Football injuries in children and adolescent players: are there clues for prevention?

Epidemiology of football-related injuries in young male football players. An additional analysis of data from a cluster-randomised controlled trial

Football carries a high risk of injury for youth players. The aim of this study was to investigate the epidemiology of football-related injuries in young male players. The data stems from a previously conducted cluster-randomised controlled trial that investigated the efficacy of 'FUNBALL', a new injury prevention programme. This study contains the data of the 503 players of the control arm. The players belonged to 22 football teams of the Under-(U)15, U17 and U19 age groups. The time-loss injuries were recorded during the season 2021-2022 according to the Football Consensus Statement. An analysis on the injury incidence (IR, calculated per 1000 hours of exposure), location, severity, category, and type was performed. Incidence rate ratios (IRRs) were used to compare the variables between the specific age groups. 187 injuries (96 in training and 91 in matches) occurred during 52 938 hours of exposure. The overall IR was 3.53 injuries/1000 h (95% confidence intervals (CI) 3.06 to 4.07). The training IR was 2.16 injuries/1000 h (95% CI 1.17 to 2.64). The match IR was 10.50 injuries/1000 h (95% CI 8.55 to 12.89). In the U19s, the overall IRR was higher compared to the U17s (IRR 1.57, CI 1.12 to 2.19; p = 0.008) and compared to the U15s (IRR 1.82, 95% CI 1.25 to 2.62; p = 0.001). The thigh was the most commonly affected body region (IR 0.92/1000 h, 95% CI 0.69 to 1.22). Muscle injuries were the most common injury type (IR 1.05/1000 h, 95% CI 0.81 to 1.37). Injury burden was 74 lost days/1000 h. The findings of this study indicate a lower injury incidence in youth players than in adult ones. We observed a higher injury incidence towards the older age groups.

The effect of core stability training on ball-kicking velocity, sprint speed, and agility in adolescent male football players

This study was conducted to investigate the effect of core stability training program on ball-kicking velocity, running speed, and agility in adolescent male football players. To this end, 36 male football players aged 12-14 were divided into the training group and control group. Before implementing the core stability training program, participants' ball-kicking velocity, sprint speed, and agility performance were measured with a Bushnell velocity radar gun, 20 m sprint test, and 505 agility test, respectively, in both training group and control group. After the measurements, the training group followed core stability training program three days a week, for eight weeks in addition to the routine training program, while the control group followed the routine training program only. Ball-kicking velocity, sprint speed, and agility performance were re-measured in both groups after the completion of the core stability training program. Significant improvements were detected in all parameters, i.e., ball-kicking velocity, sprint speed, and agility performance in the training group (p<0.05). On the other hand, in the control group, no significant change was detected in the ball-kicking velocity and sprint speed (p>0.05), whereas a significant improvement was observed in agility performance (p<0.05). Inter-group comparisons revealed statistically significant differences between the groups in ball-kicking velocity and sprint speed in favor of the training group (p<0.05), while no significant difference was found between the groups in agility performance (p>0.05). In conclusion, this study's findings suggest that core stability exercises can be incorporated into the routine training program of adolescent male football players.

Changes in the central nervous system in football players: an MRI study

BACKGROUND

Football (soccer) is the world's most popular team sport.

PURPOSE

To comprehensively examine the brain in football (soccer) players, with the use of magnetic resonance imaging (MRI) techniques.

MATERIAL AND METHODS

The study involved 65 football players and 62 controls. The MR examinations were performed using MR 1.5-T system (Optima MR 360; GE Medical Systems). The examinations were carried out in the 3D Bravo, CUBE, FSEpropeller, and diffusion-weighted imaging (DWI) sequences. The 1HMRS signal was obtained from the volume of interest in the frontal and occipital lobes on both sides.

RESULTS

The present study, based on structural MRI, shows some changes in the brains of the group of football players. The findings show asymmetry of the ventricular system in four football players, arachnoid cysts in the parieto-occipital region, and pineal cysts. NAA/Cr concentration in the right frontal lobe was lower in the football players than in the controls, and the Glx/Cr concentration in the right occipital lobe was higher. The apparent diffusion coefficient value is lower in football players in the occipital lobes.

CONCLUSION

Playing football can cause measurable changes in the brain, known to occur in patients diagnosed with traumatic brain injury. The present findings fill the gap in the literature by contributing evidence showing that playing football may lead to changes in the brain, without clinical symptoms of concussion.

Efficacy of a new injury prevention programme (FUNBALL) in young male football (soccer) players: a cluster-randomised controlled trial

OBJECTIVES

To evaluate the efficacy of a new multicomponent, exercise-based injury prevention programme in football players 13-19 years old.

METHODS

Two-arm cluster-randomised controlled trial with clubs as the unit of randomisation. 55 football teams from Kosovo of the under 15, under 17 and under 19 age groups were randomly assigned to the intervention (INT; 28 teams) or the control group (CON; 27 teams) and were followed for one football season (August 2021-May 2022). The INT group performed the 'FUNBALL' programme after their usual warm-up at least twice per week, while the CON group followed their usual training routine. The primary outcome measure was the overall number of football-related injuries. Secondary outcomes were region-specific injuries of the lower limbs (hip/groin, thigh, knee, lower leg, ankle and foot) and injury severity.

RESULTS

319 injuries occurred, 132 in the INT and 187 in the CON group. The INT group used the 'FUNBALL' programme in 72.2% of all training sessions, on average 2.2 times per week. There was a significantly lower incidence in the INT group regarding the overall number of injuries (incidence rate ratio (IRR) 0.69, 95% CI 0.55 to 0.87), the number of thigh injuries (IRR 0.62, 95% CI 0.39 to 0.98), of moderate (time loss between 7 and 28 days) (IRR 0.65, 95% CI 0.44 to 0.97) and of severe injuries (time loss >28 days) (IRR 0.51, 95% CI 0.28 to 0.91).

CONCLUSION

The 'FUNBALL' programme reduced the incidence of football-related injuries among male adolescent football players, and its regular use for injury prevention in this population is recommended.

TRIAL REGISTRATION NUMBER

NCT05137015.

Isolated Trapezoid Fracture in Adolescent Goalkeepers: A Scoping Review of the Literature and a Report of Two Cases

Purpose

Isolated trapezoid fractures are rare injuries, particularly among adolescents, constituting only 0.4% of all carpal bone fractures. This study aims to present two cases of isolated trapezoid fracture in adolescent goalkeepers and a scoping review of the literature to provide guidelines for the management of this injury.

Methods

Following PRISMA-ScR guidelines, a scoping review of reported cases was conducted. Two hundred and twenty articles were found using PubMed and Google Scholar. After full-text review, a total of 30 cases from 22 articles along with our 2 cases were analyzed based on demographics, injury mechanism, method/timing of diagnosis, prognosis, and time to recovery.

Results

Thirty-two reported cases of trapezoid fractures with a mean age of 26.7 years (75% male) were found, with pain as the most common presenting symptom. A majority (78%) had initial negative findings on radiography, and the diagnosis was primarily established through computed tomography (59%; n = 19) or magnetic resonance imaging (50%; n = 16). There was a substantial delay in diagnosis (mean 26 days), primarily because computed tomography/magnetic resonance imaging was frequently ordered late. The majority of cases (78%) were managed conservatively, with immobilization periods ranging from 4 to 12 weeks. The average duration for full recovery was 4.5 months, with operative management taking 7.3 months and conservative management taking 3.5 months.

Conclusion

Trapezoid fractures, though rare, are often not promptly diagnosed on initial plain radiographs, leading to a potential underreporting of cases. Because of the risk of complications associated with this type of injury, clinicians should maintain a high level of vigilance and consider trapezoid fracture as a possible differential diagnosis when presented with carpal pain, swelling, or limited movement, particularly after axial load incidents. Further research and guidelines are needed to enhance our understanding and management of this uncommon injury in the future.

Type of study/level of evidence

Differential diagnosis/symptom prevalence IIIb.

Injuries in male youth football: a one season prospective cohort study of 223 Danish elite players

Objectives

This study prospectively investigated injury prevalence, incidence, and burden in male elite under-17 football players (N = 223) during a full season.

Methods

The players weekly completed a standardized web-based injury survey (OSTRC-H2) and a physical exposure report throughout the study.

