Effect of specific exercise-based football injury prevention programmes on the overall injury rate in football: a systematic review and meta-analysis of the FIFA 11 and 11+ programmes

Sports-related pain prevalence in TeamGym during normal and reduced training periods: A survey of 579 Danish gymnasts

OBJECTIVES

To describe the pain prevalence and its regional body distribution in TeamGym gymnasts, and secondly, to compare pain prevalence during a period with normal training load with a period with reduced training load.

DESIGN

Cross-sectional study.

SETTING

Data from (1) a period with normal training load (Aug-Dec 2020), and (2) a period with reduced training load (COVID-19 restrictions, Jan-June 2021) were included.

PARTICIPANTS

TeamGym gymnasts aged 10-30 years.

MAIN OUTCOME MEASURES

Self-reported history of pain/discomfort.

RESULTS

In total, 65 % of the invited gymnasts completed the survey at both time points, which included 579 gymnasts. The pain prevalence due to gymnastics was 80 % with the most prevalent pain regions being knee (20 % [95 %CI 18.1; 21.8]), wrist (17 % [95 %CI 15.5; 19.0]) and foot (16 % [95 %CI 14.4; 17.8]). Gradual pain onset was described in 42 % of all cases. During the reduced training period, the number of painful regions decreased by 26 %, but regional body pain distribution remained unchanged.

CONCLUSIONS

Four of five gymnasts experienced pain/discomfort during a normal five-month training period. Knee, wrist and foot were the most common painful regions with gradual pain onset as the most frequently reported. Reduced training load decreased the absolute pain prevalence, but regional body distribution was unaffected.

Long-Term Injury Survey in a Japanese University Women's Soccer Team

BACKGROUND

Injuries are common in soccer as it is a contact sport. However, longitudinal studies spanning multiple seasons, focused on injuries in female university soccer players in Japan, are lacking. Additionally, broader comparisons on injury patterns remain unexplored. The purpose of this study was to prospectively investigate injuries among female university soccer players over three seasons.

STUDY DESIGN

Descriptive epidemiological study.

METHODS

A total of 108 players from a university women's soccer team were included. A qualified athletic trainer assessed injury type (injury or disability), site and severity according to injury occurrence (game or practice) over three seasons. An orthopedic surgeon confirmed the resulting injury.

RESULTS

The overall injury rate was 1.62/1000 athlete exposures. The game injury rate (9.86/1000 athlete exposures) was higher than the practice injury rate (1.39/1000 athlete exposures). Sprains were the most common injury in games and practices; concussions and meniscal tears were also common during games. The lower limbs, particularly the ankles and feet, were the most common anatomical injury sites in both games and practices. Severe injuries requiring long-term withdrawal were frequently observed during games and practices. These included anterior cruciate ligament (ACL) tears, meniscal injuries, and severe concussions, all of which necessitated prolonged recovery periods and withdrawal from team activities.

CONCLUSION

Injury prevention measures should be prioritized for female university soccer players, especially to address the high injury rate during games and the frequent occurrence of severe injuries.

LEVEL OF EVIDENCE

3b.

Dynamic Warm-ups Play Pivotal Role in Athletic Performance and Injury Prevention

Dynamic warm-ups (DWs) are being increasingly used before athletic performance because of their perceived potential to promote readiness to play, enhance performance, and reduce injury across the recreational and elite athlete populations. There has been widespread adoption of warm-ups before athletic activity and evolving literature suggesting best practices including the role of static versus dynamic stretching and combination of pre-performance activities. DWs have gained traction as a preferred warm-up approach over static stretching because of the increased potential to improve athletic performance and reduce injury by enhancing the musculoskeletal, neurologic, cardiovascular, and psychological systems before performance. In this article, we aim to discuss the physiological and potential athletic performance benefits of DWs, key differences compared with prior widely adopted pre-activity static stretching, injury reduction benefits, and recommendations for implementing DWs into pre-athletic performance activities including crucial components of a multifaceted sport-specific approach.

Level of Evidence

Level V, expert opinion.

Comparative Effectiveness of Multi-Component, Exercise-Based Interventions for Preventing Soccer-Related Musculoskeletal Injuries: A Systematic Review and Meta-Analysis

Background: Soccer is a high-intensity sport characterized by a considerable incidence of injuries, particularly among professional male players, with injury rates ranging from 5.9 to 9.6 per 1000 player-hours. Lower limb injuries, including those affecting the knee, ankle, hip/groin, and hamstring muscles, are particularly prevalent. Additionally, a history of prior injuries may exacerbate the risk of recurrence. In response to these concerns, various injury prevention programs have been developed and implemented, targeting different genders and age groups. Methods: This systematic review and meta-analysis, conducted with the PRISMA guidelines, critically evaluated randomized RCTs across diverse genders and age groups to assess the efficacy of multi-component exercise-based injury prevention programs in reducing musculoskeletal injuries among soccer players. Comprehensive searches were conducted in ClinicalTrials.gov, CENTRAL, EMBASE, PubMed, Scopus, and Web of Science, with no language restrictions applied. Results: A total of 15 RCTs met the predefined inclusion criteria. The intervention programs were found to be significantly effective in reducing lower limb injuries, with a pooled RR of 0.73 (95% CI: 0.63 to 0.84, p = 0.035). Subgroup analyses further revealed a significant reduction in the incidence of hamstring, knee, and ankle injuries following the implementation of these programs. Conclusions: Multi-component exercise-based injury prevention programs demonstrate considerable efficacy in reducing musculoskeletal injuries in soccer players, spanning various age groups and genders. These findings underscore the potential of such programs in professional soccer injury management and highlight their importance in the development of comprehensive injury prevention strategies.

Effectiveness of FIFA injury prevention programs in reducing ankle injuries among football players: a systematic review

Background

Ankle injuries are some of the most common injuries among footballers and can prevent players from participating in sport. The Fédération Internationale de Football Association (FIFA) developed FIFA injury prevention programs to reduce overall football injuries, but their effectiveness on a particular joint, such as the ankle, was not assessed. Therefore, this project aims to investigate if these FIFA injury prevention programs are particularly effective in reducing ankle injuries.

Method

A systematic review was conducted with the following criteria for study selection: Randomized controlled trials (RTCs) comparing the FIFA programs (FIFA 11 the old version and FIFA 11+) with the usual training for the teams. Other studies that included the number or percentage of ankle injuries as an outcome. Sample: Male and female footballers aged between 13 and 40 years old and without any restriction on particular skill levels. The Physiotherapy Evidence Database scale (PEDro) was used to assess the methodological quality of the included studies.

Results

The search strategy identified five RCTs that used the FIFA programs. The included studies had a good-to-excellent methodological quality according to the PEDro scale (ranging from 5 to 7 out of 10). The pooled data from all the included studies indicated that the FIFA 11 and FIFA 11+ programs were effective in reducing the ankle injury rate by 14%, while pooled results from the studies that used the FIFA 11+ program significantly reduced ankle injury rate by 32%. However, the FIFA 11 program was not effective in reducing the ankle injury rate.

