Neuromuscular Adaptations to Multimodal Injury Prevention Programs in Youth Sports: A Systematic Review with Meta-Analysis of Randomized Controlled Trials

Neuromuscular Training Effects on Athletes' Jumping and Lower Limb Injury: A Systematic Review

This study assessed the impact of integrated neuromuscular training (INT) on athletes' jumping performance and lower limb injury prevention. A thorough search across multiple databases, including PubMed, Web of Science, Science Direct, and the Cochrane Library, identified a sample of 19,805 athletes aged between 8.5 and 27.7 years. Results showed that INT led to a significant improvement in jumping ability (SMD = 0.45, 95% CI 0.30-0.60, P = 0.000) and a reduction in lower limb injuries (SMD = 0.68, 95% CI 0.62-0.74, P = 0.000). The most effective interventions lasted at least 25 minutes, conducted 2-5 times per week, for a minimum of 9 weeks. This approach was particularly beneficial for children and adolescents, as it enhanced their countermovement jump (CMJ) ability and helped in the prevention of injuries.

Effects of a Preseason Neuromuscular Training Program vs. an Endurance-Dominated Program on Physical Fitness and Injury Prevention in Female Soccer Players

BACKGROUND

The pre-season preparatory period is considered key for optimizing the physical fitness levels needed to withstand congested match periods and preventing injuries during the regular soccer season. This study contrasted the effects s of neuromuscular training (NMT) versus an endurance-dominated training (ET) program conducted during the preseason on measures of physical fitness and injury occurrence in female soccer players.

METHODS

Twenty-four female soccer players aged 17.0 ± 1.3 years from a professional soccer club participated in this study. Players were randomly assigned to NMT (n = 12) or ET (n = 12) groups according to their playing position. The preseason intervention program lasted six weeks, with three weekly sessions with a duration of 45-60 min per session. Exercises in the NMT group included muscle strengthening exercises, plyometrics, agility and dynamic stability exercises, while the ET group practiced a traditional pre-season training program consisting of running and sprinting exercises, fartlek, and high-intensity interval training. The training volumes were similar in the two study groups. Anthropometric measurements, physical fitness tests (i.e., linear and change-of-direction speed, muscle strength and power tests) and the overall injury rate per 1000 h of exposure (training, match) were recorded throughout the season.

RESULTS

No between group differences were found at pre (T1). Significant group-by-time interactions were observed for the 5, 10, and 30-m linear sprint speed tests (p < 0.001, 2.16 < d < 2.58), the T-test (p = 0.024, d = 1.03), the squat (p < 0.001, d = 4.04), and the countermovement jump test (p < 0.001, d = 2.21), the Loughborough soccer passing test (LSPT) (p = 0.019, d = 1.08), and the 1-RM back squat test (p < 0.001, d = 2.53). Post-hoc tests indicated that NMT provided larger improvements for SJ, CMJ, 1-RM back squat, the 5-m sprint, 10-m sprint, 30-m sprint, T-test and LSPT compared to ET (1.07 > d > 2.77). The injury rate across the season was significantly lower in the NMT (5.1/1000 h exposure) compared to ET (11.8/1000 h exposure) (p = 0.014).

CONCLUSIONS

The findings support that six-weeks of preseason NMT versus ET induced larger performance improvements, and significantly reduced injury occurrence in elite female soccer players.

Feasibility and Effects of a Neuromuscular Warm-Up Based on the Physical Literacy Model for 8-12-Year-Old-Children

Background: Physical literacy and injury prevention strategies use similar movement-related constructs and can be connected to develop comprehensive interventions. We aimed to test the feasibility and effects of a neuromuscular warm-up based on physical literacy and injury prevention strategies for 8-12-year-old children. Methods: We conducted a cluster non-randomized controlled trial. We defined a priori feasibility criteria and studied the effects of the intervention on physical literacy constructs, movement competence, and neuromuscular performance. We used generalized linear mixed models controlling for covariates and clustering with a significance level of 0.001. Results: We recruited 18 groups (n = 363) and randomly allocated nine to intervention (n = 179; female = 63.7%, age = 9.8 ± 1 years) and nine to control (n = 184, female = 53.3%, age = 9.9 ± 0.9 years). We met four of seven feasibility criteria (i.e. recruitment, adherence, enjoyment, perceived exertion). The three feasibility criteria that were not met (i.e. compliance, fidelity, follow-up) were slightly below the predefined threshold (90%). Model-adjusted mean differences for physical literacy constructs, movement competence, vertical jump height, horizontal jump distance, 20-m sprint time, and dynamic balance favored the intervention (p < .001). Conclusion: The feasibility evidence indicates that the intervention should be slightly modified before implementing it in a larger study. The observed mean differences are promising and can be used in planning future interventions.

Neuromuscular but Not Technical Performance is Affected by Time-of-Day in Semiprofessional, Female Basketball Players

Purpose: The aim of this study was to determine whether variations in technical and neuromuscular performance occur across different times of the day in basketball players. Methods: Twenty semiprofessional, female basketball players (23 ± 4 years) competing in a second-division national basketball competition completed separate testing batteries in the morning (08:30) and in the afternoon (17:30) in a randomized counterbalanced order. Testing sessions consisted of a free-throw accuracy test to assess technical performance, as well as flexibility (ankle dorsiflexion range-of-motion test), dynamic balance (modified star excursion balance test), vertical jump height (squat jump, countermovement jump with and without arm swing), strength (isometric handgrip), change-of-direction speed (V-cut test), and linear speed (20-m sprint) tests to assess neuromuscular performance. Mechanism variables were also obtained including tympanic temperature, urinary specific gravity, and rating of perceived exertion at each session. Results: Squat jump height (6.7%; p = .001; effect size (ES) = 0.33), countermovement jump height with (4.1%; p = .018; ES = 0.27) and without arm swing (5.9%; p = .007; ES = 0.30), and 20-m sprint time (-1.4%; p = .015; ES = -0.32) were significantly superior in the afternoon compared to morning. Tympanic temperature was significantly higher in the afternoon than morning (1.4%; p < .001; ES = 1.31). In contrast, no significant differences between timepoints were evident for all remaining variables (p > .05; ES = -0.33 to 0.16). Conclusions: Some neuromuscular variables exhibited a time-of-day effect with better jump and sprint performance in the afternoon compared to morning in semiprofessional, female basketball players.

Effects of different strength and velocity training programs on physical performance in youth futsal players

Futsal is a high intensity team sport with intermittent actions of short duration, so it is necessary to include different training strategies to improve explosive actions. There is a gap in the scientific literature regarding training programs that improve the performance of young futsal players. The aim of this study was to determine the effects of different strength and velocity training programs on lower body physical performance in youth futsal players. Forty-two youth futsal players were divided into control group (CG, n = 14) and a strength intervention group (SG, n = 14), which included a weekly session for 8 weeks of eccentric strength training, plyometrics and core strengthening, and a velocity intervention group (VG, n = 14), which included a weekly session during 8 weeks of training with linear speed exercises and with change of direction, accelerations with resistance bands and core strengthening. SG significantly improved horizontal jump (HJ) (p:0.02), V-CUT (p:0.91) and change of direction deficit (CODD) (p:0.01). VG showed significant improvements in HJ (p:0.01), in 25 m sprint (p:0.01), in total repeated sprint ability time (p:0.01), in V-CUT (p:0.01) and in CODD (p:0.01). SG showed significant intergroup differences (p:0.01) in COD variables with respect to CG and VG. In conclusion, SG and VG showed significant improvements in lower body performance variables in youth futsal players. In addition, the SG has substantial changes in COD compared to the other two groups, so it has a greater effect.

Coaches of youth field sports as delivery agents of injury prevention programmes: how are we training the trainers? A scoping review

OBJECTIVE

To systematically map the coach education (CE) component of injury prevention programmes (IPPs) for youth field sports by identifying and synthesising the design, content and facilitation strategies used to address competency drivers and behaviour change.

DESIGN

Scoping review.

