Epidemiology of injuries in professional football: a systematic review and meta-analysis

Molecular mechanisms of recombinant proteins PTTG1IP, ADAM12, PAPSS1, and MYO1B and their effects on wound repair induced by tendon exposure: Analysis of key genes

Tendon injury repair involves a variety of cellular and molecular pathways. The aim of this study was to explore the molecular mechanisms and interactions of recombinant proteins PTTG1IP, ADAM12, PAPSS1 and MYO1B in wound repair induced by tendon exposure. The study collected a dataset of gene expression related to tendon exposure from the GEO database. Differential gene expression analysis and Venn diagram analysis were used to identify the differentially expressed genes before and after tendon exposure injury, and potential diagnostic markers were screened. Appropriate statistical methods were used to analyze all data. The results show that the expression levels of PTTG1IP, ADAM12, PAPSS1 and MYO1B change dynamically after tendon exposure injury, and PTTG1IP, ADAM12, PAPSS1 and MYO1B play an important role in the wound repair process caused by tendon exposure. The change of its expression level and function is closely related to the wound healing process.

What contextual factors influence pain management decision making concerning player availability in professional men's football? A qualitative analysis of practitioner perceptions

PURPOSE

Football practitioners must regularly assess the risk of participation when determining player availability. At present, there is a lack of information detailing the factors that influence risk assessments. Accordingly, the following research question was explored: what contextual factors influence pain management decision-making when determining player availability in professional men's football?

METHODS

20 semi-structured interviews were conducted with club doctors (8), physiotherapists (6), and heads of medicine and performance (8) working in professional men's football in the United Kingdom. The methodology is reported using COREQ criteria and data were analysed using thematic analysis.

RESULTS

Three themes were created that explain how decision-making concerning analgesia was influenced by: (1) access to medical resources, (2) trust between staff and players, and (3) prioritising short-term success. First, the time, resources, and medical information available to staff impacted the ability to assess players and their risk tolerance in relation to analgesia. Second, decision-making was perceived as a multi-stakeholder process and the nature of relationships with players and performance staff could increase or decrease risk tolerance. Third, player decisions are made against a performance and working environment that privileges short term success over long term wellbeing.

CONCLUSION

The data support that pain management decision-making in professional men's football is influenced by the player and staff's working context. Further, practitioners viewed potential harm to a player from a socio-economic and physical perspective. These findings support the adoption of a patient-centred care approach and can inform clear recommendations from international and national governing bodies.

On-field rehabilitation in football: current practice and perceptions. A survey of the English Premier League and Football League

INTRODUCTION

Return to play related research is increasing rapidly, with two recent competency-based frameworks offering conceptualised support for on-field rehabilitation (OFR) decision-making. It is still unknown, however, who is responsible for OFR and how they typically select, monitor, and progress OFR processes.

AIMS

The purpose of this study was to investigate current OFR practice within English professional football to support practitioners with decision-making and highlight opportunities for future research related to the design, monitoring, and progression of OFR.

METHODS

Sixty-nine practitioners responsible for the design and implementation of OFR at 69 clubs (75% of the English Premier League and Football League) responded to a survey containing 30 questions (14 open and 16 closed).

RESULTS

The main findings were that therapists (physiotherapists/sports therapists) have the largest influence on OFR, followed by physical performance coaches (sports scientists/strength and conditioning coaches), technical coaches and medical doctors. There was more agreement for the ordering of specific OFR drills earlier in the process when activities are easier to control. The most frequently reported objective monitoring tool was global positioning systems (GPS), with functional/clinical experience/expertise remaining subjectively vital. GPS outputs (e.g., sprint metrics and accelerations/decelerations) were most used for between session decision-making, with verbal communication being key for within session decision-making.

CONCLUSION

Future research should use evidence of current practice, such as drill design and monitoring techniques, to explore drill-level analysis and give practitioners greater insights into which stage of current OFR frameworks specific drills fall, and how they might be more objectively progressed/regressed.

A prospective epidemiologic study of injuries and illnesses in the football matches of the 14th National Student Games of China

The aim of this study is to determine the incidence and characteristics of football player injuries and illnesses during the 14th National Student Games of China. The results indicate that 32 illnesses were reported, with 17 (53%) involving the gastrointestinal system, primarily caused by environmental factors (24, 69%). The illness incidence rate was 4.3 cases per 100 players or 10.2 cases per 1,000 player-days. Regarding injuries, 122 cases were reported, yielding an overall injury incidence rate was 38.9 per 1,000 game hours, or 1.14 per game. Most injuries resulted from collisions with other players, occurring predominantly 15 minutes before the end of the first half, and 30 minutes before the end of the game. Most of the injuries were in the ankle, thigh, knee joint, and groin. In conclusion, the injury incidence of football players in the 14th National Student Games of China is high, occurring from a variety of mechanisms. Physical contact should be emphasized during training, core strength, and stability training should be enhanced alongside comprehensive injury management and prevention strategies.

Perceptions of Elite Young Male Football Players Regarding Injury Risk Factors and Prevention Strategies

CONTEXT

Football players aged 15-20 years experience injury incidence rates similar to those of professionals, with players injured in this age group being significantly less likely to reach the professional level. Understanding the factors that influence young footballers' acceptance, adoption, and compliance with injury prevention programs is crucial. Therefore, this study aimed to describe the perceptions of male football players from premier league academies regarding injury risk factors and prevention strategies.

DESIGN

Cross-sectional observational study.

METHODS

An online survey was used to explore perceptions of injury risk factors and prevention strategies among young football players (under-17 and under-20 teams) from premier league academies.

RESULTS

A total of 504 footballers (mean age: 18 [2] y) across 9 academies in 8 different cities participated in this study. No risk factor was elected as very important by at least half of participants. The top 5 injury risk factors elected by players were "poor hydration," "inadequate warm-up," "poor rest/sleep," "inadequate diet," and "poor strength/power." At least 1 quarter of participants considered "genetics," "advanced age," "attention level," "wheatear conditions," and "alcohol consumption" as irrelevant factors for injury. There was no consensus for any prevention strategy. Fourteen strategies were ranked as efficient by at least 3 quarters of participants. The top 5 prevention strategies elected by players were "warm-up before training/matches," "functional training," "hydration before and during training/matches," "flexibility training," and "workload monitoring." Lower than a half of participants endorsed "ankle braces" and "thermal shorts" for injury prevention.

CONCLUSIONS

The results of this study offer valuable insights into the perceptions of elite young football players regarding injury risk factors and the effectiveness of preventive strategies. These perceptions are essential for understanding how athletes view injury prevention approaches in their daily routines.

How safe is kitesurfing? A review of orthopaedic kitesurfing injuries

INTRODUCTION

This narrative review aims to provide a comprehensive overview of injuries arising from kitesurfing.

METHODS

We conducted a systematic search of articles from the last 20 years relating to kitesurfing orthopaedic injuries. Two of the authors independently conducted a systematic search of Pubmed (Medline), Embase, NHS Library and Knowledge Hub, TRIP, and Google Scholar: ultimately, after exclusions, the report analysed 25 articles.

DISCUSSION

Kitesurfing is associated with a high incidence of lower limb injuries in which protective gear is uncommon. Furthermore, a lack of educational initiatives and specified strength training may compound this risk.

CONCLUSION

Notably, there is a lack of prospective evidence documenting traumatic injury. Addressing this gap is a potential next step, to enhance our understanding of injury patterns and preventative measures.

WHAT IS ALREADY KNOWN

Common kitesurfing injuries include those to the foot, ankle, and knee, typically resulting from falls or collisions with the board or water. While the majority of injuries are relatively mild, more significant injuries such as ACL rupture, PCL rupture, and polytrauma have also been reported. What are the new findings: This systematic review confirmed that the majority of injuries occur below the knee (average 50%). Injuries of the chest (average 8.5%) and head (average 10.8%) also make up a significant proportion of injuries sustained. Although the majority of injuries in kitesurfing are minor, due to the high forces typically involved, there is the potential for catastrophic injury including; neurological, internal bleeding, polytrauma and death.

Apophyseal injuries in soccer players

Soccer is the most popular sport worldwide, and it is associated with high injury rates, with most of these injuries occurring in the lower extremities. Particularly, in youth soccer players with immature skeleton, the physeal plate is two to five times weaker than the surrounding fibrous structures, and therefore more vulnerable to injury. The physeal plate consists of epiphyses and apophyses, with the former serving as tendon attachment sites and being subject to traction forces. There are two types of apophyseal injury: (i) apophyseal avulsion, which consists of an acute separation across the physeal plate; and (ii) apophysitis, an injury caused by chronic and repetitive contraction of musculotendon unit, leading to inflammation of the growth plate cartilage. Apophyses of the hip and pelvis are the most commonly injured in youth soccer players, due to vigorous contractions during sports activities and the fact that they tend to fuse later compared to other epiphyseal centers, making them more susceptible to injury. In this review, we will discuss the anatomy of lower limb apophyses and clinical and imaging findings of apophyseal injuries in youth soccer players, as well as briefly review treatment options and complications.