Conclusion

The FIFA programs, and especially the FIFA 11+ program, appear to be more effective than the usual training in preventing ankle injuries among footballers.

A Critical Review of Trunk and Hip Exercise Prescription: Applying Evidence for a Modern Approach

Exercise targeting the trunk and hip (core) musculature is common practice in rehabilitation and performance training. Historical underpinnings of core exercise focus on providing stability to the spine, thus improving the function of the spine and extremities, while instability has been postulated to result in pathology and impaired performance. Mechanistic studies on the topic are often conflicting and indeterminate, suggesting the theoretical underpinnings of targeted core exercise may be over assumed in common practice. The best modes of intervention also remain undefined, with combined methods having potential to optimize outcomes. This includes moving beyond isolated exercise camps and being inclusive of both targeted exercise and progressive multi-joint movements. The purpose of this clinical commentary is to describe the historical mechanisms of the stability-instability continuum and the role of exercise intervention. A spectrum of ideologies related to core exercise are examined, while appreciating positive outcomes of exercise interventions across healthy and pathological populations. Finally, exercise summaries were compiled to improve critical reasoning within current practice and inspire future investigations.

Level of Evidence

5.

Functional Knee Stability in Elite Field Hockey Depends on Playing Class and Gender

Field hockey, a physically demanding Olympic sport, carries a high risk of lower limb injuries, yet data on injury risk in elite field hockey are limited. Functional knee stability is important for injury prevention and a safe return to sport. This study is the first to investigate functional knee stability in elite field hockey, considering gender and playing class, and establishes reference data for functional knee stability by using a standardized test battery that assesses one- and two-legged stability, jumping tests, speed, and agility. Seventy-two elite field hockey players, 30 males and 42 females (age 19.82±3.74 years) were divided into High Playing Class (HPC) and Moderate Playing Class (MPC). HPC players showed significantly better performance in all functional tests except balance tests ( p <0.01-0.024). Females showed significantly better one- and two-leg stability ( p <0.01) with lower injury rates, indicating the relevance of gender considerations. The study emphasizes the importance of balance and stability in the prevention of lower limb injuries in Olympic field hockey and also highlights the importance of considering pre-existing deficits in functional knee capability when assessing athletes for return to sport. These results can help improve athletic performance, identify individual strengths and weaknesses, prevent injury or re-injury, and facilitate return to sport after injury.

The Protective Role of the FIFA 11+ Training Program on the Valgus Loading of the Knee in Academy Soccer Players Across a Season

Background: Improper neuromuscular control with excessive dynamic valgus loading of the knee has been identified as one of the main anterior cruciate ligament injury risk factors. This study aimed to analyze the impact of the FIFA 11+ training program on the valgus loading of the knee in academy soccer players over a competitive season. Methods: A prospective study was conducted on 85 players. The drop vertical jump test was carried out before the match and at the end of the same match at the beginning and at the end of the season over a period of 11 months. Results: An increase of the varus angle on the right limb was noted between the start and the end of the season at the beginning of the match (-4.7 ± 8.9 versus -6.9 ± 6, p = 0.003) and between the start and the end of the match in values measured at the beginning of the season (-4.7 ± 8.9 versus -7.7 ± 9, p < 0.001). An increase of the flexion angle of both limbs was noted between the start and the end of the season in values measured at the start of the match (left limb 76.8 ± 32.8 versus 98.6 ± 17.2, p < 0.001; right limb 76.4 ± 32.8 versus 96.1 ± 16.1, p < 0.001) and between the start and the end of the season in values measured at the end of the match (left limb 92.8 ± 19.1 versus 98.5 ± 16.3, p = 0.002; right limb 92.6 ± 19.2 versus 96.7 ± 14.5, p = 0.013). Conclusions: A decrease in dynamic valgus angle and an increase in knee flexion angle measured with the DVJ test were noted between the start and the end of the season, suggesting a protective role of the FIFA 11+ training program.

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

INTRODUCTION

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

EVIDENCE ACQUISITION

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

EVIDENCE SYNTHESIS

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

CONCLUSIONS

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

Is there a correlation among landing stability, ankle dorsiflexion range of motion, and ankle stiffness during single-leg landing?

BACKGROUND

Even though both landing stability and ankle dorsiflexion stiffness (ankle DR-stiffness) have been independently identified as risk factors associated with non-contact injuries, no study has specifically investigated the relationship between these two variables.

METHODS

Twenty male recreational athletes volunteered to participate in this study. Their ankle DF-ROM based on the weight-bearing lunge test, and landing stability based on the dynamic postural stability index (DPSI) and time to stabilization (TTS) were evaluated during a single-leg landing (SLL).

RESULTS

There was no statistically significant difference among ankle DF-ROM, ankle DF-stiffness, DPSI, and TTS during the SLL task (p > .05). Although a moderately positive relationship was observed between ankle DF-ROM and ankle DF-stiffness (p = .177; r = .354 [95% CI, -.153 to .653]) and a moderately negative relationship between ankle DF-ROM and TTS (p = .163; r = -.375 [95% CI, -.598 to .098]), these were not statistically significant.

CONCLUSION

The findings indicate that ankle DF-stiffness as an independent variable, does not significantly affect landing stability based on the TTS and DPSI indexes. However, its interaction with other variables, such as sex, age, and the nature of the movement task, may influence landing stability. This study area warrants further research.

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 1: an analysis by classical training components

OBJECTIVES

The primary purposes were (a) to estimate the pooled effects of injury prevention programs (IPPs) on reducing overall and some specific body regions (lower extremity, thigh, knee, and ankle) injury incidence rates (IIRs) and (b) to compare the effects of single- and multi-component IPPs on mitigating injury risk in youth team sport athletes. A secondary objective was to explore the individual effects of different components on these IIRs.

MATERIALS AND METHODS

Searches were performed up to 15 January 2024 in PubMed, Web of Science, SPORTDiscus, and Cochrane Library. Eligible criteria were: exercise-based interventions evaluated against a control group, overall IIRs were reported, and youth (≤19 years old) team sport players. Two reviewers extracted data and assessed trial quality using the Consolidated Standards of Reporting Trials (CONSORT) statement, the Physiotherapy Evidence Database Scale (PEDro), and a risk of bias tool (Cochrane Back and Neck Group). Pooled effects were calculated by Frequentist random effects pairwise and network meta-analyses.

RESULTS

Twenty-one studies were included. IPPs reduced overall, lower extremities, thigh, knee, and ankle IIRs by an average of approximately 35%. Most of the IPPs demonstrated statistically significant risk mitigation effects for overall and lower extremity injuries compared to control group. Interventions comprised exclusively of strength ([IRR = 0.3 [95%CI = 0.10-0.93]) and flexibility (IRR = 0.49 [95%CI = 0.36-0.68]), as well as those including stability exercises, were the most effective measures for reducing injuries in youth team sports.