DATA SOURCES

PubMed, PsycInfo, EMBASE, CINAHL, SportDiscus and Google Scholar electronic databases were searched using keywords related to IPPs and youth field sports.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies of IPPs in youth field sports, that provided 'train-the-trainer' education to coaches as designated delivery agents.

RESULTS

20 studies from two field sports (soccer/football; n=17, Rugby Union; n=3) fulfilled the eligibility criteria. Eleven CE interventions occurred in the preseason and 18 occurred at one time-point (single day). Five studies cited use of a behavioural change theory or model in the design of their CE, most frequently the Health Action Process Approach model (n=5); and use of behavioural change techniques varied. Twelve of twenty studies (60%) reported some form of ongoing support to coaches following the CE primary intervention concurrent with IPP implementation.

CONCLUSION

CE that occurs on 1 day (one time-point) is most popular for preparing coaches as delivery agents of IPPs in youth field sports. While recognising pragmatic barriers, more expansive in-service training, support and feedback may enhance the effective implementation of IPPs.

TRIAL REGISTRATION NUMBER

https://doi.org/10.17605/OSF.IO/FMHGD.

A single dose of dihydrocapsiate does not improve neuromuscular performance in resistance-trained young adults: A randomised, triple-blinded, placebo-controlled, crossover trial

Capsinoids may exert ergogenic effects on resistance exercises. However, the acute effects of capsinoids on neuromuscular performance in humans are unknown. Here, we aimed to investigate the acute effects of dihydrocapsiate on lower- and upper-body neuromuscular performance parameters in resistance-trained individuals. 25 young adults (n = 6 women; age = 26 ± 3 years; body mass index = 24.3 ± 2.8 kg/m2) with ≥ 1-year resistance training experience were included in this triple-blind (participants, intervention researchers, and data analysts were blinded), placebo-controlled, crossover study. Lower- and upper-body ballistic strength (countermovement jump [CMJ] height and bench press throw [BPT] peak velocity), maximum dynamic strength (estimated 1 repetition maximum in squat and bench press [BP]), and strength-endurance (mean set velocity [squat] and number of repetitions to failure [bench press]) were assessed in 2 independent sessions (≥7 days separation). Participants ingested 12 mg of dihydrocapsiate or placebo 30 min before each trial. We found no significant differences between dihydrocapsiate and placebo conditions in ballistic strength, (CMJ height 33.20 ± 8.07 vs 33.32 ± 7.85 cm; BPT peak velocity 2.82 ± 0.77 vs 2.82 ± 0.74 m/s) maximal dynamic strength (estimated squat 1RM: 123.76 ± 40.63 vs 122.66 ± 40.97 kg; estimated BP 1RM: 99.47 ± 43.09 vs 99.60 ± 43.34 kg), and strength-endurance (squat mean set velocity 0.66 ± 0.07 vs 0.66 ± 0.05 m/s; number BP repetitions to failure 13.00 ± 3.56 vs 13.00 ± 4.78) (all P ≥ 0.703). We conclude that dihydrocapsiate does not acutely improve neuromuscular performance in trained young adults.

The Effect of a Balance Training Program on the Balance and Technical Skills of Adolescent Soccer Players

Soccer is a complex sport, and balance appears to play a crucial role in the quality execution of technical skills, which are mostly performed while standing on one foot. Nevertheless, in younger ages, when learning still affects soccer performance, the effect of a balance-training program on the player's balance and technical skills remains unexplored. This research examined the effect of a balance-training program (BTP) on balance and technical skills of adolescent soccer players. Τhe participating volunteers were thirty-two soccer players (12-13 years old with 3.84 ± 0.95 years of practice), randomly separated into two groups: an experimental (EXP, n1 = 17) and a control group (CON, n2 = 15). Both groups were evaluated in static and dynamic balance and in technical skills (dribbling, passing, juggling, and shooting with dominant and non-dominant legs) before (Pre-condition) and after the intervention (Post-condition) which was an eight-week BTP for the EXP group and a placebo-training program for the CON group. Α 2 by 2 (groups×condition) mixed analysis of variance (ANOVA) with repeated measures on the condition factor was used to assess possible differences between groups. A significant groups × condition interaction effect was found in dynamic balance (p = 0.008), static (p = 0.042), and shooting (p = 0.022) with dominant leg performance. The EXP group improved (p = 0.007) its static balance by 37.82% and also significantly improved its dynamic balance and shooting accuracy with dominant leg in Post condition by 24.98% (p = 0.006) and 83.84% (p = 0.006) respectively. No significant improvement of other variables was detected in the EXP group Post condition. Dynamic and static balance, and shooting with dominant leg skills can be improved in adolescent soccer players through a specialized 8-week BTP. Balance-training program may contribute to technical skill improvement in soccer training.

The effect of three different pre-match warm-up structures on male professional soccer players' physical fitness

BACKGROUND

Optimizing the soccer players' match preparation is one of the most relevant concerns of coaches for strength and conditioning training. Thus, the aim of this study was to analyze the effects of three pre-match warm-up structures on the physical condition of male professional soccer players.

MATERIALS & METHODS

Seventeen male professional soccer players (age: 20.9 ± 2.4 years) of one Tunisian Professional Soccer League team participated in this study. Players performed three times a typical pre-match warm-up (WU) [aerobic phase (AE); neuromuscular phase (NM); velocity phase (VL); and ball-specific phase (BS) variating the order of the included phases/exercises: WU1 (AE + BS + NM + VL); WU2 (AE + NM + VL + BS); and WU3 (AE + VL + BS + NM). After each warm-up phase, players completed the following physical fitness tests: linear sprint test, countermovement jump test, 15-m ball dribbling agility test and ball shooting test. Additionally, the rate of perceived exertion (RPE) was registered after each warm-up.

RESULTS

The results indicated significant differences between WU1 and WU3, with better results in the ball shooting test and RPE in WU3. In addition, there were no significant differences in the other variables and between other warm-up structures. These findings could be of great interest for coaches to the strength and conditioning coaches for professional soccer teams in order to improve the players physical performance and perceived exertion.

Beyond athletic development: The effects of parkour-based versus conventional neuromuscular exercises in pre-adolescent basketball players

The purpose of this study was to compare the effects of a parkour-based warm-up to a conventional neuromuscular training (NMT) warm-up on the athletic capabilities of youth basketball players. This was examined through two arms: In Investigation 1, the aims were to measure the effects of the two warm-ups on physical measures of athletic performance in prepubescent basketball players. Using post-intervention semi-structured interviews, Investigation 2 aimed to gain insights from the players in relation to the perceived benefits of the two warm-ups. Pre-adolescent children were recruited from two youth level basketball teams. Participants from one club were randomly assigned to either a conventional NMT warm-up group or a parkour warm-up group, while a control group was formed of participants from the second club. Participants of both experimental groups were required to complete a 15-minute warm-up once per week before their regular basketball practice across 8-weeks. For both groups, the coach adopted the same pedagogical approach, utilising a guided discovery strategy. Pre-post test measures of overhead squat performance, countermovement jump, and 10-metre sprint speed were recorded in all three groups. Additionally, pre-post measures were recorded for a timed parkour-based obstacle course for the two experimental groups. No significant between-group differences were found between pre- and post-test measures. However, analysis using Cohen's d effect sizes revealed improvements in both intervention groups versus the control. Moreover, between group effect size differences were observed between the two experimental groups. Following the intervention, participants from both experimental groups were also invited to take part in a post-intervention semi-structured interview to discuss their experiences. The thematic analysis of these semi-structured interviews revealed three higher order themes: Enjoyment; Physical literacy; and Docility; of which the two former themes appear to align to constructs relating to the wider concept of physical literacy. In summary, warm-ups designed to improve athleticism can include less structured and more diverse movement skills than are typical of conventional NMT warm-ups. Specifically, we provide evidence that advocates for warm ups that include parkour-related activities alongside conventional NMT exercises to preserve physical fitness qualities and to simultaneously evoke a sense of enjoyment, fun, and purpose. The benefit of such activities may extend beyond athletic development and, more broadly, contribute to the development of physical literacy.