Results

Average weekly response rate was 89.5%. Football exposure accounted for 52.4% of total physical exposure. On average (±SD), the players participated in individual football, strength, and rehabilitation practices for 1.2 ± 1.5, 3.0 ± .2.1, and 1.9 ± 3.4 h/week, respectively. In total, 742 health problems were reported. Mean weekly prevalence of health problems, injuries and illnesses were 20.1%, 16.5% and 3.8%, respectively. The injury incidence per 1,000 h of football exposure, match play and team practice were 8.28 (95% CI: 7.54-9.08), 16.77 (95% CI: 13.65-20.4), and 7.24 (95% CI: 6.5-8.04), respectively. Sudden-onset and gradual-onset injuries accounted for 36.7% and 43.4% of the total proportion of health problems. Hip/groin injuries had the highest incidence (1.58/1,000 h), whereas knee injuries had the highest burden (20.86 days lost/1,000 h). On average, the players experienced 3.33 health problems (average duration: 7.8 days). On average pr. player, 2.7 (95% CI: 2.2-3.3) wks of football exposure were lost.

Conclusion

Sudden and gradual-onset injuries influenced player availability during the season. Health problem prevalence fluctuated markedly, and injury incidence was higher during match play than training. The players had substantial volumes of training beyond football-specific training and matches. Our findings could assist medical and sports science practitioneers in enhancing training and recovery processes to maximize player availability.

The effect of biological maturation on foot morphology, and their relation to postural stability performance in male footballers

BACKGROUND

Biological maturity (BM) and foot morphology (FM) can independently alter neuromuscular loading on the ankle-foot complex, potentially causing stability deficits and injury predisposition. However, the influence of BM on FM, and how much both explain neuromuscular performance in postural stability (PS) tests, has been understudied. This study aimed to investigate the effect of BM on FM, and then discover to what extent both factors explain the variance in PS performance in adolescent footballers.

METHODS

Over one season, 399 three-dimensional foot scans were gathered from 72 footballers (U12-U15). PS was measured by center of pressure (COP) displacement in bilateral and unilateral stance. The Khamis and Roche equation determined maturity status (MS), while formulae from Mirwald and Khamis and Roche estimated timing of biological maturation (TBM). Principal component analysis determined nine principal components that explained the most variance in FM. An ANCOVA determined the effect of TBM on FM principal components, with covariates of age, height, weight, playing position, and foot preference. Step-wise linear regression determined the explanation of COP displacement by the above-mentioned predictors.

RESULTS

There was significantly increased foot pronation during and after peak height velocity/puberty. MS and four foot principal components (foot arch and width, great toe width and length) were significant predictors in all PS tests (R2: 0.105-0.180).

CONCLUSIONS

TBM had a significant effect on FM presentation, and should be a part of adolescent foot assessment. While they only explained a small amount of variance, determining MS and FM may identify those requiring additional PS attention.

Effectiveness of Protective Measures and Rules in Reducing the Incidence of Injuries in Combat Sports: A Scoping Review

In recent years, much effort has been made to reduce the injury rate in combat sports. However, the question remains to what extent these measures are effective. Analysis of studies could provide evidence of the effectiveness of measures aimed at reducing the incidence of injuries. This scoping review aims (1) to map research articles dealing with the effectiveness of proper use of protective measures in reducing the incidence of injuries in combat sports; (2) to investigate to what extent the proper use of protective measures and compliance with sports rules help to reduce the incidence of injuries in combat sports; and (3) to identify gaps in the existing literature and suggest future research on this topic. The literature search was conducted on articles published between 2010 and 2023. The main inclusion criteria were studies investigating the effect of sports rules and protective equipment used during training or competition in combat sports on reducing the incidence of injuries. After meeting the criteria, only seven articles from boxing, karate, and taekwondo were included in this study. Results showed that mandatory head guards, along with modern thicker gloves, significantly reduced the rate of knockouts (KOs) and head injuries in boxing despite an increase in the number of head blows. However, the number of facial cuts increased significantly due to the removal of head guards as a piece of mandatory equipment. The use of mouth guards has significantly reduced the number of oral injuries. Changes in rules, such as shortening the duration of bouts, along with the introduction of greater competencies of referees in the supervision of bouts (the standing count, outclassed rule, and medical stops) have helped to reduce the rate of injuries in boxing. The application of a computerised scoring system also contributed to the rate of injuries reduction. The increase in the number of weight divisions had the same effect on U21 karate athletes. However, a higher incentive to attack the head area in taekwondo did not increase the incidence of injuries in youth athletes. It can be concluded that the proper use of protective measures (head and mouth guards) in combination with the rules established for health protection (higher competencies of referees and more weight divisions in competitions) effectively reduces the occurrence of injuries in combat sports. In all Olympic combat sports, the injury incidence should be regularly assessed using the Injury Incidence Rate (IIR) per 1000 min exposures (MEs). Nonetheless, further studies are needed to monitor how established rules (e.g., prohibited behaviour) affect the IIRs.

Injury Patterns and Incidence in an Elite Youth Football Academy-A Prospective Cohort Study of 138 Male Athletes

BACKGROUND

There is a lack of evidence regarding injury incidence in German elite youth football academies, and the risk of re-injury is unknown. Therefore, the objectives of this study were (1) to determine injury patterns and incidence in an elite youth football academy in Germany, (2) to monitor overuse-/trauma-related injuries over the course of the season, and (3) determine the risk of re-injury.

METHODS

A prospective cohort study was conducted in the 2012/2013 season among 138 male players from an elite youth football academy in Germany. Injuries were recorded according to the consensus statement on injury definitions and data collection in studies of football injuries. Injury incidence was reported as the number of injuries per 1000 h of exposure and the number of injuries per squad season.

RESULTS

A total of 109 injuries were reported, resulting in a cumulative time-loss of 2536 days. A squad of 25 players sustained 19.7 injuries per season, with an average of 23.3 days (15.7-30.9; 95% CI lower-upper) of absence per injury. Ligament sprains (28%), muscle strains (19%) and physeal injuries (12%) were the most common causes of time-loss. Physeal injuries were the most common severe type of injury (29%), with a mean time-loss of 29.7 days (18.2-41.2; 95% CI lower-upper). Re-injuries accounted for 3% of all injuries and resulted in significantly more time-loss than non-re-injuries (60 vs. 23 days; p = 0.01).

CONCLUSION

In the youth academies studied, a team of 25 players sustained an average of 19.7 injuries per season, resulting in a cumulative time-loss of 459 days. Physeal injuries are a major contributor to severe injuries and therefore require special attention.

Adherence to the Mediterranean diet in young male soccer players

INTRODUCTION

Nutrition is vital in health and sports performance by improving anthropometric-related parameters and dietary habits, especially in the youngest ages. The Mediterranean diet (MD) has been highly recognized for its positive health effects and low adverse environmental impact.

OBJECTIVES

We aimed to characterize adherence to the MD and analyze its association with anthropometric parameters in young soccer players.

METHODOLOGY

In the present study, 132 male young soccer players from under 9 to under 15 categories (aged 7 to 15 years) from a Portuguese football club participated. The Mediterranean Diet Quality Index for Children and Adolescents (KIDMED) questionnaire was applied to assess adherence to the MD. Anthropometric-related parameters, including body mass, height, triceps skinfold thickness (TSKF), suprailiac skinfold thickness (SISKF), body mass index (BMI) and body fat percentage (%BF), were determined. The differences between groups were performed accordingly to normal and non-normal distribution. Spearman's correlations were performed to analyze the hypothetical correlation between KIDMED and BMI.

RESULTS

Players reached an average KIDMED score of 8.36 ± 1.92, showing that 68.2% (n = 90) reached high adherence to the MD, 31.1% (n = 41) had moderate adherence to the MD, and 0.78% (n = 1) had poor adherence to the MD. When the analysis was made for age group and BMI classification, no significant differences were observed in adherence to the MD. Considering the main characteristics of the MD, 50.8% consumed fruit (vs. 49,2%), 52.3% consumed vegetables (vs. 47,7%), and only 20% consumed oleaginous dried fruits (vs. 80%). Dairy consumption throughout the day was 49,2% (vs. no: 50,8%).

CONCLUSION

Data from the present study showed that many soccer players adhered to the MD, and no differences were observed for age group or BMI classification.

The relationship of three-dimensional foot morphology to clinical assessments and postural stability in adolescent male footballers

BACKGROUND

Foot morphology is associated with altered loading of the ankle-foot complex in adolescent footballers, predisposing to pain and injury. However, usual singular plane clinical assessments do not accurately capture the 3D nature of foot morphology. A new approach is 3D laser scanning, with statistical shape model techniques creating individual-to-group comparison. However, no research exists on the adolescent, football-playing foot. Furthermore, a link between 3D foot morphology, and usual clinical and performance measures would be beneficial for practical implementation.

