Incidence of injury in indoor soccer

Injury incidence and prevention beliefs in Brazilian amateur soccer: a cross-sectional study

INTRODUCTION

Soccer, the world's most popular sport, provides health benefits but also poses risks, especially in unsupervised amateur play. Musculoskeletal injuries affect both individual and team performance, underscoring the need to explore contributing factors, attitudes, and barriers to injury prevention programs for a safer sporting environment.

OBJECTIVE

To analyze the incidence of injuries among amateur soccer players, explore beliefs related to injury prevention, and identify the preventive strategies adopted by this population.

METHODS

This was a retrospective epidemiological, cross-sectional, observational, and descriptive study utilizing a quantitative approach. Data were collected via a digital survey from June 10 to August 31, 2024.

RESULTS

Among 90 respondents, 88 were analyzed, with an injury incidence rate of 11.46 per 1,000 hours. The knee (21.8%) and ankle (20.9%) were most affected, followed by the thigh (10.9%), hip/groin (9.1%), and lower back (9.1%). Injuries caused absence from soccer in 86% of cases (mean recovery: 30 ± 70 days). Physiotherapy was sought by 43.8%, physician consultation by 38.5%, while 12.3% did not seek medical help. Although 90.9% valued injury prevention, 33% had never received guidance. Main reported causes were insufficient recovery (35%) and excessive matches (30%). Additionally, 65% acknowledged their coach's influence on prevention adherence. Open-ended responses highlighted intrinsic risks and extrinsic factors.

CONCLUSION

The findings indicate a moderate injury incidence, particularly in the lower limbs, reinforcing the multifactorial nature of injuries in amateur soccer. Despite recognizing the importance of injury prevention, many players lack guidance and structured prevention programs.

Sociocultural constructs and sensorimotor control: a scoping review examining implications for anterior cruciate injury

OBJECTIVE

There is a need to explore the many factors that may have a more subtle influence on, or relationship with, sensorimotor control as it pertains to anterior cruciate ligament injury risk. Due to well-established sex/gender-related differences in sensorimotor control, a close examination of key sociocultural constructs is warranted. This scoping review examined the connection between sociocultural constructs and sensorimotor control.

DESIGN

Scoping review.

DATA SOURCES

The following databases were searched: PubMed, Embase, Scopus, CINAHL Complete, Academic Search Complete, Pre-Prints Database and Rehabilitation Reference Center from inception to September 2023. Additionally, relevant grey literature was identified.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Two blinded reviewers independently performed screening, study selection and data extraction. Original references in English, Spanish and German reporting on sociocultural constructs and motor task performance were included.

RESULTS

Data were extracted from 68 included articles. Stereotype threat, gender and race have been examined more than other sociocultural constructs. Sensorimotor control was assessed in upper and lower quarter tasks and physical activity (PA). Task assessment methods varied, often focusing on task completion or completion speed. It is evident that sociocultural constructs influence sensorimotor control, but the exact mechanism remains unclear.

CONCLUSION

Sociocultural constructs can influence sensorimotor control and PA. Future research should further explore this connection as it relates to biomechanical profiles associated with increased injury risk. Additionally, sociocultural construct inventory scores could be added to existing injury screening programmes to create a more gendered approach to risk mitigation.

Injury Prevention Strategies in Female Football Players: Addressing Sex-Specific Risks

There has been rapid growth in women's football worldwide; however, research on injury prevention strategies and physiological considerations specific to female athletes remains insufficient. Women's football has experienced an increase in injury prevalence, despite being underrepresented in sports literature, with less than 25% of research focused on this demographic. The incidence of injuries, particularly among young elite female footballers, is notably high, impacting long-term health outcomes such as osteoarthritis and contributing to shorter playing careers. Certain injuries, such as anterior cruciate ligament (ACL) ruptures, occur at significantly higher rates in women compared to men, underscoring sex-specific risk factors that must be addressed in injury prevention programs (IPPs). This narrative review aims to evaluate the effectiveness of IPPs tailored for female football players and to address their heightened susceptibility to injuries compared to males. Research studies and review articles were identified using a literature search of the PubMed, SportDiscus, and Google Scholar databases from 1990 to December 2024. Biological factors, including hormonal influences-such as increased ACL laxity during the menstrual cycle-and musculoskeletal differences, such as muscle strength imbalances, reduced joint stability, and hip weakness, significantly contribute to this increased risk. Despite the existence of injury prevention protocols like FIFA 11+, their consistent application and adaptation to meet the unique needs of female footballers remain limited. In addition to physical injuries, mental health is a critical concern. Female football players exhibit higher rates of depression and anxiety compared to their male counterparts, influenced by factors such as injury-related stress and menstrual cycle variations. In conclusion, the growing participation of women in football highlights the urgent need for research and implementation of injury prevention strategies specifically tailored to female players.