Using Statistical Parametric Mapping as a statistical method for more detailed insights in swimming: a systematic review

Swimming is a time-based sport and hence strongly dependent from velocity. Most studies about swimming refer to velocity as discrete variable, i.e., 0-D (no time dimension). However, it was argued that using swimming velocity as a continuous variable (1-D, with time dimension) with Statistical Parametric Mapping (SPM) can bring deeper and detailed insights about swimming performance. Therefore, the aim of this study was to perform a systematic review about the current body of knowledge of using Statistical Parametric Mapping in a swimming context. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used to identify relevant articles. After screening, nine articles related to Statistical Parametric Mapping (SPM) analysis in swimming were retained for synthesis. Results showed that four articles (44.4%) aimed to understand the kinematics, isokinetic joint torque or electromyographic (EMG) pattern of the swimmer's shoulder either on land or during front crawl trials. Two articles (22.2%) focused on understanding the swimming velocity while performing the breaststroke stroke. One article (11.1%) analyzed the swimmers' propulsion at front-crawl stroke, another one (11.1%) compared swimming velocity during a complete stroke cycle in young swimmers of both sexes as a discrete variable and as a continuous variable. Also, one article (11.1%) analyzed the underwater undulatory velocity. In an EMG context, some findings verified in SPM are not possible to be discovered with traditional 0-D statistical methods. Studies about swimming velocity (breaststroke, freestyle, and underwater undulatory velocity) and propulsion (front-crawl) also highlighted the SPM advantages in comparison to traditional statistical methods. By using SPM, researchers were able to verify specifically where within the stroke cycle significant differences were found. Therefore, coaches can get more detailed information to design specific training drills to overcome hypothetical handicaps.

Effects of Multicomponent Injury Prevention Programs on Children and Adolescents' Fundamental Movement Skills: A Systematic Review With Meta-Analyses

OBJECTIVE

Fundamental movement skills (FMS) are essential to participate in physical activity. Understanding the effects of multicomponent injury prevention programs (MIPP) on FMS may help promote safe physical activity. Our objective was to synthesize the evidence on the effects of MIPP on biomechanical outcomes and neuromuscular performance measured on children and adolescents while performing FMS.

DATA SOURCE

We searched PubMed, SPORTDiscus, Web of Science, and SCOPUS.

STUDY INCLUSION AND EXCLUSION CRITERIA

We included peer-reviewed randomized controlled trials, published in English, that analyzed the effects of MIPP on biomechanics and neuromuscular performance of FMS in participants under 18 years of age.

DATA EXTRACTION

Two reviewers screened the articles, assessed the quality of the evidence using the Physiotherapy Evidence Database (PEDro) scale, and synthesized the data.

DATA SYNTHESIS

We conducted meta-analyses and reported the characteristics, outcomes, and risk of bias of studies.

RESULTS

We included 27 articles that reported data from 1,427 participants. Positive effects on FMS were reported in 23 of the 27 included articles. Vertical Jump, running speed, acceleration, and dynamic balance presented positive-significant pooled effect sizes. Dribbling and horizontal jump presented non-significant pooled effect sizes.

CONCLUSION

MIPP can positively affect FMS in children and adolescents in sports-related settings. Lack of participant compliance and implementation fidelity may affect MIPP effectiveness. Including MIPP in physical literacy interventions, physical education classes, and organized physical activity may lead to functional adaptations that help promote safe physical activity.

Is it Time to Consider Quaternary Injury Prevention in Sports?

Prevention has traditionally been categorized into three main areas: primary, secondary, and tertiary. In this Current Opinion, we present and discuss the concept of quaternary prevention in sports. Quaternary prevention aims to protect individuals from interventions that likely cause more harm than good, such as overdiagnosis, overtreatment, and overmedication. It includes preventing all types of harm associated with training and clinical interventions. Therefore, any sports injury prevention model or strategy should acknowledge the risks associated with training-related (i.e., overreaching and overuse) and clinical-related (i.e., overdiagnosis, over medicalization, and overtreatment) features. We propose a conceptual framework that integrates quaternary prevention into the contemporary injury prevention models in sports, taking into account that injury prevention is just one branch of the managerial, decision-making, and active hazard control process of risk management that athletes, coaches, and health and performance staff need to deal with. Therefore, we argue that integrating the concept of quaternary prevention into any form of prevention will significantly protect athletes from excessive, inappropriate, and ethically questionable interventions that may likely cause more harm than good.

[Groin pain in sports games: a systematic review]

BACKGROUND

In sports games, epidemiological data show that groin pain is relatively common and can lead to repeated loss of time. Consequently, it is essential to be aware of the evidence-based prevention strategies. The aim of this systematic review was to examine risk factors and prevention strategies for groin pain and to rank them based on their evidence in sports games.

METHODS

The review was conducted according to the PRISMA guidelines, using a PICO-scheme in the PubMed, Web of Science and SPOLIT databases. We included all available intervention and observational studies on the influence of risk factors and prevention strategies on groin pain in sports games. The methodological quality and level of evidence was assessed using the PEDro-Scale and OCEBM model, respectively. Finally, the quantity, quality and level of evidence was used to rank each risk factor for its grade.

RESULTS

Moderate evidence was found for four risk factors that significantly influence the risk of groin pain: male sex, previous groin pain, hip adductor strength and not participating in the FIFA 11+ Kids. Moreover, moderate evidence was found for the following non-significant risk factors: older age, body height and weight, higher BMI, body fat percentage, playing position, leg dominance, training exposure, reduced hip abduction, adduction, extension, flexion, and internal rotation-ROM, hip flexor strength, hip abductor, adductor, flexor and core strengthening with balance exercises, clinical hip mobility tests and physical capacities.

CONCLUSION

The identified risk factors can be considered when developing prevention strategies to reduce the risk of groin pain in sports games. Thereby, not only the significant, but also the non-significant risk factors should be considered for prioritisation.

Intrinsic Risk Factors for Ankle Sprain Differ Between Male and Female Athletes: A Systematic Review and Meta-Analysis

Background

Ankle sprains remain prevalent across most team sports. However, despite divergent ankle sprain injury rates in male and female athletes, little is known about potential sex-specific risk factors for ankle sprain.

Objective

To systematically investigate the sex-specific risk factors for ankle sprain.

Methods

Combinations of the key terms were entered into PubMed, Web of Science, Embase and Cochrane Library databases, and prospective studies reporting ankle sprain risk factors in males or females were included for meta-analysis.

Results

Sixteen studies were eligible for inclusion, for a total of 3636 athletes (735 female) and 576 ankle sprains (117 female). Out of 21 prognostic factors, previous ankle sprain injury (odds ratio = 2.74, P < .001), higher body mass index (SMD = 0.50, P < 0.001), higher weight (SMD = 0.24, P = 0.02), lower isometric hip abduction strength (SMD = − 0.52, P < 0.0001) and lower dynamic balance performance (SMD = − 0.48 to − 0.22, P < 0.001–0.04) were identified as risk factors in male athletes. In female athletes, out of 18 factors eligible for meta-analysis, only lower concentric dorsiflexion strength was identified as a risk factor (SMD = − 0.48, P = 0.005).

Conclusion

This meta-analysis provides novel evidence for different risk factor profiles for ankle sprain injuries between female and male athletes. Further studies, particularly in female athletes, are needed to strengthen the evidence.

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.

Effects of prevention programmes on injury risk in military personnel: a systematic review with meta-analysis

INTRODUCTION

Exercise programmes have been used to prevent injuries in military personnel, as they can reduce modifiable risk factors for injuries. Our aim was to review the literature to evaluate the effects of different exercise protocols on the prevention of injuries in military personnel.

METHODS

A systematic literature review examined the effects of different exercise protocols on the prevention of musculoskeletal injuries in the military. Several databases were explored to find experimental studies that investigated the effects of prevention programmes on the risk of injury. We have extracted from the studies: profile of participants, sample size, study design and characteristics of the control group (CG), the type of intervention and the relative risk (RR) in the experimental group and CG, with their significance levels. For data analysis, we used the RevMan V.5.3 software. The measure of RR was investigated. The risk of publication bias was analysed with Begg's test.