METHODS

Four hundred forty-seven 3D foot scans from 224 elite male footballers (U12-U19) in bilateral stance were collected and further processed with statistical shape model techniques. Weighted shape parameters for individual principal components (Modes) were extracted for each foot. Centre of pressure displacement expressed as total travelled way in millimetres was calculated for bilateral and unilateral postural stability measures. Clinical assessments (Clarke's Angle, Resting Calcaneal Stance Position) were calculated on the 3D foot scans. Differences in weighted shape parameters, postural stability measures, and clinical assessments between age groups were determined by ANOVA. Correlations determined the relationship of Modes and clinical assessments to postural stability measures. Linear regression established if clinical assessments predicted the mode describing foot arch variation.

RESULTS

Age groups significantly differed for Mode 1 (foot length), Mode 2 (foot arch), and Mode 5 (tibial rotation relative to the foot) (p < 0.05). Resting Calcaneal Stance Position (r = .663) and Clarke's Angle (r = -.445) were low-to-moderately correlated to Mode 2 (both p < 0.001), and linear regression found they were both significant predictors of Mode 2, though only moderately (R2 = .522). There were low correlations of foot morphology to the postural stability tests.

CONCLUSION

This is the first study to describe the 3D foot morphology of male football-playing adolescents, and discover the differences between age groups. This will improve understanding and assessment of foot morphology in male adolescents because 2D techniques, as discovered in this study, do not strongly correlate to, nor predict, the 3D foot arch. Foot morphology was only lowly correlated to postural stability, thus a multifaceted program would be required for improvements.

FIFA 11+ Kids program effects on jump kinetics in soccer players - A randomized controlled clinical trial

This study aimed to analyse the effects of the FIFA 11+ Kids programme on jump kinetics in soccer players. Twenty-four athletes (aged 9-11 years) were randomly allocated to the following groups: 1) the FIFA 11+ Kids programme (FT, n = 12), and 2) control training (CT, n = 12). Kinetic assessments of vertical jump (VJ), drop landing (DL), and anterior jump + maximum vertical jump (AJ) were performed on a force platform before and after eight weeks of training. Post-intervention impulse peak force and maximum impulse force (VJ) were significantly greater than the baseline values in the FT group (P < 0.001). Post-intervention landing peak force values for the first and second landings (DL) were significantly greater than the baseline values in the FT group (P = 0.01 and P = 0.05, respectively). Post-intervention landing peak force in the first landing (AJ) was significantly greater than the baseline values in the FT group (P = 0.005). The FT was effective in improving the impulsion performance during VJ. However, it increased the landing forces during DL and VJ.

The effect of progressive and individualised sport-specific training on the prevalence of injury in football and handball student athletes: a randomised controlled trial

Objective

To evaluate the effectiveness of communication and coordination combined with designing a progressive and individualised sport-specific training program for reducing injury prevalence in youth female and male football and handball players transitioning to a sports academy high school. An additional aim was to investigate the characteristics of the reported injuries.

Methods

Forty-two Norwegian athletes were randomised into an intervention or control group. Mean age, height, weight and BMI was 15.5 ± 0.5 years, 178.6 cm ± 6.3 cm, 71.3 ± 9.8 kg, 22.3 ± 2.7 BMI for the intervention group (IG) (n = 23), and 15.4 ± 0.5 years, 175.6 cm ± 6.6 cm, 67.1 ± 9.8 kg, 21.7 ± 2.4 BMI for the control group (CG) (n = 19). During the summer holiday, the intervention group received weekly progressive, individualised sport-specific training programs and weekly follow-up telephone calls from the researchers. All athletes completed a baseline questionnaire and a physical test battery. Training data and injuries were recorded prospectively for 22 weeks using the Oslo Sports Trauma Research Center Questionnaire on Health Problems (OSTRC-H2). A two-way chi-square (χ²) test of independence was conducted to examine the relationship between groups and injury.

Results

Average weekly prevalence of all injuries was 11% (95% CI: 8%-14%) in IG and 19% (95% CI: 13%-26%) in CG. Average weekly prevalence of substantial injuries was 7% (95% CI: 3%-10%) in IG and 10% (95% CI: 6%-13%) in CG. The between-group difference in injuries was significant: χ² (1, N = 375) = 4.865, p = .031, φ = .114, with 1.8 times higher injury risk in CG vs. IG during the first 12 weeks after enrolment.

Conclusions

For student athletes transitioning to a sports academy high school, progressive individualised, sport-specific training programs reduced the prevalence of all-complaint injuries following enrolment. Clubs and schools should prioritise time and resources to implement similar interventions in periods where student athletes have less supervision, such as the summer holidays, to facilitate an optimal transition to a sports academy high school.

Age related changes in the Q angle of non-professional football players

Background

Football practice involves a great muscular demand, leading to the development of the lower limbs that, on occasions, can cause deviations from the normal anthropometric values. The quadriceps angle (Q angle) is a value often taken as a reference for the alignment of the lower limbs.

Objective

To observe the changes of the Q angle in young football players, because of muscular effort, analyzing the differences between four groups of different ages and to determine whether the playing position might influence these variations.

Methods

A cross sectional study was carried out with 104 male subjects divided into four groups according to age: under 8 years-old, 8-17 years-old, 17-21 years-old and over 21 years-old. A photograph was taken in standing position and the Q angle was plotted with KINOVEA® software. As for the reliability of the measurements, intraclass intra and interobserver coefficient were 0.958 and 0.860 respectively. The study was conducted in mid-season.

Results

Q angle value is greater in those under 8 years of age and decreases gradually and significantly (p < 0.005) until 17-21 years of age, where it stabilizes at values of 5.73° ± 2.78 for right Q angle and 5.88° ± 2.55 for left Q angle. Two way ANOVA demonstrated a significant group*position interaction for goalkeepers with a medium effect size in both angles (p < 0.001) with a medium effect (η² Right Q angle = 0.31; η² Left Q angle = 0.37). The values remain unchanged in subjects over 21 years of age (p > 0.005), except for goalkeepers, who suffered a difference in the evolution of the angle within their age category (p < 0.005) and with a high effect size with the other positions (value > 0.8) except forward (value < 0.5).

Conclusion

This study determines that the Q angle in football players decreases with growth, reaching values below 15° at the end of development. Playing positions only influence players over the age of 21, and the Q-angle of goalkeepers is greater than that of other players.

Preseason Integrative Neuromuscular Training Improves Selected Measures of Physical Fitness in Highly Trained, Youth, Male Soccer Players

ABSTRACT

Hammami, R, Negra, Y, Nebigh, A, Ramirez-Campillo, R, Moran, J, and Chaabene, H. Preseason integrative neuromuscular training improves selected measures of physical fitness in highly trained, youth, male soccer players. J Strength Cond Res 37(6): e384-e390, 2023-This study examined the effects of an 8-week integrative neuromuscular training (INT) program, including balance, strength, plyometric, and change of direction exercises, on measures of physical fitness in youth male soccer players. Twenty-four male soccer players participated in this study. They were randomly allocated into an INT (n = 12; age = 15.7 ± 0.6 years, body height = 179.75 ± 6.54 cm, body mass = 78.20 ± 7.44 kg, maturity-offset = +2.2 ± 0.6 years) or an active control (CG, n = 12; age = 15.4 ± 0.8 years, body height = 178.4 ± 6.4 cm, body mass = 72 ± 8.3 kg, maturity-offset = +1.9 ± 0.7 years) group. Before and after training, tests to measure dynamic balance (Y-Balance test [YBT]), muscle strength (one repetition maximum [1RM]), muscle power (five jump test [FJT], single-leg hop test [SLHT], and countermovement jump [CMJ] height), linear sprint time (10 and 30-m), and change of direction with ball (CoDball) were performed. The analysis of covariance was used to test between-group differences (INT vs. CG) at posttest using baseline values as covariates. Significant, large, between-group differences at posttest were noted for the YBT (p = 0.016; d = 1.1), 1RM (p = 0.011; d = 1.2), FJT (p = 0.027; d = 1.0), SLHT (p = 0.04; d = 1.4), CMJ height (p < 0.001; d = 1.9), 10-m sprint (p < 0.01; d = 1.6), and CoDball (p < 0.05; d = 0.9) in favor of the INT group. Significant moderate-to-large pre-to-post changes were detected in the INT group for YBT, 1RM, CMJ height, SLHT, FJT, 10-m and 30-m sprint time, and CoDball test (d = 0.7 to 3.07, p < 0.05). No significant pre-to-post changes were observed in the CG (p > 0.05), except for 10-m sprint time (d = 1.3; p < 0.05). Exposure to INT twice weekly is effective and time efficient to improve various measures of physical fitness in highly trained youth male soccer players.

