Comprehensive warm-up programme to prevent injuries in young female footballers: cluster randomised controlled trial

A systematic review and network meta-analysis on the effectiveness of exercise-based interventions for reducing the injury incidence in youth team-sport players. Part 2: an analysis by movement patterns

The objectives of this network meta-analysis were: (a) to estimate and compare the pooled effects of some injury prevention programs (IPPs) whose exercise-based components were categorized using a movement pattern-specific taxonomy on reducing overall and some specific body regions (lower extremity, thigh, knee, and ankle) injury incidences in youth team sport athletes and (b) to explore the individual effects of these components on the injury incidence rates (IIRs) previously mentioned. Searches were performed in PubMed, Web of Science, SPORTDiscus, and Cochrane Library. Eligible criteria were: exercise-based interventions comprised of exercises involving athletic motor skill competencies and evaluated against a control group, overall IIRs were reported, and youth (≤19 years old) team sport players. For the current analysis, a taxonomy based on movement patterns was employed for exercise component identification (upper body pushing and pulling; lower body concentric and eccentric; core; mechanics; acceleration; and lower body stability). Pooled effects were calculated by frequentist random effects pairwise and network meta-analyses. Nineteen studies were included. Most of the IPPs exhibit risk reduction when compared to their control groups on overall, lower extremity, and ankle injuries. Interventions comprised of lower body concentric and eccentric, core, mechanics, and lower body stability exercises were the most effective measures for reducing these injuries. None of the IPPs demonstrated to be effective for reducing thigh injuries, and contradictory results were found for knee injuries. Individual analysis at component level revealed that the lower body (bilateral and unilateral, concentric, and eccentric) component was the only one associated with a significant reduction on overall injuries. Indirect evidence suggests that interventions incorporating lower body concentric and eccentric, core, mechanics, and lower body stability exercises might be the most effective for reducing overall, lower extremity, and ankle injuries in youth team sports.

Best practices for the dissemination and implementation of neuromuscular training injury prevention warm-ups in youth team sport: a systematic review

OBJECTIVE

To evaluate best practices for neuromuscular training (NMT) injury prevention warm-up programme dissemination and implementation (D&I) in youth team sports, including characteristics, contextual predictors and D&I strategy effectiveness.

DESIGN

Systematic review.

DATA SOURCES

Seven databases were searched.

ELIGIBILITY

The literature search followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

INCLUSION CRITERIA

participation in a team sport, ≥70% youth participants (<19 years), D&I outcomes with/without NMT-related D&I strategies. The risk of bias was assessed using the Downs & Black checklist.

RESULTS

Of 8334 identified papers, 68 were included. Sport participants included boys, girls and coaches. Top sports were soccer, basketball and rugby. Study designs included randomised controlled trials (RCTs) (29.4%), cross-sectional (23.5%) and quasi-experimental studies (13.2%). The median Downs & Black score was 14/33. Injury prevention effectiveness (vs efficacy) was rarely (8.3%) prioritised across the RCTs evaluating NMT programmes. Two RCTs (2.9%) used Type 2/3 hybrid approaches to investigate D&I strategies. 19 studies (31.6%) used D&I frameworks/models. Top barriers were time restrictions, lack of buy-in/support and limited benefit awareness. Top facilitators were comprehensive workshops and resource accessibility. Common D&I strategies included Workshops with supplementary Resources (WR; n=24) and Workshops with Resources plus in-season Personnel support (WRP; n=14). WR (70%) and WRP (64%) were similar in potential D&I effect. WR and WRP had similar injury reduction (36-72%) with higher adherence showing greater effectiveness.

CONCLUSIONS

Workshops including supplementary resources supported the success of NMT programme implementation, however, few studies examined effectiveness. High-quality D&I studies are needed to optimise the translation of NMT programmes into routine practice in youth sport.

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.

Injury Profile in Youth Female Athletes: A Systematic Review and Meta-Analysis

BACKGROUND

An increasing number of epidemiological studies assessing the incidence, prevalence and severity of injury in youth female sport are available. However, no study has sought to synthesise the current evidence base across all youth female sport. As such, a systematic review and meta-analysis of injury in this cohort is necessary to understand the diversity of injury and its associated burden between sports in addition to identifying the density of research available.

OBJECTIVE

To conduct a systematic review and meta-analysis of epidemiological data of injuries in youth female athletes with particular attention to injury incidence, mean days lost and injury burden.

METHODS

Searches were performed in PubMed, EBSCO (SPORTDiscus with Full Text MEDLINE, APA PsycINFO, CINAHL, Academic Search Complete) and Cochrane databases. Studies were considered if they reported time-loss injury incidence or prevalence in youth female (≤ 19 years old) athletes. Study quality and risk of bias were assessed using STROBE-SIIS extension, Newcastle-Ottawa Scale, and funnel plots, respectively. Injury incidence and burden rate data were modelled using a mixed-effect Poisson regression model. Days lost data were modelled using a generalised linear mixed model.

RESULTS

Thirty-two studies were included. The overall incidence rate, mean days lost per injury, and burden rate were 4.4 injuries per 1000 h (95% CI 3.3-5.9), 10 days (95% CI 6-15), and 46 days per 1000 h (95% CI 23-92), respectively. Forty percent of athletes sustained at least one time-loss injury. Competitive level was a significant moderator of match and training injury incidence, with elite youth athletes presenting greater pooled injury incidence estimates than non-elite athletes (p = 0.0315 and p = 0.0047, respectively). The influence of moderators on days lost and injury burden could not be determined due to an insufficient number of studies for analysis.

CONCLUSION

Despite a broad inclusion criterion, there is limited injury surveillance research available across youth female sport. Outside of soccer, little research density is evidenced with single studies available in popular team sports such as Australian football and rugby union. Insufficient study numbers reporting mean days lost and injury burden data were available for analysis, and pooled days lost data could only be estimated for soccer. This highlights a need for future research to report days lost data alongside injury number and exposure so burden can be calculated and the full risk of injury to youth female athletes can be identified.

The effect of the KNEE program for Netball players on the modified Star Excursion Balance Test - a randomized controlled trial

BACKGROUND

The aim was to investigate the effect of the KNEE program on postural control as measured by the modified Star Excursion Balance test (mSEBT) in Australian club level netball players.

METHODS

Two netball teams from Netball NSW Premier-League were recruited and randomized to complete either the KNEE program or a traditional warm-up. Cumulative, anterior, posteromedial, and posterolateral directions of the mSEBT were measured for both limbs at baseline, 8-weeks, and 5-months. Linear mixed models were used to assess the effect of the intervention on mSEBT outcomes.

RESULTS

When compared to a traditional warm-up, the KNEE program led to improvements in postural control in the PM direction of the mSEBT at 8 weeks (R: p = 0.005; L = 0.016) and 5 months (R: p = 0.006 and L: p = 0.026). For the cumulative score, there was a main effect of time with significant improvements between baseline and subsequent time points (p < 0.03), but there was no effect of group or interaction. No significant changes were found in ANT and PL directions.

CONCLUSION

The KNEE program when implemented as a warm-up prior to training and match-play can improve postural control in the PM direction which is integral to Netball.

Muscle injury characteristics and incidence rates in men's amateur soccer: A one season prospective study

The objectives of the study were to examine the incident rate (IR), characteristics, and mechanisms of muscle injuries of 121 men amateur soccer players that voluntarily participated in this project. Sixty-five muscle injuries with an overall IR of 3.62/1000 h, 95% CI 2.7-4.5, were reported. The most frequently injured muscle groups were the hamstrings (IR 1.78/1000 h, 95% CI 1.1-2.3), followed by the adductors (IR 1.5/1000 h, 95% CI 0.93-2.06). Most muscle injuries were characterized as mild (IR 2.3/1000 h, 95% CI 1.53-2.92) or minimal (IR 1.28/1000 h, 95% CI 1.16-2.39. Higher incidence of injury sustained during matches (IR 14.09 injuries/1000 h, 95% CI 9.49-18.7), than in training (IR 1.88 injuries/1000 h, 95% CI 1.19-2.56). The most frequent injury mechanisms were high-speed running (84.4%) and change of direction (44.4%), for hamstring and adductors-related groin injuries, respectively. Players aged over 24 years had a 7-fold increased risk to sustain a hamstring injury but a lower risk to sustain an adductor-related groin injury. Injury prevention and rehabilitation management strategies may reduce muscle injury rates in amateur soccer.