Return-to-play criteria based on infrared thermography during anterior cruciate ligament rehabilitation in football players

Reconstruction of the anterior cruciate ligament (ACL) is associated with degenerative changes during the return-to-play (RTP) process. Infrared thermography, due to its usefulness in monitoring the state of tissues, could help establish physiological criteria for monitoring the knee joint. The aim of the study was to describe normative skin temperature (Tsk) asymmetry of the knee region of interest (knee ROI) from football players during the ACL RTP process. Thirty professional and semi-professional football players, both male and female, from three different European leagues (age: 26.84 ± 3.46 years; height: 1.83 ± 0.22 m; weight: 75.38 ± 5.92 kg) were evaluated using thermography during their RTP process. A linear mixed model was then developed in which Tsk asymmetry was the dependent variable. Sex and Day were included as predictor variables with fixed effects. Athlete was included as a random effect with (Model 1 and Model 2) and without (Model 3) interaction with Day. Model 2 was fitted with a random intercept and random independent slopes, and Model 3 was fitted with a random intercept and random dependent slopes. The results showed the estimates of the model in which both predictor variables were significant. The asymmetry decreased during the days after surgery (-0.01 per day after surgery). The results might help to establish an objective criterion based on infrared thermography for monitoring the rehabilitation stages in the RTP of football players during one year of evolution. The assessment of the thermal asymmetries of the knee ROI during the RTP established a Tsk progression criterion. Medical and technical staff could implement an infrared thermography tool for knee monitoring between RTP stages.

Sensitivity to change of quadriceps and hamstrings muscle wearable electromyography outcomes during a professional soccer match

Textile electromyography (EMG) was used to investigate neuromuscular activity during professional soccer matches, providing insights into performance optimization and injury prevention. This explorative study aimed to (1) describe the EMG activity of the quadriceps and hamstrings and (2) identify the metrics most sensitive to changes between the first and second half. Seven players (age: 23.1 ± 5.7 years; height: 1.82 ± 0.05 m; weight: 77.6 ± 10 kg) were evaluated. EMG outcomes included EMG amplitude, intensity distribution, and usual bout duration for dominant (D) and non-dominant (N.D) muscles. Hamstring activity averaged 47% (D) and 43% (N.D) of %EMGMVC, while quadriceps averaged 32% (D) and 27% (N.D). Most time was spent at the lowest EMG intensity and 13% at the highest intensity. Bout amplitudes (37-54%EMGMVC) and durations (14-17s) varied between muscle groups and limbs. The hamstrings' usual EMG bout amplitude (N.D) was the most sensitive, showing a 12% reduction (effect size [ES] = 0.64, p = 0,01). The most substantial percentage change was observed in the hamstrings' duration > 100% EMGMVC (D), which decreased by 27% (ES = 0.14, p = 0.57) with other metrics showing smaller reductions. This study highlights the potential of textile EMG to quantify neuromuscular demands during soccer matches, offering valuable tools for performance monitoring and tailored interventions to enhance training and prevent injuries.

Ultrasound imaging in professional soccer: when is it adequate?

Ultrasound imaging plays an important role in the diagnosis, monitoring and treatment of injuries in professional soccer players. With the rapid increase in the availability of hand-held portable ultrasound devices and the pressure to make timely and accurate diagnosis in professional soccer where return to play time is crucial, ultrasound imaging is an essential diagnostic tool. In this article, we discuss examples of injuries that can be adequately assessed by ultrasound imaging alone and injuries where ultrasound imaging provides a useful first step to guide further investigation and management.

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.

Using a Bayesian network to classify time to return to sport based on football injury epidemiological data

The return-to-sport (RTS) process is multifaceted and complex, as multiple variables may interact and influence the time to RTS. These variables include intrinsic factors related the player, such as anthropometrics and playing position, or extrinsic factors, such as competitive pressure. Providing an individualised estimation of time to return to play is often challenging, and clinical decision support tools are not common in sports medicine. This study uses epidemiological data to demonstrate a Bayesian Network (BN). We applied a BN that integrated clinical, non-clinical factors, and expert knowledge to classify time day to RTS and injury severity (minimal, mild, moderate and severe) for individual players. Retrospective injury data of 3374 player seasons and 6143 time-loss injuries from seven seasons of the professional German football league (Bundesliga, 2014/2015 through 2020/2021) were collected from public databases and media resources. A total of twelve variables from three categories (player's characteristics and anthropometrics, match information and injury information) were included. The response variables were 1) days to RTS (1-3, 4-7, 8-14, 15-28, 29-60, > 60, and 2) injury severity (minimal, mild, moderate, and severe). The sensitivity of the model for days to RTS was 0.24-0.97, while for severity categories it was 0.73-1.00. The user's accuracy of the model for days to RTS was 0.52-0.83, while for severity categories, it was 0.67-1.00. The BN can help to integrate different data types to model the probability of an outcome, such as days to return to sport. In our study, the BN may support coaches and players in 1) predicting days to RTS given an injury, 2) team planning via assessment of scenarios based on players' characteristics and injury risk, and 3) understanding the relationships between injury risk factors and RTS. This study demonstrates the how a Bayesian network may aid clinical decision making for RTS.

Lower body strength and body composition in female football

Lower-body strength plays a crucial role in football performance and injury prevention, and thus, monitoring of strength variables has become crucial in the training process. This study aims to (1) assess knee muscle strength performance through intra- and inter-limb asymmetries and (2) examine the relationships between knee muscle strength, body composition, and vertical jump performance (squat jump and countermovement jump). Twenty-seven semiprofessional female football players (21.5 ± 4.9 years) were evaluated for body composition, isokinetic knee muscle strength (60º/s and 180º/s), and vertical jump tasks. Peak torque (PT), peak torque/body weight (PT/BW), bilateral strength deficit, and the hamstring-to-quadriceps strength ratio (H/Q) for knee extensors (KE) and flexors (KF) in both the preferred and non-preferred legs. The H/Q ratio and the bilateral strength deficit revealed no significant intra- or inter-limb asymmetries in knee muscle strength. Strong correlations were found between vertical jump performance and KE strength at both 60º/s (p ≤ 0.01) and 180º/s (p ≤ 0.01). Additionally, a significant negative correlation was observed between vertical jump performance and body fat percentage (p ≤ 0.01). These findings highlight the critical role of knee muscle strength in explosive tasks and underline the negative impact of higher body fat on lower-body strength performance.

Effectiveness of Neuromuscular Training in Preventing Lower Limb Soccer Injuries: A Systematic Review and Meta-Analysis

Background: Soccer is associated with a high risk of injuries, mainly affecting the lower limbs, leading to significant consequences for player performance and career longevity. Neuromuscular training (NMT) has been proposed as an effective preventive strategy, but its impact varies across different populations and implementation strategies. Methods: A systematic review was conducted following PRISMA guidelines. A comprehensive search of PubMed, MEDLINE, and SPORTDiscus identified randomized controlled trials, cohort studies, and systematic reviews examining the effects of NMT on lower limb injury prevention in soccer players. Study quality was assessed using the Downs and Black tool, and injury incidence rate ratios were analyzed. Results: Eleven studies, encompassing over 10,000 soccer players, were included. NMT interventions, particularly FIFA 11+, significantly reduced injury rates compared to standard warm-ups. Higher adherence and coach education enhanced program effectiveness. Female players benefited more, particularly in ACL injury prevention. No significant differences were observed between shorter (10 min) and standard (20 min) NMT protocols. Conclusions: NMT effectively reduces lower limb injuries in soccer, with adherence and proper coaching being key determinants of success. Future research should optimize program design and long-term adherence strategies to maximize benefits across all player demographics.