The associations of early specialization, sports volume, and maturity status with musculoskeletal injury in elite youth football players

Background: Youth football in schools has experienced rapid growth in China. Despite the increase of players engaging in more frequent, intensive, and organized sports training at their early ages, the controversy over early specialization (ES) still exists. This study aims to: a) investigate the training situation of players in the Chinese School Football Programme and b) examine the associations of early specialization, sports volume, and maturity status with musculoskeletal injury. Methods: A cross-sectional survey was used. Players who participated in the National School Football Winter Camp were invited to fill out a questionnaire that included the data of maturity, ES, sports volume, and injury history (n = 88 boys and n = 90 girls). Results: The results have shown that 80.3% of the athletes were classified as ES, while 19.7% of them were classified as non-ES. Almost all athletes (96%) participated in a sport for more than 8 months in a year. Most athletes (75.8%) spent more than twice of the time on organized sports than leisure activities. 30.3% of the athletes trained on average more hours per week than the number of their ages. Binomial logistic regression models reflected the significant differences in the odds ratios (OR) of reporting a history of injury among athletes with different levels of specialization (p = 0.024) and the OR of reporting a history of leg injury among players with different weekly sports volumes (p = 0.038). Significant differences were also shown in the OR of players reporting foot injuries between players with different maturity states (p = 0.046), and the Chi-squared test showed significant differences in the OR of reporting acute injuries between players with different levels of specialization (p = 0.048) and weekly activity (p = 0.022). No significant differences were found between the remaining variables. Conclusion: Most school football elite players follow the ES pathway even though ES increases the risk of injury, especially acute injury. Pre-pubertal and early pubertal players have a higher incidence of foot injuries. Players who train more hours per week than their ages have more leg injuries and acute injuries. Therefore, priority protection and intervention should be carried out for populations with a high risk of injury.

Efficacy of Multi-Component Exercise-Based Injury Prevention Programs on Injury Risk Among Footballers of All Age Groups: A Systematic Review and Meta-analysis

BACKGROUND

Playing football is associated with a high risk of injury. Injury prevention is a priority as injuries not only negatively impact health but also potentially performance. Various multi-component exercise-based injury prevention programs for football players have been examined in studies.

OBJECTIVE

We aimed to investigate the efficacy of multi-component exercise-based injury prevention programs among footballers of all age groups in comparison to a control group.

METHODS

We conducted a systematic review and meta-analysis of randomized and cluster-randomized controlled trials. CINAHL, Cochrane, PubMed, Scopus, and Web of Science databases were searched from inception to June 2022. The following inclusion criteria were used for studies to determine their eligibility: they (1) include football (soccer) players; (2) investigate the preventive effect of multi-component exercise-based injury prevention programs in football; (3) contain original data from a randomized or cluster-randomized trial; and (4) investigate football injuries as the outcome. The risk of bias and quality of evidence were assessed using the Cochrane Risk of Bias Tool and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE), respectively. The outcome measures were the risk ratio (RR) between the intervention and the control group for the overall number of injuries and body region-specific, contact, and non-contact injuries sustained during the study period in training and match play.

RESULTS

Fifteen randomized and cluster-randomized controlled trials with 22,177 players, 5080 injuries, and 1,587,327 exposure hours fulfilled the inclusion criteria and reported the required outcome measures. The point estimate (RR) for the overall number of injuries was 0.71 (95% confidence interval [CI] 0.59-0.85; 95% prediction interval [PI] 0.38-1.32) with very low-quality evidence. The point estimate (RR) for lower limb injuries was 0.82 (95% CI 0.71-0.94; 95% PI 0.58-1.15) with moderate-quality evidence; for hip/groin injuries, the RR was 0.56 (95% CI 0.30-1.05; 95% PI 0.00-102.92) with low-quality evidence; for knee injuries, the RR was 0.69 (95% CI 0.52-0.90; 95% PI 0.31-1.50) with low-quality evidence; for ankle injuries, the RR was 0.73 (95% CI 0.55-0.96; 95% PI 0.36-1.46) with moderate-quality evidence; and for hamstring injuries, the RR was 0.83 (95% CI 0.50-1.37) with low-quality evidence. The point estimate (RR) for contact injuries was 0.70 (95% CI 0.56-0.88; 95% PI 0.40-1.24) with moderate-quality evidence, while for non-contact injuries, the RR was 0.78 (95% CI 0.55-1.10; 95% PI 0.25-2.47) with low-quality evidence.

CONCLUSIONS

This systematic review and meta-analysis indicated that the treatment effect associated with the use of multi-component exercise-based injury prevention programs in football is uncertain and inconclusive. In addition, the majority of the results are based on low-quality evidence. Therefore, future high-quality trials are needed to provide more reliable evidence.

CLINICAL TRIAL REGISTRATION

PROSPERO CRD42020221772.

FIFA 11+ Kids: Challenges in implementing a prevention program

Purpose

Soccer is a popular sport among children and adolescents that exposes to a high risk of injury. Several prevention programs, including the FIFA 11+ Kids program have been developed to decrease this injury rate. The aim of the study was to investigate the knowledge and use of the FIFA 11+ Kids program among soccer coaches of skeletally immature soccer players in a Swiss canton and analyze difficulties of implementing such a prevention program.

Materials & methods

First, an online survey was sent to all soccer coaches involved in Swiss training programs for male players from 7 to 13 years of age. Coaches were identified through existing Swiss coaching networks. A total of 237 coaches completed the survey. Second, the FIFA 11+ Kids program was implemented in three soccer teams (players from 7 to 13 years of age) during 6 months in the same canton. Utilization of FIFA 11+ Kids program and compliance of coaches were recorded by the research staff.

Results

Around 84% of the included coaches in the survey were certified. Of those, 59% had been taught injury prevention during their course(s). Only 14% of the included coaches knew one of the FIFA programs (11, 11+, 11+ Kids), of those, about one-third (10 out of 237) used the FIFA 11+ Kids program. After 6 months, none of the soccer coaches applied the entire FIFA 11+ Kids program twice a week. One coach had completely abandoned the program. The main reasons for their disapproval were the time and surveillance needed and the players' lack of motivation. They stated, however, that the exercises were good if used occasionally.

Conclusion

Injury prevention should be integrated in every soccer coach education courses. An adaptation of the FIFA 11+ Kids program should be considered, especially for the youngest players.

The incidence and burden of injuries in elite English youth female soccer players

This study aimed to investigate the incidence, severity and burden of injury in English elite youth female soccer players. Qualified therapists at six English girls' academies prospectively recorded all injuries that required medical attention or caused time loss for matches and training in 375 elite youth female soccer players (under-10 [U10], U12, U14 and U16) during the 2019/2020 season. One hundred- and eleven time-loss injuries (52 from training, 59 from matches) were sustained, resulting in 1,946 days absent (779 days from training injuries, 1,167 days from match injuries) from soccer activities. The injury incidence for matches (9.3/1000 hours, 95% CIs: 7.2-11.9) was significantly greater than training (1.1/1000 hours, 95% CIs: 0.9-1.5, p < 0.001). Additionally, the injury burden for matches (183 days lost/1000 hours, 95% CIs: 142-237) was significantly greater than training (17 days lost/1000 hours, 95% CIs: 13-22, p < 0.001). Injury incidence and burden were greatest in the U16 age group and were found to increase with age. Whilst injury incidence and burden are greater in matches than training, a large proportion of preventable injuries, soft-tissue and non-contact in nature, were sustained in training. Findings provide comparative data for elite youth female soccer players.

Epidemiology of injuries in male and female youth football players: A systematic review and meta-analysis

BACKGROUND

To conduct a systematic review and meta-analysis of epidemiological data of injuries in male and female youth football players.

METHODS

Searches were performed in MEDLINE/PubMed, Web of Science, Cochrane Library, and SPORTDiscus databases. Studies were considered if they reported injury incidence rate in male and female youth (≤19 years old) football players. Two reviewers (FJRP and ALV) extracted data and assessed trial quality using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement and the Newcastle Ottawa Scale. The Grading of Recommendations Assessment, Development, and Evaluation approach determined the quality of evidence. Studies were combined using a Poisson random effects regression model.

RESULTS

Forty-three studies were included. The overall incidence rate was 5.70 injuries/1000 h in males and 6.77 injuries/1000 h in females. Match injury incidence (14.43 injuries/1000 h in males and 14.97 injuries/1000 h in females) was significantly higher than training injury incidence (2.77 injuries/1000 h in males and 2.62 injuries/1000 h in females). The lower extremity had the highest incidence rate in both sexes. The most common type of injury was muscle/tendon for males and joint/ligament for females. Minimal injuries were the most common in both sexes. The incidence rate of injuries increased with advances in chronological age in males. Elite male players presented higher match injury incidence than sub-elite players. In females, there was a paucity of data for comparison across age groups and levels of play.