CONCLUSIONS

The implementation of current IPPs in training sessions for several weeks has shown to be an effective strategy for reducing the risk of injury in youth team sport athletes by one-third. Indirect evidence suggests that strength, flexibility, and stability might be exercise components with the highest risk mitigation effects; however, more research is crucial to confirm our estimates with direct evidence.

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

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

Neurocognitive & Ecological Motor Learning Considerations for the 11+ ACL Injury Prevention Program: A Commentary

The 11+ is a structured warm-up program designed to prevent injuries in soccer players, but has proven efficacy in many populations, settings and sports. It consists of 15 exercises that target the most common injury sites, such as the knee, ankle, and groin. However, the implementation and adherence of the 11+ remain suboptimal, and recent compelling data indicates underlying mechanisms of injury risk related to neural control of movement may not be adequately targeted. Updates to the 11+ considering practical implications of neurocognitive and ecological motor learning may be warranted for coaches and practitioners. We review the evidence on how an updated 11+ may influence the cognitive and perceptual processes involved in motor control and learning, such as attention, anticipation, decision making, and feedback. How the 11+ can be adapted to the ecological constraints and affordances of the football (soccer) environment is also discussed, including the task, the individual, and the context. By considering these factors, the 11+ can be more effective, engaging, and enjoyable for the players, and thus improve its adoption and compliance. The 11+ has the capability to not only a physical warm-up, but also a neurocognitive and ecological preparation for the game. Therefore, the purpose of this manuscript is to describe the conceptual design of a new ecological neurocognitively enriched 11+, that builds on the strong foundation of the original intervention with considerations for the newly discovered potential neural control of movement risk factors.

Effectiveness of FIFA 11+ Injury Prevention Programs in Reducing Head and Neck Injuries, Including Concussion, Among Soccer Players: A Systematic Review and Meta-Analysis

The Federation Internationale de Football Association (FIFA) 11+ and 11+ Kids injury prevention programs have shown success in reducing overall injury risk in soccer players, yet their specific impact on head and neck injuries remains inadequately explored.

PURPOSE

To evaluate the effectiveness of FIFA 11+ and 11+ Kids injury prevention programs in reducing the incidence of head and neck injuries among soccer players.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, 2 investigators independently conducted searches in databases (Cochrane Library, PubMed, Web of Science, and PEDro) using keywords like "FIFA 11+," "football," "soccer," and "injury prevention." Only randomized controlled trials assessing FIFA 11+ programs in soccer players were included. Data analysis used the random effects model with RevMan Meta-Analysis software (version 5).

RESULTS

Among 397 studies, 4 met inclusion criteria. Pooled results from 7109 players and 532,341 exposure hours indicated a significant 40% reduction in head and neck injuries per 1000 hours of exposure in the intervention group compared to the control group (injury risk ratio 0.60, 95% CI, 0.41-0.88).

CONCLUSION

Implementing FIFA 11+ injury prevention programs significantly reduces the risk of head and neck injuries in soccer players, offering a compelling alternative to traditional warm-ups. This study contributes valuable evidence for optimizing injury prevention strategies in soccer training regimens.

Performing Lower-Limb Strength Exercises Before or After Training Does not Influence Fatigue Indices in Competitive Youth Soccer Players

ABSTRACT

Gantzer, C, Huff, D, Butterick, B, Chalmers, S, Marshall, P, Lovell, R, and Siegler, JC. Performing lower-limb strength exercises before or after training does not influence fatigue indices in competitive youth soccer players. J Strength Cond Res 38(10): 1760-1767, 2024-A multicenter approach was used to conduct a controlled, laboratory-based study ( Part A ) in conjunction with an ecologically focused, field-based study ( Part B ) of the influence of timing on hamstring fatigue induced by lower-limb strength exercises. Part A required players to perform the FIFA 11+ warm-up before a simulated soccer training session, whereas the other session involved removing the lower-limb strength exercises from the warm-up and delivering them after the simulated session. For Part B , players completed 2 live training sessions, where one session included the Nordic hamstring exercise (NHE) as part of a standardized warm-up before training and the other session incorporated the NHE at the end of training. Maximal hamstring force (MVC), rate of force development (RFD), countermovement jump (CMJ), and sprint speed (SS) were assessed before, during, and after the simulation and field training, respectively, to quantify fatigue across both study cohorts. There was no suggestion that timing of the intervention had an influence fatigue in either Part A or B , with no condition (MVC [ Part A & B ]: p > 0.43; RFD: p = 0.43; CMJ: p = 0.10; SS: p = 0.62), time (MVC: p > 0.30; RFD: p = 0.72; CMJ: p = 0.87; SS: p = 0.85), or interactions (MVC: p > 0.93; RFD: p = 0.78; CMJ: p = 0.99; SS: p = 0.94) evident. Our findings suggest youth soccer coaches should not be concerned with the timing of interventions, allowing them to focus instead on adherence and player buy-in.

Lost in research translation: Female athletes are not male athletes, especially at the hip

Altered shape of the proximal femur (cam morphology) or acetabulum (pincer morphology) is indicative of femoroacetabular impingement, which can result in hip pain and osteoarthritis of the hip. As mechanical load during growth affects the resulting bone shape, there is strong evidence in males that cam morphology develops during skeletal growth while physes are open, rather than as an adaptation after growth plates are closed (skeletal maturity). This adaptation is particularly evident in athletes who participate at elite levels prior to skeletal maturity. The research providing this evidence, however, has primarily focused on male athletes. Despite the lack of inclusion in the research, females consistently comprise two thirds of the clinical and surgical populations with structural hip pain or pathology. Knowledge gained from male-dominated cohorts may not appropriately transfer to female athletes, especially at the hip. This perspectives article briefly reviews differences between females and males in femoral and acetabular structure, hormones, timing of puberty/maturation, hypermobility, activity level and movement control-factors which affect hip structure development and loading. Without female-focused research, the application of research findings from male athletes to female athletes may lead to ineffective or even inappropriate recommendations and treatments. Thus, there is a critical need for investment in research to promote life-long hip health for females.

Preventive interventions for throwing injuries in baseball players: a scoping review

BACKGROUND

Shoulder and elbow pain are the common complaints associated with throwing injuries in baseball players. Prospective studies evaluating the effectiveness of stretching in increasing posterior shoulder flexibility or strengthening the external rotator muscles as preventive strategies for throwing injuries in baseball players have been published. However, there are limited reviews highlighting the role of preventive interventions for throwing injuries in baseball players. Therefore, this scoping review aimed to summarize the existing literature on preventive interventions for throwing injuries in baseball players.

METHODS

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, and Scopus databases on 3 March 2023. Two independent reviewers screened the studies based on the eligibility criteria. We extracted existing literature on preventive interventions and effectiveness for throwing injuries in baseball players, and participants' characteristics and results were extracted from the studies. This scoping review was performed in accordance with the Extended Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement for Scoping Reviews.