Do Exercise-Based Prevention Programs Reduce Injury in Endurance Runners? A Systematic Review and Meta-Analysis

BACKGROUND

Endurance running is a popular sport and recreational activity yet is associated with a high prevalence of injury. Running related injuries (RRIs) are a leading cause of drop-out and represent a substantial financial burden to runners and healthcare services. There is clear evidence for the use of exercise-based injury prevention programs in games-based and youth sport settings, yet the research investigating the use of exercise to reduce injury risk in endurance runners has not been adequately reviewed recently.

OBJECTIVES

The aim of this review and meta-analysis was to systematically summarize the current research that has investigated the effect of exercise-based prevention programs and their state of supervision on the risk of RRIs in endurance runners.

METHODS

Three databases were searched for relevant studies. Selection and review were completed by two independent reviewers using the following inclusion criteria: (1) study population used endurance running training for health, occupational, or performance outcome(s); (2) participants performed running as their main form of exercise (> 50% of their total training time); (3) study was a randomized controlled trial; (4) a non-running-based exercise intervention was used; (5) a running-only or placebo exercise control group was included; (6) injury rate or incidence was reported; (7) injuries were recorded prospectively alongside the exercise training. Two meta-analyses were conducted using random-effects models, one based on log risk ratio and one based on log incidence rate ratio. The Cochrane Risk of Bias Assessment Tool 2 was used to evaluate the quality of studies and the Grading of Recommendations Assessment, Development and Evaluations approach was employed to grade the certainty of evidence.

RESULTS

A total of nine articles containing 1904 participants were included in analysis. Overall pooled results showed no significant differences between intervention and control groups in injury risk (z = - 1.60; p = 0.110) and injury rate (z = - 0.98; p = 0.329), while a post hoc analysis evaluating supervised interventions only showed that injury risk was significantly lower in the intervention group compared to the control group (z = - 3.75, p < 0.001). Risk of bias assessment revealed that seven studies included in the analysis were of low quality.

CONCLUSIONS

Exercise-based interventions do not appear to reduce the risk and rate of running-related injuries. Supervision may be essential for exercise-based intervention programs to reduce risk of RRIs, possibly due to increased compliance. Studies with more robust designs that include supervised exercise interventions should be prioritized in the future.

TRIAL REGISTRY

Clinical Trial Registration: PROSPERO CRD42021211274.

Proprioceptive training methods (PTM) in female soccer players - a systematic review

BACKGROUND

Although previous studies have reported that proprioceptive training methods (PTM) have positive effects, there is a relatively small number of studies regarding the impact of PTM in women's soccer. Therefore, there is a need to systematize the given results. In this regard, this systematic review aimed to investigate the effect of proprioceptive training methods in female soccer players.

METHODS

The studies' search and analysis were done according to the PRISMA guidelines. The following databases were checked (Google Scholar, PubMed Cochrane and ProQuest), with additional publication time criteria (2000-2023) using the following keywords: proprioceptive, balance, neuromuscular, training, exercise, intervention, method, activity, female football players, female soccer players, woman soccer players.

RESULTS

A total of 7 studies were included in the quantitative synthesis that meet all the criteria with the number of participants being 2.247. Based on the analysis of the previous research and detailed discussion, the main findings of the study resulted in the partial improvement of explosive strength (66%), strength (50%), muscle imbalance and flexibility (50%) and the prevention and reduction of lower extremity injuries in female soccer players (60%). Only one study reported no significant differences between groups, where rate of major injuries was higher in experimental group.

CONCLUSION

The obtained results indicate the necessity to implement proprioceptive training in female soccer training programs, in order to influence the prevention and reduction of injuries and improve balance, proprioceptive ability and body control.

Gender-specific hip strength disparities correlate with injury patterns in NCAA men's and women's soccer players

BACKGROUND

In National Collegiate Athletic Association (NCAA) soccer athletes, men have higher rates of hip and groin strains, whereas women have higher rates of knee ligament injuries. Strength imbalances of the hip and thigh, specifically in agonist-antagonist muscles, are known risk factors for these injuries.

OBJECTIVE

To perform hip and thigh strength assessments in NCAA soccer players to evaluate for differences between genders and correlations with gender-specific injury patterns.

DESIGN

With a handheld dynamometer, weight-normalized isometric strength of six muscle groups (hip abductors, hip adductors, hip flexors, hip extensors, knee flexors, knee extensors) was calculated in NCAA soccer players. The strength ratio of each agonist-antagonist muscle was also calculated (hip abductors/adductors, hip flexors/extensors, knee extensors/flexors).

PARTICIPANTS

Thirty-six NCAA soccer players (18 men, 18 women) from a single NCAA Division III institution.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Weight-normalized strength of six muscle groups and their agonist-antagonist strength ratios were compared between genders using linear mixed-effects models.

RESULTS

Compared with male players, female players had decreased weight-normalized strength for hip abduction (0.170 vs. 0.204, p = .012) and hip extension (0.172 vs. 0.211, p = .021). Otherwise, weight-normalized strength was similar between genders. When comparing agonist-antagonist strength ratios, there was a significant difference between female and male players for hip flexion:extension (1.70 vs. 1.35, p = .008), whereas the hip abduction: adduction ratio did not reach statistical significance (1.45 vs. 1.62, p = .080).

CONCLUSIONS

NCAA male and female soccer players had different hip strength profiles that fit their injury patterns. Male NCAA soccer players have higher rates of hip and groin strains, and men in the cohort had strength ratios that were deficient in the hip flexors and adductors compared with women. Female NCAA soccer players have higher rates of knee sprains and anterior cruciate ligament tears, and women in the cohort had strength ratios that were deficient in the hip abductors and extensors, which function to stabilize the knee. These strength disparities could be the focus of future gender-specific soccer injury prevention programs.

Injury prevention for women and girls playing Australian Football: programme cocreation, dissemination and early adopter coach feedback

Background

Adherence to injury prevention programmes may improve with greater end-user involvement and application of implementation frameworks during development. We describe the cocreation, initial dissemination and feedback from programme early adopters (coaches), to develop the first evidence-informed injury prevention programme for women playing community Australian Football (Prep-to-Play).

Methods

We used a pragmatic seven-step process for developing sports injury prevention programmes to (1) gain organisational support, (2) compile research evidence, (3) consult experts, (4) engage end-users, (5) test programme acceptability, (6) evaluate against theory and (7) gain early adopter feedback. All Australian Football-registered coaches of women's/girls' teams were sent a postseason survey to determine initial awareness, adoption and implementation (steps 5 and 6). Purposively selected coaches were invited to interviews/focus groups (step 7) to identify competency, organisational and leadership implementation drivers with a deductive thematic analysis applied.

Results

Prep-to-Play was cocreated using previous efficacious programmes and expert input (steps 1-4), and disseminated via the national sporting organisation in preseason 2019 to all registered coaches (step 5). 343 coaches (90 women) completed the postseason survey and 22 coaches (5 women) participated in an interview (n=9) or focus group (n=13) (steps 6 and 7). 268 coaches (78%) were aware of Prep-to-Play. Of those aware, 218 (81%) had used (at least one element) Prep-to-Play, and 143 (53%) used it at least twice per week. Competency drivers included local expert-delivered face-to-face workshops complimented by online content and ongoing support. Organisational drivers included coach education integrated into existing league/club. Leadership drivers included compulsory injury prevention education integrated into coach reaccreditation processes or incentivisation via recognition (eg, professional development points).

Conclusions

Cocreation and organisational support resulted in high programme awareness and adoption. However, high fidelity implementation and maintenance may need to be facilitated by competency, organisational and leadership drivers. Responsibility should be shared among all stakeholders.

Monitoring of sprint and change of direction velocity, vertical jump height, and repeated sprint ability in sub-elite female football players throughout their menstrual cycle

AIMS

The aim of this study was to investigate the associations between the early follicular (EF, i.e., menstruation), late follicular (LF), and middle luteal (ML) phases of the menstrual cycle and different factors that may influence football performance.

METHODS

To this end, 11 eumenorrheic sub-elite female football players underwent field tests to assess sprint speed, lower extremity power, repeated sprint ability, velocity on change of direction, and technical skills at each cycle phase.

