Is there a correlation between coaches' leadership styles and injuries in elite football teams? A study of 36 elite teams in 17 countries

Secondary injury prevention reduces hamstring strain and time-loss groin injury burdens in male professional football

OBJECTIVES

This study aimed to assess the effectiveness of a systems-based secondary injury prevention intervention aimed at early detection and management of hamstring strain injury (HSI) and time-loss groin injury in an Australian male professional football club.

DESIGN

Prospective cohort study.

SETTING

Australian male professional football club.

PARTICIPANTS

Data were collected from male professional football players (n = 73) from a single football club.

MAIN OUTCOME MEASURES

Unilateral knee flexion and side-lying hip adduction maximum voluntary isometric contractions were monitored routinely in-season, two days post-match (≥40 h [h]) during a three-season intervention period. Strength reductions greater than the tests' minimal detectable change percentage prompted intervention. HSI and time-loss groin injury burdens were calculated per 1000 player hours and compared with those from an immediately preceding two-season control period, to assess the effectiveness of the intervention.

RESULTS

Across the intervention period, there was a decrease in HSI (4.98 days absence/1000 h (19.8%) decrease) and time-loss groin injury burdens (0.57 days absence/1000 h (49.1%) decrease) when compared with the control period.

CONCLUSIONS

A systems-based secondary injury prevention intervention shows preliminary positive findings in reducing HSI and time-loss groin injury burdens within a male professional football club, compared with usual care only.

Exploring the interplay of interpersonal and contextual dynamics in youth sports injuries: a comprehensive narrative review

Injuries are recognised in sports and exercise medicine as not isolated incidents but complex outcomes. This is because an athlete's health trajectory is understood to be shaped by dynamic, complex linkages between individual performance, biology, and the wider social and cultural contexts and systems in which individuals perform. Despite this recognition, little attention has been paid to how interpersonal and contextual dynamics can potentially affect the risk of injury by influencing the choices and decisions made by coaches, parents and athletes. To address this gap, this narrative review bridges insights from sociocultural studies in sports with the findings of sports injury research. The narrative review aims to identify and summarise how interpersonal and contextual dynamics influence the risk of youth sports injuries. The results reveal the pressures faced by athletes, often leading to compromised health. Moreover, the review underscores the importance of designing complex interventions and strategies to promote healthier practices in youth sports. Specifically, intervention programmes should prioritise raising awareness of injury risks, cultivating effective communication skills and fostering supportive training environments.

To play or not to play, that is the question: an interview study with amateur football coaches on perceptions of pain during sports participation

Amateur football coaches play a key role in preventing, assessing and treating pain among their players, as they are often the first point of contact and may be the main source of advice and guidance. The objective of this study was to explore amateur football coaches' perceptions of pain during sports participation and their approach to pain management. We conducted a qualitative interview study with 20 amateur football coaches from a strategically selected sample of male and female, and junior and senior teams. A semistructured interview guide and conventional qualitative content analysis were used. One overall theme emerged: To play or not to play-coaches navigating difficult terrain with limited resources. The theme included four main categories: How can pain be understood?; Can pain be avoided?; How to manage players with pain?; What resources do we need? Different ways of understanding pain emerged, and coaches described that players have different pain thresholds. Pain was seen as a part of the game that cannot be completely avoided. In general, there was a restrictive attitude regarding pain medication, though actual consumption was not known. Coaches emphasised shared responsibility with players to achieve adequate training loads, a positive communication climate surrounding pain, and a need for education and competence. In conclusion, coaches expressed various interpretations of pain during sports participation and pain management, where they need to take on great responsibility despite limited medical competence. Coaches believed that adequate pain management is important, and their keys to reducing the risk of pain included structured and customised training, a well-balanced training load and recovery, and a positive communication climate in the team. Coaches often decide whether players experiencing pain can participate in team training and match play, emphasising the need for education support and access to medical competence.

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.

Psychological risk factors for a first hamstring strain injury in soccer: a qualitative study

Introduction

Hamstring strain injuries (HSIs) remain one of the most burdensome injuries in soccer. Current recommendations to prevent sports injuries suggest the importance for coaches and medical staff to consider psychological and contextual risk factors and to specify them according to the injury type and context. HSI risk factors in soccer have been widely investigated, mainly from physiological and biomechanical perspectives. However, psychological and health-related risk factors are still unexplored. Therefore, the objective of this study was to determine the psychological and health-related risk factors for a first HSI in male competitive soccer.

Method

Individual semi-structured interviews were conducted with ten male competitive soccer players, who had recently sustained a HSI. Based on multifactorial models of sports injury causation, soccer players' individual, contextual, and situational risk factors at the time of their first HSI were investigated. Interviews were analyzed using thematic analysis with deductive and inductive approaches.

Results

Individual psychological risk factors included common at-risk personality traits, obsessive passion for soccer with competitive motivational goals, strong athletic identity, and poor health literacy. The injured players were exposed to a controlling coaching style, with a fear of negative staff evaluations, and had recently experienced life stressors. They were injured during matches or overload periods and were highly engaged in the activity.

Discussion

Previously injured soccer players exhibit a lack of perspective concerning the repercussions of their actions on their health. From a preventive viewpoint, these results suggest enhancing the players' health literacy, supporting their autonomy, and moderating the controlling coaching style.

Process mining to investigate the relationship between clinical antecedents and injury risk, severity and return to play in professional sports

Objective

This paper presents an exploratory case study focusing on the applicability and value of process mining in a professional sports healthcare setting. We explore whether process mining can be retrospectively applied to readily available data at a professional sports club (Football Club Barcelona) and whether it can be used to obtain insights related to care flows.

Design

Our study used discovery process mining to detect patterns and trends in athletes' Post-Pre-Participation Medical Evaluation injury route, encompassing five phases for analysis and interpretation.

Results

We examined preprocessed data in event log format to determine the injury status of athletes in respective baseline groups (healthy or pathological). Our analysis found a link between thigh muscle injuries and later ankle joint problems. The process model found three loops with recurring injuries, the most common of which were thigh muscle injuries. There were no differences in injury rates or the median number of days to return to play between the healthy and pathological groups.

Conclusions

This study explored the applicability and value of process mining in a professional sports healthcare setting. We established that process mining can be retrospectively applied to readily available data at a professional sports club and that this approach can be used to obtain insights related to sports healthcare flows.

[Injury prevention in football : A challenge for team doctors and coaching team]

High injury rates and long injury-related downtimes demonstrate the need for effective and differentiated injury prevention strategies in football. Preventive measures should take place in various fields and should not be reduced to training programmes or medical approaches. The so-called "Big 6 of injury prevention" provide an overview of the key areas that should be addressed. In modern sports medicine, it should be a matter of course that the team doctor already participates in the primary prevention strategies and does not only get involved in the post-traumatic treatment. Similarly, a decision on a player's return to play after an injury should not be based solely on the medical assessment of the team doctor. Good communication and interdisciplinary cooperation, therefore, form the basis for successful prevention.