Do Different Two-Dimensional Camera Speeds Detect Different Lower-Limb Kinematics Measures? A Laboratory-Based Cross-Sectional Study

Background/Objectives: Football poses a high risk of sustaining lower-limb injuries, particularly anterior cruciate ligament (ACL) injuries, owing to the frequent jumping and landing movements. Identifying risk factors for these injuries is crucial to successful prevention. Two-dimensional (2D) video analysis is a commonly employed tool for assessing movement patterns and determining injury risk in clinical settings. This study aims to investigate whether variations in the camera frame rate impact the accuracy of key angle measurements (knee valgus, hip adduction (HADD), and lateral trunk flexion (LTF)) in male football players during high-risk functional tasks such as single-leg landing and 45° side-cutting. Methods: This laboratory-based cross-sectional study included 29 football players (mean (SD) age: 24.37 [3.14] years). The frontal plane projection angle (FPPA), HADD, and LTF during single-leg landing and side-cutting tasks were measured using two different camera frame rates: 30 frames per second (fps) and 120 fps. The 2D kinematic data were analyzed using Quintic Biomechanics software. Results: Significant differences in FPPA scores during single-leg landing were observed between the 30 fps and 120 fps for both the dominant (mean difference = 2.65 [95% confidence interval [CI]: 0.76-4.55], p = 0.008) and non-dominant leg (3.53 [1.53-5.54], p = 0.001). Additionally, the FPPA of the right leg during the side-cutting task showed significant differences (2.18 [0.43-3.93], p = 0.016). The LTF of the right leg during side-cutting displayed a significant variation between frame rates (-2.69 [-5.17--0.22], p = 0.034). No significant differences in HADD were observed. Conclusions: Compared with a 30 fps camera, a high-speed (120 fps) camera demonstrated a superior performance in delivering accurate kinematic assessments of lower-limb injury risk factors. This improved precision supports injury screening, rehabilitation monitoring, and return-to-play decision-making through determining subtle biomechanical deficits crucial for lower-limb injury prevention and management.

Shoulder injuries in amateur soccer players. An exploratory cross-sectional survey

OBJECTIVES

To investigate the prevalence, incidence of players reporting shoulder injuries in a non-probability sample of Italian amateur soccer players. We also wanted to explore the characteristics of injuries, predictive factors and differences between men's and women's leagues.

DESIGN

Cross-sectional study.

SETTING

Anonymous online survey.

PARTICIPANTS

Adult athletes playing on a first team of the Italian National Amateur Soccer League.

MAIN OUTCOME MEASURES

Period prevalence, incidence, and characteristics of players reporting shoulder injuries over a soccer season.

RESULTS

Fifty-one out of 431 respondents reported shoulder injuries. The pooled period prevalence was 12.0% (95%CI [9, 15]), with an incidence of .46 (95%CI [.35, .60]) injured/1000 h of players exposure. Goalkeepers were more likely to be injured than outfield players (OR 5.15, 95%CI [2.27, 11.25]). The injury type stated was mainly contusion (n = 22, 43.1%). Among those reporting injuries, thirty-four (66.6%) respondents stated 0-7 days as time loss from sport activity, with no significant difference due to role (p=.161) CONCLUSIONS: Shoulder injuries have a relatively low impact on the participation of adult amateur players in soccer activities. Technical and medical staff need to monitor players after an injury to the shoulder in order to provide appropriate training, prevention of complications and educational programs.

Global prevalence and pattern of injuries in basketball players: a systematic review

INTRODUCTION

Basketball, as a widely popular sport, can be associated with a high risk of injury. This study aimed to provide a comprehensive overview of basketball-related injuries in various groups through the utilization of a systematic review methodology.

EVIDENCE ACQUISITION

An extensive search was conducted in the four valid databases using three groups of keywords up to November 2023 based on the PRISMA guidance. Two reviewers independently performed the steps of the study, including study selection, data extraction, and quality assessment. In case of any disagreements, the opinion of a third researcher was sought to achieve agreement in each step. The agreement between the reviewers was examined by computing Cohen's kappa coefficient. The quality assessment of the articles in this study was conducted using the Joanna Briggs Institute (JBI) critical appraisal tools.

EVIDENCE SYNTHESIS

The prevalence range of injuries in these people was between 0.38% and 92.0%. Ankle injuries in 12 out of 28 studies (42.86%), knee injuries in 7 out of 28 studies (25.00%), head and tooth injuries in 3 out of 28 studies (10.71%), and shoulder and hand injuries in three out of 28 studies (10.71%) had the highest prevalence among various injuries. Five out of six studies (83.33%) showed a higher percentage of the injuries in males. Only a study compared the prevalence of injuries between people with various ages.

CONCLUSIONS

These findings emphasize the need for injury prevention and management strategies, particularly targeting vulnerable areas like the ankle and knee.

The Epidemiology of Injuries and Illnesses During SailGP Season 4: A Prospective Cohort Study

INTRODUCTION

Sailing is a high-intensity sport that demands a combination of physical strength, endurance, and technical skill. Sail Grand Prix (SailGP), inaugurated in 2019, epitomises a transformative approach to professional sailing. This study aims to provide a comprehensive analysis of injury and illness epidemiology among SailGP elite sailors, comparing injury and illness types and locations across different sailing activities.

METHODS

This prospective cohort study analysed injury and illness data from professional sailors throughout season 4 (2023/2024) of the professional sailing league. Data were collected on the number of hours spent in training, racing, and foiling, alongside injury reports, categorising injury types and locations. Incidence rates were calculated per 1000 h of sailing and 365 athlete days. Injuries were stratified by sex, position on the boat, and specific sailing activities to provide a detailed comparison.

RESULTS

A total of 100 sailors participated in the Sail GP 2024 season, accumulating 4919.84 h of recorded sailing activity: 2186.03 h in racing and 2733.80 h in training. The overall injury incidence rate was 9.96 per 1000 h of activity (95% CI: 7.17-12.75) and 7.43 per 365 athlete days (95% CI: 4.99-9.86). The injury rate was notably higher for foiling at 26.52 per 1000 h (95% CI: 19.09-33.94) compared to general sailing at 14.51 per 1000 h (95% CI: 10.44-18.57). Racing posed a greater injury risk than training, with an injury rate of 11.89 per 1000 h (95% CI: 7.77-16.46) compared to 8.41 per 1000 h for training (95% CI: 5.12-12.07). Grinders had the greatest rate of injuries at 3.86 (2.24, 5.69) injuries per 1000 h of sailing. The illness incidence rate was 5.14 per 1000 h (95% CI: 3.21-7.28), with respiratory illnesses being the most frequently reported.

CONCLUSION

This study highlights the injury and illness risks amongst elite sailors in Sail GP. Males were at higher risk of injury, with the position of grinders being the most commonly injured. Ankle and knee injuries were the most prevalent. Future research should focus on developing sport-specific injury prevention programmes and examining long-term outcomes in sailors.

The effect of knee-flexion angle on peak force and muscle activation during isometric knee-flexor strength testing using the Nordbord device in soccer players

Isometric knee-flexor testing is commonplace in soccer, yet data to inform choice of knee-flexion angle are limited. This study aimed to compare peak force production and muscle activation between two isometric knee-flexor tests. To compare peak force, 43 male soccer players (age 21.5 ± 5 years; stature 180.3 ± 6.3 cm; body mass 74.6 ± 8.9 kg) completed 3 × 5-second maximal efforts on the Nordbord device (Vald Performance) with a 0- (ISO-Prone) and 30-degree (ISO-30) knee angle, respectively. To compare peak muscle activation, a further 13 trained male participants (25 ± 6 years; 178.2 ± 5.6 cm; 79.6 ± 13.2 kg) completed 3 × 5-second maximal efforts with wireless surface electromyography electrodes placed on the Gluteus Maximus, Adductor Magnus, Semitendinosus, Biceps Femoris (long and short heads) and Medial Gastrocnemius. Paired samples t-tests were used to detect differences in force output between tests and Pearson's correlations to quantify associations. A Yuen's modified t-test estimated the trimmed mean differences in muscle activation between tests. Higher peak forces were observed in the ISO-30, with mean differences of 56.4N (36.8 to 75.9 [95% CI]) and 52.9N (33.7 to 72.3 [95% CI]) for right (367 vs 314N) and left legs (351 vs 294N), respectively. Moderate correlations were observed in peak force for left (r = 0.55 (0.29 to 0.73 [95%CI])) and right (r = 0.64 (0.42 to 0.79 [95%CI]) legs. No differences in muscle activation were observed. Peak force varies between the ISO-Prone and ISO-30, with moderate associations between tests, indicating that the tests should not be used interchangeably.

Injury risk profile for soccer players: identification of the risk factors for soccer-related injuries - an umbrella review

This review aimed to identify risk factors for soccer injuries and provide researchers the needed elements to build a soccer-player's injury risk profile. An umbrella review was conducted following the PRIOR criteria (OSF registration link: https://osf.io/jr7xe/). A literature search was run to identify studies investigating soccer-related injury risk factors. We included systematic reviews published between 2013 and 2023 related to soccer and analysed the identified risk factors to classify these in intrinsic and extrinsic, group in categories and identify relationships between risk factors and injury location. Among 240 risk factors, 181 (75.4%) were classified as intrinsic and 59 (24.6%) as extrinsic. We grouped risk factors in 14 categories. Finally, we found relationships between risk factors and injury locations for 159 factors, with the knee representing the body area most affected by risk factors (N = 101), followed by the ankle (N = 65) and the thigh (N = 65).