RESULTS

A total of 13 694 titles and studies were recovered from the databases and by manual search. After the removal of duplicate titles and studies that did not meet the eligibility criteria, 17 studies were selected. The protocols were composed of neuromuscular training, stretching, agility training or combined exercises. The meta-analysis showed that injury prevention exercise programmes reduced the risk of musculoskeletal injuries in military personnel by 14% (RR=0.86; 95% CI=0.76 to 0.98).

CONCLUSION

Injury prevention exercise programmes promoted a slight reduction in the risk of musculoskeletal injuries in military personnel.

LEVEL OF EVIDENCE

Very low.

TRIAL REGISTRATION NUMBER

CRD 42017077946.

Part 2 of the 11+ as an effective home-based exercise programme in elite academy football (soccer) players: a one-club matched-paired randomised controlled trial

Background:Although the 11+ is known to reduce injuries and improve performance in adolescent footballers, its duration presents a notable barrier to implementation. Hence, this study investigated injury and performance outcomes when 65 elite male academy footballers either performed Part 2 3x/week at training (TG) or at home (HG).Methods:Time to stabilisation (TTS), eccentric hamstring strength (EH-S) and countermovement jump height (CMJ-H) were collected 4 times during the 2019 football season. Linear mixed models were used to evaluate main and interaction effects of group and time. Bonferroni post-hoc tests were used to account for multiple comparisons. Differences in time loss and medical attention injuries were determined using a two-tailed Z test for a comparison of rates.Results:Relative to baseline, EH-S (HG 4.3 kg, 95% CI 3 to 5.7, p < 0.001; TG 5.5 kg, 95% CI 4.3 to 6.6, p < 0.001) and CMJ-H (HG 3.5 cm, 95% CI 2.2 to 4.7, p < 0.001; TG 3.2 cm, 95% CI 2.2 to 4.3, p < 0.001) increased, with no difference between groups observed at the end of the season. All injury outcomes were similar.Conclusion: Rescheduling Part 2 did not affect performance or increased injury risks in academy footballers.

The effects of eccentric hamstring exercise training in young female handball players

Purpose

The multidimensional role of hamstring muscle group strength in athletic performance and injury prevention is well documented, and nordic hamstring exercise (NHE) is a popular method for the development of hamstring strength. Our aim was to examine the EMG characteristics of the eccentric NHE as well as the effects of long-term eccentric NHE training on muscle strength and vertical jump performance in 10- to 11-year-old female handball players.

Methods

Players from the same handball team were randomly assigned to an eccentric NHE training (13 players) or a control group (10 players). Both groups continued their regular handball training routine, but the NHE group performed additional eccentric NHE exercises once or twice a week, with progressively increasing volume, over 20 weeks. To test training effects, countermovement jump (CMJ) height, eccentric hamstring impulse, peak torque, and angle of peak torque were evaluated before, during and after the training period. In the pre-exercise test, EMG activity of the medial and lateral hamstring muscle was also assessed during NHE.

Results

Hamstring activities ranged between 98 and 129%. Lateral hamstring activity was greater than medial only in the right leg during NHE. Eccentric hamstring impulse improved in both legs at 10 weeks in both groups. Then, at 20 weeks, it remained unchanged in the NHE but decreased in controls. A similar adaptation was seen in eccentric hamstring torque, without change in the optimum knee angle. CMJ height improved only in the NHE.

Conclusion

It is concluded that NHE activates the hamstring musculature effectively, and a favourable mechanical adaptation to long-term NHE exercise in girls can be triggered as early as 11 years of 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.

Identification of Neuromuscular Performance Parameters as Risk Factors of Non-contact Injuries in Male Elite Youth Soccer Players: A Preliminary Study on 62 Players With 25 Non-contact Injuries

Introduction: Elite youth soccer players suffer increasing numbers of injuries owing to constantly increasing physical demands. Deficits in neuromuscular performance may increase the risk of injury. Injury risk factors need to be identified and practical cut-off scores defined. Therefore, the purpose of the study was to assess neuromuscular performance parameters within a laboratory-based injury risk screening, to investigate their association with the risk of non-contact lower extremity injuries in elite youth soccer players, and to provide practice-relevant cut-off scores.

Methods: Sixty-two elite youth soccer players (age: 17.2 ± 1.1 years) performed unilateral postural control exercises in different conditions, isokinetic tests of concentric and eccentric knee extension and knee flexion (60°/s), isometric tests of hip adduction and abduction, and isometric tests of trunk flexion, extension, lateral flexion and transversal rotation during the preseason period. Non-contact lower extremities injuries were documented throughout 10 months. Risk profiling was assessed using a multivariate approach utilizing a Decision Tree model [Classification and Regression Tree (CART) method].

Results: Twenty-five non-contact injuries were registered. The Decision Tree model selected the COP sway, the peak torque for knee flexion concentric, the functional knee ratio and the path of the platform in that hierarchical order as important neuromuscular performance parameters to discriminate between injured and non-injured players. The classification showed a sensitivity of 0.73 and a specificity of 0.91. The relative risk was calculated at 4.2, meaning that the risk of suffering an injury is four times greater for a player, who has been classified as injured by the Decision Tree model.

Conclusion: Measuring static postural control, postural control under unstable condition and the strength of the thigh seem to enable a good indication of injury risk in elite youth soccer players. However, this finding has to be taken with caution due to a small number of injury cases. Nonetheless, these preliminary results may have practical implications for future directions in injury risk screening and in planning and developing customized training programs to counteract intrinsic injury risk factors in elite youth soccer players.

Implementation of an Injury Prevention Program in NCAA Division I Athletics Reduces Injury-Related Health Care Costs

Background:

The estimated cost per year of injuries in collegiate athletics has been reported to be billions of dollars in the United States. Injury prevention programs are often assessed only by their ability to reduce injuries, and there is little evidence of any potential reduction in associated health care costs.

Purpose:

To investigate changes in injury-related health care costs at a National Collegiate Athletic Association (NCAA) Division I university after the implementation of an injury prevention program.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Included were 12 sports teams that used the injury prevention program (user group) and 16 teams that did not implement the program (nonuser group). The injury surveillance and prevention system (Sparta Science) utilized a commercially available force-plate system to assess kinematic variables, flag high-risk athletes, and guide individual conditioning programs. Data were obtained from 3 academic years before (2012-2014) and 2 academic years after (2015-2016) implementation of the Sparta Science system. The number of injuries and associated health care costs (surgery, clinic visits, imaging, and physical therapy) were compared between users and nonusers.

Results:

Total average annual injuries did not change significantly between users and nonusers after implementation of the program; however, users demonstrated a 23% reduction in clinic visits as compared with a 14% increase for nonusers (P = .049). Users demonstrated a 13% reduction in associated health care encounters, compared with a 13% increase for nonusers (P = .032). Overall health care costs changed significantly for both groups, with an observed 19% decrease ($2,456,154 to $1,978,799) for users and an 8% increase ($1,177,542 to $1,270,846) for nonusers (P < .01 for both). Costs related to associated health care encounters also decreased by 20% for users as compared with a 39% increase for nonusers (P = .027).

Conclusion:

This study demonstrated the ability to significantly reduce injury-related health care costs in NCAA Division I athletes via a comprehensive injury surveillance and prevention program utilizing force-plate technology. Given the substantial and appropriate focus on value of care delivery across the US health care system, we recommend the continued study of sports injury surveillance and prevention programs for reducing injury-related health care costs.