CONCLUSION

The high injury incidence rates and sex differences identified for the most common location and type of injury reinforce the need for implementing different targeted injury-risk mitigation strategies in male and female youth football players.

The Effect of FIFA 11+ on the Isometric Strength and Running Ability of Young Soccer Players

Soccer is the world's game, and keeping athletes healthy while playing the game has often been a focus of study. There is a high occurrence of musculoskeletal injuries reported in soccer. FIFA 11+ was developed as an intervention to help prevent such injuries. FIFA 11+ has previously been studied for its efficacy as an injury prevention program, but not for its effect on sports performance in an adolescent population. The purpose of this study was to look at the effect of implementing the FIFA 11+ intervention on strength, speed, and agility. Twenty youth soccer players were randomly divided into an intervention group (INT) and a control group (CON). The intervention lasted for eight weeks and performance assessments were completed pre- and post-intervention. Post-test INT knee flexor strength was significantly higher than pre-test scores (p < 0.05). INT also demonstrated significantly higher hamstring to quadriceps strength ratio (H/Q) after the intervention (p < 0.05), while the CON H/Q did not change significantly. 30-m sprint performance of both groups improved from pre- to post-test (p < 0.05). Shuttle run performance was significantly improved in post-test scores for INT players (p < 0.05), but did not change significantly for the CON players. It is suggested that implementing FIFA 11+ before training in young soccer players can lead to performance benefits as well as injury prevention benefits.

Effects of the "FIFA11+ Kids" Program on Injury Prevention in Children: A Systematic Review and Meta-Analysis

FIFA11+ Kids is a warm-up program specially designed to prevent football injuries in children. This systematic review and meta-analysis aimed to summarize the effects of FIFA11+ Kids on injury prevention in young football players. PubMed, Web of Science, Embase, Cochrane Library, and China National Knowledge Infrastructure were searched from 1 January 2016 to 24 August 2022. The primary outcome was overall injuries, and the secondary outcomes were severe, ankle, knee, and lower extremity injuries. Risk ratios (RRs) were calculated for each outcome. Methodological quality was assessed using the Physiotherapy Evidence Database (PEDro) scale. A total of 230 articles were screened, 6 of which were finally included in the meta-analysis. Compared with normal warm-up training, FIFA11+ Kids significantly reduced overall injury risk (RR = 0.52 [95% CI, 0.44-0.62]; p < 0.00001), severe injury risk (RR = 0.33 [95% CI, 0.18-0.61]; p = 0.0004), lower extremity injury risk (RR = 0.51 [95% CI, 0.41-0.65]; p < 0.00001), knee injury risk (RR = 0.45 [95% CI, 0.29-0.72]; p = 0.0009), and ankle injury risk (RR = 0.56 [95% CI, 0.35-0.89]; p = 0.01) in young football players. FIFA11+ Kids was found to be an effective approach to decrease the injury risk among young football players, which is worth generalizing extensively.

Biological Maturation Predicts Dynamic Balance and Lower Limb Power in Young Football Players

Biological maturation has an increasingly important role in youth sports. The aim of the study was to evaluate the relationship between dynamic balance and lower limb power and biological maturation in young football players. Seventy-two healthy, young male elite football players (age: 10 ± 2) participated in the study. Dynamic balance was assessed using a modified Star Excursion Balance Test (mSEBT). Power of the lower limbs was examined by a Countermovement Jump test (CMJ) and Single Leg Hop for Distance (SLHD). Furthermore, anthropometry and biological maturation (age, peak height velocity, and maturity offset) were assessed. There was a strong positive correlation between vertical jump (r = 0.75), distance long jump (r = 0.84), and biological maturation. A moderate positive correlation was found between dynamic balance (mSEBT COM, PL, and PM) and maturity offset. There was a significant association between mSEBT, CMJ, and SLHD (p < 0.05). Moreover, maturity offset explained 75% of vertical jump and 74% of distance long jump performance, respectively, and 12% of dynamic balance. Biological maturation should be considered when assessing athletic performance, establishing rehabilitation, and sports training in youth football players.

The FIFA 11+ Kids Injury Prevention Program Reduces Injury Rates Among Male Children Soccer Players: A Clustered Randomized Controlled Trial

BACKGROUND

The Fédération Internationale de Football Association (FIFA) 11+ Kids is an exercise-based injury prevention program developed by an international group of experts to prevent injuries among child soccer players.

HYPOTHESIS

It was hypothesized that the FIFA 11+ Kids program would be more effective than performing a typical warm-up regimen in reducing overall injuries among soccer players aged 7 to 13 years.

STUDY DESIGN

A clustered randomized controlled trial.

LEVEL OF EVIDENCE

Level 1.

METHODS

A total of 94 boys' soccer teams, including 780 players, were randomly allocated into an experimental or control group. Complete datasets were collected from 45 teams (377 players) and 43 teams (363 players) in the experimental and control groups, respectively. The experimental group underwent the FIFA 11+ Kids program as a warm-up during training sessions and matches at least twice a week, and the control group continued performing their usual warm-ups. Participants were prospectively followed during 1 season (6 months). The primary outcomes included the incidence of overall and recurrent injuries and their mechanism and severity. The secondary outcome was the rate of compliance with the intervention program.

RESULTS

A total of 43 injuries were reported in the experimental group in 50,120 hours of exposure (0.85 injuries/1000 exposure hours). A total of 86 injuries were reported in the control group in 42,616 hours of exposure (2.01 injuries/1000 exposure hours). The injury risk ratio was 0.43 (0.29-0.61), suggesting that the experimental group experienced 57% fewer injuries than those in the control group.

CONCLUSION

The FIFA 11+ Kids program reduced overall injury rates in children playing soccer more than the usual warm-ups.

CLINICAL RELEVANCE

The results of this study provide evidence for children's coaches to consider including the FIFA 11+ Kids program in their warm-up regimen. Such a program may prevent injury risk and decrease absenteeism and injury-related financial burdens.

Incidence, burden, and pattern of injuries in Spanish male youth soccer players: A prospective cohort study

OBJECTIVES

To explore the incidence, burden, and pattern of injuries in Spanish male youth soccer players during a 9-month competitive season (from September to May-June).

DESIGN

Prospective cohort study.

PARTICIPANTS

314 young (10-19 years) soccer players.

MAIN OUTCOME MEASURES

Incidence, burden, location, type, severity, mechanism, and circumstance of injuries, as well as potential differences by tactical position, month of the year, age group, and maturity status.

RESULTS

A total of 146 time-loss injuries were sustained by 101 different players. This resulted in an overall injury incidence of 3.1 injuries per 1000 h, a training injury incidence of 1.8 injuries per 1000 h, and a match injury incidence of 11.2 injuries per 1000 h. The probability of injury over the season was 34%. Most of the injuries affected the lower extremity and were classified as muscle/tendon injuries, with hamstring muscle injuries representing the most burdensome diagnosis. The incidence of injuries increased with age and maturation, but a heightened risk of overuse injuries during periods around peak height velocity was also identified.

CONCLUSIONS

These findings suggest a need for implementing specific injury prevention measures. Due to the high burden shown, these measures should mainly focus on reducing the number and severity of hamstring muscle injuries.

Association between Selected Screening Tests and Knee Alignment in Single-Leg Tasks among Young Football Players

This study aimed to examine the relationship between knee valgus in the frontal plane projection angle (FPPA) during single-leg squat (SLS), single-leg landing (SLL), and other selected clinical tests in young athletes. Forty-three young healthy elite football players (age: 13.2 (1.7) years) that were regularly training in a local sports club participated in the study. The FPPA was assessed using 2D video analysis. The screening tests included the passive single-leg raise (PSLR), hip external and internal rotation (hip ER and IR), sit and reach test, weight-bearing lunge test (WBLT), modified star excursion balance test (mSEBT), countermovement jump (CMJ), single-leg hop for distance (SLHD), and age peak height velocity (APHV). There was a significant positive relationship between the knee valgus angles in the SLS test and the sit and reach test (r = 0.34) and a negative relationship with the hip ER ROM (r = −0.34) (p < 0.05). The knee valgus angles in the SLL were negatively associated with the hip IR (r = −0.32) and ER ROM (r = −0.34) and positive associated with the WBLT (r = 0.35) and sit and reach test (r = 0.33) (p < 0.05). Linear regression analysis showed that the results of the hip ER ROM and sit and reach tests were independent predictors of the FPPA in the SLS test (r2 = 0.11, p = 0.03 and r2 = 0.12, p = 0.02, respectively). The conducted study showed that individuals with more hip range of motion, more spine flexion extensibility, and less ankle dorsiflexion ROM may be more likely to experience high degrees of knee valgus in FPPA.