Effects of changing the head coach on soccer team's performance: A systematic review

The aim of this review was to identify and synthesise the most significant literature addressing the effects of changing the HC on soccer team's performance, identifying the most frequently researched outcomes and characterizing their methodologies. A systematic review of PubMed, Scopus, Web of Science and SPORTDiscus databases was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA, 2020) guidelines. The following keywords and synonyms were entered in various combinations in the title, abstract or keywords: "football*" OR soccer AND "coach*" OR "manager*" AND "replacement" OR "turnover" OR "substitution*" OR "change". Solely original articles written in English that contained data about the effects of the change in the HC on performance in professional male soccer were included. A total of 94 titles were identified, of which 24 met the eligibility criteria. The quality of the studies was considered excellent. The most common topic of analysis was the effects of the HC on match outcomes (i.e., win, draw, loss, points won, goals average). Some studies suggest that the HCs dismissal has small but positive impacts on a team's short-term performance, while other findings suggest that little-to-no impact is observed following HC departure. The dismissal of the HC does not guarantee increase success of an underperforming team. Some studies suggest that hiring an appropriate coach could positively affect match performance in the short-term. Due to limited variations in study designs, further research is needed before robust conclusions can be drawn.

'Considering the reality, I am very lucky': how professional players and staff perceive injury prevention and performance protection in women's football

OBJECTIVE

To explore the beliefs and perceptions of professional female footballers and staff regarding injury prevention and performance protection in professional women's football.

METHODS

This qualitative study applied semistructured interviews with 18 participants from 3 top-tier teams from 2 countries (Portugal and England) and 4 nationalities, including 2 physiotherapists, 5 players, 3 team doctors, 2 head coaches, 3 strength and conditioning coaches, 2 managers, and 1 head of performance. Data analysis applied constant comparison analysis, using principles of grounded theory. There were no major differences in the perspectives of players and staff, and the findings are presented together.

RESULTS

Identifying and reporting injuries and recognising potential injury risk factors were mentioned to influence the prevention of injury. Participants stated that the growth and evolution of women's football could influence injury risk. Before reaching the professional level, exposure to potential risk factors, such as lack of recovery, limited awareness and opportunities for prevention (eg, preventive exercises and load management strategies), was believed to impact players' injury risk. Players further described their experiences and the 'bumpy road' to becoming a professional player, their current context and potential future improvements for women's football regarding injury prevention and performance protection.

CONCLUSION

Professional female football players face different injury risks during different moments of their careers. According to elite players and staff, amateur and semiprofessionals have limited resources and lack injury prevention strategies. Professional players and staff perceived the current preventive measures as good and relied on the value of individualised care and a multidisciplinary approach. In the future, more resources and structured injury prevention strategies are needed in youth and non-professional levels of women's football to reduce injury risk and allow more players to reach their maximal performance.

The Relationship Between Athlete Perceptions of Coaching Leadership Behaviors and Athlete Grit

Coach leadership style has long been positively correlated with athlete experiences such as motivation, health (i.e., burnout), and performance outcomes (i.e., enhanced execution time to complete tasks) (24). More recently, grit (18) has been positively correlated with athlete experiences such as engagement (39) and decreased burnout (32). Given the impact coaches have on their athletes and the positive psychological benefits of grit, it is reasonable to explore the intersections of coaching behaviors and grit. As such, the purpose of the current study was to examine the relationship between athlete perceptions of coach leadership behaviors and athlete grit. Intercollegiate athletes completed measures of grit and the leadership behaviors of their coach. A significant positive relationship was observed between the grit perseverance subscale and the leadership behavior of training and instruction (r =.30, p < .05). Additional analyses revealed that athletes' perceptions of coach positive feedback significantly predicted their perseverance. Taken together, these findings suggest a link between positive coach feedback and athlete perseverance. Implications of these results for professional practice and future research are discussed.

Epidemiology of time-loss injuries within an Australian male professional football club: A 5-year prospective observational study of 21,343 player hours

This study aimed to establish injury incidence rates (IIRs) and burden within an Australian male professional football club (n = 73) and to investigate longitudinal trends across five consecutive seasons (2016/17-2020/21). There was an overall IIR of 9.18 injuries per 1000 hours (h) (95% CI [7.89, 10.47]). The IIR was approximately seven times greater (rate ratio (RR): 6.85; 95% CI [5.13, 9.19]; p < 0.01) in matches (31.29 injuries per 1000 h; 95% CI [25.25, 37.33]) compared to training (4.49 injuries per 1000 h; 95% CI [3.51, 5.47]). The overall injury burden was 254.1 days lost per 1000 h (95% CI [220.9, 292.3]). Compared with the reference 2016/17 season, there were significant increases in minimal (RR: 6.94; 95% CI [1.27, 128.73]) and mild injuries (RR: 3.76; 95% CI [1.21, 16.39]) in season 2017/18 and decreases in moderate (RR: 0.40; 95% CI [0.19, 0.80]) and contact injuries (RR: 0.35; 95% CI [0.12, 0.90]) in season 2019/2020. Time-loss injury is common and represents a major burden in Australian male professional football, with injuries more frequently sustained during matches. Injury prevention practices should specifically be directed towards muscle/tendon and ligament injuries of the lower limb, particularly anterior cruciate ligament, ankle sprain and hamstring strain injuries.

What Factors Do Clinicians, Coaches, and Athletes Perceive Are Associated With Recovery From Low Back Pain in Elite Athletes? A Concept Mapping Study

OBJECTIVE: Identify factors that elite sport clinicians, coaches, and athletes perceive are associated with low back pain (LBP) recovery. DESIGN: Concept mapping methodology. METHOD: Participants brainstormed, sorted (thematically), and rated (5-point Likert scales: importance and feasibility) statements in response to the prompt, "What factors are associated with the recovery of an elite athlete from low back pain?" Data cleaning, analysis (multidimensional scaling, hierarchical cluster analysis, and descriptive statistics), and visual representation (cluster map and Go-Zone graph) were conducted following concept mapping guidelines. RESULTS: Participants (brainstorming, n = 56; sorting, n = 34; and rating, n = 33) comprised 75% clinicians, 15% coaches, and 10% athletes and represented 13 countries and 17 sports. Eighty-two unique and relevant statements were brainstormed. Sorting resulted in 6 LBP recovery-related themes: (1) coach and clinician relationships, (2) inter-disciplinary team factors, (3) athlete psychological factors, (4) athlete rehabilitation journey, (5) athlete non-modifiable risk factors, and (6) athlete physical factors. Participants rated important recovery factors as follows: athlete empowerment and psychology, coach-athlete and athlete-clinician relationships, care team communication, return-to-sport planning, and identifying red flags. CONCLUSION: Factors perceived as important to LBP recovery in elite athletes align with the biopsychosocial model of community LBP management. Clinicians should consider that an athlete's psychology, relationships, care team communication, and rehabilitation plan may be as important to their LBP recovery as the formulation of a diagnosis or the medications or exercises prescribed. J Orthop Sports Phys Ther 2023;53(10):1-16. Epub 10 August 2023. doi:10.2519/jospt.2023.11982.