RESULTS

The initial database search yielded 1170 articles, four of which met the eligibility criteria. Of the included studies, two were randomized controlled trials, and the remaining two were prospective cohort studies. Eligible studies targeted youth-to high school-level players and focused on preventive programs for throwing injuries that manifest in the upper extremities of baseball players. The outcome measure most commonly used to quantify the effectiveness of prevention programs was the incidence of shoulder and elbow injuries, although the definitions vary among studies. The prevention program included sleeper stretching, shoulder external rotation strengthening exercises, and comprehensive prevention programs (focusing on improving the elbow, shoulder, and hip range of motion; rotator cuff and periscapular muscle strength; posture; and lower extremity balance). Each prevention program was reported to have the potential to reduce the incidence of throwing injuries in baseball players, and two studies suggested that high compliance with the program led to a lower injury risk.

CONCLUSION

This scoping review confirmed the presence of studies that examined preventive interventions for throwing injuries in baseball players. Preventive interventions that may reduce throwing injuries in baseball players include sleeper stretching, shoulder external rotation strengthening exercises, and comprehensive prevention programs. However, the characteristics of participants (eg, age, sports level, and position) and the definition of injury varied among previous studies. Injury profiles and prevention strategies may differ according to age, sport level, and position of players, and more studies are needed to prove this issue.

The Effects of Nordic Hamstring Exercise on Performance and Injury in the Lower Extremities: An Umbrella Review

Due to their potential positive outcomes, hamstring eccentric exercises are becoming increasingly popular in training regimens. Among the various exercises, the Nordic Hamstring Exercise (NHE) is the most common. Despite its popularity, there are still some doubts about its benefits and risks. So, the aim of this umbrella review was to summarize the effects of NHE on performance and injury prevention. Following the PRISMA guidelines, a comprehensive literature search was conducted across multiple e-databases, according to the P (injured and non-injured athletes or recreationally active or healthy individuals) I (NHE) C (no intervention, placebo, or other interventions) O (performance or injury) S (systematic reviews) model. The quality of the studies was accessed with the AMSTAR-2. From the 916 systematic reviews found, only 10 could be included. They encompassed 125 studies, enrolling 17,260 subjects. The results from the studies indicate that NHE interventions demonstrated positive effects on sprint performance, muscle activation, eccentric strength, and muscle architecture (fascicle length, muscle thickness, and pennation angle). Furthermore, NHE is effective in preventing hamstring injuries (up to 51%). In conclusion, NHE should be integrated in training (especially, in the warm-up phase) for both enhancing athletic performance and preventing hamstring injuries. For achieving more positive results, it is recommended that high-volume is followed by low-volume maintenance, targeting 48 reps/week.

Practitioners' perspective of non-contact injury risk factors and injury prevention programming in professional North American male soccer

OBJECTIVE

To evaluate non-contact injury prevention strategies of professional men's soccer clubs in elite North American league soccer. To understand the application, perceived effectiveness and barriers to implementation.

DESIGN

Online cross-Sectional Study.

SETTING

North American elite soccer teams.

PARTICIPANTS

96 medical and performance support staff of elite North American teams.

MAIN OUTCOME MEASURE

The survey consisted of 20 questions and captured 1) practitioners' demographics; 2) perceptions of risk factors; 3) the use of assessment and monitoring strategies; and 4) perceptions of the implementation of injury prevention programmes'.

RESULTS

Injury prevention programmes were perceived as 'effective' (Median 4, Interquartile range 4-4) and reduced injury rates (n = 94, 98%, 95 CI% 93 to 99). A range of potential risk factors were rated as "very important" (4.58 ± 0.52 Likert scale points; mean ± standard deviation). A multi-disciplinary approach to the design, application and monitoring of programmes was generally adopted. Competing training priorities (n = 75, 78%, 95 CI% 69 to 85) and game schedules (n = 71, 74%, 95 CI% 64 to 82) were the most prevalent barriers to injury prevention implementation.

CONCLUSIONS

Injury prevention programmes were perceived as effective in reducing non-contact injuries. Managing the conflicting priorities between scheduling training, tactical and conditioning goals were considered the key barriers to desired implementation.

Platelet-Poor versus Platelet-Rich Plasma for the Treatment of Muscle Injuries

ABSTRACT

Muscle injury in sport results in significant lost time and potential for reinjury for athletes. Autologous blood product, namely, platelet-rich plasma (PRP), has been investigated for possible augmentation of the treatment timeline with prevention of reinjury; however, conflicting results have been identified. A growing body of basic science and clinical literature is forming that supports the use of platelet-poor plasma (PPP) for muscle injury. The purpose of this study was to provide a background of the basic science of PRP versus PPP for muscle injury and to identify and review the clinical evidence for both autologous blood products, including the author's clinical experience utilizing the blood products. At the tissue level, PRP causes myoblast proliferation while PPP has led to myoblast induction, potentially identifying improved native muscle healing. Conflicting studies have been identified for the use of PRP for muscle injury. A growing body of positive results for PPP was identified, but high-quality comparative studies are needed.

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.

Does Playing Football (Soccer) Really Increase the Risk of Knee Osteoarthritis? A Systematic Review and Meta-analysis

OBJECTIVE: To evaluate the relationship between football (soccer) participation and tibiofemoral knee osteoarthritis (OA), considering the influence of competitive level and previous knee injuries. DESIGN: Etiology systematic review with meta-analysis. LITERATURE SEARCH: PubMed, Embase, AMED, and Cochrane were searched for relevant publications. STUDY SELECTION CRITERIA: Studies of football players that included a control group consisting of mainly sedentary nonfootball players, and the relationship of knee OA, were considered. The studies had to report radiographically verified knee OA and specify football activity. DATA SYNTHESIS: Eleven studies, involving 1805 football players and 4022 control individuals were included. Subgroups consisting of data regarding level of play and previous injuries were also synthesized. RESULTS: The overall prevalence of knee OA among football players was increased among professional and recreational players, compared with controls. When knee injuries were excluded, there was no difference in knee OA between football players and controls (OR = 1.25; 95% CI: 0.61, 2.54). Football players with a previous knee injury had a greater risk of knee OA when compared with football players with no history of previous knee injury (OR = 4.16; 95% CI: 1.97, 8.77). CONCLUSION: Football players were at increased risk of knee OA. However, after excluding participants with a history of previous knee injury, there were no differences in knee OA between football players and controls. Previous knee injury was important for developing knee OA. Playing football, in the absence of major knee injuries, did not increase the risk of knee OA. J Orthop Sports Phys Ther 2024;54(5):1-12. Epub 26 February 2024. doi:10.2519/jospt.2024.12029.

Lower HAGOS subscale scores associated with a longer duration of groin problems in football players in the subsequent season

Introduction

Groin injuries represent a considerable problem in football. Although the Adductor Strengthening Programme reduced groin injury risk, players can still experience groin symptoms throughout the season. This study aimed to determine whether preseason Copenhagen Hip and Groin Outcome Score (HAGOS) and a history of previous injury can identify individuals at risk of having a longer duration of groin problems the subsequent season, using an 'any physical complaint' definition of injury.