Sports injuries patterns in children and adolescents according to their sports participation level, age and maturation

Background

Growth can make young athletes more vulnerable to sports injuries. Increased knowledge about injury profile and its predictors is an important part of an overall risk management strategy but few studies have produced information.

Methods

Information about injury profile and sports participation (SP) level was obtained by LESADO and RAPIL II questionnaires. They were distributed to 651 participants aged between 10 and 18 years attending four schools. Maturity measures were evaluated through maturity offset (MO) and Tanner-Whitehouse III method. Bivariate analysis was used to identify the set of candidate predictors for multinomial logistic regression analysis that was used to determine significant predictors of injury type and body area injury location.

Results

Regarding injury type predictors recreative boys had more chances of having a sprain or a fracture than a strain. Also, recreative and scholar girls had more chances of having a sprain than a strain. As MO decreased, the chances of girls having a strain or a fracture when compared to sprains were higher. For body area location boys with 10–11 years were more likely to have upper limbs injuries than boys of other ages. This was also confirmed by MO. Spine and trunk injuries were more likely to occur in federate and no sports participation girls.

Conclusions

Injury type and body area injury location differed significantly by SP level, age group and MO.

Apophysitis Among Male Youth Soccer Players at an Elite Soccer Academy Over 7 Seasons

Background:

Apophyseal injuries are common in children and adolescent athletes. These injuries are believed to be caused by repetitive overloading, which can create inflammatory and degenerative conditions in growing bone prominences. However, their prevalence, diagnosis, and treatment in young soccer players have been understudied.

Purpose:

To evaluate characteristics of apophyseal injuries in adolescent athletes at an elite soccer academy.

Study Design:

Case series; Level of evidence, 4.

Methods:

All apophyseal injuries between July 2008 and June 2015 were evaluated. For each injury, the authors recorded the type and location, age of the player, injury date, imaging modalities, and time absent from training/competition.

Results:

Over the 7 seasons of this study, 210 apophyseal injuries were documented, including 172 simple apophyseal injuries and 38 apophyseal avulsion fractures. The rate of apophyseal injuries was 0.35 per 1000 hours of training exposure. A total of 196 (93.3%) cases were primary injuries, and the rest (6.7%) were reinjuries. Ultrasonography was the most commonly used imaging modality for diagnosis (172 cases; 81.9%). The most common location of apophyseal injuries was the anterior inferior iliac spine (AIIS). Return to sport was faster in athletes with apophyseal injury at the ischiopubic ramus, those with simple apophyseal injuries, and younger athletes.

Conclusion:

The most common location for apophyseal injury among soccer players was the AIIS. Return to training and competition differed according to injury location, type of apophyseal injury, and age.

ACL injury prevention: Where have we come from and where are we going?

Anterior cruciate ligament (ACL) injuries are one of the most common and severe knee injuries across sports. As such, ACL injury prevention has been a focus of research and sports medicine practice for the past three-plus decades. Examining the current research and identifying both clinical strategies and research gaps, the aim of this review is to empower clinicians and researchers with knowledge of where the ACL injury prevention literature is currently and where it is going in the future. This paper examines the mechanism of ACL injury prevention, screening, implementation, compliance, adherence, coronavirus, and areas of future research. Clinical significance: The time lag between research and practical implementation in general healthcare settings can be as long as 17 years; however, athletes playing sports today are unable to wait that long. With effective programs already established, implementation and adherence to these programs is essential. Strategies such as coaching education, increasing awareness of free programs, identifying barriers, and overcoming implementation obstacles through creative collaboration are just a few ways that could help improve both ACL injury prevention implementation and adherence.

Quantitative evaluation of ankle cartilage in asymptomatic adolescent football players after season by T2-mapping magnetic resonance imaging

BACKGROUND

Ankle sprain affects the structure and function of ankle cartilage. However, it is not clear whether the daily training and competition affect the ankle cartilage without acute injury. Changes in ankle cartilage without injury may influence future strategies to protect ankle function in athletes. This study aimed to evaluate whether the composition of ankle cartilage significantly altered in asymptomatic adolescent football players after a whole season of training and competition using T2-mapping magnetic resonance imaging (MRI).

MATERIALS AND METHODS

12 local club's U17 asymptomatic adolescent football players without abnormalities in routine MRI were included. Routine and T2-mapping MRI were performed to measure the cartilage thickness of tibiotalar joint (TT) and posterior subtalar joint (pST) and T2 values in pre- and post-seasons. All of them took the right side as dominant foot.

RESULTS

In the pre- and post-seasons, cartilage T2 values in TT (talus side) and pST (calcaneus side) were higher than that of TT (tibial side) and pST (talus side) (all p < 0.05), which was caused by magic angle effect and gravity load. No statistically significant differences in thickness after season in the other cartilages of ankle were found compared with that before the season (all p > 0.05). However, T2 values of TT (tibial side and talus side) cartilage in the dominant foot were significantly reduced after season (p = 0.008; p = 0.034). These results indicate that the microstructure of articular cartilage changes in the joints with greater mobility, although no trauma occurred and the gross morphology of cartilage did not change.

CONCLUSION

Changes in the T2 values of tibiotalar joint cartilage in the dominant foot of healthy young athletes before and after the season suggest that the microstructure of cartilage had changed during sports even without injury. This finding suggests that the dominant ankle joint should be protected during football to delay degeneration of the articular cartilage.

Body Composition Assessment and Mediterranean Diet Adherence in U12 Spanish Male Professional Soccer Players: Cross-Sectional Study

Soccer is the most practiced team sport in the world. Due to the importance of nutrition in soccer performance, controlling the body composition and dietary guidelines of players takes place starting from lower categories. The objective of this study was to evaluate body composition and adherence to the Mediterranean diet of U12 players from a professional soccer team and to identify their dietary weak points. Seventy-one U12 male soccer players participated in the study. Weight, height, percentiles, skinfolds, and body fat were measured by a certified anthropometrist following the procedures recommended by the International Society for the Advancement of Kinanthropometry. The Mediterranean diet adherence test (KIDMED) was the questionnaire used to evaluate eating habits. In addition, a comparison was made among field positions. The results showed percentiles and body fat percentages appropriate for their age. Furthermore, the average score on the KIDMED test showed that the players generally adhered well to the Mediterranean diet, although they should improve their consumption of fruits and vegetables, as well as avoid skipping breakfast. Moreover, goalkeepers and defenders had a higher percentile BMI and percentage of fat than midfielders and forwards. In addition, these players had lower KIDMED values than midfielders and forwards. Although U12 soccer players have an appropriate body composition and adherence to the Mediterranean diet, there are differences between the different field positions that should be assessed by coaches, doctors, and nutritionists/dietitians.

Functional performance and interlimb asymmetries of young football players during single-leg jump tests

Background

Jumps are predominant components in football (soccer). Interlimb functional difference in single-leg jump performance is a risk factor for lower extremities injuries. Screening uninjured athletes is essential to design prevention strategies and implement individual training interventions. The aims of this cross-sectional study were (1) to provide age-specific mean values and limb symmetry index (LSI) in young football players, (2) to detect age effect on LSI and interlimb functional differences and (3) to investigate the association of age with single-leg functional performance and LSI.

Methods

A total of 146 male football players (age 14.2 ± 2.3) performed the countermovement jump, jump for distance, side hop and speedy jump tests. Descriptive statistics, mean values (dominant/non-dominant) and LSI were provided according to age groups (U11–U19). Two-way mixed analysis of variance (ANOVA), one-way ANOVA and Pearson’s correlation were used for the statistical analysis.

Results

Participants showed on average perfect LSI (103.8 ± 14.2%) amongst all tests and age groups. Interlimb functional differences occurred in three out of four tests (p < 0.05), without age interaction (p > 0.05). Age effect was positively associated with single-leg functional performance (p < 0.05), but not with LSI (p > 0.05), in all tests and age groups.

Conclusion

An LSI ≥100% in single-leg jump tests is proposed as a benchmark in young football players, but interlimb performance differences may occur without age interaction. Nevertheless, the growth process plays a crucial role in the development of functional capacities: older players may show a higher single-leg jump performance, but not a higher LSI, than younger players. In football practice, preventive intervention is advisable to counteract interlimb performance differences, for which unilateral strength, power and plyometric training is recommended.