Health Systems in High-Performance Sport: Key Functions to Protect Health and Optimize Performance in Elite Athletes

Enabling athletes to achieve peak performances while also maintaining high levels of health is contextually complex. We aim to describe what a 'health system' is and apply the essential functions of stewardship, financing, provision of services and resource generation to an Australian high-performance sport context. We introduce a fifth function that health systems should not detract from athletes' ability to achieve their sports goals. We describe how these functions aim to achieve four overall outcomes of safeguarding the health of the athletes, responding to expectations, providing financial and social protection against the costs of ill health, and efficient use of resources. Lastly, we conclude with key challenges and potential solutions for developing an integrated health system within the overall performance system in high-performance sport.

Players', Head Coaches', And Medical Personnels' Knowledge, Understandings and Perceptions of Injuries and Injury Prevention in Elite-Level Women's Football in Ireland

BACKGROUND

To manage injuries effectively, players, head coaches, and medical personnel need to have excellent knowledge, attitudes, and behaviours in relation to the identification of risk factors for injuries, the implementation of injury prevention initiatives, as well as the implementation of effective injury management strategies. Understanding the injury context, whereby specific personal, environmental, and societal factors can influence the implementation of injury prevention initiatives and injury management strategies is critical to player welfare. To date, no qualitative research investigating the context of injuries, has been undertaken in elite-level women's football. The aim of our study was to explore the knowledge, attitudes, and behaviours of players, head coaches, and medical personnel in the Irish Women's National League (WNL) to injury prevention and injury management.

METHODS

We used qualitative research methods to explore the knowledge, attitudes, and behaviours of players, head coaches, and medical personnel in the Irish WNL to injury prevention and injury management. Semi-structured interviews were undertaken with 17 players, 8 medical personnel, and 7 head coaches in the Irish WNL. The data were analysed using thematic analysis. Our study is located within an interpretivist, constructivist research paradigm.

RESULTS

The participants had incomplete knowledge of common injuries in elite-level football, and many held beliefs about risk factors for injuries, such as menstrual cycle stage, which lacked evidence to support them. Jumping and landing exercises were commonly used to reduce the risk of injuries but evidence-based injury prevention exercises and programmes such as the Nordic hamstring curl, Copenhagen adduction exercise, and the FIFA 11+ were rarely mentioned. Overall, there was dissatisfaction amongst players with their medical care and strength and conditioning (S & C) support, with resultant inadequate communication between players, head coaches, and medical personnel.

CONCLUSION

Poor quality and availability of medical care and S & C support were considered to be a major obstacle in the effective implementation of injury risk reduction strategies and successful return-to-sport practices. More original research is required in elite-level women's football to explore injury risk factors, injury prevention initiatives, and contextual return-to-sport strategies, so that players, head coaches, and medical personnel can use evidence that is both up-to-date and specific to their environment.

Most modifiable risk factors for hamstring muscle injury in women's elite football are extrinsic and associated with the club, the team, and the coaching staff and not the players themselves: the UEFA Women's Elite Club Injury Study

PURPOSE

To describe the perceived importance of suggested hamstring injury risk factors according to chief medical officers (CMOs) of European women's professional football clubs. A secondary objective was to compare if these perceptions differed between teams with a lower-than-average and higher-than-average hamstring injury burden.

METHODS

The CMOs of eleven European professional women's football clubs were initially asked to suggest modifiable risk factors for hamstring injury. These risk factors were rated in according with their perceived importance on a 5-graded Likert scale. Participating teams were divided in two groups depending on their hamstring injury burden during the 2020/21 season. The LOW group consisted of six teams that had a lower-than-average hamstring injury burden. The HIGH group consisted of five teams that had a higher-than-average hamstring injury burden.

RESULTS

Twenty-one risk factors were suggested, most of which were extrinsic in nature, hence associated with the coaching staff, the team or the club organization rather than with the players themselves. The risk factors with the highest average importance were: "lack of communication between medical staff and coaching staff" and "load on players" (each with a weighted average of 3.9), followed by "lack of regular exposure to high-speed football actions during training" and "playing matches 2-3 times a week" (weighted average of 3.8 and 3.7). Differently from the LOW group, the HIGH group perceived the coaching factors (style of coach leadership, training/exercise surveillance by coaching staff) as more important.

CONCLUSION

In accordance to the eleven CMOs recruited in this study, most risk factors for hamstring injuries are extrinsic in nature and associated with the club, the team, and the coaching staff, and not the players themselves.

LEVEL OF EVIDENCE

Level III.

Association of Selected Fitness Variables with Perceived Performance Levels in Lawn Tennis Players

Objectives Lawn tennis is an explosive sport that involves various fitness parameters such as explosive strength, endurance, power, and agility. Improved physical fitness leads to superior athletic performance. The coach's perception is contingent upon his perception of the player at the time the athlete is comparing himself to the coach. Thus, this study aimed to determine the association between chosen fitness factors and perceived performance by coach in lawn tennis players. Thus, the study aims to detect the relationship between different fitness variables and perceived level of performance in lawn tennis player.

Materials and Methods Fifty-two lawn tennis players from two sports academies were measured for various parameters of fitness and perceived performance level as rated by the coach.

Statistical Analysis The association between selected fitness metrics and perceived performance in lawn tennis players was investigated using Pearson's correlation test. Furthermore, the data were analyzed with paired t-test for male and female group, and ANOVA was used to analyze the difference between the levels of performance.

Results Fatigue index, closed kinetic chain upper extremity stability (CKCUEST) test, and peak power and energy expenditure taken by metabolic equivalent (MET) calculation was found to be statistically different between males and females. While comparing BMI with the peak power, there was a weak positive correlation for males, while for female there was no correlation. Metabolic equivalent, energy expenditure, and peak power were positively correlated with the level of performance; however, fatigue index and level of performance had a negative nonsignificant correlation.

Conclusion Peak power, fatigue index, energy expenditure, and BMI were found to be associated in males, but not in females. Peak power and energy expenditure were connected to performance in both genders.

Risk factors for hamstring muscle injury in male elite football: medical expert experience and conclusions from 15 European Champions League clubs

Objectives

To describe the perceived importance of suggested hamstring injury risk factors according to chief medical officers (CMOs) of European male professional football clubs. A secondary objective was to compare if these perceptions differed between teams with a lower-than-average hamstring injury burden and teams with a higher than average hamstring injury burden.