RESULTS

Performance during the 15-m change of direction ability test, 15-m ball dribbling test, squat jump height, total sprint time [sum of 7 sprints] and decrement score [(mean sprint time/best sprint time × 100) - 100], maximum and mean heart rate, and perceived exertion did not significantly differ among menstrual cycle phases. Conversely, the linear sprint velocity over 10, 20, 30-m distances was decreased in EF vs LF (10-, 20- and 30-m) and in ML vs LF (10- and 20-m) (p < 0.05). The 40-m sprint velocity did not change in the different menstrual cycle phases.

CONCLUSION

Overall, our study suggests that sex hormone fluctuations during the menstrual cycle are not associated with vertical jump, velocity on change of direction, and repeated sprint ability, but may influence linear sprint velocity over short distances (10, 20, and 30 m).

A 2D video-based assessment is associated with 3D biomechanical contributors to dynamic knee valgus in the coronal plane

Introduction

Adolescent athletes involved in sports that involve cutting and landing maneuvers have an increased risk of anterior cruciate ligament (ACL) tears, highlighting the importance of identifying risky movement patterns such as dynamic knee valgus (DKV). Qualitative movement screenings have explored two-dimensional (2D) scoring criteria for DKV, however, there remains limited data on the validity of these screening tools. Determining a 2D scoring criterion for DKV that closely aligns with three-dimensional (3D) biomechanical measures will allow for the identification of poor knee position in adolescent athletes on a broad scale. The purpose of this study was to establish a 2D scoring criterion that corresponds to 3D biomechanical measures of DKV.

Methods

A total of 41 adolescent female club volleyball athletes performed a three-task movement screen consisting of a single-leg squat (SLS), single-leg drop landing (SLDL), and double-leg vertical jump (DLVJ). A single rater scored 2D videos of each task using four criteria for poor knee position. A motion capture system was used to calculate 3D joint angles, including pelvic obliquity, hip adduction, knee abduction, ankle eversion, and foot progression angle. Receiver operating characteristic curves were created for each 2D scoring criterion to determine cut points for the presence of movement faults, and areas under the curve (AUC) were computed to describe the accuracy of each 2D criterion compared to 3D biomechanical data.

Results

3D measures indicated knee abduction angles between 2.4°-4.6° (SD 4.1°-4.3°) at the time point when the center of the knee joint was most medial during the three tasks. AUCs were between 0.62 and 0.93 across scoring items. The MEDIAL scoring item, defined as the knee joint positioned inside the medial border of the shoe, demonstrated the greatest association to components of DKV, with AUCs ranging from 0.67 to 0.93.

Conclusion

The MEDIAL scoring criterion demonstrated the best performance in distinguishing components of DKV, specifically pelvic obliquity, hip adduction, ankle eversion, and foot progression. Along with the previously published scoring definitions for trunk-specific risk factors, the authors suggest that the MEDIAL criterion may be the most indicative of DKV, given an association with 3D biomechanical risk factors.

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.

An 8-week injury prevention exercise program combined with change-of-direction technique training limits movement patterns associated with anterior cruciate ligament injury risk

Knee ligament sprains are common during change-of-direction (COD) maneuvers in multidirectional team sports. This study aimed to compare the effects of an 8-week injury prevention exercise program containing COD-specific exercises and a similar program containing linear sprint exercises on injury- and performance-related variables during a 135° COD task. We hypothesized that the COD-specific training would lead to (H1) stronger reductions in biomechanical variables associated with anterior cruciate ligament (ACL) injury risk during COD, i.e. knee abduction moment and angle, hip internal rotation angle and lateral trunk lean, and (H2) more effective improvements in COD performance according to the COD completion time, executed angle, ground contact time, and approach speed. Twenty-two sports science students (40% female) completed biomechanical assessments of COD movement strategies before and after participating in two supervised 25-min training sessions per week over 8 weeks. We observed significant 'training x group' interaction effects in support of H1: the COD-specific training but not the linear sprint training led to reduced peak knee abduction moments (interaction, p = 0.027), initial knee abduction (interaction, p < 0.001), and initial lateral trunk lean angles (interaction, p < 0.001) compared to baseline. Although the COD-specific training resulted in sharper executed angles (interaction, p < 0.001), the sprint-specific training group showed reduced COD completion (interaction, p = 0.037) and ground contact times (interaction, p < 0.001). In conclusion, a combination of generic and COD-specific injury prevention training resulted in COD technique adaptations that can help to avoid ACL injury-prone COD movements but may negatively affect COD speed.

Anterior cruciate ligament injuries in female athletes: risk factors and strategies for prevention

Anterior cruciate ligament (ACL) injuries are among the most common and debilitating knee injuries in professional athletes with an incidence in females up to eight-times higher than their male counterparts. ACL injuries can be career-threatening and are associated with increased risk of developing knee osteoarthritis in future life. The increased risk of ACL injury in females has been attributed to various anatomical, developmental, neuromuscular, and hormonal factors. Anatomical and hormonal factors have been identified and investigated as significant contributors including osseous anatomy, ligament laxity, and hamstring muscular recruitment. Postural stability and impact absorption are associated with the stabilizing effort and stress on the ACL during sport activity, increasing the risk of noncontact pivot injury. Female patients have smaller diameter hamstring autografts than males, which may predispose to increased risk of re-rupture following ACL reconstruction and to an increased risk of chondral and meniscal injuries. The addition of an extra-articular tenodesis can reduce the risk of failure; therefore, it should routinely be considered in young elite athletes. Prevention programs target key aspects of training including plyometrics, strengthening, balance, endurance and stability, and neuromuscular training, reducing the risk of ACL injuries in female athletes by up to 90%. Sex disparities in access to training facilities may also play an important role in the risk of ACL injuries between males and females. Similarly, football boots, pitches quality, and football size and weight should be considered and tailored around females' characteristics. Finally, high levels of personal and sport-related stress have been shown to increase the risk of ACL injury which may be related to alterations in attention and coordination, together with increased muscular tension, and compromise the return to sport after ACL injury. Further investigations are still necessary to better understand and address the risk factors involved in ACL injuries in female athletes.

Motivation and goal-pursuit for injury prevention training in amateur football coaches: a cross-sectional study using the Health Action Process Approach

BACKGROUND

Adoption of injury prevention exercise programmes (IPEPs) in team sports is contingent on behaviour change among coaches. The aim was to study motivation and goal-pursuit in IPEP use among coaches of amateur football players.

METHODS

A cross-sectional study using web-based questionnaires was administered to coaches in one Swedish regional football district. The study was carried out one season after dissemination of the IPEP Knee Control+. The questionnaire was based on the Health Action Process Approach and covered perceptions and beliefs about using Knee Control+. Questions were rated on 1-7 Likert scales.

RESULTS

440 coaches participated (response rate 32%). Coaches were neutral about injury risks (median 4-5) and knowledge about preventing injuries (median 5) but had positive outcome expectancies of preventive training (median 6). Coaches who had used an IPEP perceived they had more knowledge about preventing injuries than non-users (median 5 vs 4, small effect size d=0.43). Coaches who used Knee Control+ were positive about their practical ability to use it (median 6) and had high intention to prioritise continuous use (median 7). Highly adherent coaches to higher extent believed that specific training may prevent injuries and had plans for how to instruct the players and how to work around barriers compared with low adherent coaches.

CONCLUSION

Coaches need more knowledge and support on IPEP usage and how to structure training. Coaches who had adopted Knee Control+ had high belief in their abilities but may need constructive plans on how to use the programme and to overcome barriers.

Prepare to fail or failing to prepare? Acute performance after the 11+ with and without strength exercises

Objectives

The 11+ is an effective injury prevention warm-up programme but is often poorly adopted in practice. One reason for low compliance is the claim that the strength training part of the programme acutely impairs muscle performance before the football activity. This study aims to compare the acute effects of the 11+ with (WU+S) or without (WU-S) the strength training part on performance.

Methods

Fifteen female junior football players completed WU+S and WU-S on two separate days in randomised order. Maximal voluntary torque in knee extension and flexion (60°/s and 180°/s) and countermovement jump (CMJ) were tested before and after performing the warm-up protocol. Sprint performance and rating of perceived exertion (RPE) were assessed post-warm-up.