Adolescent Running Biomechanics - Implications for Injury Prevention and Rehabilitation

Global participation in running continues to increase, especially amongst adolescents. Consequently, the number of running-related injuries (RRI) in adolescents is rising. Emerging evidence now suggests that overuse type injuries involving growing bone (e.g., bone stress injuries) and soft tissues (e.g., tendinopathies) predominate in adolescents that participate in running-related sports. Associations between running biomechanics and overuse injuries have been widely studied in adults, however, relatively little research has comparatively targeted running biomechanics in adolescents. Moreover, available literature on injury prevention and rehabilitation for adolescent runners is limited, and there is a tendency to generalize adult literature to adolescent populations despite pertinent considerations regarding growth-related changes unique to these athletes. This perspective article provides commentary and expert opinion surrounding the state of knowledge and future directions for research in adolescent running biomechanics, injury prevention and supplemental training.

Epidemiology of Injuries in National Collegiate Athletic Association Women's Ice Hockey: 2014-2015 Through 2018-2019

CONTEXT

The National Collegiate Athletic Association (NCAA) has sponsored women's ice hockey championships since 2001, and sponsorship has grown over time.

BACKGROUND

Routine examinations of injuries sustained by athletes are important for identifying and understanding patterns that can be used to inform sport safety practices.

METHODS

Exposure and injury data collected in the NCAA Injury Surveillance Program from 2014-2015 through 2018-2019 were analyzed. Injury counts, rates, and proportions were used to describe injury characteristics, and injury rate ratios were used to examine differential injury rates.

RESULTS

The overall injury rate was 5.89 per 1000 athlete-exposures; preseason injury incidence rose sharply during 2016-2017 through 2018-2019. Head/face injuries (15.2%), knee injuries (13.2%), and shoulder injuries (12.9%) were the most commonly injured body parts, and injuries were most often classified as contusions (18.9%), strains (18.7%), and sprains (15.5%). Concussion (11.9%) was the most commonly reported specific injury, and concussion rates notably increased during 2017-2018 through 2018-2019.

SUMMARY

Study findings were generally consistent with the existing epidemiological evidence. Injury incidence in preseason and the etiology of strains warrant further attention in this population.

Neuromuscular Training and Motor Control in Youth Athletes: A Meta-Analysis

Our purpose in this review was to determine the effects of bodyweight-only neuromuscular training (NMT) programs on motor control of movement among youth athletes. We searched three electronic databases (CrossRef, Google Scholar, and PubMed), using the following inclusion criteria for selecting research studies: (a) healthy male and female participants aged 8-18 years who were engaged in organized sports; (b) interventions up to 16-weeks duration; (c) incorporation of a control group; and (d) interventions that utilized only exercises using participants' body mass. We calculated pooled estimates of effect sizes (standardized mean difference) for changes in motor control across nine studies (12 comparisons) using the inverse-variance random effects model for meta-analyses and 95% confidence intervals. Among the nine studies included in our meta-analysis, there was a moderate, significant effect in favor of neuromuscular training programs (0.79 [95% CI: 0.38, 1.20], Z = 3.76 [p = 0.0002]) on motor control. Heterogeneity was high and significant (I²= 77% [p = 0.00001]). Moderator analyses for age and stature revealed NMT programs to be more effective in younger, shorter, and lighter individuals. We found larger effect sizes in males, and for programs >8 weeks in duration. We concluded that the older and heavier an individual is, the less effective bodyweight-only NMT programs became, particularly for female participants. These results reinforce the notion that exercise to enhance motor control should be emphasized during pre-adolescence.

The Influence of Growth, Maturation and Resistance Training on Muscle-Tendon and Neuromuscular Adaptations: A Narrative Review

The purpose of this article is to provide an overview of the growth, maturation and resistance training-related changes in muscle-tendon and neuromuscular mechanisms in youth, and the subsequent effect on performance. Sprinting, jumping, kicking, and throwing are common movements in sport that have been shown to develop naturally with age, with improvements in performance being attributed to growth and maturity-related changes in neuromuscular mechanisms. These changes include moderate to very large increases in muscle physiological cross-sectional area (CSA), muscle volume and thickness, tendon CSA and stiffness, fascicle length, muscle activation, pre-activation, stretch reflex control accompanied by large reductions in electro-mechanical delay and co-contraction. Furthermore, a limited number of training studies examining neuromuscular changes following four to 20 weeks of resistance training have reported trivial to moderate differences in tendon stiffness, muscle CSA, muscle thickness, and motor unit activation accompanied by reductions in electromechanical delay (EMD) in pre-pubertal children. However, the interaction of maturity- and training-related neuromuscular adaptions remains unclear. An understanding of how different neuromuscular mechanisms adapt in response to growth, maturation and training is important in order to optimise training responsiveness in youth populations. Additionally, the impact that these muscle-tendon and neuromuscular changes have on force producing capabilities underpinning performance is unclear.

Combining the Copenhagen Adduction Exercise and Nordic Hamstring Exercise Improves Dynamic Balance Among Male Athletes: A Randomized Controlled Trial

BACKGROUND

Copenhagen adduction exercise (CAE) and Nordic hamstring exercise (NHE) reduce the incidence of groin and hamstring injuries. Efficient dynamic balance can improve motor performance and reduce the risk of injuries in athletes. However, the effects of these exercises on dynamic balance have not been investigated.

HYPOTHESIS

CAE and NHE, as well as a combination of both exercises, would improve dynamic balance among amateur male athletes.

STUDY DESIGN

Randomized controlled trial.

LEVEL OF EVIDENCE

Level 1.

METHODS

A total of 200 male athletes aged 21.9 ± 2.4 years were included in the study and randomly assigned to 4 groups: CAE group (n = 50), NHE group (n = 50), CAE and NHE group (n = 50), and a control group (n = 50). A total of 177 male athletes completed the study. The primary outcome measure was the limit of stability (LoS), which was measured using the Biodex Stability System to assess the performance of the dynamic balance. The LoS of the athletes' performance was measured pre- and postintervention after 6 weeks.

RESULTS

The LoS significantly improved in all treatment groups, including CAE (44.5% ± 5.3%), NHE (43.2% ± 5.3%), and CAE + NHE (48.4% ± 5.1%) groups when compared with the control group (28.3% ± 4.8%) after 6 weeks (all Ps < 0.01). The improvement of LoS was significantly greater in the CAE + NHE group compared with other groups (CAE, NHE, and control groups).

CONCLUSION

There was a significant increase in dynamic balance performance postintervention among male athletes. CAE and NHE may improve injury prevention programs.

CLINICAL RELEVANCE

The results of this study provide evidence for athlete trainers and coaches to consider including the CAE and NHE as components of injury prevention programs to improve balance capacity and performance in athletes. Such improvements in balance may prevent injury risk and decrease absenteeism and injury-related financial burdens.

Warm-Ups and Coaches' Perceptions: Searching for Clues to Improve Injury Prevention in Youth Basketball

Introduction: Regular use of neuromuscular training (NMT) warm-up programs improves performance and prevents injuries. However, low level of adoption of these programs remains a problem. Understanding the current warm-ups in youth basketball and coaches' perceptions on injury prevention can guide the design of superior implementation strategies. This study describes warm-ups in youth basketball and coaches' injury prevention-related knowledge, attitudes, beliefs, and information sources.

Methods: Youth basketball coaches (n = 50) completed a preseason questionnaire. The questionnaire covered warm-up length, use of aerobic/agility/balance/strength/other exercises in the warm-up, injury-related knowledge, attitudes, beliefs, and sources of information.

Results: Typical warm-up duration was ≤ 10 min (48.0% of coaches, 95% CI: ±13.8%). All coaches included aerobic exercises in their warm-up. Agility, strength, and balance exercises were utilized by 80.0% (95% CI: ±11.7%), 70.7% (95% CI: ±13.6%), and 26.8% (95% CI: ±13.6%) of coaches, respectively. Most coaches agreed to some extent that basketball injuries are preventable (94%) and that participating in a NMT warm-up program would reduce player's risk of injury (92%). Other coaches were identified as the most common source of information on warm-ups and injury prevention.

Discussion: Coaches use parts of effective NMT warm-up programs, but balance exercises are not well adopted. Considering the level of evidence supporting the importance of balance exercises in injury prevention, it is crucial to improve the implementation of NMT warm-up programs in youth basketball, for example, through educational courses. As fellow coaches were identified as the most important source of information, coaches' role in knowledge translation should be emphasized.