Methods

First, CMOs of 15 European professional male football clubs were asked to suggest risk factors for hamstring injury in their club. The perceived importance of the suggested risk factors was then rated by all participants on a 5-graded Likert scale. Participating teams were divided in two groups depending on their hamstring injury burden during the 2019/2020 and 2020/2021 seasons. The LOW group consisted of seven teams that had a lower than average hamstring injury burden. The HIGH group consisted of eight teams that had a higher-than-average hamstring injury burden.

Results

Twenty-one risk factors were suggested. The majority were extrinsic in nature, associated with coaching staff, team or club rather than players themselves. 'Lack of communication between medical staff and coaching staff' had the highest average importance (weighted average=3.7) followed by 'Lack of regular exposure to high-speed football during training sessions' (weighted average=3.6). The HIGH group perceived the player factors fatigue and wellness as more important than the LOW group.

Conclusion

According to CMOs recruited in this study, most risk factors for hamstring injuries are extrinsic and associated with the club and coaching staff, and not the players themselves.

Exploring leadership behaviors of the coaches of champion teams

Participation in sports at school is highly valued since it is believed that it develops students' social skills and adds to personal development. Owing to the fact that the behaviors of the coaches have an important effect on the development of the student athletes, this quantitative study was designed with the aim to evaluate the perceptions of young student athletes of the champion school teams of their coaches' leadership behaviors. The study also sought to determine the variables affecting these perceptions. A total of 236 young student athletes who were the members of the champion teams of basketball, handball, volleyball, futsal, badminton, wrestling and swimming in the period of 2021-2022 evaluated their coaches' leadership qualities. One of the major results was that the young student athletes had positive perceptions of their coaches. Adopting Chelladurai's model, training and instruction was found to be particularly important in achieving high performance. More specifically, the Mann Whitney U test results revealed that the athletes' perceptions differed by gender and by being involved in team or individual sports; however, Kruskal-Wallis test revealed perceptions did not differ by age. The significance of this study lies in its practical implications for sport coaches, coaching practice, physical education teachers and practitioners in sport psychology.

Barriers and facilitators to injury prevention in ladies Gaelic football: A qualitative study

OBJECTIVES

Injury rates have remained high in ladies Gaelic football over the last decade and treatment costs continue to increase significantly. Injury prevention programmes are a proposed solution and their efficacy has been demonstrated in Gaelic games, however, anecdotally their adoption is low. The aim of this study was to determine the barriers and facilitators to uptake, implementation, and long-term adoption of an injury prevention strategy for adult Ladies Gaelic football players and coaches.

DESIGN

Semi-structured interviews were conducted with 23 participants (13 coaches, 10 players). Four coaches were at intercounty level and nine were at club level, while two players competed at intercounty and club level and eight played solely at club level. The interviews were audio-recorded, transcribed verbatim and thematically analysed.

RESULTS

Stakeholder attitudes, accessibility, education, communication, and injury prevention programme characteristics were perceived as key barriers to an injury prevention strategy succeeding. Injury prevention promotion, injury prevention programme characteristics, leadership, and communication, were identified as the main factors that would facilitate the success of a strategy.

CONCLUSIONS

By utilising the views of stakeholders, the initial uptake, adherence, and long-term adoption of an injury prevention strategy in Ladies Gaelic football may be maximised.

A review of machine learning applications in soccer with an emphasis on injury risk

This narrative review paper aimed to discuss the literature on machine learning applications in soccer with an emphasis on injury risk assessment. A secondary aim was to provide practical tips for the health and performance staff in soccer clubs on how machine learning can provide a competitive advantage. Performance analysis is the area with the majority of research so far. Other domains of soccer science and medicine with machine learning use are injury risk assessment, players' workload and wellness monitoring, movement analysis, players' career trajectory, club performance, and match attendance. Regarding injuries, which is a hot topic, machine learning does not seem to have a high predictive ability at the moment (models specificity ranged from 74.2%-97.7%. sensitivity from 15.2%-55.6% with area under the curve of 0.66-0.83). It seems, though, that machine learning can help to identify the early signs of elevated risk for a musculoskeletal injury. Future research should account for musculoskeletal injuries' dynamic nature for machine learning to provide more meaningful results for practitioners in soccer.

Factors Influencing Team Performance: What Can Support Teams in High-Performance Sport Learn from Other Industries? A Systematic Scoping Review

Background

The primary aim of our systematic scoping review was to explore the factors influencing team function and performance across various industries and discuss findings in the context of the high-performance sport support team setting. These outcomes may also be used to inform future research into high-performance teamwork in sport.

Methods

A systematic scoping review of literature published in English since 2000 reporting team-based performance outcomes and included a performance metric that was ‘team outcome based’ was conducted using search of the Academic Search Ultimate, Medline, Business Source Ultimate, APA PsycInfo, CINAHL, SPORTDiscus, and Military database (ProQuest) using the terms: ‘team’, ‘function’ OR ‘dysfunction’, ‘Perform*’ OR ‘outcome’.

Results

Application of the search strategy identified a total of 11,735 articles for title and abstract review. Seventy-three articles were selected for full-text assessment with the aim to extract data for either quantitative or qualitative analysis. Forty-six of the 73 articles met our inclusion criteria; 27 articles were excluded as they did not report a performance metric. Eleven studies explored leadership roles and styles on team performance, three studies associated performance feedback to team performance, and 12 studies explored the relationship between supportive behaviour and performance. Team orientation and adaptability as key figures of team performance outcomes were explored in 20 studies.

Conclusions

Our findings identified 4 key variables that were associated with team function and performance across a variety of industries; (i) leadership styles, (ii) supportive team behaviour, (iii) communication, and (iv) performance feedback. High-performance teams wishing to improve performance should examine these factors within their team and its environment. It is widely acknowledged that the dynamics of team function is important for outcomes in high-performance sport, yet there is little evidence to provide guidance. This inequality between real-world need and the available evidence should be addressed in future research.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40798-021-00406-7.

Elit genç futbol akademisi sporcularında yaralanma insidansı: 3 yıllık geriye dönük takip

Aim: The aim of this study was to investigate the incidence and characteristics of injuries suffered by elite soccer academy athletes. Materials and Methods: A retrospective analysis was made of the health records between 2016 and 2019 of athletes in the elite male soccer academy of an elite football club. The cause, type, location, recurrence, and severity of the injuries, where the injuries occured and time lost due to the injuries were recorded. The injury incidence and prevalence were calculated. Results: Overall, total injuries and seasonal incidence rate were 1.49 (1.33-1.68) and 8.06 (7.16-0.04) per 1000 hours, respectively. The injury burden ranged between 11.83 (10.53-13.29) days and 51.43 (49.11-53.85) days. The injury characteristics were not statistically different according to age groups (p˃0.05). Conclusion: Youth soccer players in the U19 and U21 age groups had more injuries than other junior age groups in a typical soccer season. It was concluded that there were more match injuries, the thigh was the most injured area, muscle injuries were more common, and the hamstring was the most frequently injured muscle.