Methods

Preseason HAGOS score and weekly groin problems were registered with the Oslo Sports Trauma Research Center Overuse questionnaire during one full season in 632 male semiprofessional adult players.

Results

The prognostic model showed a decreased number of weeks with groin problems for each increase in HAGOS score for 'groin-related quality of life' (QOL) (IRR=0.99, p=0.003). A 10-point higher 'QOL' score predicted 10% fewer weeks of groin problems. Additionally, previous hip/groin injury was associated with a 74% increase in the number of weeks with symptoms (p<0.001).

Conclusion

The HAGOS questionnaire applied preseason can detect players at risk of getting more weeks with groin problems the following season. The 'QOL' subscale seems to be the superior subscale for estimating subsequent groin problem duration. While HAGOS appears promising in identifying players at risk, previous groin injury is the most robust indicator, showing a substantial 74% increase in weeks with symptoms.

Uncovering injuries in Brazilian elite women's football: A prospective cohort study

OBJECTIVES

To elucidate the injury profile in Brazilian elite women's football.

DESIGN

Prospective cohort study.

METHODS

Time-loss injuries, along with match and training exposure, were monitored throughout a full season in four Brazilian elite clubs.

RESULTS

Sixty-three out of 133 players (47 %) sustained 112 time-loss injuries along the season, leading to 0.8 injuries per player on average. The overall injury incidence rate was 5.0 injuries per 1000 h of exposure. Sudden onset injuries occurred at a rate of 4.2/1000 h of overall exposure, with rates of 15.9/1000 h during matches and 2.9/1000 h during training sessions. Forty-eight percent of the time-loss injuries were attributed to non-contact events. Gradual onset injuries accounted for 16 % of the injuries, resulting in a rate of 0.8/1000 h of overall exposure. The most affected locations were knee and thigh (29 % of all injuries for each), followed by ankle (17 %) and hip/groin (13 %). Muscle/tendon was the most affected tissue (47 % of all injuries), followed by ligament/joint capsule (33 %), bone (10 %), and cartilage/synovium/bursa (7 %). Ankle sprains, hamstring strains, and anterior cruciate ligament injuries accounted for over one-third of the injuries. Mild, moderate, and severe injuries account for 40 %, 43 %, and 17 % of cases, respectively. Overall, 18 % of cases were categorized as re-injuries, and 40 % of those occurred within 2 months of the index injury.

CONCLUSIONS

This study provides the initial understanding into the injury profile of Brazilian elite women's football. This information should serve as a guiding resource for injury prevention programs.

A rare soccer-related injury: Traumatic posterior hip fracture-dislocation - Case series and overview of the literature

BACKGROUND

Soccer is one of the most popular sports with millions of active professional and non-professional players worldwide. Traumatic hip dislocations are rare in soccer but can lead to major sequelae both physically and psychologically. The aim of this review was to obtain insight into the outcomes after surgerically repaired hip fracture-dislocation in soccer players as well as rehabilitation and prevention.

METHODS

Two cases of a posterior hip fracture-dislocation that occurred during an amateur soccer match are presented and mechanism of injury, complications and rehabilitation were analysed. Follow-up of both patients was at least one year after surgery. Questionnaires and physical examinations were obtained to quantify and qualify outcome.

RESULTS

In both cases the hip-dislocations were reduced within 3 h after injury. Semi-elective open reduction and internal fixation was performed within seven days. In one case, there was a concomitant Pipkin fracture and sciatic nerve neuropathy. There were no postoperative complications. Follow-up showed full of range of motion and normal hip functionality in both cases. However, both patients indicated a reduced quality of life and anxiety related to the accident.

CONCLUSION

Traumatic hip fracture-dislocations during soccer practice are extremely rare. Despite uncomplicated fracture healing after surgery and return of hip function, both patients still suffer from psychological problems resulting in a decreased quality of life. Further research is required to enhance psychological outcomes, as well as to facilitate return to pre-injury levels of participation and engagement in sports following traumatic hip fracture-dislocations related to soccer.

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.

Traumatic muscle injury

Traumatic muscle injury represents a collection of skeletal muscle pathologies caused by trauma to the muscle tissue and is defined as damage to the muscle tissue that can result in a functional deficit. Traumatic muscle injury can affect people across the lifespan and can result from high stresses and strains to skeletal muscle tissue, often due to muscle activation while the muscle is lengthening, resulting in indirect and non-contact muscle injuries (strains or ruptures), or from external impact, resulting in direct muscle injuries (contusion or laceration). At a microscopic level, muscle fibres can repair focal damage but must be completely regenerated after full myofibre necrosis. The diagnosis of muscle injury is based on patient history and physical examination. Imaging may be indicated to eliminate differential diagnoses. The management of muscle injury has changed within the past 5 years from initial rest, immobilization and (over)protection to early activation and progressive loading using an active approach. One challenge of muscle injury management is that numerous medical treatment options, such as medications and injections, are often used or proposed to try to accelerate muscle recovery despite very limited efficacy evidence. Another challenge is the prevention of muscle injury owing to the multifactorial and complex nature of this injury.

Micro-doppler radar to evaluate risk for musculoskeletal injury: Protocol for a case-control study with gold standard comparison

BACKGROUND

Beyond causing significant morbidity and cost, musculoskeletal injuries (MSKI) are among the most common reasons for primary care visits. A validated injury risk assessment tool for MSKI is conspicuously absent from current care. While motion capture (MC) systems are the current gold standard for assessing human motion, their disadvantages include large size, non-portability, high cost, and limited spatial resolution. As an alternative we introduce the Micro Doppler Radar (MDR); in contrast with MC, it is small, portable, inexpensive, and has superior spatial resolution capabilities. While Phase 1 testing has confirmed that MDR can identify individuals at high risk for MSKI, Phase 2 testing is still needed. Our aims are to 1) Use MDR technology and MC to identify individuals at high-risk for MSKI 2) Evaluate whether MDR has diagnostic accuracy superior to MC 3) Develop MDR algorithms that enhance accuracy and enable automation.

METHODS AND FINDINGS

A case control study will compare the movement patterns of 125 ACL reconstruction patients to 125 healthy controls. This study was reviewed and approved by the Pennsylvania State University Human Research Protection Program (HRPP) on May 18, 2022, and the IRB approval number is STUDY00020118. The ACL group is used as a model for a "high risk" population as up to 24% will have a repeat surgery within 2 years. An 8-camera Motion Analysis MC system with Cortex 8 software to collect MC data. Components for the radar technology will be purchased, assembled, and packaged. A micro-doppler signature projection algorithm will determine correct classification of ACL versus healthy control. Our previously tested algorithm for processing the MDR data will be used to identify the two groups. Discrimination, sensitivity and specificity will be calculated to compare the accuracy of MDR to MC in identifying the two groups.