Results

Warm-up with strength training reduced peak torque in knee flexion at 180°/s more than WU-S, while no differences were found at 60°/s. Knee extension work was reduced more with WU+S than WU-S at 180°/s, but no differences at 60°/s. Peak torque angle and CMJ were unaffected. Players were slower on 20 and 30 m sprints after WU+S than WU-S. The RPE was higher after WU+S than WU-S, but there were no differences in readiness to train between the two protocols.

Conclusion

Performing the 11+ programme as a warm-up routine with the strength training part can impair subsequent knee flexion torque at high velocity and sprint performance in female junior football players compared with performing the 11+ warm-up without the strength part.

[Management of muscle trauma in popular sports]

Muscle injuries make up the majority of injuries in popular sports. The causes for the development are multifactorial and can be divided into functional disorders and a lack of knowledge regarding training control. Insufficient warm-up and overtraining both increase the danger of the occurrence of the injury. Knowledge of the different types of muscle injuries and their incorporation into an exact classification enable the establishment of a correct treatment plan and can have a positive influence on the healing process. In addition to acute treatment the knowledge and application of preventive programs are necessary as these can significantly reduce the prevalence of muscle injuries in sports.

Injury data collection and utilisation practices in university sports teams: A cross-sectional study

OBJECTIVES

This study aimed to examine injury surveillance practices in a variety of university sports teams and barriers and facilitators for injury data collection and utilisation.

DESIGN

Cross-sectional study.

SETTING

University sports teams in Japan.

PARTICIPANTS

Medical, coaching, and other staff (non-medical/-coaching staff) of the university sports teams in Japan.

MAIN OUTCOME MEASURES

The survey included 31 questions that examined the barriers and facilitators for injury data collection, and the type of data on injury and exposure collected.

RESULTS

Injury data were collected during matches for 69 teams (48.3%) and training for 61 teams (42.7%). Injuries were primarily captured by athletic trainers in teams with medical staff, coaching staff and athletes in teams without medical staff. Common barriers in collecting and utilising injury data included limited funding for trained personnel and lack of time for medical staff to record data. Facilitating factors included clarification of the methods employed in recording and utilising injury data for teams with medical staff and the deployment of trained personnel to record injuries for teams without medical staff.

CONCLUSIONS

Approximately half of the Japanese university teams collected injury data. Considering barriers and facilitators is crucial to facilitate the collection and utilisation of injury data.

Effectiveness of Injury Prevention Programs With Core Muscle Strengthening Exercises to Reduce the Incidence of Hamstring Injury Among Soccer Players: A Systematic Review and Meta-Analysis

CONTEXT

Muscles in the hamstring group are frequently injured in sporting activities. Injury prevention programs (IPPs), including eccentric training of the hamstrings, have proven to be of great value in decreasing the injury rate of hamstring muscles.

OBJECTIVE

To examine the effectiveness of IPPs that include core muscle strengthening exercises (CMSEs) in reducing hamstring injury rates.

DATA SOURCES

This systematic review with meta-analysis was based upon the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A systematic search was conducted for relevant studies published from 1985 to 2021 using the following databases: Cochrane Library, MEDLINE, AMED, PubMed, Web of Science, and Physiotherapy Evidence Database (PEDro).

STUDY SELECTION

The initial electronic search found 2694 randomized controlled trials (RCTs). After removing duplicate entries, 1374 articles were screened by their titles and abstracts, and 53 full-text records were assessed, of which 43 were excluded. The remaining 10 articles were reviewed in detail, from which 5 studies met our inclusion criteria and were included in the current meta-analysis.

STUDY DESIGN

Systematic review and meta-analysis of RCTs.

LEVEL OF EVIDENCE

Level 1a.

DATA EXTRACTION

Two researchers independently completed the abstract review and performed full-text reviews. A third reviewer was consulted to reach a consensus if any discrepancies were noted. Details were recorded about the participants, methodological aspects, eligibility criteria, intervention data, and outcome measures, including age; number of subjects in the intervention/control group; number of injuries in each group; and the duration, frequency, and intensity of the training conducted in the intervention.

RESULTS

The pooled results of 4728 players and 379,102 exposure hours showed 47% hamstring injury reduction per 1000 h of exposure in the intervention group compared with the control group with an injury risk ratio of 0.53 (95% CI [0.28, 0.98], P = 0.04).

CONCLUSION

The results indicate that CMSEs incorporated with IPPs reduce susceptibility and risk of hamstring injuries in soccer players.

Implementation of the injury prevention exercise programme Knee Control+: a cross-sectional study after dissemination efforts within a football district

BACKGROUND

The Reach, Effectiveness, Adoption, Implementation, and Maintenance (RE-AIM) framework can be used for evaluation of implementation initiatives in sports injury prevention. The aim was to evaluate the implementation of the injury prevention exercise programme Knee Control+ among amateur clubs and coaches in one regional football district using all five dimensions of the RE-AIM framework.

METHODS

Dissemination of Knee Control+ during the 2021 season with information and webinars within one regional football district. This was followed by a cross-sectional study with questionnaires to club personnel and coaches after the season.

RESULTS

The reach of Knee Control+ was fair to high, 83% of club personnel and 66% of coaches knew about the programme. 41% of club personnel and 51% of coaches had adopted it. Perceived programme effectiveness was high (6 on a 1-7 Likert scale) among coaches. Regarding implementation and maintenance, 27% of club personnel had informed coaches about Knee Control+ and 57% planned to inform coaches. The coaches had implemented the programme mainly as recommended, but half used the programme once per week or less. Intention to maintain use of the programme was high (7 on a 1-7 Likert scale) among coaches.

CONCLUSION

The reach of Knee Control+ was fair to high, and adoption was fair in clubs, but there was a lack of policies for preventive training. Active strategies probably need to accompany dissemination of programme material. Reach, perceived effectiveness, adoption, implementation and planned maintenance were positive among coaches, but further studies are needed to analyse long-term maintenance.

Efficacy of a Neuromuscular Warm-up Program in Reducing the Risk of School Sports Injury among Chinese Children: A Cluster Randomized Controlled Trial

Background

Children who participate in sports have reduced cardiovascular risk, obesity, and type 2 diabetes. However, sports participation also comes with an inherent risk of sports-related injuries.

Purpose

To examine the efficacy of a school-based neuromuscular warm-up program (NWP) in reducing the risk of school sports injury (SSI) in children and the impact of different levels of compliance on the effectiveness of the program.

Study Design

Randomized controlled trial; Level of evidence, 1.

Methods

A total of 421 students from grades 4 to 6 at a single school (age range, 9-14 years) were randomized by grade to an intervention group and a control group. The intervention group participated in a 13-week simplified (8-minute) NWP designed to reduce SSI risk. The control group participated in a standard warm-up of the same length and duration. Exposure, compliance, and injury data were collected via a weekly form. The primary injury outcome was all SSIs. Secondary outcomes included injuries from physical education (PE) and non-PE class, upper and lower extremity injuries, other location injuries, and time-loss injuries. A Poisson regression model using an intent-to-treat analysis was performed to estimate the incidence rate ratio (IRR) for all injuries in the intervention group compared with the control group. To examine the influence of level of compliance, we divided the intervention group into low compliance (participation 1-2 times/wk) and high compliance (participation >2 times/wk) then compared the difference on injury rates (IRs) between these groups and the control group.

Results

There were significant differences between the intervention and control groups regarding all SSIs (IRR, 0.47; 95% CI, 0.23-0.96; P = .038), PE class injuries (IRR, 0.37; 95% CI, 0.14-0.99; P = .048), and other location injuries (IRR, 0.20; 95% CI, 0.05-0.82; P = .025). The compliance analysis revealed that although the low-compliance group was able to reduce the risk of SSIs (IR, 4.43; 95% CI, 2.49-6.37) compared with the control group (IR, 7.60; 95% CI, 5.61-9.59), the high-compliance group produced a better effect in reducing the SSI risk (IR, 1.80; 95% CI, 0.04-3.56).

Conclusion

The simplified NWP used in this study was efficacious in the reduction of SSIs in children.

Registration

ChiCTR2100043875 (Chinese Clinical Trial Registry; http://www.chictr.org.cn).

High Compliance with the 11+ Injury Prevention Program Results in Better Win-Loss Records

Background

The 11+ injury prevention program (IPP) has been shown to decrease injury rates. However, few studies have investigated compliance and its overall relationship to team performance.