Sports-Related Injuries in Deaf Competitive Squad Athletes-Results of a Retrospective Self-Assessment

BACKGROUND

Deaf squad athletes regularly participate in national/international competitions and most prepare for competitions in clubs with hearing athletes. Hearing loss is associated with difficulties in balance control which may impair functionality. The aim of this study is to provide epidemiological data on sports injuries in deaf squad athletes.

METHODS

In this retrospective study, data on main sport, training and competitions, injury rates, and downtimes were collected. Questionnaires from n = 65 athletes (n = 15 females, n = 50 males; age 28.00 ± 0.40 years) were finally analyzed. All injuries during the athlete's career within nine body regions were recorded. The influence of contact sports, supervision by Olympic Training Center (OSP), and hearing aids on injury rates and downtimes were analyzed.

RESULTS

An amount of 89.20% were additionally registered in a regular sports club. A total of 1430 injuries were recorded during 465,400 training hours (3.07 injuries/1000 training hours). The highest prevalences were found for hand/fingers (43.00%) and ankle/foot (14.00%). Contact sport athletes had higher injury rates and longer downtimes (5.66 versus 1.28 injuries/1000; p < 0.001; 2.45 versus 1.11 weeks/1000; p = 0.011). OSP athletes showed lower injury rates (0.92 versus 4.38 injuries/1000, p = 0.004). Longer downtimes were recorded for athletes without hearing aids during training (2.29 weeks/1000 versus 0.96 weeks/1000; p = 0.045).

CONCLUSIONS

Deaf athletes are exposed to additional training and competition in hearing sports. The negative impact of contact sports may be attributed to hearing loss. Hearing aids in training seem to be protective. Athletes should consider supervision by OSP. The results of this study may help to improve treatment and integration of deaf athletes into hearing sports.

Video Analysis of Acute Lower Extremity Injury Mechanisms in Soccer Demonstrates Most Anterior Cruciate Ligament, Achilles, and Muscle Injuries Occur Without Direct Contact: A Systematic Review and Meta-analysis

PURPOSE

To systematically review the literature for studies using video analysis to evaluate acute lower extremity injury mechanisms in soccer players.

METHODS

The study was preregistered on PROSPERO. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. Three databases were searched for Level I to IV studies that quantified lower extremity injury mechanisms in soccer players using video analysis. Data recorded included study demographics, injury type, mechanisms, contact, phase of play, timing, and sagittal plane kinematics. Study methodological quality was analyzed using the Quality Appraisal for Sports Injury Video Analysis Studies scale. Forest plots of proportions were generated for injuries occurring in the first versus second half, defensive versus offensive phase, and contact versus noncontact injury.

RESULTS

Nineteen articles (mean Quality Appraisal for Sports Injury Video Analysis Studies score 14.3 ± 1.9; all Level IV evidence, 1,652 videos, 17 professional males, 1 professional female, 1 both male/female) were included. Anterior cruciate ligament (ACL) tears (49% [42%-55%]), muscle strains (hamstring: 71% [47%-87%]), and Achilles tears (80%-83%) had a high percentage of noncontact (NC) injury mechanisms. Direct and indirect contact-predominant injuries include medial collateral ligament sprains (14% NC) and foot/ankle sprains (6% [4%-10%] NC). Most ACL injuries (68% [61%-75%]) occurred while defending, and quadriceps strains (81%-89%) occurred while attacking.

CONCLUSIONS

In soccer, video analysis shows that a high proportion of acute ACL, Achilles, and muscle injuries occur through noncontact mechanisms, while medial collateral ligament and foot/ankle injuries usually happen with direct contact. ACL injuries are more likely to be sustained when defending, specifically when pressing/tackling, and muscle injuries result from sprinting, kicking, and lunging. Most noncontact-predominant injuries occurred at a higher percentage in the first half, whereas contact-predominant injuries occurred at a higher percentage in the second half.

LEVEL OF EVIDENCE

Level IV, systematic review and meta-analysis of Level IV studies.

Systematic Video Analysis of ACL Injuries in Male Professional English Soccer Players: A Study of 124 Cases

Background

Improving our understanding of the situations and biomechanics that result in anterior cruciate ligament (ACL) injury will support the design of effective injury risk mitigation programs. A few video analyses have been published in recent years, but not specifically involving English soccer.

Purpose

To describe the mechanisms, situational patterns, and biomechanics (kinematics) of ACL injuries of players involved in matches involving teams in the top 2 tiers of professional English soccer (the Premier League and the Championship).

Study Design

Case series; Level of evidence, 4.

Methods

We identified 148 consecutive ACL injuries across 11 seasons of professional English soccer. Overall, 124 (84%) injury videos were analyzed for mechanism and situational patterns, while biomechanical analysis was possible in 91 injuries. Three independent reviewers evaluated each video. ACL injury epidemiology (month, timing within the match, and location on the playing field at the time of injury) was also reported.

Results

More injuries occurred in defensive (n = 79; 64%) than offensive (n = 45; 36%) playing situations; 24 (19%) injuries were direct contact, 52 (42%) indirect contact, and 47 (38%) noncontact. Of the indirect and non-contact ACL injuries (n = 100), most (91%) occurred during 4 main situational patterns: (1) pressing/tackling (n = 50; 50%); (2) being tackled (n = 18; 18%), (3) landing from a jump (n = 13; 13%), and (4) regaining balance after kicking (n = 10; 10%). These injuries generally involved a knee flexion strategy (with minimal hip/trunk flexion and reduced plantarflexion) in the sagittal plane and appearance of knee valgus in most cases (70%; 96% of identifiable cases). More (n = 71; 57%) injuries occurred in the first half of matches than in the second half (P < .01).

Conclusion

Indirect contact rather than noncontact was the main ACL injury mechanism in male elite English soccer players. Four main situational patterns were described, with pressing/tackling and being tackled accounting for two-thirds of all indirect and noncontact injuries. Biomechanical analysis confirmed a multiplanar mechanism, with knee loading patterning in the sagittal plane accompanied with dynamic valgus. More injuries occurred in the first half of matches.

A session-by-session analysis of psychological and external workload demands prior to muscle-tendon injuries in Brazilian professional soccer players: a pilot study

OBJECTIVES

This study aimed to compare the psychological demands and external workload experienced in the seven sessions leading up to injuries and the demands in the month preceding the injury week among professional Brazilian soccer players.

METHODS

Initially, 33 players participated, but only 15 were included in the analysis due to the occurrence of 23 muscle-tendon injuries recorded according to International Olympic Committee (IOC) guidelines. The study assessed muscle-tendon injuries, rate of perceived exertion (RPE), and psychological variables (i.e. mental load, motivation, and mental fatigue) using specific questionnaires, while weekly accumulated workload (i.e. total distance, high-speed running distance, sprint running distance, number of sprints, and actions accelerating and decelerating) was recorded using Global Position System devices.

RESULTS

The results indicated that players experienced higher external loads, particularly in high-intensity running variables, along with increased mental load and mental fatigue during the match prior to injury occurrence (p < 0.05).

CONCLUSION

These findings highlight the significance of carefully monitoring both external and psychological demands during competition, which is essential for developing effective recovery strategies and modulate the subsequent microcycle training loads in order to reduce the risk of suffer a muscle-tendon injury.

Severe Injuries of Former Portuguese Football Players: A Post-Career Burden?

BACKGROUND/OBJECTIVES

Football players have a high injury risk due to the physical demands of their profession, which can negatively affect their quality of life (QoL) in the long term. The aim of this study is to characterize the severe injuries that former Portuguese football players suffered throughout their professional careers and investigate the resulting impacts on the physical domain of QoL after retirement.

METHODS

This study includes 84 former Portuguese football players (48.8 ± 8.2 years) who underwent reform between 1988 and 2018 and played in professional leagues (15.2 ± 3.2 years of career duration), namely, first division leagues (n = 43) and secondary division leagues (n = 41). Quantitative and qualitative interview data are used by a validated interview guide and from results of the physical domain obtained by the application of the World Health Organization Quality of Life questionnaire (WHOQOL-Bref).

RESULTS

Former players had 2.1 ± 1.5 severe injuries throughout their careers. The most common injuries involve the knee (47.5%) and foot/ankle (17.2%), with the anatomical area of the knee as the most likely to require surgical intervention (60%). The association between tactical-positional status and the incidence of severe injuries is significant, with defenders sustaining less severe injuries throughout their careers. This study found a statistically significant linear model (F(1.82) = 8.089, p < 0.006) that explains 7.9% of the variation in the physical domain of QoL (R2ajuste = 0.079). For each severe injury sustained throughout a career, there is an estimated decrease of 2.7 values in QoL perception in the physical domain.