CONCLUSIONS

We describe the rationale and methodology of a case-control study using novel MDR technology to detect individuals at high-risk for MSKI. We expect this novel approach to exhibit superior accuracy than the current gold standard. Future translational studies will determine utility in the context of clinical primary care.

Major Increase in Incidence of Pediatric ACL Reconstructions From 2005 to 2021: A Study From the Norwegian Knee Ligament Register

BACKGROUND

The incidence of pediatric and adolescent anterior cruciate ligament reconstruction (ACLR) is increasing in several countries. It is uncertain whether this trend applies to countries that traditionally prefer an initial nonoperative treatment approach whenever possible, like Norway. Nationwide, long-term patient-reported outcomes and revision rates after ACLR in the pediatric population are also lacking.

PURPOSE

To determine the incidence of pediatric ACLR in Norway since 2005, as well as to detect trends in surgical details and describe patient-reported outcomes up to 10 years after ACLR.

STUDY DESIGN

Descriptive cohort study.

METHODS

This study is based on prospectively collected data on girls ≤14 years and boys ≤16 years, registered in the Norwegian Knee Ligament Register at the time of their primary ACLR, between 2005 and 2021. The main outcome was the incidence of ACLR, adjusted to the corresponding population numbers for each year. The time trend was analyzed by comparing the mean of the first and last 3-year period (2005-2007 and 2019-2021). Patient-reported outcomes were assessed using the Knee injury and Osteoarthritis Outcome Score preoperatively and at 2, 5, and 10 years postoperatively.

RESULTS

A total of 1476 patients (1484 cases) were included, with a mean follow-up of 8.1 years (range, 1-17). The incidence of pediatric ACLRs per 100,000 population increased from 18 to 26, which corresponds to an increase of 40% for boys and 55% for girls. Concurrent meniscal procedures increased significantly from 45% to 62%, and the proportion of meniscal repairs increased from 19% to 43% when comparing the first and last time period. The mean Knee injury and Osteoarthritis Outcome Score values for the Sport and Recreation and Quality of Life subscales were between 72 and 75 at the 2-, 5- and 10-year follow-up. The 5-year revision rate was 9.9%.

CONCLUSION

There was a major increase in incidence of pediatric ACLR in Norway during the study period. There was a shift in the approach to concomitant meniscal procedures from resection to repair, with more than a doubling of the proportion of meniscal repairs. Patient-reported outcomes revealed long-lasting reduced knee function.

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.

Coaches' experiences of injury prevention in youth elite athletes: An interview study of 10 coaches

INTRODUCTION

Injury prevention is important to reduce the high injury risk in youth elite athletes studying at sports high schools. Coaches are considered important in youth elite sports and injury prevention.

OBJECTIVES

The aim was to investigate perceptions and experiences of injury prevention among coaches at sports high schools.

METHODS

A manifest qualitative content analysis with an inductive approach was used based on ten semi-structured interviews with coaches who work at sports high schools.

RESULTS

An overarching theme "Coaches of youth athletes value injury prevention but have limited knowledge and support" was identified and five main categories were formed. Coaches perceived themselves to play an important role in injury prevention, yet they described limited time for knowledge acquisition and highlighted the close collaboration with other professions as a key in injury prevention.

CONCLUSION

A coach's knowledge and support are critical factors in injury prevention of youth elite athletes. Evidence-based as well as non-evidence-based approaches are used, and the biopsychosocial perspective was not always taken into consideration. A need for more interprofessional collaboration and knowledge acquisition regarding injury prevention is warranted.

Adherence to Injury Prevention Exercise Programmes in Amateur Adolescent and Adult Football: A Detailed Description of Programme Use from a Randomised Study

BACKGROUND

Injury prevention exercise programmes (IPEPs) efficaciously reduce injuries. However, it is challenging to achieve sufficient adherence across a season. The main aim was to describe adherence to IPEPs in three groups of coaches and players partaking in a cluster randomised trial. Secondary aims were to describe perceptions of IPEPs, use of programme material, and overall preventive strategies.

METHODS

This is a sub-study analysing data from a three-armed randomised trial with teams randomised to use either a comprehensive IPEP (extended Knee Control) or an adductor strength programme, and non-randomised teams that already used a self-chosen IPEP regularly at study start (comparison group). Teams were instructed to use their respective intervention across the 2020 football season. Male and female, adolescent (≥ 14 years of age), and adult amateur players took part. Coaches and players responded to weekly and end-of-season questionnaires. Data were presented descriptively.

RESULTS

Weekly player data were reported by 502 players (weekly response rate 65%), 289 (58%) responded to end-of-season questionnaires. Teams in the extended Knee Control and comparison group used their respective IPEP in 483/529 (91%) and 585/641 (91%) of training sessions, and teams in the adductor group in in 199/315 (63%) sessions. Regarding utilisation fidelity, 42-52% of players in each group used 1-10 repetitions per exercise. Seven out of 17 teams in the adductor group had progressed as recommended in terms of number of repetitions. Two teams (10%) in the extended Knee Control group, and 7/24 of comparison teams used the same exercises across the season. Coaches accessed the IPEPs by different means (printed material, films, workshops, etc.), but half did not use the provided digital material. The players appreciated that the IPEPs could reduce injury risk and that they improved their exercise performance, but disliked that they had less time for football and that the exercises were boring. Forty-nine players had experienced pain during IPEP performance.

CONCLUSIONS

Adherence with the IPEPs was generally high. To meet different coach needs, programme material should be available via different digital and printed resources. The number of players reporting pain during IPEP performance is a noteworthy finding.

TRIAL REGISTRATION

Clinical Trials gov identifier: NCT04272047. Registered February 17, 2020. https://clinicaltrials.gov/ct2/show/NCT04272047 .

Star Excursion Balance Test as a Predictor of Musculoskeletal Injury and Lower Back Pain in Non-Professional Soccer Players

Soccer is a sport with worldwide popularity but has a substantial risk of injury. Clinical screening tools are an important factor in strategies of injury prevention. The purpose of the study was to examine the relationship between the Star Excursion Balance Test (SEBT) and injury and lower back pain (LBP) in amateur soccer players. The research was performed as a longitudinal cohort study on 42 amateur male soccer players with 15.8 ± 6.6 years of soccer playing (age: 25.5 ± 6 years). Participants were surveyed with regard to their soccer playing, injuries, and LBP, and the SEBT was performed. They were followed for 3.5 months. At the follow-up, an additional set of data regarding injuries and LBP was gathered. Significant differences were found in all directions and in the composite score of the SEBT between uninjured and injured players. Shorter distance in all directions and a lower composite score were associated with injury in general. Shorter distances in all but the anterior direction and a lower composite score were associated with lower extremity injury, and shorter anterior distance was associated with LBP. Amateur soccer players with lower SEBT scores are more prone to injuries in general, as well as injuries of the lower extremities. SEBT presents as a useful clinical screening tool in identifying amateur soccer players at risk of injury.