International survey of injury surveillance practices in competitive swimming

OBJECTIVE

The purpose of this study was to identify the injury surveillance practices being used in competitive swimming environments. It explored the nature of the data collected, the injury definitions used and the perceived effectiveness of injury surveillance. Finally, this study also examined barriers to injury surveillance.

DESIGN

Online cross-sectional.

PARTICIPANTS

Twenty-two responders working in competitive swimming.

OUTCOME MEASURES

Injury surveillance methods, data collected, perceived level of effectiveness and barriers associated with injury surveillance.

RESULTS

Fifteen responders participated in injury surveillance, with 13 responders using a recognised definition for injury. Ten responders did not use any sports injury classification system. Ten responders found injury surveillance to be very effective at identifying injury trends, while previous injury history and training load data were perceived to be most influential in preventing injury. Limited time, funding and compliance were common obstacles, while poor staff communication and engagement were barriers to the effective implementation of injury surveillance.

CONCLUSIONS

The implementation of injury surveillance is related to the system objectives, competitive level of those under surveillance and the resources available. This implementation requires the balance of adhering to the principles outlined in prominent consensus statements and overcoming the barriers associated with implementing a system effectively.

Leadership experiences of elite football team physicians during the COVID-19 pandemic: a pilot study

Objectives

The purpose of this study was to explore the leadership experiences of elite football team physicians during the COVID-19 pandemic.

Methods

A pilot-study based on a cross-sectional design by means of an electronic survey was conducted. The survey relied on 25 questions divided into distinct sections including among others professional and academic experience, leadership experiences and perspectives.

Results

A total of 57 physicians (91% male; mean age: 43 years) gave their electronic informed consent and completed the survey. All participants agreed that the demands of their role had increased during the COVID-19 pandemic. Fifty-two (92%) participants reported that they felt they were expected to take more of a leadership role during the COVID-19 pandemic. Eighteen (35%) reported feeling under pressure to make clinical decisions which were not in keeping with best clinical practice. Additional roles, duties and demands expected of team doctors during the COVID-19 pandemic were subdivided into communication, decision-making, logistical, and public health demands.

Conclusion

The findings from this pilot study suggest that the way in which team physicians at professional football clubs operate has altered since the onset of the COVID-19 pandemic, with greater demands placed on leadership skills including decision-making, communication and ethical stewardship. This has potential implications for sporting organisations, clinical practice and research.

Still poorly adopted in male professional football: but teams that used the Nordic Hamstring Exercise in team training had fewer hamstring injuries – a retrospective survey of 17 teams of the UEFA Elite Club Injury Study during the 2020–2021 season

Objectives

The primary objective was to study the adoption of the NHE programme in European football teams in the 2020/21 season and to compare it to the previous study. A second objective was to compare hamstring injury rates between teams that used the NHE programme in the team training and teams that used the NHE only for players with previous or current hamstring injuries.

Methods

Data about the implementation of the NHE programme and injury rates were included for 17 teams participating in the Elite Club Injury Study during the 2020/2021 season.

Results

One team (6%) used the full original NHE programme, and another four teams used it for all or most players in the team (team training group, n=5). Eleven teams used NHE only for players with a previous or current hamstring injury (individual training group), and one team did not use NHE. The team training group had fewer hamstring injuries (5 vs 11 per team, p=0.008) and a lower injury burden (12 vs 35 lay-off days per 1000 hours, p=0.003) than the individual training group.

Conclusion

Similar to previous reports, low adoption of the NHE programme was seen in the 2020/2021 season. The low adoption rate (13%) relates to the number of teams fully or partly using NHE programmes. Teams that used NHE for the whole team or most players had a lower hamstring injury burden than teams that used NHE only for individual players.

The effect of mid-season coach turnover on running match performance and match outcome in professional soccer players

The aim of this research was to examine the physical match performance and match outcome before and after coach turnover in professional soccer teams compared with a control group containing coaches working continuously for 3 consecutive seasons. Analysed data included 325 performances of teams led by dismissed coaches (DC), 313 of teams led by new coaches (NC), and 580 of teams led by unchanged coaches (UnC). Variables, such as average number of collected points, total distance (TD), total distance per minute (TD/min), high-speed running (HSR), sprinting and number of high-intensity runs (NHIR), were analysed in the last 15 games of DC and 15 matches of NC. These periods were divided into 3 blocks out of 5 matches (5-match blocks). NC collected a significantly higher number of points than DC (p = 0.015), whereas average points collected by UNC were significantly greater than DC (p < 0.001 and NC (p = 0.012). TD and TD/min for DC were significantly lower (p < 0.001) compared with both NC and UnC, whereas significant differences in HSR (p = 0.003) and NHIR (p = 0.03) were identified between DC and NC. The current study reported that mid-season coach turnover may result in short-term improvement in team results and physical match performance. However, this effect disappears after a period of approximately 5 games.

Gender Differences in the Relationships Between Coach Transformational Leadership and Player Satisfaction and Commitment: A Meta-Analytic Review

This study meta-analyzed the relationships between coach transformational leadership and player satisfaction and commitment. We also examined the potential moderating effect of player gender on these relationships. In total, 182 effect sizes were obtained from 26 studies comprised of 6,715 participants. The analyses revealed that the overall direct effect of transformational leadership was moderate on both athletic satisfaction and exercise commitment. The effect of charismatic construct of transformational leadership was moderate on athletic satisfaction as well as exercise commitment. Finally, player gender was found to moderate the effects of the relationship between transformational leadership and athletic satisfaction and exercise commitment of players. Specifically, female players' satisfaction and commitment were more positively affected by transformational leadership compared with their male counterparts. Our findings suggests that effective leadership in sports is dependent on the interaction among leadership behaviors of the coach, personal characteristics of the players, and situational factors and highlights the importance of transformational leadership as an important requirement for creating a more positive and sustainable sports environment.

A Temporal Study on Coach Behavior Profiles: Relationships With Athletes Coping and Affects Within Sport Competition

The study aimed to identify coach behavior profiles and explore whether athletes from distinct profiles significantly differed on coping and affects experienced within 2 hr before the competition and during the competition (measuring them 2 hr after the competition). A sample of 306 French athletes (Mage = 22.24; SD = 4.91; 194 men and 112 women) participated in the study. The results revealed the emergence of two profiles: (a) a coaching engaged profile that stands out for moderate physical training and planning, technical skills, mental preparation, goal setting, competition strategies, personal rapport, and moderate negative personal rapport; and (b) a less engaged coaching profile with low physical training and planning, technical skills, mental preparation, goal setting, competition strategies, personal rapport, and moderate negative personal rapport. Memberships of coach behavior profiles were not confounded by athletes' practice experience, athlete's gender, and coach experience. Results of latent profile analyses with Bose-Chaudhuri-Hocquenghem method (BCH) method revealed that coping and affective states significantly differed across the coach behavior profiles. As a whole, the less engaged coaching profile engenders the worst outcomes in competition. In conclusion, the detection of less adaptive coaching profiles would be crucial to prevent negative outcomes in athletes during the competition. This might be using intervention programs adapted to the peculiarities of athletes from a particular coach behavior profiles.

