression methods could improve real-life applicability of injury prediction models in football.

Methods

Predictor selection and model development was conducted on a pre-existing dataset of 24 male participants from a single English football team's 2015/2016 season.

Results

The elastic net for zero-inflated Poisson penalty method was successful in shrinking the total number of predictors in the presence of high levels of multicollinearity. It was additionally identified that easily measurable data, that is, mass and body fat content, training type, duration and surface, fitness levels, normalised period of 'no-play' and time in competition could contribute to the probability of acquiring a time-loss injury. Furthermore, prolonged series of match-play and increased in-season injury reduced the probability of not sustaining an injury.

Conclusion

For predictor selection, the elastic net for zero-inflated Poisson penalised method in combination with the use of ZIP regression modelling for predicting time-loss injuries have been identified appropriate methods for improving real-life applicability of injury prediction models. These methods are more appropriate for datasets subject to multicollinearity, smaller sample sizes and zero-inflation known to affect the performance of traditional statistical methods. Further validation work is now required.

Epidemiology of hip and groin injuries in Swedish male first football league

PURPOSE

This study aimed to investigate the incidence, pattern, and burden of hip/groin injuries in Swedish professional male football players over five consecutive seasons.

METHODS

Injury history from 16 football teams in the Swedish male first football league was evaluated during five consecutive seasons. The team's medical staff recorded team exposure and time-loss injuries prospectively between 2012 and 2016.

RESULTS

In total, 467 time-loss injuries located in the hip/groin area were recorded among 1,687 professional male football players, with an overall incidence and burden of 0.82/1,000 h and 15.6/1,000 h, respectively. There appeared to be an increased risk of hip/groin injuries during the last two seasons (2015-2016); however, the difference was not statistically significant (n.s). Recurrent injury rate was relatively low (14%), and overuse injuries accounted for the majority of injuries and absence days. Muscle injuries were the main injury type, while kicking and sprinting/running were the primary causes of injury. Goalkeepers had the lowest percentage of injuries and absence days.

CONCLUSION

Hip/groin injuries are a substantial problem in football, but does not seem to be an increasing phenomenon in the Swedish male first football league. Index and overuse injuries accounted for the majority of injuries and absence days. Thus, the focus should be on preventing hip/groin injuries to lower the injury rate. These new findings should be taken into consideration when designing and implementing preventive training interventions.

LEVEL OF EVIDENCE

II.

Radiographic analysis of lower limb alignment in professional football players

INTRODUCTION

To radiographically analyze lower limb alignment in adult asymptomatic professional football players and to correlate these values to clinical measurements.

MATERIALS AND METHODS

Twenty-four asymptomatic players [24.2 (3.6) years] were enrolled. Standard bilateral lower limb anteroposterior weight-bearing radiographs were acquired and clinical measurement of intercondylar/intermalleolar (ICD/IMD) distance was performed. Coronal plane mechanical alignment was assessed by five angles: leg mechanical axis (LMA), lateral proximal femoral angle (LPFA), lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), and lateral distal tibial angle (LDTA). Their values were compared to the reference values for adult population. An inter-individual comparison between right/left and dominant/non-dominant leg was added. The sum of bilateral LMA was correlated against ICD/IMD and against ICD/IMD adjusted for body height.

RESULTS

Football players presented with ICD/IMD of 46.5 (19.8) mm. Two, out of five, lower leg coronal angles showed significant differences (p < 0.001) compared to reference data from literature: LMA 5.8 (3.0)º vs.1.2 (2.2)º and MPTA 83.5 (2.6)º vs. 87.2 (1.5)º. No significant differences between left/right leg and dominant/non-dominant leg were established. Summed up bilateral LMA showed a high correlation to IMD/ICD (r = 0.8395; R² = 0.7048), and even higher to ICD/IMD adjusted for body height (r = 0.8543; R² = 0.7298).

CONCLUSIONS

This study was radiographically confirming increased varus of elite football players toward general population. Apex of the varus deformity was located in the proximal tibia. Clinical measurement of ICD/IMD adjusted for body height highly correlated with the radiographic values of coronal alignment; therefore, it may be used in population studies.

Prevalence of Asymptomatic Intra-articular Changes of the Knee in Adult Professional Soccer Players

Background:

Currently, there are few data on the association between participation in soccer and the condition of the knee joints in adult professional players.

Hypothesis:

A high percentage of professional soccer players will have asymptomatic intra-articular changes of the knee.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

The condition of the intra-articular structures (osteophytes, cartilage, and menisci) in 94 knee joints of 47 adult professional soccer players (mean ± SD age, 25.7 ± 4.6 years; body mass index, 22.8 ± 1.4 kg/m²) was analyzed. A 1.5-T magnetic resonance imaging scanner was used to perform the imaging, and the anonymized data were analyzed by 2 experienced radiologists.