Current Clinical Concepts: Exercise and Load Management of Adductor Strains, Adductor Ruptures, and Long-Standing Adductor-Related Groin Pain

Adductor-related groin pain is a common problem in sports. Evidence-based management of athletes with adductor strains, adductor ruptures, and long-standing adductor-related groin pain can be approached in a simple yet effective and individualized manner. In most cases, managing adductor-related pain in athletes should be based on specific exercises and loading strategies. In this article, I provide an overview of the different types of adductor injuries, from acute to overuse, including their underlying pathology, functional anatomy, diagnosis, prognosis, mechanisms, and risk factors. This information leads to optimal assessment and management of acute to long-standing adductor-related problems and includes primary, secondary, and tertiary prevention strategies that focus on exercise and load-based strategies. In addition, information on different options and contexts for exercise selection and execution for athletes, athletic trainers, and sports physical therapists in adductor injury rehabilitation is provided.

The effects of hip- vs. knee-dominant hamstring exercise on biceps femoris morphology, strength, and sprint performance: a randomized intervention trial protocol

BACKGROUND

The hamstrings are an important muscle group that contribute to horizontal force during sprint acceleration and are also the most injured muscle group in running-based sports. Given the significant time loss associated with hamstrings injury and impaired sprinting performance following return to sport, identifying exercises that drive adaptations that are both protective of strain injury and beneficial to sprint performance is important for the strength and conditioning professional. This paper describes the study protocol investigating the effects of a 6-week training program using either the hip-dominant Romanian deadlift (RDL) or the knee-dominant Nordic hamstring exercise (NHE) on hamstring strain injury risk factors and sprint performance.

METHODS

A permuted block randomized (1:1 allocation) intervention trial will be conducted involving young, physically-active men and women. A target sample size of 32 will be recruited and enrolled participants will undergo baseline testing involving extended-field-of-view ultrasound imaging and shear wave elastography of the biceps femoris long head muscle, maximal hamstrings strength testing in both the RDL and NHE, and on-field sprint performance and biomechanics. Participants will complete the 6-week training intervention using either the RDL or NHE, according to group allocation. Baseline testing will be repeated at the end of the 6-week intervention followed by 2 weeks of detraining and a final testing session. The primary outcome will be regional changes in fascicle length with secondary outcomes including pennation angle, muscle cross sectional area, hamstring strength, and maximal sprint performance and biomechanics. An exploratory aim will determine changes in shear wave velocity.

DISCUSSION

Despite extensive research showing the benefits of the NHE on reducing hamstring strain injury risk, alternative exercises, such as the RDL, may offer similar or potentially even greater benefits. The findings of this study will aim to inform future researchers and practitioners investigating alternatives to the NHE, such as the RDL, in terms of their effectiveness in reducing rates of hamstring strain injury in larger scale prospective intervention studies.

TRIAL REGISTRATION

The trial is prospectively registered on ClinicalTrials.gov (NCT05455346; July 15, 2022).

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.

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.

Agreement between isokinetic eccentric hamstring strength, Nordic hamstring strength and Nordic break-point angle in a sample of trained and healthy individuals

Different eccentric strength assessments are used to identifying the risk of hamstring injury in athletes. However, there is scarce information to determine the association between Nordic-based measurements and the gold standard measurement of eccentric hamstring strength in an isokinetic dynamometer. To investigate the relationship of different measures of eccentric hamstring strength (break-point angle and eccentric strength during Nordic exercise) with eccentric hamstring peak torque measured with an isokinetic dynamometer. Forty-six participants volunteered to participate in this study. Eccentric peak force in the Smart-Nordic System and break-point angle measured as trunk lowering at >20°/s and >150°/s² during the Nordic exercise via high-frequency video-analysis were compared to eccentric hamstring peak torque in an isokinetic dynamometer set to produce knee extension at 30°/s. There was a moderate association between peak eccentric strength with the Smart-Nordic and isokinetic eccentric hamstring peak torque (r = -0.65, p < 0.001, 95%CI = [-0.76-(-0.50)]). The association between Nordic break-point angle measured at 20°/s (r = 0.49, p < 0.001, 95%CI = [0.30-0.64]) and at 150°/s² (r = 0.52, p < 0.001, 95%CI = [0.33-0.66]) presented statistically significant but lower associations with isokinetic eccentric hamstring peak torque. All Nordic-based measurements presented acceptable associations with the gold standard isokinetic eccentric hamstring peak torque. However, peak eccentric force measured on the Smart-Nordic device had a better agreement with eccentric peak torque measured with an isokinetic dynamometer than the video-based measurements.Highlights Peak eccentric force measured on the isometric strain-gauges device had a better agreement with eccentric hamstring peak torque measured with an isokinetic dynamometer than the break-point angle.The Nordic-based measurements are an alternative cost-effective method to assess eccentric muscle strength and weakness when the access to isokinetic dynamometry is not feasible.Caution should be taken with certain variables such as participants body mass, hip position and movement speed when interpreting the results of Nordic-based measurements.

Who Does Not Respond to Injury Prevention Warm-up Programs? A Secondary Analysis of Trial Data From Neuromuscular Training Programs in Youth Basketball, Soccer, and Physical Education

OBJECTIVES: To identify factors associated with nonresponse to neuromuscular training (NMT) warm-up programs among youth exposed to NMT warm-ups. METHODS: This is a secondary analysis of youth (aged 11-18 years) in the intervention groups of 4 randomized controlled trials in high school basketball, youth community soccer, and junior high school physical education. Youth who were exposed to NMT and who sustained an injury during the study were considered nonresponders. Odds ratios (ORs) were based on generalized estimating equations logistic regression controlling for clustering by team/class and adjusted for age, weight, height, balance performance, injury history, sex, and sport (soccer/basketball/physical education). RESULTS: A total of 1793 youth were included. Youth with a history of injury in the previous year had higher odds (OR = 1.64; 95% CI: 1.14, 2.37) of injury during the study, and females were more likely (OR = 1.67; 95% CI: 1.21, 2.31) to sustain an injury than males who were participating in NMT. Age was not associated with the odds of sustaining an injury (OR = 1.10; 95% CI: 0.93, 1.30). Soccer players benefited most from greater adherence, with 81% lower odds of injury (OR = 0.19; 95% CI: 0.06, 0.57) when completing 3 NMT sessions a week compared with 1 session per week. CONCLUSION: Factors associated with nonresponse to an NMT warm-up program were female sex, history of injury during the previous 12 months, and lower weekly NMT session adherence in some sports (soccer). J Orthop Sports Phys Ther 2023;53(2):94-102. Epub: 9 December 2022. doi:10.2519/jospt.2022.11526.

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.