CONCLUSIONS

The higher the number of severe injuries sustained during a career, the lower the perception of QoL in the physical domain of former players in their post-career. These findings highlight the need to optimize training programs and injury prevention and recovery protocols for long-term QoL improvement in the physical domain of football players.

Classification of myo-connective tissue injuries for severity grading and return to play prediction: A scoping review

OBJECTIVES

To conduct a systematic literature search to identify currently used classifications of acute non-contact muscle injuries in sporting adults.

DESIGNS

Scoping review.

METHODS

A systematic literature search from January 1, 2010 to April 19, 2022 of Medline and SPORTDiscus yielded 13,426 articles that were screened for eligibility. Findings from included studies were qualitatively synthesized. Classifications and their grading, as well as outcomes and definitions were extracted.

RESULTS

Twenty-four classifications were identified from the 37 included studies, most of which had low evidence study designs. Majority (57 %) of classifications were published after 2009 and were mostly developed for hamstring or other lower limb injuries. The six most cited classifications accounted for 70 % of the reports (BAMIC, modified Peetrons, Munich, Cohen, Chan and MLG-R). Outcome reporting was sparse, making it difficult to draw conclusions. Still, significant relationships between grading and time to return to play were reported for the BAMIC, modified Peetrons, Munich and Cohen classifications. Other classifications either had a very low number of reported associations, reported no associations, reported inconclusive associations, or did not report an assessment of the association. Other outcomes were poorly investigated.

CONCLUSIONS

There is no agreed-upon use of muscle classification, and no consensus on definitions and terminology. As a result, reported outcomes and their relationship to severity grading are inconsistent across studies. There is a need to improve the generalizability and applicability of existing classifications and to refine their prognostic value. High-level evidence studies are needed to resolve these inconsistencies.

Breaking new grounds in injury risk screening in soccer by deploying unsupervised learning with a special focus on sex and fatigue effects

In injury prevention, a vertical drop jump (DJ) is often used for screening athletes at risk for injury; however, the large variation in individual movement patterns might mask potentially relevant strategies when analysed on a group-based level. Two movement strategies are commonly discussed as predisposing athletes to ACL injuries: a deficient leg axis and increased leg stiffness during landing. This study investigated the individual movement pattern of 39 female and male competitive soccer players performing DJs at rest and after being fatigued. The joint angles were used to train a Kohonen self-organising map. Out of 19,596 input vectors, the SOM identified 700 unique postures. Visualising the movement trajectories and adding the latent parameters contact time, medial knee displacement (MKD) and knee abduction moment allow identification of zones with presumably increased injury risk and whether the individual movement patterns pass these zones. This information can be used, e.g., for individual screening and for feedback purposes. Additionally, an athlete's reaction to fatigue can be explored by comparing the rested and fatigued movement trajectories. The results highlight the ability of unsupervised learning to visualise movement patterns and to give further insight into an individual athlete's status without the necessity of a priori assumptions.

Intra and Inter-Test Reliability of Isometric Hip Adduction Strength Test with Force Plates in Professional Soccer Players

Assessing the reliability of measurement instruments and equipment is essential to ensure the accurate tracking of athletes over extended periods, minimizing the measurement errors caused by chance or other factors. However, a less common but equally important analysis is the verification of inter-measurement agreement, which complements the reliability results. Purpose: To evaluate the intra- and inter-test reliability of an isometric hip adduction strength and asymmetries test in professional soccer players. Methods: Twenty-three professional male soccer players were evaluated on two occasions, 1 week apart. The force signal was collected using force plates (Pasco PS-2141), and the data processing was performed using Matlab software (R2023a, MathWorks, Natick, MA, USA). The peak force, interval RFD, peak RFD, peak force asymmetry and RFD were analyzed. Intraclass correlation coefficients (ICCs) and coefficients of variation (CV) were calculated to corroborate the intra- and inter-test reliability. In addition, the degree of agreement of the asymmetries was corroborated through the kappa index. Results: The peak force demonstrated an acceptable absolute reliability (CV < 10%) for the intra-test and test-retest condition, an excellent relative intra-test reliability and a good to moderate reliability for the test-retest reliability. However, the peak force asymmetry showed a moderate test-retest reliability and agreement. For the intra-test condition, the RFD variables demonstrate a moderate to excellent relative reliability; however, all demonstrate unacceptable absolute reliability (CV > 10%) in at least one of the evaluation sessions. A moderate to poor test-retest reliability and unacceptable absolute reliability were observed for all the RFD variables. Conclusions: The peak force is the variable with the highest intra- and inter-test reliability, so its use is recommended to longitudinally assess the maximum strength of the adductors in professional soccer players, but not the asymmetry orientation of the peak force. The RFD variables should be interpreted with caution due to their inconsistent reliability, and it is necessary to improve the methods used to achieve adequate reliability.

Injuries in weightlifting and powerlifting: an updated systematic review

ABSTRACT

Objective

To systematically review the literature on the incidence, prevalence, anatomical injury localisation and risk factors in Olympic weightlifting and powerlifting.

Design

Updated systematic review, PROSPERO registration (CRD42022382364).

Data sources

Four databases (PubMed, Embase, SPORTDiscus and Web of Science) were searched on 19 February 2024.

Eligibility

Reports assessing injury incidence and prevalence in Olympic weightlifting and powerlifting, published between January 2015 and February 2024, were included in addition to reports from a previous systematic review. The 'Quality Assessment Tool for Observational Cohort and Cross-sectional Studies' was used to assess methodological quality.

Results

Of 1765 screened records, eight new reports were found, resulting in 17 reports in the review. 12 reports covered weightlifting and seven covered powerlifting, with two of the reports included in both categories as they addressed both sports. In weightlifting, the period prevalence of injuries during competitions was 10.7%-68%, the incidence was 2.4-3.3 injuries/1000 hours of training, and the most common injury sites were the knee, lower back, shoulder and hands/fingers. In powerlifting, one report showed a point prevalence of 70%. Injury incidence was 1.0-4.4 injuries/1000 hours of training, and the most common injury sites were the lower back/pelvis, shoulder and elbow/upper arm. Both sports showed a high prevalence of pelvic floor dysfunction (eg, urinary incontinence) among females (50%) compared with males (9.3%).

Conclusions

This updated systematic review supports the conclusions of previous reviews and shows new findings that pelvic floor dysfunction is very common in both sports. Due to the distinctly different study designs and settings, further direct comparisons between sports were difficult. In weightlifting, reports mainly focused on injuries during competitions. In powerlifting, injury incidence was low, but injury prevalence was high when defining injury as a painful condition that impairs training/competition.

Muscle Pain Code: a novel tool for screening the risk of time-loss muscle injury in professional male football players

OBJECTIVE

To investigate the association of a novel post-match muscle pain map, named Muscle Pain Code (MPC), with the risk of subsequent time-loss muscle injury in a cohort of professional football (soccer) players.

METHODS

The MPC classifies pain in four codes: code 0, 'no pain;' code 1, 'generalized muscle pain;' code 2, 'diffused site muscle pain;' and code 3, 'specific site muscle pain.' Over four consecutive seasons, MPC was collected on the second post-match day and players were followed for occurrence of time-loss muscle injury over the next five days. Players exposed to at least 45 minutes in two consecutive matches within seven days were included as cases for analysis.

RESULTS

Eighty players participated in the study. Of 1,656 cases analyzed, 229 resulted in time-loss muscle injuries. Only 2% of cases with codes 0 and 1 resulted in time-loss muscle injuries. Conversely, 63% and 78% of codes 2 and 3 were followed by time-loss muscle injuries, respectively. Compared with the reference scenario (i.e. code 0 on MPC), the risk of subsequent time-loss muscle injury was significantly higher when players recorded code 2 (odds ratio, 4.29; 95%CI, 3.62 to 4.96) or code 3 (odds ratio, 5.01; 95%CI, 4.05 to 5.98) on MPC, but not when they recorded code 1 (odds ratio = -0.27; 95%CI, 1.05 to 0.56).

CONCLUSIONS

Players experiencing well-outlined pain area on the second post-match day were more likely to incur a time-loss muscle injury in the subsequent days compared to those experiencing spreading pain or no pain.

Injury epidemiology in Australian women's professional football

OBJECTIVE

To describe the injury epidemiology of the Australian women's professional football (soccer) league (A-League W) over 7 consecutive seasons.

DESIGN

Prospective observational cohort study.

METHODS

Match-loss injury data was collected from each A-League W club (n = 8-9) for each competition round (n = 12/season) over 7 seasons (2013/14-2019/20). Data was collected by the head physiotherapist in each club based on the governing body regulations and after initial familiarisation with collection methods. Injuries were collected weekly through a standardised protocol for all clubs and were classified by setting, mechanism, severity, the type and location on the body based on club, round and season. Generalised Linear Models were used to estimate the injury incidences (injury/round/season), whilst rate ratios were reported for total injuries and within abovementioned injury classifications for the change between seasons.