Hypothesis/Purpose

To examine if level of compliance while implementing the 11+ would impact team performance outcomes (wins, losses and ties). The authors hypothesized that higher team compliance to the IPP would be consistent with improved overall team performance (more wins and fewer losses).

Study Design

Prospective, cluster randomized controlled trial.

Methods

This study was conducted in NCAA men's soccer teams for one season and examined the efficacy of the 11+ IPP. The outcome variables examined were levels of compliance and team performance record: wins, losses, and ties. Twenty-seven teams (n=675 players) served as the intervention group (IG) and used the 11+ program while 34 teams (n=850 players) served as the control group (CG). Compliance and team performance were recorded. There were three compliance categories that were defined prospectively, low (LC, < 1 dose/week), moderate (MC, >1 and <2 doses/week), and high (HC, >2 doses/week). Descriptive and inferential tests were used to compare the CG, the IG, and compliance to team performance. Three independent t-tests were used to analyze outcome to group (IG vs. CG). A one way-MANOVA test was used to analyze compliance to win/loss/tie record, followed up by one-way ANOVA tests to analyze how compliance impacted wins, losses and ties, independently. Partial η2 measures were calculated to determine the effect size of level of compliance on outcome. A Tukey post-hoc analysis was used to analyze specific differences between levels of compliance and specific outcome measures.

Results

There were significantly more wins (IG: 10.67±2.63 versus CG: 8.15±3.83, CI, 7.95 - 9.69, p = 0.005) and fewer losses (IG: 5.56±1.97 versus CG: 8.12±3.59, CI, 5.66 to 7.43, p = 0.002) recorded for the teams using the 11+ program. There was a statistically significant difference between levels of compliance (high, moderate or low) on the dependent variables (wins, losses, and ties), F(3, 22) = 3.780, p =0.004; Wilks' Λ = .435; partial η2 = .340.

Conclusion

The 11+ has the capacity to improve overall team performance in male collegiate soccer teams. The higher the compliance, the more favorable the team performance. This research may be a vital addition when attempting to persuade coaching staffs to adopt an IPP into their training regimen.

Level of Evidence

Level I.

The effects of high-velocity hamstring muscle training on injury prevention in football players

Background: Explosive and fast body movements, sprints, jumps and quick changes of direction, which are characteristic of the football training, place considerable strain on the hamstring muscles. Due to the high occurrence of hamstring injuries, new preventive strategies are required that focus on high-velocity training. The purpose was to assess the effectiveness of high-velocity elastic-band training in reducing the occurrence of hamstring injuries in football players. Methods: Male football players from 15 teams (n = 319) playing in national competitions participated in this study. The players were involved in a 5-week exercise period in either the intervention group (INT) or the control group (CON), with a follow-up period of ∼4 months where hamstring injuries and exposure time were recorded. The INT group had two to three sessions per week of elastic-band training with low-load, high-velocity leg curls while lying prone; the CON group performed self-paced football-specific drills. Results: The incidence rate of hamstring injuries was 6.5% in the INT group (8 out of 123 players) and 9.2% in the CON group (18 out of 196 players). Although the INT group showed almost 1/3 reduction in hamstring injury incidence compared to the CON group, the difference was not statistically significant (p > 0.05). Moreover, no differences (p > 0.05, odds ratio [OR] = trivial-to-small) in distribution between the groups were found in hamstring injury characteristics (leg dominance and mechanism) except for the distribution of injuries that occurred during matches or training (p = 0.036; OR = 6.14, moderate). Conclusion: The program of high-velocity elastic-band training did not prove to be effective in preventing hamstring muscle injuries in football players despite displaying some positive indications that could be considering when creating injury prevention programs.

The Effects of FIFA 11+ Kids Prevention Program on Kinematic Risk Factors for ACL Injury in Preadolescent Female Soccer Players: A Randomized Controlled Trial

This study aimed to investigate the effects of the 8-week FIFA 11+ Kids program on kinematic risk factors for ACL injury in preadolescent female soccer players during single-leg drop landing. For this, 36 preadolescent female soccer players (10-12 years old) were randomly allocated to the FIFA 11+ Kids program and control groups (18 players per group). The intervention group performed the FIFA 11+ Kids warm-up program twice per week for 8 weeks, while the control group continued with regular warm-up. Trunk, hip, and knee peak angles (from initial ground contact to peak knee flexion) were collected during the single-leg drop landing using a 3D motion capture system. A repeated measure ANOVA was used to analyze groups over time. Significant group × time interactions were found for the peak knee flexion, with a medium effect size (p = 0.05; effect size = 0.11), and peak hip internal rotation angles, with a large effect size (p < 0.01; effect size = 0.28). We found that the FIFA 11+ Kids program was effective in improving knee flexion and hip internal rotation, likely resulting in reducing ACL stress during single-leg drop landing in young soccer players.

Potential Effects of Dynamic Stretching on Injury Incidence of Athletes: A Narrative Review of Risk Factors

The use of dynamic stretching as a replacement for static stretching in the warm-up is widespread based on the reports of static stretching-induced performance impairments. While acute and chronic static stretching has been reported to reduce musculotendinous injuries, especially with explosive and change of direction actions, the influence of dynamic stretching on injury incidence lacks a similar volume of literature for acute and chronic responses. It was the objective of this narrative review to examine the acute and training effects of dynamic stretching on injury incidence and possible moderating variables such as dynamic stretching effects on range of motion, strength, balance, proprioception, muscle morphology, and psycho-physiological responses. One study demonstrated no significant difference regarding injury incidence when comparing a dynamic stretching-only group versus a combined dynamic stretching plus static stretching group. The only other study examined functional dynamic stretching training with injured dancers and reported improved ankle joint stability. However, several studies have shown that dynamic activity with some dynamic stretching exercises within a warm-up consistently demonstrates positive effects on injury incidence. Regarding moderating variables, while there is evidence that an acute bout of dynamic stretching can enhance range of motion, the acute and training effects of dynamic stretching on strength, balance, proprioception, and musculotendinous stiffness/compliance are less clear. The acute effects of dynamic stretching on thixotropic effects and psycho-physiological responses could be beneficial for injury reduction. However, the overall conflicting studies and a lack of substantial literature compared with SS effects points to a need for more extensive studies in this area.

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.

Knowledge in Motion: A Comprehensive Review of Evidence-Based Human Kinetics

This comprehensive review examines critical aspects of evidence-based human kinetics, focusing on bridging the gap between scientific evidence and practical implementation. To bridge this gap, the development of tailored education and training programs is essential, providing practitioners with the expertise and skills to effectively apply evidence-based programs and interventions. The effectiveness of these programs in improving physical fitness across all age groups has been widely demonstrated. In addition, integrating artificial intelligence and the principles of slow science into evidence-based practice promises to identify gaps in knowledge and stimulate further research in human kinetics. The purpose of this review is to provide researchers and practitioners with comprehensive information on the application of scientific principles in human kinetics. By highlighting the importance of evidence-based practice, this review is intended to promote the adoption of effective interventions to optimize physical health and enhance performance.

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.

Suggested improvements to the 11+ as identified by coaches, players, strength and conditioning staff and medical staff in New Zealand Football

The aim of this study was to investigate the experience with the 11+, attitudes towards injury prevention, and potential improvements to the 11+ and the delivery of injury prevention strategies within football. A qualitative study design was used to investigate the views of four stakeholder groups (players, coaches, strength and conditioning staff and clinicians). Twenty-two adults participated (nine women; median age 35.5 years). Participants were purposively recruited and were based in New Zealand. They represented various levels of football, including different genders, ages and levels of play. Focus group interviews were conducted, which were recorded, transcribed and subject to thematic analysis. Four key themes were identified: understanding of the 11+ injury prevention warm-up, content of an ideal injury prevention programme, structure of the programme and education, adherence and dissemination. The study found that while participants appeared to have good awareness of the existing 11+ programme and an interest in injury prevention, adherence and enthusiasm towards the programme was limited. Participants highlighted a number of elements that may help shape the development of a new injury prevention strategy, including a desire to retain many of the elements of the 11+ and to have a proven programme. Participants wanted greater variety, more football-specific elements and to implement a new strategy throughout a session, rather than being seen as a stand-alone warm-up. Whether the intervention should also include strength-based exercises, or whether this should be promoted outside of a football training session, was less certain.