Throwing in the deep end: athletes, coaches and support staff experiences, perceptions and beliefs of upper limb injuries and training load in elite women's water polo

To understand elite athlete, coach and support staff experiences, perceptions and beliefs in women’s water polo with managing upper limb injuries and monitoring training loads. Inductive qualitative design. Twenty athletes, coaches and support staff were purposively recruited and participated in semistructured interviews. Participants either had experienced an upper limb injury or had experience managing athletes with upper limb injuries. Interviews were conducted in-person or virtually, audio-recorded, deidentified, transcribed verbatim and cleaned to ensure accuracy. Data were thematically analysed. Analysis identified five cohesive themes: (1) upper limb injury management is adequate—but prevention, communication and knowledge need improving, (2) current training load monitoring generates uncertainty and lack of consistency of processes—due to reliance on internal, and lack of external load monitoring, (3) optimal training load monitoring requires objective measurement of training load—that accurately measures the external load of athletes’ upper limbs, (4) athlete-centred philosophy matters—including athlete-centred care to facilitate individually tailored rehabilitation programmes and their inclusion in management decisions, (5) mental, social and emotional aspects of upper limb injury management matter—acknowledging feelings of loss of team inclusion, fear of missing out and frustration felt by athletes as well as the emotional labour felt by coaches when supporting athletes with an upper limb injury. Upper limb injury management and training load monitoring are evolving areas where objective measurement of training load may assist in increasing consistency of communication, collaboration and coordination between all stakeholders, and to address uncertainty. Stakeholders placed value in intangible qualities such as trust and care in their relationships with other collaborators—facilitating athlete physical, mental and emotional recovery following upper limb injuries.

Lower limb injuries in an english professional football club: injury analysis and recommendations for prevention

BACKGROUND

Lower limb injuries constitute a problem in the sport of football. Our aim is to explore patterns and trends of lower limb injuries in an English professional football club.

METHODS

This is a descriptive epidemiological study. Reports provided by the club's physical therapy team were screened for injuries among professional football players sustained over four seasons, from 2015/2016 to 2018/2019. Data included setting of injury (in-match or training), anatomical location of injury, type of injury, number of days off and month of injury.

RESULTS

A total of 296 lower limb injuries were recorded in our study, with a rate of 11.14 per 1000 football hours. Injury rate during games was 51.38 per 1000 football hours, significantly greater than that during training at 3.81 per 1000 football hours (p = 0.021). The thigh was significantly the most commonly injured location at 4.67 per 1000 football hours (p < 0.001). Grade I tears were the most common injury type at 1.73 per 1000 football hours, significantly greater than grade III tears (p = 0.027), contusions (p = 0.043), fractures (p = 0.02), and lacerations (p = 0.019). Injury rates were found to be greatest during preseason and declined as season progressed. On average, an injury sidelined the affected footballer for a total of 20 days.

CONCLUSION

Lower limb injuries were more common during matches than training. The thigh is the most common injury location, and grade I muscle tear was the most common type of injury. Injury rates were higher early on in the season. Potential prevention strategies include spacing out competition, adopting training and exercise regimens that cater for recovery, and increasing research regarding injury mechanisms.

Considerations for the Medical Management of the Circus Performance Artist and Acrobat

Medical management of the circus performer encompasses a wide variety of multicultural, transdisciplinary and multifaceted decision-making considerations. There is a paucity of research evidence investigating both the unique diversity of skill sets and cultural considerations in addition to injury patterns of performers within the circus environment. Since a previously established framework for supporting the health and well-being of the circus performer across various aspects of medical management does not exist in the literature, most recommendations in this regard must come from practical experience working with this highly specialized performance athlete population. The purpose of this clinical commentary is to provide the reader with a greater understanding of the unique challenges associated with the medical management of performance artists and acrobats as well as recommendations for developing an integrated approach for mitigating injury risk within a highly specialized, diverse athlete population.

LEVEL OF EVIDENCE

5.

Increased occurrence of ACL injuries for football players in teams changing coach and for players going to a higher division

PURPOSE

To identify football-specific factors associated with ACL injuries that can be targeted for sport-specific injury prevention.

METHODS

A study-specific questionnaire was developed to study the characteristics of ACL injuries in football including intrinsic, extrinsic, and injury specific factors. The questionnaire was available at the Swedish national knee ligament registry's website for the football players to voluntarily fill out. Data are presented on group level for all football players in total and for females and males separate to examine gender-specific differences. The results are based on answers collected over a 3-year period from 2875 football players, 1762 (61%) males and 1113 (39%) females.

RESULTS

ACL were more frequently sustained during games 66% than during practices 25%. The injury mechanism was non-contact in 59% and contact in 41%. For the contact injuries during games, no action was taken by the referee in 63% of the situation and a red card was shown in 0.5%. The risk of ACL injury was highest early in the football game with 47% sustained during the first 30 min and 24% in the first 15 min. Players changing to a higher level of play 15% had a higher rate of ACL injuries than players changing to a lower level 8%. This difference was especially seen in female football players with 20% of ACL injuries being sustained by players going to a higher division compared to 7% for those going to a lower division. 15% of the male and 21% of the female ACL injuries occurred in teams with a coach change during the season. Knee control exercises to warm up was used by 31% of the female players and 16% of the males. 40% of the players reported that they did not plan on returning to football.

CONCLUSION

Neuromuscular training programs have proven to reduce ACL injuries, but greater adherence to these remains a challenge as only 1 in 5 of the ACL-injured football players report using them. Teams changing coach and players going to a higher division appear to have an increased risk of ACL injury warranting attention and further investigations.

LEVEL OF EVIDENCE

IV.

Comparison of player-dependent and independent high-speed running thresholds to model injury risk in football

High-speed running (HSR) loads have been linked with non-contact injury risks in team-sports. This study investigated whether player-specific speed zones, reflecting individual fitness characteristics, impact the associations between non-contact injury and acute and chronic HSR loads. Semi-professional soccer players from two clubs (n = 47) were tracked over two seasons using 10 Hz GPS (5552 observations). HSR distances were calculated arbitrarily (≥5.5 m·s^-1), and in an individualised fashion based on the final speed of the 30-15 intermittent fitness test. Cumulative running loads were represented by exponentially weighted moving averages with 7-(acute) and 28-day (chronic) decay parameters. Physiotherapists collected non-contact, lower-limb, time-loss injury data (n = 101). Injury models using session type (training vs matches), coach, as well as arbitrary or individualised running loads were constructed via mixed-effect logistic regression. Session type had the largest effect on injury (training vs match OR = 0.28; 95%CI:0.17-0.44). Variations in individualised or arbitrary acute and chronic HSR loads within the mid-range of the observed data had negligible effects on predicted injury risk. However, the uncertainty of estimated effects at extreme values of acute and chronic HSR loads prevented any conclusive findings. Therefore, the efficacy of using customised speed thresholds in quantifying load for injury risk mitigation purposes remains unclear.