The gender and sex data gap in anterior cruciate ligament injuries in paediatric patients

Anterior cruciate ligament (ACL) injury is a concerning problem in the paediatric population, impacting joint health and longevity. Moreover, ACL injury hampers physical activity, which is important for children's social network and general well-being. Recent data demonstrates a rise in paediatric ACL reconstructions, affecting both girls and boys. However, it is unclear whether this rise reflects a higher injury rate or a more proactive approach towards surgery, as information on nonoperated patients is lacking. Regarding gender differences, increasing evidence implies that girls engaged in pivoting sports experience a higher incidence of ACL injuries and reinjuries compared to boys. Furthermore, data suggest that girls have inferior outcomes and lower return-to-sport rates than boys. The social context in which girls compete in sports is likely a significant contributing factor to the risk of serious knee injuries. Lack of attention and insufficient data on gender-based differences in ACL injuries, outcomes and evidence-based treatment guidelines highlight the need for further research on this topic. LEVEL OF EVIDENCE: Level IV.

Relative Energy Deficiency in Sport (REDs) and knee injuries: current concepts for female athletes

In athletes, a mismatch between caloric intake and energy expended in exercise can eventually lead to Relative Energy Deficiency in Sport (REDs), where the athlete suffers from physiological derangements and decreased sport performance. The prevalence of REDs is higher in females than males. Females are already at a higher risk of knee injuries, which has been attributed to a multitude of factors such as hormonal influences, differences in musculoskeletal anatomy and neuromuscular control compared to males. The literature demonstrates an even higher risk of knee injuries in female athletes with symptoms of REDs. We propose the various factors that influence this risk. A reduction in anabolic hormones can affect muscle development and tendon repair. A relationship between poor neuromuscular control and knee injury has been established, and this can be further worsened in patients with menstrual dysfunction. Chronic deficiency in nutrients such as collagen and vitamin D can result in poorer recovery from microtrauma in tendons and ligaments. All these factors may contribute to increasing the risk of knee injuries, which may include anterior cruciate ligament tears, patella tendinopathy and patellofemoral pain syndrome. This review aims to educate sports clinicians to have a high index of suspicion when treating knee injuries in females; to screen and then manage for REDs if present, for holistic patient care.

Exploring Injury Prevention Strategies for Futsal Players: A Systematic Review

Futsal carries a high risk of injury for players. This systematic review aimed to assess the existing literature on injury prevention strategies for futsal players. The literature was searched using PubMed, Web of Science, and Scopus databases from inception to 20 March 2024. Relevant articles were searched using the terms "futsal" AND "injury" AND "prevention". Fourteen studies were included in the review. The review identified several injury prevention strategies with potential benefits for futsal players. Structured warm-up routines were shown to improve balance and eccentric strength and to reduce total, acute, and lower limb injuries. Proprioceptive training methods were suggested to improve joint stability and landing mechanics, which may reduce the risk of injury. Furthermore, multicomponent methods that include components such as core stability and flexibility have shown potential for reducing injury rates in futsal players. Finally, by reducing fatigue and improving movement control, strength training procedures designed to correct muscular imbalances may improve performance, which may ultimately minimize the risk of injury. This systematic review demonstrates the potential benefits of different injury prevention strategies for futsal players. The combination of several strategies, such as proprioceptive training, multicomponent programs, warm-up routines, and strength training specifically designed to address muscular imbalances, appears promising.