Effects of the FIFA 11+ program on performance, biomechanical measures, and physiological responses: A systematic review

BACKGROUND

The side effects of the FIFA 11+ program on performance have not been generally reviewed. The objective of this study was to synthesize the literature on the effects of the 11+ on players' performance.

METHODS

Five online databases (PubMed, Scopus, ScienceDirect, Springer, and Google Scholar) were searched (from April 2006 to March 2022) using predefined keywords and sub-keywords. The potential references were primarily recorded through Endnote and imported to Covidence. Out of the 123 references screened by 2 blinded researchers through the software, 59 full texts were assessed for eligibility, 33 of which were ultimately included. The quality of the studies and the risk of bias were then assessed. Study ID, title, place, aim, design, start/end dates, population description, study criteria, statistical analysis, and outcomes were extracted.

RESULTS

Studies were conducted on male and female players aged 10-32 years old. The quality of the studies was moderate to high, and except for unclear bias for blinding outcome assessment, the risk of bias for all domains was low. Long-term application of the 11+ improved most biomechanical measures and physiological responses except for lower extremity stability, ankle evertors time latency, ankle dorsiflexion, and proprioception. Conversely, the 11+ showed acute negative effects on physical performance compared to dynamic warm-ups and non-significant effects on technical abilities.

CONCLUSION

Mid-to-long-term implementation of the 11+ improved the majority of biomechanical and a couple of physical measures but showed no effects on technical skills. Precaution must be observed for using the 11+ before competitions, as it could acutely decrease physical/technical performance. Given the contradictory nature of the literature, further studies should evaluate the short-to-mid-term effects of the 11+. Further studies are required to address ankle responses to the 11+ intervention.

[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.

Musculoskeletal Injury Risk in a Military Cadet Population Participating in an Injury-Prevention Program

Background and Objectives: Musculoskeletal injuries are a major health hazard among military personnel. Previous research has proposed several exercise-based strategies for prevention. The purpose of this study was to investigate the effect of an exercise-based injury-prevention program on the incidence of musculoskeletal injury, motor performance and psychosocial status. Materials and Methods: Thirty-six Estonian Military Academy cadets were randomly assigned into either an intervention or control group. The intervention group followed a neuromuscular exercise-based injury-prevention warm-up program, three times per week for 6 months. The control group continued with the usual warm-up. The main outcome measure was injury incidence during the study period. Additionally, evaluation of isokinetic lower-extremity strength, postural sway, physical fitness and psychosocial status was included pre- and post-intervention. Results: During the 6-month study period, the musculoskeletal injury incidence was 43% in the intervention group and 54% in the control group (RR = 0.8; 95% CI = 0.41 to 1.99). The noted 20% risk reduction was not statistically significant (p = 0.59). Furthermore, there were no statistically significant differences between the intervention and control group in motor performance or psychosocial status measures. Conclusions: In conclusion, no effect of the exercise-based injury-prevention program on injury risk, motor performance or psychosocial status could be detected.

Effects of Different Hamstring Eccentric Exercise Programs on Preventing Lower Extremity Injuries: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis aims to investigate the effects and differences of various hamstring eccentric training protocols for the prevention of lower limb injuries, and we further propose a more refined hamstring eccentric training protocol for the prevention of lower limb injuries. A literature search for the effects of hamstring eccentric training on lower extremity sports injuries was conducted using the PubMed, Web of Science, and EMBASE databases, and the literature was searched covering the period from the date of the database's creation to 20 August 2022. A meta-analysis of the included literature was performed using R.4.21 for lower extremity injuries, injuries in various parts of the lower extremity, and subgroup analysis for exercise frequency, exercise cycle, and exercise population. A total of 23 randomized controlled trial (RCT) studies were found to be included in the meta-analysis, and 15 of these trials, totaling 14,721 patients, were determined to be included in the overall lower extremity injury prevention effect. The analysis showed that the implementation of a hamstring eccentric training program reduced lower extremity injuries by 28%, and it resulted in a 46% decrease in hamstring injury rate and a 34% decrease in knee injury rate. The subgroup analysis revealed that the frequency of exercise was most significant in the twice-a-week exercise group, that the exercise program was most effective in preventing injuries in the 21-30-week exercise period, and that the program was most effective in preventing injuries in elite athletes and amateur adult athletic populations, compared with adolescents.

Extended Knee Control programme lowers weekly hamstring, knee and ankle injury prevalence compared with an adductor strength programme or self-selected injury prevention exercises in adolescent and adult amateur football players: a two-armed cluster-randomised trial with an additional comparison arm

OBJECTIVE

To evaluate the preventive efficacy of an extended version of the Knee Control injury prevention exercise programme (IPEP) compared with an adductor strength programme and to a comparison group using a self-selected IPEP in amateur adolescent and adult male and female football players.

METHODS

Two-armed cluster-randomised trial with an additional non-randomised arm. All 251 amateur teams (players 14-46 years) in one regional football district were approached. Teams meeting inclusion criteria were randomised to (1) extended Knee Control or (2) an adductor strength programme. Teams already using an IPEP were allocated to a comparison group and received no new intervention. Players responded to weekly questionnaires about football exposures and injuries during a 7-month season.

RESULTS

Seventeen teams in the extended Knee Control, 12 in the adductor and 17 in the comparison group participated, with 502 players. For the primary outcomes, no difference in injury incidence in three lower-limb injury locations combined (hamstring, knee and ankle) was seen between extended Knee Control and the adductor group, whereas extended Knee Control had 29% lower incidence than the comparison group (incidence rate ratio 0.71, 95% CI 0.52 to 0.98). No between-group differences in groin injury incidence were seen. The weekly injury prevalence rates in the three lower limb locations combined (hamstring, knee and ankle) were 17% lower (prevalence rate ratio (PRR) 0.83, 95% CI 0.69 to 1.00) and 26% lower (PRR 0.74, 95% CI 0.63 to 0.87) in extended Knee Control compared with the adductor and comparison groups, respectively.

CONCLUSION

No difference in injury incidence was seen between the extended Knee Control and the adductor programme whereas extended Knee Control reduced injury incidence by nearly one-third compared with a self-selected IPEP. Players in extended Knee Control had lower injury prevalence compared with an adductor or self-selected IPEP.

TRIAL REGISTRATION NUMBER

NCT04272047; Clinical trials.

Movement retraining programme in young soccer and rugby football players: A feasibility and proof of concept study

INTRODUCTION

Movement screening to identify abnormal movement patterns can inform development of effective interventions. The primary objective of this study was to evaluate the feasibility of using a movement screening tool in combination with a tailored movement control retraining programme in young soccer and rugby football players. A secondary objective was to investigate changes in movement control patterns post-intervention, to provide proof of concept (PoC) for movement retraining.

METHODS

52 male amateur players, including 34 soccer players (mean age 15 ± 2 years) and 18 rugby players (mean age 15 ± 1 years) participated. They were screened for movement control ability using a shortened version of the Hip and Lower Limb Movement Screening (Short-HLLMS) and completed an eight-week movement control retraining programme. Evaluation of feasibility included consent from players invited, adherence, attendance at the exercise sessions, drop-out and adverse events. Short-HLLMS total score and The Copenhagen Hip and Groin Outcome Score (HAGOS) were analysed to provide PoC for retraining movement control.

RESULTS

feasibility outcomes were favourable. Significant statistical changes occurred post-intervention in the Short-HLLMS total score (paired-samples t-test) and in three HAGOS subscales (symptoms, physical function in daily living and in sport and recreation) (Wilcoxon-Signed Rank Test) in both groups.

CONCLUSIONS

Feasibility of using the Short-HLLMS in combination with a movement control retraining programme in soccer and rugby players was promising. The data provided PoC for the potential application of a shortened version of the HLLMS to evaluate changes in movement control and to inform targeted motor control programmes.

Incidence and prevalence of hamstring injuries in field-based team sports: a systematic review and meta-analysis of 5952 injuries from over 7 million exposure hours

OBJECTIVE

This study aimed to systematically review and meta-analyse the incidence and prevalence of hamstring injuries in field-based team sports. A secondary aim was to determine the impact of other potential effect moderators (match vs training; sport; playing surface; cohort age, mass and stature; and year when data was collected) on the incidence of hamstring injury in field-based team sports.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

CINAHL, Cochrane Library, MEDLINE Complete (EBSCO), Embase, Web of Science and SPORTDiscus databases were searched from database inception to 5 August 2020.