Despite maintaining a high daily training availability, a quarter of athletes start the season injured and three quarters experience injury in an Australian State Academy of Sport

OBJECTIVES

To 1) investigate the incidence, prevalence, burden and characteristics of injuries; and 2) explore the frequency of physiotherapy and medical servicing for elite sports academy athletes over a 12-month season.

DESIGN

Prospective cohort study.

METHODS

Medical attention and time-loss injuries were prospectively recorded by Physiotherapy and Medical (Sports Physician) staff for 94 athletes (72.3% females). The number of linked physiotherapy and medical servicing appointments was also recorded. Injury incidence rates (IIR), point and period prevalence, and injury burden were calculated and compared by athlete gender, sport, and categorisation (performance level) using incidence rate ratios (IRR).

RESULTS

The number of injuries reported was 193 in 71 (75.5%) athletes. The IIR was 2.1 (95%CI: 1.8 to 2.4) injuries per 365 days, with no gender difference observed (IRR: 1.1, 0.8 to 1.4). The injury burden was 43.5 (95%CI: 37.8 to 50.1) days absent per 365 days. More than one-quarter (point prevalence, 26.6%) of athletes commenced the season with an injury. In-season injury risk was 2.5 fold greater in athletes who started the season with an injury compared to athletes who started the season without an injury (IRR: 2.5, 1.9 to 3.4). The majority (81.2%) of the 1164 appointments recorded were physiotherapy, with an overall 4.3:1.0 physiotherapy to medical appointment ratio.

CONCLUSIONS

One in four athletes began the elite pathway season with a pre-existing injury, while also demonstrating a 2.5 fold greater risk of subsequent injury in the scholarship period. Sports should not assume their athletes are uninjured at the beginning of their scholarship. Injury profiles, and physiotherapy and medical servicing varied across sports. To reduce health as a barrier in the successful transition of talented young athletes to elite athletes, injury management strategies at the commencement of recruitment and throughout the scholarship should be prioritised in the development pathway.

Coaches' attitudes to injury and injury prevention: a qualitative study of Irish field hockey coaches

Translating injury prevention research into practice has been challenging, which may be due to a poor understanding of the contextual factors influencing the occurrence of injury. Coaches are key figure in sporting environments and hold pivotal roles in preventing injury. Therefore, the aim of this study was to investigate the attitudes of field hockey coaches to injury and injury prevention. Thirteen field hockey coaches from the amateur Irish Hockey League were interviewed. Reflexive thematic analysis led to three general dimensions comprised five higher-order themes, categorised from 16 lower-order themes. Coaches had positive beliefs regarding the benefits of injury prevention over injury management. However, they lacked the necessary knowledge and skills to successfully implement injury prevention strategies with players. Coaches recognised the importance of empowering players to self-manage training loads to promote injury prevention but acknowledged the need to protect younger players from increased loads. Many barriers to injury prevention were not controllable by coaches including fixture congestion and poor structuring of the sport's domestic calendar. While coaches can play a key role in the implementation of injury prevention strategies, there is also a requirement to examine how system level barriers to injury prevention can be reduced.

[Employees in professional European football: comparison of the personnel structure in sports medicine, sports sciences and physiotherapy between Bundesliga, La Liga, Serie A and Premier League]

INTRODUCTION

Regional and league-specific differences in injury risk and time loss have been observed in professional European football. Besides time of play or different pre-season preparations, possible reasons may also include medical and sport-scientific support. A survey of what UEFA deems to be the best four football clubs has therefore been conducted to investigate the personnel status in the fields of medicine, physiotherapy, massage, sports science and athletic and "strength and conditioning" coaching in order to compare the Erste Bundesliga with the first leagues of the other countries.

METHODS

The study is based on a survey of all 78 teams in the highest football leagues of Germany (Bundesliga), Spain (La Liga), Italy (Serie A) and England (Premier League). The teams were contacted directly and a questionnaire concerning their personnel deployment in the different fields was handed out.

RESULTS

The Bundesliga was found to have a significantly lower total number of employees compared with the other European leagues (6.9 vs. 11.02; p < 0.0001). The number of physicians in the Bundesliga is significantly higher (2.2 vs. 1.76; p = 0.0259), but the number of physicians dedicating more than 80 % of their total medical practice to the team was significantly lower in the Bundesliga (0.2 vs. 1.45; < 0.0001). In the group of physiotherapists (1.8 vs. 3.6; p < 0.001), massage therapists (2.1 vs. 2.69; p = 0.0094), sports scientists (0.3 vs. 1.12; p < 0.0001) and athletic and "strength and conditioning" coaches (0.5 vs. 1.83; p < 0.0001), there were also significant differences between the staff structure in the Bundesliga compared with the grouped results of the other leagues.

CONCLUSION

The personnel structure and the personnel employment in the Bundesliga in sports medicine and sports sciences differs significantly from La Liga, Serie A and the Premier League with the latter three leagues having more personnel and the personnel having closer ties to their teams. Further investigation is necessary to find out if this may be a reason for the differences in injury rates observed between these leagues. A special focus should be placed on country-specific differences in the professions including education and scope of work.

High Incidence of Anterior Cruciate Ligament Injuries Within the First 2 Months of the Season in Amateur Team Ball Sports

BACKGROUND

The incidence of anterior cruciate ligament (ACL) injuries is commonly reported as an annual incidence rate. There is relatively little information about the seasonal aspects of these injuries. The aim of the current study was to analyze the distribution of ACL injuries during the season in nonprofessional soccer, handball, and basketball based on a retrospective analysis of a hospital-based registry.

HYPOTHESIS

ACL injuries in soccer, handball, and basketball were more common within the first 2 months of the season in comparison with the rest of the year.

STUDY DESIGN

Case series.

LEVEL OF EVIDENCE

Level 4.

METHODS

Injury occurrence during the calendar year was divided into 6 periods of 2 months, with segment 1 (S1) representing the first 2 months of the season. For soccer, S1 corresponded to September and October. The season started 1 month later for handball and basketball, so S1 represented October and November. Chi-square tests were used to analyze the distribution of ACL injuries among segments according to gender, age, sports, and injury mechanism (contact/noncontact).