RESULTS

Injury incidence rate ranged between 0.68 (95 % CI: 0.27-1.74) and 1.17 (95 % CI: 0.59-2.34) injuries/match/round across the 7 seasons analysed. There was no significant change over time in injuries by occurrence (i.e. match, training or other), mechanism (contact or non-contact), type or region. The most common injuries were joint and ligament injuries (0.24 (95 % CI: 0.05-1.17)-0.85 (95 % CI: 0.38-1.91) injuries/round/season), ankle injuries (0.13 (95 % CI: 0.02-0.95)-0.41 (95 % CI: 0.13-1.32) injuries/round/season) and non-contact mechanisms (0.48 (95 % CI: 0.18-1.27)-1.07 (95 % CI: 0.52-2.2) injuries/round/season).

CONCLUSIONS

Injury incidence trends did not show a significant change over the seven seasons of the A-League W reported here. Key areas of concern for female players remain injuries to the ankle, thigh and knee. Whilst specific to the Australian environment, these outcomes provide further understanding of the type and rate of injury trends in female footballers.

Epidemiology and clinical characteristics of football injuries among academy players in Ghana

ABSTRACT

Objective

To determine the epidemiology and clinical characteristics of match and training injuries among football players at an academy in Ghana.

Methods

In this prospective observational study, we followed 80 youth and adult football players at a Ghanaian academy over a season of 39 weeks. Medical attention and time-loss injuries, as well as exposure times of players, were recorded by resident physiotherapists using a standardised injury surveillance form. The average weekly injury prevalence was calculated. Injury incidence rates were calculated per 1000 exposure hours, with significance indicated as 95% CIs.

Results

126 injuries were recorded during the season, with an average weekly injury prevalence of 4.1%. The overall injury incidence was 4.5 (95% CI 3.8 to 5.4) injuries per 1000 hours with under 14 (5.8 (3.3 to 10.2)/1000 hours) and under 18 players (5.7 (4.4 to 7.4)/1000 hours) recording a higher incidence than under 16 (5.1 (3.5 to 7.4)/1000 hours) and senior players (2.7 (1.9 to 3.9)/1000 hours). Match injury incidence was 13 times higher than training injury incidence (27.4 (21.5 to 34.9) vs 2.3 (1.8 to 3.0) injuries/1000 hours). Injuries to the lower extremities had the highest incidence (3.9 (2.1 to 7.2) injuries/1000 hours), with the knee being the most commonly injured site (n=30, 23.8%). The most common type of injury was a joint sprain (1.9 (1.5 to 2.5) injuries/1000 hours), and the most common injury mechanism was direct contact with another player (1.5 (1.1 to 2.0) injuries/1000 hours). Most injuries were moderately severe (2.0 (1.5 to 2.6) injuries/1000 hours).

Conclusion

Ghanaian academy football players have a substantial risk of sustaining injuries, especially among younger players. Further studies should focus on developing specific injury prevention programmes in under-researched football-playing populations.

Predictors of Risk of Muscle Injury in Non-Professional Soccer Players: An Ambispective Cohort Study

(1) Background: Soccer accounts for 30% of all sports injuries. Muscle injuries in soccer, not caused by trauma or contact, are the most common. The objective was to assess the risk of injury based on the footwear used by soccer players and the playing field and to identify the best predictive model of muscle injuries; (2) Methods: An ambispective cohort study. The primary variable was the number of muscle injuries in the last three seasons. The secondary variables were age, body mass index, type of soccer shoes and turf, training load and position on the field. The possible confounding variables were motivation for the choice of footwear, date of injuries, time playing and regular first-team player status; (3) Results: 156 players were recruited. The risk of injury is 1.03 (95% CI: 0.83; 1.27) times more frequent in players competing on artificial turf. The risk of injury is slightly higher in first-team players than in substitutes (RR = 1.02; 95% CI: 0.79; 1.32). There was no statistically significant relationship between the position on the field (p = 0.91), the type of shoe (p = 0.69) and the motivation to buy the shoes (p = 0.82), regarding the risk of muscle injury in these athletes. The best model to estimate risk of injury includes age, training load and soccer shoe type as confounding variables (AIC = 190.5; p = 0.10; χ2(3) = 10.14; p = 0.02); (4) Conclusions: The risk of muscle injury is higher in non-professional soccer players competing on artificial pitches and in those who are regular starters on their teams. Field position, soccer shoe and motivation to purchase the soccer shoe are variables that do not increase the risk of muscle injury in these athletes. The best predictive model of injury includes age, training load and shoe type.

Effects of an Instability Training Program Using Global Versus Selective Instability Devices on Dynamic Balance and Ankle Stability in Young Amateur Soccer Players

Background/Objectives: Both Sides Utilized it is one of the most employed global instability devices (GID), but it is difficult to progress and select a particular foot structure. In this sense, the Blackboard has been created as selective instability device (SID). The aim of this study is to compare the effects of both devices on balance and ankle stability. Methods: The study was designed as a randomized controlled clinical trial. Twenty healthy amateur soccer players were divided into two groups: GID and SID. Both performed balance training (4-weeks, 3 days/week). Ankle balance and stability were assessed. Paired t-tests were used to analyze the pre-, post-, and between-groups differences. Results: No differences were found between the groups. Significant intra-group changes were found in both groups for posterolateral balance and summation. Moreover, posteromedial balance increased in the GID group. No changes were found in ankle stability results. Conclusions: A balance intervention using GID or SID is effective in improving general and posterolateral balance. Moreover, the GID intervention improved posteromedial balance.

Testing in Football: A Narrative Review

Football clubs regularly test and monitor players, with different approaches reflecting player age and competitive level. This narrative review aims to summarise justifications for testing and commonly used testing protocols. We also aim to discuss the validity and reliability of specific tests used to assess football players and provide a holistic overview of protocols currently used in football or those demonstrating potential utility. The PubMed, SportDiscus, and Google Scholar databases were screened for relevant articles from inception to September 2024. Articles that met our inclusion criteria documented tests for several purposes, including talent identification or the assessment of growth/maturation, physiological capacity, sport-specific skill, health status, monitoring fatigue/recovery, training adaptation, and injury risk factors. We provide information on specific tests of anthropometry, physical capacity, biochemical markers, psychological indices, injury risk screening, sport-specific skills, and genetic profile and highlight where certain tests may require further evidence to support their use. The available evidence suggests that test selection and implementation are influenced by financial resources, coach perceptions, and playing schedules. The ability to conduct field-based testing at low cost and to test multiple players simultaneously appear to be key drivers of test development and implementation among practitioners working in elite football environments.

Well-being fluctuations and injuries during an entire season in male professional soccer players: an observational study

This study aimed to describe and relate the well-being perception and injury incidence of soccer players in an entire soccer season. For 37 weeks, twenty-eight male professional soccer players (25.2 ± 4.3 years old; 22.8 ± 1.4 kg/m2) daily scored (from 1: bad; to 5: perfect) well-being perception (fatigue, sleep, muscle soreness, stress and mood and Hooper Index (HI) as general status). Injuries were also registered. Results showed that players had the lowest well-being perception during Preseason (in terms of HI, fatigue, muscle soreness and stress), being lower than EarlySeason (ps < 0.05, ds > 1.0) and/or InSeason (ps < 0.05, ds > 1.0). The injury incidence was 8.3 ± 9.2/1000 h, being always higher in training compared to competition (35.0 vs 11.1/1000 h). A lower stress perception (worse) correlated with a higher rate of new injuries during PreSeason (r = -0.84), while a greater muscle soreness and fatigue correlated with the new injuries occurring in the following week during the whole season (r = -0.38 and r = -0.39, respectively). As a conclusion, the well-being perception of professional soccer players was especially low during Preseason, with fatigue, muscle soreness and stress as the most affected items that correlated with injury incidence.

Injection therapy in professional footballers

BACKGROUND

Injection therapy offers a minimally invasive approach for symptomatic relief that allows concurrent training, limiting time loss and providing a faster recovery. However, there is a lack of scientific evidence to support it, and there are controversies about its use. The present narrative review aims to present the available scientific literature on injection therapies in professional footballers (PF), highlighting the advantages and disadvantages of its use in the most common injuries.

METHODS

The authors searched and reviewed contemporary literature on injection therapies in PF in electronic databases, summarizing them in a narrative review.

RESULTS

Injection therapies such as hyaluronic acid and PRP have shown an adequate safety profile that allows their use. Current evidence suggests that hyaluronic acid injections are a valid option for managing symptomatic cartilage injuries. At the same time, PRP injections have failed to prove beneficial in treating muscle injuries and should be avoided until further evidence proves the opposite. Yet, PRP may have potential use in partial ACL injuries, anterior inferior tibiofibular ligament injuries (ankle syndesmosis), and fifth metatarsal fractures and needs further study. Due to the long-term health repercussions, other injection therapies should be preferred over corticosteroids in PF.