ELIGIBILITY CRITERIA

Prospective cohort studies that assessed the incidence of hamstring injuries in field-based team sports.

METHOD

Following database search, article retrieval and title and abstract screening, articles were assessed for eligibility against predefined criteria then assessed for methodological quality using the Critical Appraisal Tool for prevalence studies. Meta-analysis was used to pool data across studies, with meta-regression used where possible.

RESULTS

Sixty-three articles were included in the meta-analysis, encompassing 5952 injuries and 7 262 168 hours of exposure across six field-based team sports (soccer, rugby union, field hockey, Gaelic football, hurling and Australian football). Hamstring injury incidence was 0.81 per 1000 hours, representing 10% of all injuries. Prevalence for a 9-month period was 13%, increasing 1.13-fold for every additional month of observation (p=0.004). Hamstring injury incidence increased 6.4% for every 1 year of increased average cohort age, was 9.4-fold higher in match compared with training scenarios (p=0.003) and was 1.5-fold higher on grass compared with artificial turf surfaces (p<0.001). Hamstring injury incidence was not significantly moderated by average cohort mass (p=0.542) or stature (p=0.593), was not significantly different between sports (p=0.150) and has not significantly changed over the last 30 years (p=0.269).

CONCLUSION

Hamstring injury represents 10% of all injuries in field-based team sports, with 13% of the athletes experiencing a hamstring injury over a 9-month period most commonly during matches. More work is needed to reduce the incidence of hamstring injury in field-based team sports.

PROSPERO REGISTRATION NUMBER

CRD42020200022.

Efectividad de los ejercicios nórdicos sobre la incidencia de lesiones de isquiotibiales en futbolistas profesionales y amateur masculinos entre los 15 y 41 años. Revisión sistemática

Introducción: Las lesiones musculares son comunes en futbolistas, siendo la lesión de isquiotibiales la más frecuente. Objetivo: Analizar la evidencia existente sobre los efectos de los ejercicios nórdicos en la incidencia de lesiones de isquiotibiales en jugadores de fútbol profesional y amateur masculinos entre los 15 y 41 años. Materiales y métodos: Se llevó a cabo una revisión sistemática siguiendo las recomendaciones de la declaración PRISMA, realizando la búsqueda de artículos en PubMed, BVS, Cochrane, Web OF Science y SCOPUS, además de consultar Google Scholar. La búsqueda se realizó basada en la estrategia PICO con los siguientes términos: hamstring muscles, exercise, rehabilitation, therapy, athletic injuries, soccer. Resultados: un total de 257 artículos resultaron de la búsqueda, siendo 5 los artículos incluidos en este estudio. Todos los estudios evidenciaron efectos positivos de los ejercicios nórdicos para los deportistas. Conclusiones: los ejercicios nórdicos redujeron la incidencia de lesión de isquiotibiales en 4 de los estudios analizados, el porcentaje de cumplimiento de las sesiones de intervención condicionaron la calidad de los efectos mientras que el momento de aplicación de la intervención (pre- o post-entreno) no influyó

Higher Adherence to Anterior Cruciate Ligament Injury Prevention Programs Is Associated With Lower Injury Rates: A Meta-Analysis and Meta-Regression

Background: Athletes who participate in sports that involve cutting and pivoting movements are particularly susceptible to anterior cruciate ligament (ACL) injury. Preventing this injury is the best way to combat its health consequences and costs. There may be a dose-response relationship between adherence and injury reduction. Purpose: We sought to examine whether athletes’ adherence to injury prevention programs (IPPs) is associated with reductions in ACL and lower extremity (LE) injuries. Methods: We conducted a systematic review of the PubMed, EMBASE, and Cochrane Library databases, searching for studies published between 2011 and 2021. Studies were included if they reported on the use of an ACL IPP compared with a control group and recorded the rate of injuries to calculate a rate ratio, as well as adherence to the program as a percentage of sessions performed. For the meta-analysis, the rate ratios were pooled using the DerSimonian-Laird random-effects model. Results: For the 15 studies included (11 randomized controlled trials and 4 cohort studies), the random-effects model grouped athletes’ adherence to an IPP as high (76% or more of the sessions), moderate (51%–75% of the sessions), and low (50% or fewer of the sessions). We found that athletes with the highest level of IPP adherence had a significantly lower incidence of ACL injury. The rate ratios for moderate and low adherence did not demonstrate a reduced incidence of ACL injury. Injury prevention program participation was also associated with a decrease in LE injury rates. Conclusion: This systematic review and meta-analysis found that athletes with high adherence to IPPs had reduced rates of ACL and LE injuries. Our findings suggest that educating coaches and athletes on the dose-dependent benefits of IPPs may promote the routine incorporation of these programs into warm-up sessions to decrease the risk of ACL and LE injuries.

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.

Passive Muscle Stiffness of Biceps Femoris is Acutely Reduced after Eccentric Knee Flexion

Eccentric hamstring exercises reportedly prevent hamstring strain injury in the biceps femoris long head (BFlh). However, information on the favorable adaptive responses in the BFlh to eccentric hamstring exercises is limited. We aimed to examine the acute effect of maximal isokinetic eccentric knee flexion on passive BFlh stiffness as a potential risk factor for the hamstring strain injury using ultrasound shear wave elastography. Ten young participants randomly performed both tasks involving five consecutive repetitions of isokinetic concentric and eccentric knee flexion with maximal effort on different legs. Passive BFlh shear modulus was taken before and 30, 60, 90, and 120 s after each task. Passive BFlh shear modulus was significantly reduced at all time points after eccentric knee flexion, whereas there was no significant change in passive BFlh shear modulus after the concentric task. The present findings indicate that passive BFlh stiffness would reduce specifically after low-volume, slow-velocity eccentric knee flexion exercise. The findings may help provide practitioners with a basis to develop more effective exercise programs for preventing HSI.

Mind the gap! A survey comparing current strength training methods used in men's versus women's first team and academy soccer

PURPOSE

Much less is known about strength and conditioning (S&C) practice in women's versus men's soccer. The aim of this study was to compare S&C practice between coaches working in men's or women's soccer, at first team or academy level, worldwide.

METHODS

A total of 170 participants, who were involved with S&C support at their soccer club (in Europe, USA and South America, within men's or women's first team or academy settings) completed a comprehensive online survey, designed to evaluate (i) their academic qualifications and S&C coaching experience; and their preferred methods for (ii) physical testing; (iii) strength and power development; (iv) plyometric training; (v) speed development; and (vi) periodization.

RESULTS

Women's academies had fewer weekly in-season S&C sessions than men's academies (1.6±0.6 vs. 2.3±0.9, p=0.005). Relatively, fewer women's academy S&C coaches (6%) used Olympic weightlifting movements than men's academy S&C coaches (32%, p=0.030). Relatively, more women's academy coaches (47%) used the Nordic hamstring exercise (NHE) compared to men's academy coaches (15%, p=0.006), but relatively more women's vs. men's first team coaches (61% vs. 38%, p=0.028) and women's vs. men's academy (61% vs. 38% coaches, p=0.049) utilised rating of perceived exertion-based load prescriptions.

CONCLUSION

Notable differences in S&C practice exist between coaches of men's and women's soccer squads, particularly at academy level. Fewer weekly S&C sessions in women academy players may have implications for physical development, while the greater use of subjective load prescriptions in both academy and first team women's squads may lead to sub-optimal performance gains.

Growth, maturation and injuries in high-level youth football (soccer): A mini review

Understanding the challenges football (soccer) players face during adolescence is fundamental to avoid disruptions in their development due to injury. This mini review will describe basic concepts of somatic growth and biological maturity, examine data from 53 prospective epidemiological studies on high-level youth football players and discuss how age, growth and maturity may affect the injury patterns observed. Based on the existing evidence, at least every third player sustains an injury during a football season. The thigh (median for studies of boys: 25%, median for girls: 21%), ankle (b: 18%, g: 30%), knee (b: 17%, g: 18%) and hip/groin (b: 14%, g: 10%) are the body parts injured most often, while muscle strains (b: 31%, g: 25%), sprains (b: 20%, g: 27%) and contusions (b: 17%, g: 16%) are the most common injury types. Injury trends are, however, not consistent throughout adolescence, and players' age, maturity status and position relative to peak height velocity (PHV) have shown to influence the number, type and location of injuries sustained. Despite a high volume of observational injury studies published on high-level youth players, girls (7 studies) and settings outside of Europe (included in 23% of studies) are underrepresented and should receive extra attention in the future. Based on the available epidemiological data, tailored injury reduction programmes can be considered in youth football, alongside application of general training principles such as progression, variation and individualization which may be especially important during vulnerable phases such as the adolescent growth spurt.