Effects of a Neuromuscular Warm-Up Program in Youth Female Soccer Players

The protective effects of different warm-up injury prevention routines in youth female soccer players have been demonstrated in the literature, however, there is a paucity of information regarding the effects that these kinds of programs have on soccer-specific physical performance variables. The purpose of this study was to assess the effectiveness of a 12-week neuromuscular warm-up program on physical performance in youth female soccer players. Players (age: 13.94 ± 0.82 years) were divided into two groups. One group performed a neuromuscular activation program (n = 21) twice per week whereas the other group (control, n = 17) continued with their habitual warm-up routine for the same duration. Both groups of players performed strength, jumping and balance tests before and after the intervention period. Substantially greater improvements were detected in the mean velocity for the squat (p < 0.001; Effect Size = 0.95) and the hip thrust (p < 0.001; Effect Size = 0.51) in the experimental group in comparison to the control group. In addition, after the intervention period players in the experimental group showed an increase in the jumping height in the unloaded double-leg and single-leg counter-movement jumps (p = 0.003-0.012; Effect Size = 0.42-0.46). The results of this study provide evidence that a 12-week neuromuscular warm-up program can be effective to improve different physical performance variables in youth female soccer players.

Comparison of incidence, prevalence, severity and profile of health problems between male and female elite youth judokas: A 30-week prospective cohort study of 154 athletes

OBJECTIVES

To describe and compare the incidence, prevalence, severity, and profile of injuries (acute and overuse) and illness between female and male youth elite judokas during 30 weeks of a sports season.

DESIGN

Prospective cohort study.

METHODS

A total of 154 elite youth judokas (83 males and 71 females) were assessed from January to August 2019 in a training period organized by the Brazilian Judo Confederation. We conducted a prospective 30-week follow-up study on acute and overuse injuries and illness among youth female and male judokas through the Oslo Sports Trauma Research Center questionnaire on health problems (OSTRC-H). Every week, the OSTRC-H was sent to all youth judokas electronically, starting in the first week of preseason. The incidence rate, prevalence, and severity of illnesses and acute and overuse injuries were compared between sexes using an independent t-test (variables with normal distribution) or Mann Whitney U test (variables with non-normal distribution) with α set a 0.05.

RESULTS

Female and male judokas showed 16.96 and 16.57 injuries per 1000 athletic exposures, respectively (p = 0.383). Female judokas showed a higher average weekly prevalence of health problems (38.8%) than male judokas (29.0%). In addition, females had a greater prevalence of substantial health problems (p < 0.001), injuries (p < 0.001), and overuse injuries (p < 0.001) than males.

CONCLUSION

There were no differences in the incidence rate of injuries between sexes. Youth female judokas showed a higher prevalence of all health problems than youth male judokas. For both sexes, the knee and shoulder were the most affected joints for acute and overuse injuries, respectively.

The FIFA 11+ Shoulder Injury Prevention Program Was Effective in Reducing Upper Extremity Injuries Among Soccer Goalkeepers: A Randomized Controlled Trial

BACKGROUND

Soccer is one of the most popular sports worldwide. Goalkeepers are more likely to injure their upper limbs, particularly their shoulders, than outfield players. To reduce upper extremity injuries, the FIFA 11+ Shoulder Injury Prevention Program (FIFA 11+S) was developed.

PURPOSE

The purpose of this study was to assess the effectiveness of the FIFA 11+S program in reducing the incidence of upper extremity injuries among amateur soccer goalkeepers.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 726 goalkeepers, who were blinded to study intent, were randomly assigned to the experimental group (n = 360) or control group (n = 366). The experimental group was instructed to perform the FIFA 11+S program before all training sessions for 1 season (6 months). The control group was instructed to continue performing their usual routine warm-up program before training sessions for 1 season. Primary outcomes included the incidence of upper extremity injury and incidence of mechanism, type, and severity of injury measured using injury risk ratios (IRR); compliance with the experimental and control interventions was also recorded.

RESULTS

A total of 50 injuries (0.62 injuries per 1000 exposure-hours) were reported in the experimental group, and 122 injuries (1.94 injuries/1000 hours) were reported in the control group. The FIFA 11+S program reduced the total number of upper extremity injuries by 68% (IRR = 0.32 [95% CI, 0.27-0.34]) compared with the usual warm-up. The FIFA 11+S program reduced the incidence of contact injury (IRR = 0.30 [95% CI, 0.25-0.31]), noncontact injury (IRR = 0.40 [95% CI, 0.35-0.43]), initial injury (IRR = 0.34 [95% CI, 0.29-0.36]), recurrent injury (IRR = 0.20 [95% CI, 0.17-0.21]), and overuse injury (IRR = 0.40 [95% CI, 0.35-0.43]). Participants in the experimental group demonstrated a significant decrease in injuries of minor (IRR = 0.32 [95% CI, 0.27-0.34]) and moderate severity (IRR = 0.33 [95% CI, 0.29-0.35]) compared with the control group. We noted no difference in compliance between the experimental and control groups (80% vs 73%, respectively; P = .92).

CONCLUSION

The FIFA 11+S program resulted in 50% fewer upper extremity injuries among soccer goalkeepers, compared with a regular warm-up.

REGISTRATION

ACTRN12618001080213 (Australian New Zealand Clinical Trials Registry).

Purposeful Heading in Youth Soccer: A Review

Recent public concern over the short- and long-term effects of repetitive head impacts (RHI) associated with purposeful heading in soccer has led researchers to study a multitude of variables related to this important aspect of the game. Of particular interests are the effects of soccer heading in the youth population (≤ 13 years old) whose brains are undergoing rapid development. We conducted a review on youth soccer heading that includes purposeful heading frequency, head impact biomechanics, head injuries, clinical outcomes, and modifying factors. We have concluded that youth soccer players head the ball at a low frequency that typically increases with age and with a finding that boys head the ball more often than girls do. Interestingly, although girls head the ball less frequently than boys do, they tend to sustain higher head impact magnitudes. Head injuries are more likely to occur in girls versus boys and during games because of contact with another player. Clinical outcome measures of concussion are often utilized to study the effects of soccer heading, in both field and laboratory environments. Immediately following soccer heading, youth often report having a headache and demonstrate some deficits in balance measures. Modifying factors that may benefit soccer players participating in purposeful heading activities include stronger neck musculature, wearing headgear, and the use of mouthguards. Research involving youth soccer players needs to be expanded and funded appropriately to better understand the consequences of RHI in both the short and long term.

Impact of Three Strengthening Exercises on Dynamic Knee Valgus and Balance with Poor Knee Control among Young Football Players: A Randomized Controlled Trial

The observed dynamic knee valgus and the limited dynamic balance described in the literature are modifiable risk factors for injuries in athletes. Therefore, identification and appropriate prevention are crucial in managing the development of young athletes. The aim of the study was to assess the effectiveness of three exercises strengthening the muscles: gluteal medius, popliteal and tibialis posterior to reduce dynamic knee valgus and improve the dynamic balance of the lower limbs in young football players with poor knee control. A total of 134 footballers were assessed for eligibility, and finally 45 participants (age 12–15) met the inclusion criteria. Participants were assessed with 2D video kinematic analysis during single-leg squats to assess the knee valgus angles and the dynamic balance (Y-Balance Test). No significant interactions between groups (Control and Exercise) and time (baseline and after 6 week) were noted for dynamic valgus for the left and right knee (p > 0.05). For the dynamic balance, there were statistically significant results, but not clinically relevant for anterior, posteromedial, and composite direction for the right lower limbs and for the anterior direction for left lower limbs in the exercise group. However, there were no significant differences (p > 0.05) in all of the YBT scores for both lower limbs between groups. This study demonstrated that there were no statistically significant differences in dynamic knee valgus angles and dynamic balance values after 6 weeks of exercise program in young footballers with poor knee control. Future randomized trials should focus on more comprehensive exercises, where possible using biofeedback methods to improve knee kinematics.

Neuromuscular Training Warm-up Prevents Acute Noncontact Lower Extremity Injuries in Children's Soccer: A Cluster Randomized Controlled Trial

Background:

Prevention of sports injuries is essential in youth, as injuries are associated with less future physical activity and thus greater all-cause morbidity.

Purpose:

To investigate whether a neuromuscular training warm-up operated by team coaches is effective in preventing acute lower extremity (LE) injuries in competitive U11-U14 soccer players.

Study Design:

Randomized controlled trial; Level of evidence, 1.

Methods:

Twenty top-level U11 to U14 soccer clubs in Finland were randomized into intervention and control groups and assessed for 20 weeks. Participants included 1403 players (280 female, 1123 male; age range, 9-14 years): 673 players (44 teams) in the intervention group and 730 players (48 teams) in the control group. The intervention group team coaches were introduced to a neuromuscular training warm-up to replace the standard warm-up 2 to 3 times per week. The control teams were asked to perform their standard warm-up. Injury data collection was done via weekly text messages. The primary outcome measure was a soccer-related acute LE injury, and the secondary outcome measure was an acute noncontact LE injury.