Performance Effects with Injury Prevention Exercise Programmes in Male Youth Football Players: A Randomised Trial Comparing Two Interventions

BACKGROUND

Increased performance from injury prevention exercise programmes (IPEPs) may affect injury risks positively and support the implementation of IPEPs. The primary aim was to study the performance effects of injury prevention exercises from two different IPEPs, the Knee Control IPEP and the further developed Knee Control+ IPEP, in youth male football players, and the secondary aim was to compare potential differences in performance effects between the IPEPs.

METHODS

Four male youth football teams were tested for agility, hop and sprint performance at the start of the second half of the competitive season and after the end of the 8-week season. Per randomisation, two teams used Knee Control and two teams Knee Control+.

RESULTS

In total, 47 players executed a median of 13 IPEP sessions (range 11-21 sessions). No improvements in performance were seen in the group as a whole. The intervention groups showed small declines in sprint and agility performance. There was a significant between-group difference in change for the 505 agility test, with improved performance in the Knee Control and worse performance in the Knee Control+ group, ΔKC vs KC+ = - 0.012 (95% CI - 0.19 to -0.04), d = 0.98.

CONCLUSIONS

No clinically meaningful performance effects were seen from the Knee Control or Knee Control+ IPEP in youth male athletes and no meaningful differences were seen between Knee Control and Knee Control+ regarding effects on performance tests.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03251404 . Registered on 16 August 2017.

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.

Effects of a 10 vs. 20-Min Injury Prevention Program on Neuromuscular and Functional Performance in Adolescent Football Players

Background

Regular injury prevention training is not only effective in reducing sports injury rates, but also in improving neuromuscular and performance-related variables. However, it is currently unknown if this effect can be modified by varying the training dosage.

Objective

To compare the effects of two injury prevention programmes with a different training duration on neuromuscular control and functional performance in adolescent football players.

Methods

342 (15.4 ± 1.7 years) male football players from 18 teams were initially included. The teams were cluster-randomized into two intervention groups. Both groups performed an injury prevention program twice a week during one football season (10 months) using the same exercises but a different duration. One intervention group (INT10, n = 175) performed the program for 10 min, while the other intervention group (INT20, n = 167) for 20 min. At the beginning and end of the season, balance control (Balance Error Scoring System = BESS), jump performance (Squat Jump, Countermovement Jump) and flexibility (Sit and Reach Test, ankle flexibility, hip flexibility) tests were performed. For the final analysis, nine teams with 104 players were considered.

Results

Significant group by time interactions were found for the sit and reach test (p < 0.001) and ankle flexibility (p < 0.001) with higher improvements in the INT20 group. Improvements over the period of one season but no group differences were found for the BESS, Squat Jump and hip flexibility.

Conclusion

Within a single training session, performing structured neuromuscular training with a longer duration is more effective than a shorter duration for improving lower extremity flexibility.

Integrated Strength and Fundamental Movement Skill Training in Children: A Pilot Study

Competence in fundamental movement skills is essential to enable children to be physically active. We investigated the effect of an integrated fundamental movement skill with a strength training intervention on children’s fundamental movement skills. Seventy-two (53% female) 10- to 11-year-old children from three primary schools assented to take part in this study (87% compliance). Schools were randomly allocated to a control (no intervention; n = 21), fundamental movement skill (FMS) (n = 18) or FMS and strength (FMS⁺; n = 20) group. Interventions were delivered twice weekly for four weeks, in addition to normal physical education. FMS competence was measured through the Canadian agility and movement skills assessment (CAMSA) (product-process) and through countermovement jump (CMJ) and 40-m sprint tests (product). Improvements were observed in the CAMSA in both FMS (4.6, 95% confidence intervals 2.9 to 6.4 Arbitrary Units (AUs), second-generation p-value (p_δ) = 0.03) and FMS⁺ (3.9, 2.1 to 5.3 AU, p_δ = 0.28) with no difference beyond our minimum threshold of 3 AU observed between these intervention groups (p_δ = 1). Clear improvements in CMJ were observed in FMS⁺ relative to the control (25, 18 to 32%, p_δ = 0) and FMS groups (15, 6.1 to 24%, p_δ = 0). These preliminary data suggest combined FMS and strength training warrants further investigation as a tool to develop fundamental movement skills in children.

The relationship between physical fitness attributes and sports injury in female, team ball sport players: a systematic review

BACKGROUND

Understanding the relationships between physical fitness characteristics and sports injury may assist with the development of injury minimisation programs. The purpose of this systematic review was to investigate the association between physical fitness attributes and sports injury in female, team ball sport players.

METHODS

Four scientific databases (MEDLINE, EMBASE, SPORTDiscus, Scopus) and reference lists of relevant research were searched for eligible studies up to September 2, 2019. Full-text articles examining the relationship between physical fitness and sports injury in female, team ball sport players were included. A modified Downs and Black checklist was used to assess methodological quality. Data synthesis determined summary conclusions based on the number of significant relationships divided by the total relationships investigated and reported as a percentage. Level of certainty was identified for summary conclusions based on level of evidence. Sub-analyses regarding competition level, age, and single injury types were also conducted.

RESULTS

A total of 44 studies were included. Data synthesis revealed no associations (low to moderate certainty) between body composition (1/9; 11%), flexibility (18-20%), and balance (2/8; 25%) and 'any injury' classification. No associations (mostly of moderate certainty) were found between flexibility (0-27%), muscular strength (0-27%), and body composition (14-33%) and various body region injury classifications, whereas mixed summary conclusions were shown for balance (0-48%). Many associations between physical fitness and sports injury were deemed 'unknown' or with an insufficient level of certainty. Sub-analyses revealed no association between strength and noncontact ACL injuries (0/5; 0%) or ankle sprains (0/12; 0%), and between flexibility and ankle sprains (1/5; 20%); however, insufficient certainty of these results exists. Clear associations were concluded between balance and lower body injuries in female, non-elite (10/16; 63%) and junior (9/12; 75%) team ball sport players, with moderate and insufficient certainty of these results, respectively.

CONCLUSION

Limited evidence is available to demonstrate relationships between physical fitness and sports injury in female, team ball sport players. High-quality evidence investigating the multifactorial nature of sports injury, including the interactions physical fitness qualities have with other injury determinants, is needed to better understand the role of physical fitness in minimising sports injuries in female, team ball sport players.

TRIAL REGISTRATION

CRD42017077374 (PROSPERO on September 14, 2017).

Comparison of 10 vs. 20 min neuromuscular training for the prevention of lower extremity injuries in male youth football: A cluster randomised controlled trial

The aim of this study was to compare the effects of 20 min neuromuscular training with a programme of 10 min in youth football players. 342 (15.4 ± 1.7 years) male football players from 18 teams were included, and cluster-randomized by team into two intervention groups. Both groups performed an injury prevention programme twice a week over five months using the same exercises but a different duration. The first intervention group (INT10, n = 175) performed the programme for 10 min, the second intervention group (INT20, n = 167) for 20 min. Primary outcomes were lower extremity (LE) injuries. Secondary outcomes were injury type, severity, mechanism and compliance to the intervention. 13 teams with 185 players were included for final analysis. No significant group difference was found between INT10 (6.37 per 1000 h) and INT20 (7.20 per 1000 h) for the incidence rate ratio of the lower extremities (IRR = 1.03, 95% confidence interval 0.59, 1.79), nor for the distribution of injury location, type, severity or mechanism. The results show that performing preventive exercises for 10 min is no less effective than 20 min in youth football players. Shorter training sessions can, therefore, be effectively used for injury prevention.

TRIAL REGISTRATION

DRKS00015282.