CONCLUSIONS

There is a paucity of evidence on the use and benefits of injection therapies in PF despite its extensive use among physicians. Viscosupplementation may have a role in improving symptomatic cartilage injuries. In contrast, PRP injection therapy needs further high-quality clinical trials to assess its role in PF sports injuries.

Changes in injury type among NBA athletes in response to the COVID-19 pandemic

CONTEXT

The 2019-2020 NBA season was altered significantly by the COVID-19 pandemic with a midseason suspension of games, the NBA 'bubble' tournament, and a shortened offseason. Concerns were raised regarding player conditioning and the potential increased risk of injury due to the schedule changes. The purpose of this study was to determine the impact of the COVID-19 pandemic and associated schedule changes on NBA injuries. It was hypothesized that injury rates would be higher in the year following the pandemic and teams who participated in the bubble would have higher injury rates in the following season than non-bubble teams. Furthermore, the types of injuries would shift toward more severe injuries in the condensed 2019-20 season and the following 2020-21 season.

DESIGN

Retrospective Cohort Study.

METHODS

The NBA's public injury reports were queried to identify players listed on an injury report. Standardized injury events were calculated for four pre-COVID-19 seasons (2015-2019), the COVID-19 season (2019-2020), and the post-COVID-19 season (2020-2021). Injury characteristics including type and location were extracted for each year and differences within each period were calculated.

RESULTS

When excluding injury events related to COVID-19 health and safety protocols, the overall injury events per 1000 exposures were not significantly different between time periods of pre-COVID-19, COVID-19, and post-COVID-19 seasons; (p = 0.199), and no difference was found in the rates of teams who participated in the bubble. Injuries, including soreness and strains, significantly decreased while fracture injuries significantly increased in the COVID-19 year.

CONCLUSIONS

The COVID-19 pandemic led to an increased number of games missed, but no increase in injury rates when accounting for health and safety protocols. Additionally, bubble participation had no impact on injury rates. However, despite no changes in injury rates, the types of injuries changed with an increased proportion of severe injuries and decreased proportion of minor injuries.

A systematic review of the efficacy of neural mobilisation in sport: A tool for the neural tension assessment

INTRODUCTION

Any sport places great physical demands on the lower limbs and lumbar spine. Sport can lead to nerve entrapment syndromes, making nerve tissue a target for therapeutic intervention.

METHODS

A systematic review of clinical trials and cohort studies using neurodynamics as a method of assessment and treatment in sports patients was conducted. Risk of bias was assessed using the PEDro and NOS scales.

RESULTS

Ten studies were eventually included in this study. Age ranged from 18 to 33 years. Neural tension is underappreciated in sport as a risk factor for injury. Treatment of nerve tissue included glide/tension type neural mobilisations. Studies ranged from 3 to 8 sets, 5 to 20 repetitions, with a time of 60 s and 1-6 weeks of treatment.

CONCLUSIONS

Neurodynamics manoeuvres proves to be most beneficial in increasing range of motion and decreasing perceived muscle tension in the athlete population. A significant effect was also observed in the monopodal jump test, the 6-m jump test and the cross-jump test. There is also limited and scarce evidence on the use of neural testing in sports injuries.Further studies on the application and assessment of neural stress in sport are warranted.

Effects of mid-season camp period loading on sports injury anxiety and physical performance of professional male soccer players

OBJECTIVE

This study aimed to investigate the effects of 3-week mid-season camp period loading on sports injury anxiety level and physical performances of professional male soccer players.

METHODS

Thirty-four male soccer players [mean age 21.76 (3.42) y] were included in the study. Sports injury anxiety level with the Sports Injury Anxiety Scale, quadriceps muscle strength was assessed with the digital hand dynamometer, flexibility was assessed with the sit-and-reach test, dynamic balance was assessed with the Y balance test, power was assessed with the single-leg jump test, agility was assessed with the t-test, and sprint was assessed with the 20-m sprint test.

RESULTS

There was no significant difference between the pretest and posttest values of Sport Injury Anxiety Scale scores (p = 0.657). A significant difference was found between the pretest and posttest values of quadriceps muscle strength and dynamic balance (p = 0.040, p = 0.048, respectively). There was no significant difference between the pretest and posttest values of flexibility, single-leg jump, agility, and sprint (p = 0.289, p = 0.128, p = 0.064, p = 0.471, respectively).

CONCLUSION

The 3-week mid-season camp period loading improved quadriceps muscle strength and dynamic balance, but did not affect the sports injury anxiety level, flexibility, jumping performance, agility, and sprint. The results should be considered by sports professionals. It is recommended that further studies be conducted on the effects of different camp period contents, durations and loads in regions with different physical conditions (sea level, high altitude, etc.).

Knee muscle strength, body composition, and balance performance of youth soccer players

BACKGROUND

Muscle strength and balance abilities have been related to game performance injury prevention. This study aimed to (1)  assess knee muscle strength performance based on intra- and inter-limb asymmetries, (2)  investigate the relationships between knee muscle strength, body composition, and balance, and (3) analyze the variance in the overall stability index (OSI) explained by knee muscle strength indicators after controlling for age and body composition.

METHODS

The sample included 104 young male soccer players (16.0 ± 1.6 years). Body composition, knee muscle strength, and balance ability were assessed. A paired samples t-test was used to examine differences between the preferred leg (PL) and the non-preferred leg (NPL). Pearson correlations and hierarchical multiple regression were conducted to explore the relationships between strength, body composition, and balance.

RESULTS

No significant inter-limb asymmetries were detected for the knee flexors (KF) and knee extensors (KE) performance. The hamstrings-to-quadriceps ratio does not suggest the existence of intra-limb asymmetries (p = 0.06). Significant and negative correlations were found between KF (r = -0.38, p ≤ 0.01) and KE (r = -0.58, p ≤ 0.01) for the PL. Concerning the NPL, KE also revealed a significant and negative relationship with balance (r = -0.30, p ≤ 0.01). Significant and positive relationships were found between bodyweight, fat-free mass, and balance. After controlling for age and body composition, knee muscle strength could explain between 13% and 30% of the variance observed in the OSI (NPL and PL, respectively).

CONCLUSIONS

The results underline knee muscle strength as an important predictor of balance. Thus, training programs targeting knee muscle strength development should be considered during the season periodization by coaches and their staff throughout the players' developmental stages.

SUPER rehabilitation of hamstring strain injuries in soccer players: Delphi consensus study

INTRODUCTION

Hamstring strain injuries (HSI) are one of the most common injuries for soccer players and there is a need for new clinical-based studies on the rehabilitation of these injuries.

OBJECTIVE

This study aimed to create a consensus on physiotherapy and rehabilitation approaches used in HSI by physiotherapists with super league experience in Turkey.

METHODS

Twenty-six male physiotherapists (duration of experience in professional life, on athlete health, and in the super league: 12.84 ± 6.04 years, 12.19 ± 5.96 years, 8.71 ± 5.31 years, respectively) from different institutions participated in the study. The research was carried out in three rounds using the Delphi method.

RESULTS

Data collected using LimeSurvey and Google Forms were analyzed using the Microsoft Excel and SPSS 22 software. The response rates over the three rounds were 100%, 96%, and 96%, respectively. The 10 main items that were agreed upon in Round 1 were divided into 93 sub-items. Their numbers in the second and third Rounds were 60 and 53, respectively. At the end of Round 3, the highest consensus was on eccentric exercise, dynamic stretching, interval running, and movement-enhancing field training. All sub-items at this round were classified as SUPER (S: Soft tissue restoration techniques; U: Using supportive approaches; P: Physical fitness exercises; E: Electro-hydro-thermal methods; and R: Return to sport activities).

CONCLUSION

SUPER rehabilitation provides a new conceptual framework in terms of approaches used by clinicians in rehabilitation for athletes with HSI. Recognizing the lack of evidence for the various approaches involved, clinicians can modify their practice and researchers can explore whether these approaches are scientifically correct.