Results:

A total of 656 acute LE injuries occurred: 310 in the intervention group and 346 in the control group. The overall acute LE injury incidence was 4.4 per 1000 hours of exposure in the intervention group and 5.5 per 1000 hours of exposure in the control group, with no significant difference between groups (incidence rate ratio [IRR], 0.82 [95% CI, 0.64-1.04]). There were 302 acute noncontact LE injuries: 129 in the intervention group (incidence, 1.8 per 1000 hours) and 173 in the control group (2.7 per 1000 hours). A significant reduction in acute noncontact LE injuries of 32% (IRR, 0.68 [95% CI, 0.51-0.93]) was observed in the intervention group compared with the control group. Furthermore, significant reductions in injury incidence in favor of the intervention group were seen in the subanalyses of acute noncontact LE injuries, leading to ≤7 days of time loss and fewer ankle and joint/ligament injuries.

Conclusion:

A neuromuscular training warm-up operated by team coaches was found to be effective in preventing acute noncontact LE injuries in children’s soccer, but this was not seen in all acute LE injuries.

Clinical Relevance:

We encourage children’s soccer coaches and health care professionals to implement neuromuscular training warm-up in youth sports.

Registration:

ISRCTN14046021 (ISRCTN registry).

A systematic review on conservative treatment options for OSGOOD-Schlatter disease

OBJECTIVES

Osgood-Schlatter disease (OSD) is a sport- and growth-associated knee pathology with locally painful alterations around the tibial tuberosity apophysis. Up to 10% of adolescents are affected by OSD. Treatment is predominantly conservative. The aims of this systematic review are to comprehensively identify conservative treatment options for OSD, compare their effectiveness in selected outcomes, and describe potential research gaps.

METHODS

A systematic literature search was conducted using CENTRAL, CINAHL, EMBASE, MEDLINE, and PEDro databases. In addition, ongoing and unpublished clinical studies, dissertations, and other grey literature on OSD were searched. We also systematically retrieved review articles for extraction of treatment recommendations.

RESULTS

Of 767 identified studies, thirteen were included, comprising only two randomised controlled trials (RCTs). The included studies were published from 1948 to 2019 and included 747 patients with 937 affected knees. Study quality was poor to moderate. In addition to the studies, 15 review articles were included, among which the most prevalent treatment recommendations were compiled.

CONCLUSION

Certain therapeutic approaches, such as stretching, have apparent efficacy, but no RCT comparing specific exercises with sham or usual-care treatment exists. Carefully controlled studies on well-described treatment approaches are needed to establish which conservative treatment options are most effective for patients with OSD.

Injuries in youth football and the relationship to player maturation: An analysis of time-loss injuries during four seasons in an English elite male football academy

A better insight into injuries in elite-youth football may inform prevention strategies. The purpose of this prospective cohort study was to investigate the frequency, incidence, and pattern of time-loss injuries in an elite male football academy, exploring injuries in relation to age and maturation status. Across four consecutive playing seasons, playing exposure and injuries to all academy players (U'9 to U'21) were recorded by club medical staff. Maturation status at the time of injury was also calculated for players competing in U'13 to U'16 aged squads. Time-loss injury occurrence and maturation status at time of injury were the main outcome measures. A total of 603 time-loss injuries were recorded, from 190 different players. Playing exposure was 229 317 hours resulting in an overall injury rate of 2.4 p/1000 h, ranging from 0.7 p/1000 h (U'11) to 4.8 p/1000 h (U'21). Most injuries were traumatic in mechanism (73%). The most common injury location was the thigh (23%), and the most common injury type was muscle injury (29%) combining to provide the most common injury diagnosis; thigh muscle injury (17%). In U'13-U'16 players, a higher number of injuries to early-maturing players were observed in U'13-U'14 players, while more injuries to U'15-U'16 players occurred when classed as "on-time" in maturity status. Maturation status did not statistically relate to injury pattern; however, knee bone (not-fracture) injuries peaked in U'13 players while hip/groin muscle injuries peaked in U'15 players.

Association of Skeletal Maturity and Injury Risk in Elite Youth Soccer Players: A 4-Season Prospective Study With Survival Analysis

BACKGROUND

The association between injury risk and skeletal maturity in youth soccer has received little attention.

PURPOSE

To prospectively investigate injury patterns and incidence in relation to skeletal maturity in elite youth academy soccer players and to determine the injury risks associated with the skeletal maturity status, both overall and to the lower limb apophysis.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

All injuries that required medical attention and led to time loss were recorded prospectively during 4 consecutive seasons in 283 unique soccer players from U-13 (12 years of age) to U-19 (18 years). The skeletal age (SA) was assessed in 454 player-seasons using the Fels method, and skeletal maturity status (SA minus chronological age) was classified as follows: late, SA >1 year behind chronological age; normal, SA ±1 year of chronological age; early, SA >1 year ahead of chronological age; and mature, SA = 18 years. An adjusted Cox regression model was used to analyze the injury risk.

RESULTS

A total of 1565 injuries were recorded; 60% were time-loss injuries, resulting in 17,772 days lost. Adjusted injury-free survival analysis showed a significantly greater hazard ratio (HR) for different status of skeletal maturity: early vs normal (HR = 1.26 [95% CI, 1.11-1.42]; P < .001) and early vs mature (HR = 1.35 [95% CI, 1.17-1.56]; P < .001). Players who were skeletally mature at the wrist had a substantially decreased risk of lower extremity apophyseal injuries (by 45%-61%) compared with late (P < .05), normal (P < .05), and early (P < .001) maturers.

CONCLUSION

Musculoskeletal injury patterns and injury risks varied depending on the players' skeletal maturity status. Early maturers had the greatest overall adjusted injury risk. Players who were already skeletally mature at the wrist had the lowest risk of lower extremity apophyseal injuries but were still vulnerable for hip and pelvis apophyseal injuries.

Injury incidence and burden in a youth elite football academy: a four-season prospective study of 551 players aged from under 9 to under 19 years

OBJECTIVE

Investigate the incidence and burden of injuries by age group in youth football (soccer) academy players during four consecutive seasons.

METHODS

All injuries that caused time-loss or required medical attention (as per consensus definitions) were prospectively recorded in 551 youth football players from under 9 years to under 19 years. Injury incidence (II) and burden (IB) were calculated as number of injuries per squad season (s-s), as well as for type, location and age groups.

RESULTS

A total of 2204 injuries were recorded. 40% (n=882) required medical attention and 60% (n=1322) caused time-loss. The total time-loss was 25 034 days. A squad of 25 players sustained an average of 30 time-loss injuries (TLI) per s-s with an IB of 574 days lost per s-s. Compared with the other age groups, U-16 players had the highest TLI incidence per s-s (95% CI lower-upper): II= 59 (52 to 67); IB=992 days; (963 to 1022) and U-18 players had the greatest burden per s-s: II= 42.1 (36.1 to 49.1); IB= 1408 days (1373 to 1444). Across the cohort of players, contusions (II=7.7/s-s), sprains (II=4.9/s-s) and growth-related injuries (II=4.3/s-s) were the most common TLI. Meniscus/cartilage injuries had the greatest injury severity (95% CI lower-upper): II= 0.4 (0.3 to 0.7), IB= 73 days (22 to 181). The burden (95% CI lower-upper) of physeal fractures (II= 0.8; 0.6 to 1.2; IB= 58 days; 33 to 78) was double than non-physeal fractures.

SUMMARY

At this youth football academy, each squad of 25 players averaged 30 injuries per season which resulted in 574 days lost. The highest incidence of TLI occurred in under-16 players, while the highest IB occurred in under-18 players.

Structure, Intensity and Player Duels in Under-13 Football Training in Switzerland

We evaluated the structure (i.e., the different training parts), contents (i.e., the various activities used), intensity and occurrence of contact situations and headers during training sessions in under-13 football in Switzerland. A total of 242 players from 20 different teams on average aged 11.4 (SD 0.7) years participated. The participants were filmed during a typical training session while they were equipped with a heart rate sensor. The sessions were systematically recorded to allow for detailed analyses. Furthermore, a preliminary and explorative analysis of the influence of the level of play on these results was conducted. The overall findings indicated that training included 33.4% playing forms, 29.5% training forms, 28.4% inactivity time and 8.7% athletics. The highest heart rates were achieved in the playing forms (166 min⁻¹, 83% HR_max) compared to the other two activities (training forms 154 min⁻¹, 77% HR_max; athletics 150 min⁻¹, 75% HR_max). Each player had 12.8 duels and 0.6 headers per training. Overall, most duels were conducted from the anterior direction. Playing forms induce higher cardio-circulatory load as well as a better learning environment. Potentially dangerous situations like contact with other players or headers occurred in a single player on average every six min during a training session.