Perceptions of the technical staff of professional teams regarding injury prevention in Spanish national futsal leagues: a cross-sectional study

Futsal is a sport with increasing popularity and level of performance, both in male and female categories. Also, there are several injuries along a season, so it is needed to know how to reduce this burden. The purpose of this study was to describe the perceptions of technical staff on injury risk factors, risk testing and preventive measures, and the strategies used by them within professional male and female futsal teams. A cross-sectional study was designed during the 2017–2018 season. A total of 32 futsal teams involved in male and female Spanish national futsal leagues completed, through an online survey platform, a questionnaire about injury risk factors, risk testing and preventive measures. Findings showed that: (a) most teams reported enough human resources, but insufficient material and time resources, (b) the main risk factors detected were previous injuries, strength deficits and dehydration, (c) functional movement patterns, flexibility tests and self-report questionnaires were the most applied tests for detecting injury risks in their players and (d) most of the main preventive measures used by technical staff matched with the best valued by them. Technical staff defined properly the main risk factors in futsal performance, as well as they applied preventive strategies with scientific support. The information provided in this research could be of interest for sport scientists and technical staff when designing more accurate and efficient injury prevention programs in futsal.

Injury prevention programmes with plyometric and strengthening exercises improve on-field performance: a systematic review

Importance

Injury prevention programmes (IPPs) have been demonstrated to be highly efficacious in protecting young athletes from anterior cruciate ligament and other lower-extremity injuries. However, the effectiveness of these programme in practice has been limited due to poor adherence among coaches of organised sports teams.

Objective

A change in messaging from injury reduction to performance enhancement may be an effective strategy for improving adherence. We conducted a systematic review to address whether implementing IPP can also provide benefits on sports performance as measured by on-field tests.

Evidence review

Data Sources: PubMed, EMBASE and Cochrane Library databases were searched from January 2000 to August 2018.

Study Selection: English-language studies were selected if they evaluated on-field performance testing before and after participation in the IPP or compared with another programme/control. No limitations were placed on study design or study population. Studies were excluded if they evaluated programme without an explicit focus on injury prevention or reported on injury risk factors that were not related to athletic performance.

Study design

Systematic review

Data extraction

Study design, population, sport and level, comparison group and duration/frequency of the IPP were extracted from full-text articles. The results of performance testing were summarised into the following categories: balance, sprinting, agility, jumping, physical fitness and sport-specific skills.

Findings

The evidence shows that IPP can have beneficial effects on measures of sports performance and physical fitness. Factors that resulted in significant improvement included longer frequency and duration of the programme, as well as inclusion of plyometric and muscle strengthening exercises.

Conclusions

There is a wide variety of measures used for athletic performance. IPPs that are done more frequently for longer durations and that include strengthening and plyometric exercises have been shown to improve athletic performance. Enhanced performance with tests that can be conducted on the field with existing equipment may help convince coaches and athletes to improve adherence with the IPP exercises.

Level of evidence

Level II

The Effect of the "11+ Kids" Program on the Isokinetic Strength of Young Football Players

PURPOSE

The "11+ Kids" injury-prevention program has been shown to reduce injuries and related costs in youth football players less than 14 y of age. A major argument to convince coaches to use this exercise-based injury-prevention program is a potential performance enhancement of the players. Therefore, this study investigated the effects of the "11+ Kids" program on isokinetic strength.

METHODS

Two teams were randomly assigned to the intervention and control groups. The intervention group replaced their warm-up by the "11+ Kids" and the control group warmed up as usual. Two days before and after the 10-wk intervention, isokinetic strength of the hip adductors and abductors, knee flexors and extensors, and ankle invertors and evertors was tested.

RESULTS

Thirty-one players (mean age 11.5 [0.8] y) completed the study. The intervention group showed large improvements in all isokinetic strength measures (P < .001 for all measures; Cohen d = 0.8-1.4), whereas the control group only showed negligible to medium positive effects (P values ranging from .006 to .718; Cohen d = -0.1 to 0.7). The intervention was beneficial compared with the control group regarding isokinetic strength of the hip adductors (P < .001), knee flexors (P = .002), and ankle evertors (P < .001) and invertors (P = .005).

CONCLUSIONS

Given the relatively short intervention period of 10 wk, the observed improvements relate to a practically meaningful effect of the intervention. The gain in strength may improve players' performance and may contribute to a reduction of injury risk in the long-term application.

The 11+ Kids warm-up programme to prevent injuries in young Iranian male high-level football (soccer) players: A cluster-randomised controlled trial

OBJECTIVE

To assess the effectiveness of the 11+ Kids warm-up programme regarding injury reduction in male high-level children's football players.

DESIGN

Cluster-randomised controlled trial.

METHOD

Male youth football teams of Iran's high-level football schools were invited to participate. Inclusion criteria were: teams are competing in the highest league of their province; players are between 7 and 14 years old; regular training takes place at least twice per week. Teams were excluded if they used an injury prevention measure. Participating clubs were randomised to an intervention (INT, N = 20 teams) and a control group (CON, N = 22 teams), stratified by the number of teams and the age group. The groups were blinded against each other. The follow-up period was one season (9 months). INT replaced their warm-up by 11+ Kids. CON performed a standard warm-up programme. The primary outcome was the injury incidence density (injuries per 1000 h of football exposure), compared between groups by incidence rate ratios (RR).

RESULTS

In total, 64,047 h of football exposure of 962 players (INT = 443 players, 31,934 h of football, CON = 519 players, 32,113 h of football) were recorded. During the study, 90 (INT = 30; CON = 60) injuries occurred. The overall injury incidence density in INT was reduced by 50% compared to CON (RR 0.50; 95%-CI 0.32, 0.78). No injuries occurred during the execution of the intervention exercises.

CONCLUSIONS

The 11+ Kids reduces injuries in high-level children's football players, thus supporting player health and potentially performance and player development.

The burden of hospitalized sports-related injuries in children: an Australian population-based study, 2005-2013

Background

There is concern about recent increase and severity of sports-related injuries in children. Despite the benefits of sports participation, injuries may carry long-term health consequences. We aimed to evaluate the prevalence, characteristics and types of hospitalized sports-related injuries in children.

Methods

Population-based study of all acute sports-related injuries requiring hospitalization in children 5 to 15 years of age in New South Wales (NSW), Australia, 2005–2013. Health information was obtained from the NSW Admitted Patient Data Collection, a census of all hospital admissions from public and private hospitals. Children with a recorded ICD10-AM injury code (S00-T79) and sport-related activity code (U50-U70) were included. Prevalence and trend in injuries by age group, sporting code, body region affected and type of injury were assessed.

Results

There was a total of 20,034 hospitalizations for sports-related injuries (2.7% of all hospitalizations in children aged 5–15 years), involving 21,346 recorded injuries in 19,576 children. The overall population hospitalization period prevalence was 227 per 100,000 children aged 5–15 years in 2005–2013, remaining stable over time (RR 0.99; 95% CI 0.98–1.00). Football codes such as rugby league/union and soccer combined represented nearly two thirds of the total (60%). The most common body regions affected were the forearm (31%) head (15%) and hand injuries (13%). Fractures accounted for 65% of injuries followed by dislocations (10%) and traumatic brain injury (10%). Compared to other age groups, children aged 5–8 years had double the proportion of shoulder (15% vs. 7%) while 13–15 year olds had higher proportion of lower-leg (14% vs. 8%) and knee (6% vs.2%) injuries. One in seven injuries sustained while playing rugby league/union, baseball and hockey were traumatic brain injuries. A total of 444 (2.2%) of children had more than one hospitalization for sports-related injuries.

Conclusion

On average, six children were hospitalized every day for sports-related injuries in the last decade with trends remaining stable. The most common sports involved were football codes, one in three injuries involved the forearm and two thirds were fractures. These findings can be used to inform health policy and sporting governing bodies to target preventive interventions and promote safe sports participation in children.

Electronic supplementary material

The online version of this article (10.1186/s40621-018-0175-6) contains supplementary material, which is available to authorized users.

A Multinational Cluster Randomised Controlled Trial to Assess the Efficacy of '11+ Kids': A Warm-Up Programme to Prevent Injuries in Children's Football

Objective

The objective of this study was to assess the efficacy of a newly developed warm-up programme (‘11+ Kids’) regarding its potential to reduce injuries in children’s football.