Effect of additional Nordic hamstring exercise or sprint training on the modifiable risk factors of hamstring strain injuries and performance

The Nordic hamstring exercise (NHE) has commonly been investigated in isolation, however, within practice multiple modalities are commonly incorporated. However, the NHE has a low level of compliance within sport, with sprinting being potentially being preferred. The present study aimed to observe the effect of a lower-limb program with either additional NHE or sprinting on the modifiable risk factors hamstring strain injury (HSI) and athletic performance. 38 collegiate athletes were randomly assigned into three groups: control standardised lower-limb training program (n = 10 (2 female, 8 male), age = 23.50 ± 2.95 years, height = 1.75 ± 0.09 m, mass 77.66 ± 11.82 kg), additional NHE (n = 15 (7 female, 8 male), age = 21.40 ± 2.64 years, height = 1.74 ± 0.04 m, mass 76.95 ± 14.20 kg) and additional sprinting (n = 13 (4 female, 9 male), age = 22.15 ± 2.54 years, height = 1.74 ± 0.05 m, mass 70.55 ± 7.84 kg). All participants performed a standardised lower-limb training program twice per week for seven weeks, including Olympic lifting derivatives, squatting movements, and the Romanian deadlift, with experimental groups performing with either additional sprinting or NHE. Bicep femoris architecture, eccentric hamstring strength, jump performance, lower-limb maximal strength and sprint ability were measured pre and post. All training groups demonstrated significant (p < 0.001), small-moderate increases in Bicep femoris architecture (g = 0.60-1.22), with significant (p < 0.001), small-large increases in absolute and relative eccentric peak force (g = 0.60-1.84). Significant and small increases were observed in take-off velocity and mean propulsion force (p < 0.02, g = 0.47-0.64), with non-significant and small increases for both the sprint and control training groups for mean propulsion force (p > 0.05, g = 0.42-0.50). Nordic and sprint training groups had significant and small increases in peak absolute and relative net force (p < 0.001, g = 0.44-0.60). The control group had a non-significant trivial increase in absolute peak net force (p > 0.05, g = 0.22), with a significant and small increase in relative peak relative net force (p = 0.034, g = 0.48). Significant and small decreases for the NHE and sprinting training groups was observed for 0-10 m, 0-20 m, and 10-20 m sprint time (p < 0.010, g = 0.47-0.71). Performing multiple modalities, with either additional NHE or sprinting, as part of a complete resistance training program was superiorly effective for measures of modifiable risk factors HSI, with similar increases observed in measures of athletic performance derived from the standardised lower-limb training program.

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.

Epidemiology of musculoskeletal injuries in combat sports practitioners

Study aim: The purpose of this study was to determine the impact of the type of combat sport and the degree of athletic proficiency on the specificity of musculoskeletal injuries suffered by Muay Thai and Mixed Martial Arts practitioners.

Material and methods: The study involved 64 practitioners of two combat sports, MT (age 26.9 ± 8.1, experience 7.4 ± 5.8 years) or MMA (age 26.2 ± 6.4 years, experience 6.6 ± 4.1 years). The research was conducted using a Google Forms survey.

Results: The groups did not differ significantly (p < 0.05) in terms of risk of injury (average 3.1 in MT, 2.6 in MMA). Injuries (mainly fractures 21% and 7% of practitioners) affected the lower limb (44% and 33% practitioners) and were significantly higher in MT, p < 0.05. There were significant (p < 0.05) correlations between training experience and the number of training hours per week compared to the frequency and severity of injuries in both groups.

Conclusion: Injuries to athletes who mainly use striking techniques are more common in the lower limbs and they are more likely to be fractures. Longer training experience, more training hours and a higher level of athletic proficiency significantly increase the risk of injuries and their severity among people practicing both types of combat sports.

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.

Injury prevention programs including balance exercises with compliance and follow-up reduce the incidence of knee injuries in athletes: A systematic review and meta-analysis

BACKGROUND: The knee is one of the most common injuries in sports. However, the incidence of knee injuries can be decreased by enhancing balance and neuromuscular control. OBJECTIVE: The aim of this systematic review and meta-analysis was to investigate how injury prevention programs (IPPs) that include balance training influence knee injury rates in athletes. METHODS: Data were obtained from different databases (1985–2021). Only randomised controlled trials that used IPPs that include balance training, were considered. Two investigators extracted data from the qualifying documents. The critical outcome data elements derived from the included studies were the number of ACL/knee injuries, ACL/knee injury rates, exposure hours, compliance rate, and follow-up duration. RESULTS: Compared to the control groups, those who participated in the IPP had a 54% lower risk of knee injuries per 1000 hours of exposure (IRR 0.457 (95% CI 0.346–0.603), P= 0.001) and a 60% lower risk of ACL injuries per 1000 hours of exposure (IRR 0.401 (95% CI 0.215–0.750), P= 0.004). CONCLUSIONS: IPPs that include balance training may reduce the risk of knee injuries.

The Effect of Shoulder and Knee Exercise Programmes on the Risk of Shoulder and Knee Injuries in Adolescent Elite Handball Players: A Three-Armed Cluster Randomised Controlled Trial

Background

The risk of injury in adolescent handball is high, and shoulder and knee injuries are among the most frequent and burdensome. The Swedish Knee Control programme reduced the risk of anterior cruciate ligament injuries in female youth football players and traumatic knee injuries in male and female youth floorball players. However, to date, Knee Control has not been evaluated in an elite youth sport setting. The literature on the prevention of shoulder injuries in sport is scarce, and there are to our knowledge no previous studies evaluating the preventative efficacy of injury prevention exercise programmes (IPEPs) on shoulder injuries in adolescent handball players.

Objectives

To study the preventive efficacy of IPEPs on shoulder and knee injuries in adolescent elite handball players.

Methods

Eighteen Swedish handball-profiled secondary schools (clusters) with players aged 15–19 years, 54% males were randomised into either the Shoulder Group or Knee Group (interventions) or a Control Group. Players in the Shoulder Group were instructed to perform the Shoulder Control programme, and  players in the Knee Group to perform the Knee Control programme, three times per week during May 2018 to May 2019. Control Group players continued their usual training. Outcomes were shoulder and knee injuries defined by the Oslo Sports Trauma Research Center Overuse Injury Questionnaire. Intention-to-treat analyses were performed using Cox regression models with hazard rate ratios (HRRs) with corresponding 95% confidence intervals (CI).

Results

Six clusters (199 players) in the Shoulder Group, six clusters (216 players) in the Knee Group and six clusters (212 players) in the Control Group were included. There were 100 shoulder injuries and 156 knee injuries. The Shoulder Group had a 56% lower shoulder injury rate, HRR 0.44 (95% CI 0.29 to 0.68), and the Knee Group had a 31% lower knee injury rate, HRR 0.69 (95% CI 0.49 to 0.97) than the Control Group. The absolute risk reduction was 11% and 8%, and the number needed to treat was 9 and 13, respectively.

Conclusions

Adolescent elite handball players who performed the Shoulder Control and the Knee Control programmes had a lower risk of shoulder and knee injuries, respectively, than players who continued their usual training. Further research on how these two programmes can be combined to reduce knee and shoulder injuries in a time effective way is warranted.

Trial registration ISRCTN15946352.

Key points

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.

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

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