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 the FIFA 11+ and a modified warm-up programme on injury prevention and performance improvement among youth male football players

Introduction

The effects of the FIFA11+ programme (the 11+) on ankle and groin injuries and performance have remained questionable. The latter, particularly, has potentially reduced the implementation rate and applicability of the programme. This study aimed to evaluate the mid-to-long-term effects of the 11+ and a modified programme including football-specific exercises on injury prevention and performance improvement.

Materials and methods

Three teams of the Iranian Youth League (division two) volunteered to participate in this study and were randomly assigned to two intervention groups (F11+; n = 29, M11+; n = 31) and a control group (n = 30). The F11+ followed the FIFA 11+ programme, whereas the M11+ performed modified exercises three times weekly as a warm-up protocol before training and competition through a football season. The control group carried out its routine warm-ups, including joggings, basic football drills, and static stretches, while having no injury prevention approaches. Lower extremity injuries, as well as exposure time for each player, were recorded. The football-specific performance was assessed using the Illinois Agility and Slalom Dribbling tests. ANOVA, Fisher Freeman Halton, and chi-square tests were used to analyze the data.

Results

Injury incidences differed significantly between groups (p = 0.02, C = 0.40), with M11+ reporting the lowest incidence. Significant differences between the pre- and posttest as well as differences between the groups for development over time were revealed for the Illinois agility and dribbling speed (p≤0.01). Both performance tests demonstrated a large time effect, as the effect sizes for time in agility and dribbling speed were 0.74 (CI = [0.66; 0.79]) and 0.86 (CI = [0.79; 0.87]), respectively. The effect size for the interaction can be categorized as medium, with 0.38 (CI = [0.25; 0.49]) for agility and 0.52 (CI = [0.40; 0.61]) for dribbling speed. M11+ showed the largest improvement in both.

Discussion

Mid-to-long-term application of a structured dynamic warm-up that integrates injury prevention and performance approaches may lower injury incidences and improve youth subelite players’ performance. Although additional studies with larger samples are needed to prove the results of the current study, the amateur clubs/teams could integrate such twofold dynamic warm up into their routine training plan and benefit its advantages on injury prevention and performance improvement.

Barriers and facilitators to the adoption and implementation of evidence-based injury prevention training programmes: a narrative review

While there is a multitude of evidence supporting the efficacy of injury prevention training programmes, the literature investigating the implementation of these programmes is, in contrast, rather limited. This narrative review sought to describe the commonly reported barriers and facilitators of the implementation of injury prevention training programmes among athletes in organised sport. We also aimed to identify necessary steps to promote the uptake and sustainable use of these programmes in non-elite athletic communities. We identified 24 publications that discussed implementing evidence-based injury prevention training programmes. Frequently reported barriers to implementation include the perceived time and financial cost of the programme, coaches lacking confidence in their ability to implement it, and the programme including exercises that were difficult or confusing to follow. Frequently reported facilitators to implementation include the coach being aware of programme efficacy, shared motivation to complete the programme from both coaches and athletes, and the ability to easily integrate the programme into practice schedules. The current literature is focused on high-income, high-resource settings. We recommend that future studies focus on understanding the best practices of programme dissemination in culturally and economically diverse regions. Programmes ought to be of no financial burden to the user, be simply adaptable to different sports and individual athletes and be available for use in easily accessible forms, such as in a mobile smartphone application.

Hamstring Injury Rehabilitation and Prevention in the Female Athlete

Hamstring injuries (HSIs) are common in female athletes and are associated with a lengthy recovery period and a high rate of reinjury. Currently, the majority of existing literature investigating HSI rehabilitation has been conducted using male participants. However, female athletes display intrinsic anatomical and biomechanical differences compared to males that influences the way this population experiences HSIs and HSI rehabilitation. HSI rehabilitation and injury prevention guidelines for female athletes must take these differences into account. Female athletes display anatomical differences such as increased anterior pelvic tilting, gluteus maximus weakness, an increased pelvic width-to-femoral length ratio, and an increased degree of femoral anteversion, all of which can predispose females to HSIs. Maneuvers designed to strengthen the gluteal musculature and transverse abdominis can overcome these risk factors. Females show increased joint laxity and a greater range of motion of hip flexion and internal rotation compared to males. Females have lower passive hamstring stiffness than males, therefore hamstring flexibility exercises may not be as necessary during rehabilitation for females as in the male athlete population. Female athletes may instead benefit from trunk stabilization exercises and agility training due to neuromuscular control deficits that arise from the maturation and growth of the female pelvis. Existing literature on hamstring injury prevention shows consistent use of the Nordic Hamstring Exercise and balance exercises may reduce the risk of sustaining an HSI in both males and females, though more studies are needed to ascertain the optimal regimen for injury prevention in the female athlete population specifically. The goal of this clinical commentary is to discuss sex-specific anatomic and biomechanical differences of the lumbar, pelvic, and hip regions with the aim of providing guidelines for rehabilitation and injury prevention of HSIs in female athletes.

Level of Evidence

5.

Mechanistic evidence and exercise interventions: Causal claims, extrapolation, and implementation

RATIONALE

Exercise interventions and policies are widely prescribed in both sport and healthcare. Research investigating exercise interventions and policies is generally conducted using an Evidence-Based framework, placing an emphasis on evidence gathered from randomised controlled trials (RCTs).

AIMS AND OBJECTIVES

To explore the idea that, in addition to the assessment of evidence from RCTs when investigating exercise interventions, mechanistic studies ought to also be assessed and considered.

METHODS

This article assesses the rationale supporting the use of RCTs as evidence for exercise interventions, and the use of evidence of mechanisms in establishing efficacy, determining external validity, and tailoring interventions.

RESULTS AND CONCLUSIONS

The article argues that evidence from mechanistic studies ought to be considered alongside evidence from RCTs because: as RCTs investigating exercise interventions tend to be of low quality, mechanistic studies ought to be used to reinforce the evidence base; further, evidence from mechanistic studies is highly useful for both questions of extrapolation and implementation. This article argues for this on theoretical grounds, and also draws on a number of case studies.

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.

Quo Vadis Nordic Hamstring Exercise-Related Research?-A Scoping Review Revealing the Need for Improved Methodology and Reporting

The objective of this scoping review is to assess Nordic Hamstring Exercise quality (ANHEQ) of assessments and interventions according to the ANHEQ rating scales and to present practical recommendations for the expedient design and reporting of future studies. A total of 71 Nordic Hamstring Exercise (NHE) assessments and 83 NHE interventions were selected from the data sources PubMed, Scopus, and SPORTDiscus. Research studies which were presented in peer-reviewed academic journals and implemented the NHE during laboratory-based assessments or multi-week interventions met the eligibility criteria. NHE assessments analyzed force (51%), muscle activation (41%), knee angle kinematics (38%), and bilateral symmetry (37%). NHE interventions lasted 4-8 weeks (56%) and implied an exercise volume of two sessions per week (66%) with two sets per session (41%) and ≥8 repetitions per set (39%). The total ANHEQ scores of the included NHE assessments and interventions were 5.0 ± 2.0 and 2.0 ± 2.0 (median ± interquartile range), respectively. The largest deficits became apparent for consequences of impaired technique (87% 0-point-scores for assessments) and kneeling height (94% 0-point-scores for interventions). The 0-point-scores were generally higher for interventions compared to assessments for rigid fixation (87% vs. 34%), knee position (83% vs. 48%), kneeling height (94% vs. 63%), and separate familiarization (75% vs. 61%). The single ANHEQ criteria, which received the highest score most frequently, were rigid fixation (66% of assessments) and compliance (33% of interventions). The quality of NHE assessments and interventions was generally 'below average' or rather 'poor'. Both NHE assessments and interventions suffered from imprecise reporting or lacking information regarding NHE execution modalities and subsequent analyses. Based on the findings, this scoping review aggregates practical guidelines how to improve the design and reporting of future NHE-related research.