Methods

Children’s football teams (under 9 years, under 11 years, and under 13 years age groups) from Switzerland, Germany, the Czech Republic and the Netherlands were invited. Clubs were randomised to an intervention group and a control group, and followed for one season. The intervention group replaced their usual warm-up by ‘11+ Kids’, while the control group warmed up as usual. The primary outcome was the overall risk of football-related injuries. Secondary outcomes were the risks of severe and lower extremity injuries. We calculated hazard ratios using extended Cox models, and performed a compliance analysis.

Results

In total, 292,749 h of football exposure of 3895 players were recorded. The mean age of players was 10.8 (standard deviation 1.4) years. During the study period, 374 (intervention group = 139; control group = 235) injuries occurred. The overall injury rate in the intervention group was reduced by 48% compared with the control group (hazard ratio 0.52; 95% confidence interval 0.32–0.86). Severe (74% reduction, hazard ratio 0.26; 95% confidence interval 0.10–0.64) and lower extremity injuries (55% reduction, hazard ratio 0.45; 95% confidence interval 0.24–0.84) were also reduced. Injury incidence decreased with increasing compliance.

Conclusion

‘11+ Kids’ is efficacious in reducing injuries in children’s football. We observed considerable effects for overall, severe and lower extremity injuries. The programme should be performed at least once per week to profit from an injury preventive effect. However, two sessions per week can be recommended to further increase the protective benefit.

Trial Registration

ClinicalTrials.gov identifier: NCT02222025.

Electronic supplementary material

The online version of this article (10.1007/s40279-017-0834-8) contains supplementary material, which is available to authorized users.

Effects of the '11+ Kids' injury prevention programme on severe injuries in children's football: a secondary analysis of data from a multicentre cluster-randomised controlled trial

BACKGROUND

To assess the effects of the injury prevention programme '11+ Kids' on reducing severe injuries in 7 to 13 year old football (soccer) players.

METHODS

Football clubs (under-9, under-11 and under-13 age groups) from the Czech Republic, Germany, the Netherlands and Switzerland were cluster-randomised (clubs) into an intervention (INT) and a control group (CON). INT replaced their usual warm-up by '11+ Kids' two times a week. CON followed their regular training regime. Match and training exposure and injury characteristics were recorded and injury incidence rates (IRs) and 95% CIs calculated. For the present analysis, only severe injuries (absence from training/match ≥28 days) were considered. Hazard ratios (HR) were calculated using extended Cox models.

RESULTS

The overall IR of severe injuries per 1000 football hours was 0.33 (95% CI 0.25 to 0.43) in CON and 0.15 (95% CI 0.10 to 0.23) in INT. There was a reduction of severe overall (HR 0.42, 95% CI 0.24 to 0.72), match (0.41, 0.17 to 0.95) and training injuries (0.42, 0.21 to 0.86) in INT. The injury types that were prevented the most were: other bone injuries 66%, fractures 49% and sprains and ligament injuries 37%. Severe injuries located at the knee (82%), hip/groin (81%), the foot/toe (80%) and the ankle (65%) were reduced tremendously.

CONCLUSIONS

'11+ Kids' has a large preventive effect on severe injuries by investing only 15 to 20 min per training session. The present results should motivate coaches to implement effective injury prevention programmes such as the '11+ Kids' in children's football.

TRIAL REGISTRATION NUMBER

NCT02222025.

Economic evaluations of strategies to prevent sports and recreational injury among children and adolescents: a systematic review

Objective

To identify, summarise and critically assess studies reporting costs and consequences of sport and recreation injury prevention strategies among children and adolescents.

Design

Systematic review.

Methods and data sources

We searched MEDLINE (Ovid), EMBASE, CINAHL, Pubmed, Econlit and SPORTDiscus and PEDE. Included studies were peer reviewed full economic evaluations or cost analyses of sport/recreation injury prevention among children and adolescents≤18 years of age. The Pediatric Quality Appraisal Questionnaire was used for quality assessment.

Results

The initial search yielded 1896 unique records; eight studies met inclusion criteria. Six studies were related to injury prevention in the context of recreation, two were related to sports. For recreation studies in cycling and swimming: costs per head injury averted was US$3109 to $228 197; costs per hospitalisation avoided was US$3526 to 872 794; cost per life saved/death avoided was US$3531 to $103 518 154. Sport interventions in hockey and soccer were cost saving (fewer injuries and lower costs). Global quality assessments ranged from poor to good. Important limitations included short time horizons and intermediate outcome measures.

Conclusions

Few rigorous economic evaluations related to sport and recreation injury prevention have been conducted. The range of estimates and variation in outcomes used preclude specific conclusions; however, where strategies both improve health and are cost saving, implementation should be prioritised. Future economic evaluations should incorporate time horizons sufficient to capture changes in long-term health and use utility-based outcome measures in order to capture individual preferences for changes in health states and facilitate comparison across intervention types.

Comparison of the '11+ Kids' injury prevention programme and a regular warmup in children's football (soccer): a cost effectiveness analysis

OBJECTIVE

To evaluate a potential reduction in injury related healthcare costs when using the '11+ Kids' injury prevention programme compared with a usual warmup in children's football.

METHODS

This cost effectiveness analysis was based on data collected in a cluster randomised controlled trial over one season from football teams (under-9 to under-13 age groups) in Switzerland. The intervention group (INT) replaced their usual warmup with '11+ Kids', while the control group (CON) warmed up as usual. Injuries, healthcare resource use and football exposure (in hours) were collected prospectively. We calculated the mean injury related costs in Swiss Francs (CHF) per 1000 hours of football. We calculated the cost effectiveness (the direct net healthcare costs divided by the net health effects of the '11+ Kids' intervention) based on the actual data in our study (trial based) and for a countrywide implementation scenario (model based).

RESULTS

Costs per 1000 hours of exposure were CHF228.34 (95% CI 137.45, 335.77) in the INT group and CHF469.00 (95% CI 273.30, 691.11) in the CON group. The cost difference per 1000 hours of exposure was CHF-240.66 (95%CI -406.89, -74.32). A countrywide implementation would reduce healthcare costs in Switzerland by CHF1.48 million per year. 1002 players with a mean age of 10.9 (SD 1.2) years participated. During 76 373 hours of football, 99 injuries occurred.

CONCLUSION

The '11+ Kids' programme reduced the healthcare costs by 51% and was dominant (ie, the INT group had lower costs and a lower injury risk) compared with a usual warmup. This provides a compelling case for widespread implementation.

Strength training as superior, dose-dependent and safe prevention of acute and overuse sports injuries: a systematic review, qualitative analysis and meta-analysis

Objective

This review aims to analyse strength training-based sports injury prevention randomised controlled trials (RCT) and present best evidence recommendations for athletes and future research. A priori PROSPERO registration; CRD42015006970.

Design

Systematic review, qualitative analysis and meta-analysis. Sorting of studies and quality assessments were performed by two independent authors. Qualitative analyses, relative risk (RR) estimate with robustness and strength of evidence tests, formal tests of publication bias and post-hoc meta-regression were performed.

Data sources

PubMed, Embase, Web of Science and SPORTDiscus were searched to July 2017.

Eligibility criteria for selecting studies

RCTs on strength training exercises as primary prevention of sports injuries.

Results

Six studies analysed five different interventions with four distinct outcomes. 7738 participants aged 12–40 years were included and sustained 177 acute or overuse injuries. Studies were published in 2003–2016, five from Europe and one from Africa. Cluster-adjusted intention-to-treat analysis established RR 0.338 (0.238–0.480). The result was consistent across robustness tests and strength of evidence was high. A 10% increase in strength training volume reduced the risk of injury by more than four percentage points. Formal tests found no publication bias.

Conclusion

The included studies were generally well designed and executed, had high compliance rates, were safe, and attained consistently favourable results across four different acute and overuse injury outcomes despite considerable differences in populations and interventions. Increasing strength training volume and intensity were associated with sports injury risk reduction. Three characteristically different approaches to prevention mechanisms were identified and incorporated into contemporary strength training recommendations.