RESULTS

A total of 371 ACL injuries were included (soccer, 258, handball, 56, basketball, 57). Overall, the distribution of ACL injuries was not uniform across the segments (P < 0.01). Almost one-third of the ACL injuries occurred in S1 (n = 104; 28%). Significant differences could be observed according to sports (P < 0.01). There were fewer ACL injuries in S2 for soccer compared with basketball (P < 0.05). In S5, there were significantly more ACL injuries in soccer compared with handball and basketball (P < 0.05).

CONCLUSION

A high occurrence of ACL injuries was reported immediately within the first 2 months of the season in nonprofessional soccer, handball, and basketball sports.

CLINICAL RELEVANCE

These findings indicate that ACL injury prevention programs should be started in the preseason period to allow for gradual increases of load.

Sports Injury Prevention is Complex: We Need to Invest in Better Processes, Not Singular Solutions

In recent years, an understanding has developed that sports injuries are the emergent outcomes of complex, dynamic systems. Thus, the influence of local contextual factors on injury outcomes is increasingly being acknowledged. These realisations place injury prevention research at a crossroads. Currently, injury prevention researchers develop universally applicable injury prevention solutions, but the adoption of these solutions in practice is low. This occurs because implementation contexts are both unique and dynamic in nature, and as a result singular, static solutions are often incompatible. In contrast, practitioners address injury prevention through iterative cycles of trial and error, aiming to optimise the injury prevention process within their own unique contexts. The purpose of this critical review is to draw attention to the misalignment between research and practice-based approaches to injury prevention. In light of this, we propose alternative research approaches that acknowledge the process-driven nature of injury prevention in practice. We propose that a core focus of sport injury prevention research should be to provide practitioners with useful and relevant information to support their decision making around their localised injury prevention practice. Through this approach, injury prevention research ceases to be about what works, and begins to engage with understanding what works in what contexts and why?

Injury rates decreased in men's professional football: an 18-year prospective cohort study of almost 12 000 injuries sustained during 1.8 million hours of play

BACKGROUND

The UEFA Elite Club Injury Study is the largest and longest running injury surveillance programme in football.

OBJECTIVE

To analyse the 18-season time trends in injury rates among male professional football players.

METHODS

3302 players comprising 49 teams (19 countries) were followed from 2000-2001 through 2018-2019. Team medical staff recorded individual player exposure and time-loss injuries.

RESULTS

A total of 11 820 time-loss injuries were recorded during 1 784 281 hours of exposure. Injury incidence fell gradually during the 18-year study period, 3% per season for both training injuries (95% CI 1% to 4% decrease, p=0.002) and match injuries (95% CI 2% to 3% decrease, p<0.001). Ligament injury incidence decreased 5% per season during training (95% CI 3% to 7% decrease, p<0.001) and 4% per season during match play (95% CI 3% to 6% decrease, p<0.001), while the rate of muscle injuries remained constant. The incidence of reinjuries decreased by 5% per season during both training (95% CI 2% to 8% decrease, p=0.001) and matches (95% CI 3% to 7% decrease, p<0.001). Squad availability increased by 0.7% per season for training sessions (95% CI 0.5% to 0.8% increase, p<0.001) and 0.2% per season for matches (95% CI 0.1% to 0.3% increase, p=0.001).

CONCLUSIONS

Over 18 years: (1) injury incidence decreased in training and matches, (2) reinjury rates decreased, and (3) player availability for training and match play increased.

Assessment of External Load During Matches in Two Consecutive Seasons Using the Mediacoach® Video Analysis System in a Spanish Professional Soccer Team: Implications for Injury Prevention

(1) Background: Knowledge of competition loads is a relevant aspect of injury prevention. We aimed to describe the training and match injury incidence and physical demand variables observed during a competition using a multi-camera video analysis system (Mediacoach^®) (LaLiga^TM, Madrid, Spain) in a professional Spanish soccer team during two consecutive seasons. (2) Methods: 30 players (age: 26.07 ± 3.78 years) participated in the study. Physical variables of 74 matches were collected retrospectively. Injury characteristics of both seasons were also collected. Differences in these variables between the two seasons and by player position and correlations between variables were explored. (3) Results: There were statistically significant differences between the two seasons in the total distance traveled and the distance traveled at a high-intensity sprint (p < 0.05). During the two seasons, there was an average of 4.7 ± 2.2 injuries. The total distance traveled was different according to the playing position, and statistically significant correlations were found in the total distance and sprint at a high intensity for certain positions with different injury severity (4) Conclusions: The match performance data recorded by the Mediacoach^® system may provide relevant information by player position to technical and medical staff for injury prevention.

THE GAP BETWEEN RESEARCH AND CLINICAL PRACTICE FOR INJURY PREVENTION IN ELITE SPORT: A CLINICAL COMMENTARY

As clinicians strive to apply evidence-based principles, team-based practitioners have identified a large gap as it relates to published research, ideal applications of evidence-based practice, and actual clinical practice related to injury prevention in elite sport within the United States. For rehabilitation professionals, especially those intimately involved in the research of injury prevention, the solution often seems quite clear and defined. However, preventing injury by implementing the latest recommendation from the most recent prospective study on the using the FIFA 11 + warm-up, a Copenhagen Adduction exercise, or a plyometric drill with elite athletes may not be as effective as was seen among the cohort used in the study. In addition to extrapolating research, clinicians face additional challenges such as variance among professions, schedule density, and off-season contacts with athletes. There is an inherent difficulty in the application of research to practice in elite sport as it relies on the teamwork of not only the practitioner and athlete, but the entire sporting organizational structure and those involved in athlete participation. The purpose of this clinical commentary is to explore the difficulty with application of research in clinical practice and to discuss potential strategies for improving carry over from research to clinical practice.

Strength development and non-contact lower limb injury in academy footballers across age groups

Non-contact lower limb injuries are common in academy football. Yet, the impact these injuries have on strength development in academy footballers remains unclear. This study aimed to investigate the impact of non-contact lower limb injury on hip, groin, and knee flexor strength development in male academy youth footballers. Furthermore, this study: reports normative strength data of emerging field-based tests that can be easily deployed in football academies; explores the effect of age on injury occurrence; and highlights the number of days lost from injury in male youth footballers. Assessments of hip adductor, abductor, and eccentric knee flexor strength were obtained from 195 academy football players during pre-season and at the end of season. In-season injuries were recorded by medical staff. Those footballers who sustained non-contact lower limb injury were compared with those who did not sustain a non-contact lower limb injury. No between-group differences were observed for any strength assessments when controlled for pre-season measures. Stronger footballers at pre-season experienced strength loses, while those weaker players gained strength across the season. Hip strength development was impaired in older age group footballers. Sustaining a non-contact lower limb injury had minimal impact on strength development. In the absence of in-season lower limb strength monitoring, development in academy youth footballers may not progress as expected, and in particular, stronger and older youth athletes may benefit from individualized strength training.