Blocking proteinase-activated receptor 2 signaling relieves pain, suppresses nerve sprouting, improves tissue repair, and enhances analgesic effect of B vitamins in rats with Achilles tendon injury

ABSTRACT

Tendon injury produces intractable pain and disability in movement, but the medications for analgesia and restoring functional integrity of tendon are still limited. In this study, we report that proteinase-activated receptor 2 (PAR2) activation in dorsal root ganglion (DRG) neurons contributes to chronic pain and tendon histopathological changes produced by Achilles tendon partial transection injury (TTI). Tendon partial transection injury increases the expression of PAR2 protein in both somata of DRG neurons and their peripheral terminals within the injured Achilles tendon. Activation of PAR2 promotes the primary sensory neuron plasticity by activating downstream cAMP-PKA pathway, phosphorylation of PKC, CaMKII, and CREB. Blocking PAR2 signaling by PAR2 small-interference RNA or antagonistic peptide PIP delays the onset of TTI-induced pain, reverses the ongoing pain, as well as inhibits sensory nerve sprouting, and promotes structural remodeling of the injured tendon. Vitamin B complex (VBC), containing thiamine (B1), pyridoxine (B6), and cyanocobalamin (B12), is effective to ameliorate TTI-induced pain, inhibit ectopic nerve sprouting, and accelerate tendon repair, through suppressing PAR2 activation. These findings reveal a critical role of PAR2 signaling in the development of chronic pain and histopathological alterations of injured tendon following Achilles tendon injury. This study suggests that the pharmaceuticals targeting PAR2, such as VBC, may be an effective approach for the treatment of tendon injury-induced pain and promoting tendon repair.

Assessing Lower-Extremity Visuo-Motor Reaction Time in Young Male Soccer Players: Test-Retest Reliability and Minimum Detectable Change of the Brain Pro System

A reliable, versatile means of assessing visuo-motor reaction time (V-MRT) is important to football (soccer) players for many reasons, including the fact that faster V-MRT is a critical sport skill that may even play a role in reducing common sports injuries to the lower muscle extremities that can be associated with lost time on the field. We aimed to determine the test-retest reliability and minimum detectable change (MDC) of the Brain Pro System for assessing lower-extremity V-MRT in young male football players. We had 68 participants (M age = 16.35, SD = 1.71 years) perform two assessment sessions one-week apart. For test-retest reliability, we calculated a one-way intra-class correlation coefficient (ICC) at the 95% confidence interval and provided the standard error of measurement (SEM) and minimum detectable change (MDC) (MDC = SEM × 1.96 × √2) for V-MRTs. We obtained excellent V-MRT test-retest reliability for dominant lower-extremity, non-dominant lower-extremity, and dominant and non-dominant lower-extremities (ICC2,1 = .93, 95%CI = .89-.96; ICC2,1 = .94, 95%CI = .91-.96; ICC2,1 = .96, 95%CI = .94-.97; respectively). The calculated MDC for the dominant lower-extremity V-MRT, the non-dominant lower-extremity V-MRT, and dominant and non-dominant lower-extremities (random) V-MRT were 1.21 seconds, 1.13 seconds, and 1.21 seconds, respectively. Brain Pro System had excellent reliability for assessing lower-extremity V-MRT in young male football players. The MDC values at the 95% confidence level (MDC95) we obtained were reliable for assessing clinically meaningful V-MRT changes.

The Acute: Chronic Workload Ratio and Injury Risk in Semiprofessional Football Players

The purpose of this study was to analyze the association and predictive capacity between the acute:chronic workload ratio (ACWR) and non-contact injuries in a semiprofessional football team. Seventeen football or soccer players from a Spanish Third Division football team participated voluntarily in this study. A prospective longitudinal study was developed during the 2020/2021 season. Twenty-four weeks were analyzed from October to March, including a regenerative microcycle due to the absence of competition during Christmas. Rate of perceived exertion (RPE) and session-rate of perceived exertion (sRPE) were registered for every training and game session. Afterward, acute and chronic workloads were calculated, and ACWR was subsequently derived from them. Furthermore, non-contact injuries were registered during the period mentioned. The main findings were that there is a poor correlation between the ACWR and non-contact injuries (r=0.069 (p<0.05)), and the use of the ACWR by itself is insufficient to predict the occurrence of non-contact injuries in a semiprofessional football team. Consequently, the ACWR is not an useful predictive tool for injuries in semiprofessional football teams.

High-Intensity GPS-Derived Parameters in Semi-Professional Soccer: Home vs. Away Roles of the Team and Their Relationship with the Match's Final Score

High-intensity activities are related to success in football. We looked at whether high-intensity activity differed between home and away matches and its impact on the final score. Thirty football players (20.3 ± 0.8 years) were recruited from a Spanish semi-professional team. Footballers wore a GPS device to monitor high-intensity parameters from competition matches. The final score of every match was also recorded. Playing at home showed greater total distance (TD) > 24 km/h, >27 km/h, >85% Vmax, and the number of sprints > 24 km/h (all p < 0.05) than playing away. Positive correlations were also found between the match score and high-speed running (HSR) distance covered by the team per minute (r = 0.401), TD > 21 km/h (r = 0.417), TD > 24 km/h (r = 0.343), number of sprints > 24 km/h (r = 0.337), and HSR per minute (r = 0.459) (all p < 0.05). The results suggest that playing at home is associated with greater high-intensity effort than playing away. Moreover, the volume of high-intensity effort influences the final score.

Knee and Hip Muscle Strength of Male Soccer Players from Different Competitive Levels

In soccer, knee and hip muscle strength assessments have been recommended for injury prevention. The aims of this study were threefold: (1) to compare knee and hip muscle strength between professional players competing at different levels; (2) to compare strength performance according to the preferred leg (PL) and the non-preferred leg (NPL); and (3) to compare knee and hip muscle strength performance at two moments of the season. This study included 33 professional soccer players: 13 were in the elite group (EG), and 20 were in the sub-elite group (SEG). Body composition, isokinetic knee strength at 60º/s, and hip adduction strength were assessed at two different moments (M1 and M2). Values of peak torque (PT), peak torque/bodyweight (PT/BW), and the hamstring-to-quadriceps strength ratio (H:Q) for knee extensors (KEs) and knee flexors (KFs) for both legs were used for analysis. The statistical analysis included the Mann-Whitney U and the Wilcoxon Signed Rank tests. At M1, the EG presented a significantly better performance in KF PT/BW and in the squeeze strength test for the PL and the NPL (p ≤ 0.01). At M2, the EG performed substantially better in KE PT/BW and KF PT/BW (p ≤ 0.01). No substantial strength differences were observed in knee and hip muscle performance between the PL and the NPL. From M1 to M2, significant increases were found in knee strength in both groups (p ≤ 0.01). Overall, the EG players outperformed significantly their lower-division peers in strength assessments. The results indicate significant knee and hip muscle strength increases during the season, probably as a response to the exposure to training and competition.

A Rehabilitation Algorithm After Lateral Ankle Sprains in Professional Football (Soccer): An Approach Based on Clinical Practice Guidelines

Lateral ankle sprain (LAS) is one of the most common types of injury in professional football (soccer) players with high risk of recurrence. The rehabilitation after LAS in professional football players is often still time-based and relies on anecdotal experience of clinicans. There is still a lack of utilization of criteria-based rehabilitation concepts after LAS in professional football. The aims of this clinical commentary are (1) to critically discuss the need for criteria-based rehabilitation concepts after LAS in professional football players, (2) to highlight the current lack of these approaches and (3) to present a novel clinical guideline-based rehabilitation algorithm. Short time-loss (15 days) and high recurrence rate (17%) raise the question of trivialization of LAS in professional football. Despite consequences for many stakeholders involved (players, teams, clubs, insurers), there is still a lack of of criteria-based, step-by-step approaches. The use of a criteria-based rehabilitation approach might reduce the high recurrence rate after LAS in professional football players and will lead, in turn, to increased long-term player availability. Practical experiences of he authors demonstrate the feasibility of such an approach. The effectiveness of this novel rehabilitation algorithm remains to be evaluated in future studies. Level of Evidence: 5.

Injury incidence and characteristics in adolescent female football players: A systematic review with meta-analysis of prospective studies

To observe overall, training, and match injury incidence in female youth football. We also aimed to quantify the incidence of injuries by affected tissue and body location. The following databases were examined: PubMed, Web of Science, Scopus, SPORTDiscus, Cochrane and PEDro. Papers that reported overall injury incidence, training or match injury incidence were included. Additionally, studies had to be performed in adolescent female football players (13-19 years of age). The Newcastle-Ottawa Scale and the checklist of items that must be included in epidemiological football reports were used to assess methodological quality of the included articles. For the meta-analyses, a random effect model was used. A total of 13 studies were included. There were 2,333 injuries; incidence was higher during games (12.7/1000 h) compared to training sessions (2.3/1000 h). The injury match-to-training ratio was 5.8. The lower limbs were the region in which the greatest number of injuries occurred, with the ankle (1.2/1000 h) and knee (0.8/1000 h) having the most injuries. In relation to injured tissue, ligament injuries represented an incidence of 1.3/1000 h, followed by muscle injuries (0.9/1000 h). This study represents the first step towards the creation and implementation of preventative measures in female youth football. The results suggest that attention should be focused on ankle and knee injuries, since they are the most frequent and can lead to sport retirement in some cases depending on the severity.