Results:

Cartilage of both knee joints was affected in 97.9% of soccer players. Meniscal lesions were detected in 97.8% of joints, affecting both joints in 93.6% of athletes. Grade 2 cartilage lesions were the most prevalent (36%-60% depending on the lesion site), and grade 4 lesions were detected in 12.7% of joints. The medial femoral condyle and medial tibial plateau were most frequently affected by cartilage lesions (85.1%). Among meniscal lesions, grade 2 lesions were the most prevalent, being detected in 71% of the cases. Grade 3 lesions were detected in 13.8% of the joints. The posterior horn of the lateral meniscus was the most common site of meniscal lesions (affected in 95.7% of the joints). Osteophytes were detected in 4.2% of joints.

Conclusion:

The prevalence of asymptomatic cartilage and meniscal lesions in the knees of adult professional soccer players is extremely high and is not associated with the reduction of sports involvement. This research should promote the correct interpretation of magnetic resonance imaging data obtained from soccer players with acute trauma and the reduction of the number of unwarranted surgical procedures.

Isometric Posterior Chain Peak Force Recovery Response Following Match-Play in Elite Youth Soccer Players: Associations with Relative Posterior Chain Strength

The purpose of this study was to determine changes in two tests of lower limb isometric posterior chain force (IPC-F) following 90 min of match-play in elite youth soccer players and the interaction between relative strength and recovery profile. 14 players (age: 16 ± 2 years) performed 3 × 3 second IPC-F tests unilaterally at 30° and 90° of knee and hip flexion pre- and post-match, +24 h, +48 h, and +72 h post-match. Peak force was recorded for both limbs, combined and expressed relative to bodyweight (N/kg). A two-way repeated measures analysis of variance was performed to determine differences in force output between joint angles, time intervals and subjects. As there was no interaction between angle and time (p = 0.260), we report the change between timepoints as mean ∆ in 90° + 30° IPC-F. Relative to pre-match IPC-F, there were significant decreases post (∆ = −18%; p > 0.001) and at +24 h (∆ = −8%; p = 0.040), no significant difference at +48 h (∆ = 0%; p = 0.992) and a significant increase at +72 h (∆ = +12%; p = 0.005). There was a large inter-individual variability in recovery profile at both angles and substantial differences between post-match deficits at 90° (−10.8%) compared to 30° (−20.7%). Higher pre-match IPC-F was correlated with the magnitude of IPC-F deficits at both angles and all time points (r = 0.56 to 0.70, p = < 0.01) except for post-match 90°. Regular IPC-F monitoring to determine the magnitude of match-induced fatigue and track recovery may help inform decision-making regarding modifications to individual players training load, particularly as there is a large inter-individual variability in response to competition. Further research is warranted to better understand and address the finding that stronger players showed larger force deficits and slower recovery following match-play.

Professional soccer is associated with radiographic cam and pincer hip morphology

PURPOSE

Femoroacetabular impingement (FAI) syndrome is characterized by a triad: symptoms, clinical signs and imaging findings. Some individuals, especially athletes, have only imaging alterations. The objective of this study was to evaluate the prevalence of cam and pincer morphology in professional soccer players compared with a control group of non-athletes and to investigate the association between the age at which players start playing competitive soccer more than three times per week and duration of the soccer career with the prevalence of these radiographic findings.

METHODS

The prevalence of cam and pincer morphology in sixty professional adult male soccer players and thirty-two male controls was determined using pelvic anteroposterior radiography. Data were recorded for all hips and correlated with the age at which the players started competitive soccer practice and with the duration of their soccer career.

RESULTS

The prevalence of morphological FAI in the soccer players was 92.5% versus 28.1% in the controls (p < 0.001). The duration of the soccer career was positively correlated with the alpha angle (p = 0.033) and negatively correlated with the retroversion index (p = 0.009). The age at which competitive play began was inversely correlated with the alpha angle (p < 0.001).

CONCLUSION

The study showed a high prevalence of cam and pincer morphology in Brazilian professional soccer players compared with controls. The duration of the soccer career was associated with an increased alpha angle and a decreased retroversion index, and the age at which competitive soccer participation began was negatively associated with alpha angle values. Finally, this manuscript provides data about the association between greater exposure to soccer and cam and pincer morphological changes in the hip; specifically, cam morphology was more common in patients who began participating in sports at earlier ages. This information serves as an alert for coaches of youth teams to manage the training load in youth athletes.

LEVEL OF EVIDENCE

III.

Proprioception is not associated with lower extremity injuries in U21 high-level football players

Football is a contact sport with a significant risk of injury. Although proprioception is well studied in rehabilitation, little is known about the association between proprioception and the occurrence of sport injuries. The purpose of this study was to look into the association between ankle and knee proprioception and lower extremity injuries in young football players. Seventy-three football players from the highest U-21 league in Iran volunteered to participate in this study. Before the start of the 2017-2018 competitive season, joint position sense was measured at 30°, 60° and 90° knee flexion and at 10° and 15° ankle dorsiflexion, and inversion using the Biodex Isokinetic pro 4 system. The teams' medical staff recorded football-related lower extremity injuries. We used mixed effects Cox regression models to calculate hazard ratios (HRs) with 95% CIs, acknowledging the clustered data structure. Twenty-two players (30.1%) suffered one or more lower extremity injuries during the season. None of the proprioception measures examined was significantly associated with the risk of lower extremity injuries. Based on these results of our sample, joint position sense does not seem to be associated with lower extremity injuries in young male football players.