Evaluation of Bony Femoral Morphological Parameters in Anterior Cruciate Ligament Injury Using Magnetic Resonance Imaging: A Retrospective Unmatched Case-Control Study

Background Over time, there has been a noticeable increase in anterior cruciate ligament (ACL) injuries. The current imperative is to anticipate predisposing factors and proactively prevent ACL injuries. The occurrence of ACL injuries has been linked to diverse factors associated with the morphology of the distal femur. Objectives Through this study, we aim to compare the anatomic variables of distal femur morphology such as notch width (NW), bicondylar width (BW), notch entrance width (NEW), and notch width index (NWI) between patients with ACL injuries and non-injured patients using MRI. We also aim to make a comparison of these factors between male and female genders to assess the gender variability. Material and methods A retrospective case-control study was conducted amongst patients who underwent MRI Knee scan for clinical suspicion of internal derangement during the study period. We selected the first 125 individuals who were found to have ACL injury in the MRI scans and selected another 125 individuals who had an intact ACL in the scans, to serve as controls in the study. Demographic information was retrieved from the hospital's electronic records, and the assessment of NW, NWI, BW, and NEW was conducted through a review of MRI sequences. They were then compared between the cases and control groups, as well as between male and female genders. Results The ACL-injured group exhibited statistically significant reductions in NW and NWI. While 17.39 mm was the mean NW among cases, 17.86 was the mean value among controls. Similarly, the mean NWI was 0.25 among patients with ACL injuries and 0.27 among controls. Gender-based comparisons also revealed statistically significant differences in NW and NWI measurements, where females were reported to have comparatively lower measurements. The mean NW for males and females in the injured group were 18.26 mm and 15.40 mm, respectively, while it was 18.71 mm and 16.90 mm, respectively, in the control group. In the case of NEW, males in the injured group had a slightly higher value (21.33 mm) than the controls (20.65). Females on the other hand exhibited a lower mean value of NEW in ACL-injured group (18.51 mm) in comparison to the non-injured (18.79 mm). BW did not seem to show a significant difference between the two groups. Conclusions In the studied population, ACL injuries demonstrated a higher occurrence in individuals with a narrow femoral intercondylar NWI. If any of these characteristics are identified in an MRI, it may be helpful to identify individuals who are at a higher risk of developing ACL injuries and may thereby help in planning preventative strategies.

Magnetic Resonance Imaging-Based Morphometric Analyses of the Bicruciate Injury of the Knee: Is There a Clue in the Distal Femur?

BACKGROUND

The morphology of the distal femur's intercondylar notch has been implicated in the susceptibility to and severity of cruciate ligament injuries. While previous research has primarily focused on isolated anterior cruciate ligament (ACL) or posterior cruciate ligament (PCL) injuries, the relationship between notch morphology and combined cruciate injuries remains less understood.

OBJECTIVE

This study aimed to explore the association between femoral notch morphology and the severity of combined cruciate ligament injuries in adult males.

METHODS

In this retrospective cohort study, MRI scans from 118 adult male participants with and without knee dislocations (60 cases with Schenk classification Type II or higher knee dislocations and 58 controls) were analyzed. The study period ranged from 2015 to 2023. Femoral notch width, notch width index (NWI), and notch shape (U shape, A shape) were assessed using a Philips Multiva 1.5 Tesla system (Philips, Amsterdam, Netherlands). The statistical significance of differences in measurements between cases and controls was evaluated using independent sample t-tests performed with IBM SPSS Statistics, version 26 (IBM Corp., Armonk, NY).

RESULTS

The case group exhibited a significantly smaller mean femoral notch width (15.88 mm ± 2.7 mm) and NWI (0.238 ± 0.58) compared to the control group (notch width 18.29 mm ± 3.4 mm, NWI 0.25 ± 0.31), with p-values of 0.004 for both measurements. The notch shape was predominantly A-shaped in the case group (n = 49) as opposed to U-shaped in the control group (n = 41).

CONCLUSIONS

The study identifies a significant association between reduced femoral notch dimensions and the severity of complex cruciate ligament injuries. These findings support the notion that specific femoral notch morphologies may predispose individuals to more severe ligamentous injuries.

Epidemiology of Injuries in Men's Professional and Amateur Football (Part I)

Background (1): Football is the most popular sport among men, associated with a certain risk of injury, which leads to short- and long-term health consequences. While the injury profile of professional footballers is known, little is known about the injury profile of amateur footballers; amateur football is a major and diverse area, the development of which should be a priority for football associations around the world and UEFA. The aim of this study was to perform a systematic review of epidemiological literature data on injuries in professional and amateur football players belonging to certain leagues. Methods (2): A systematic review according to the PRISMA guidelines was performed until June 2023 in the databases PubMed, Web of Science, Google Academic, Google Scholar, and Diva portal. Forty-six studies reporting injury incidence in professional and amateur men's football were selected and analyzed. Two reviewers independently extracted data and assessed study quality using an adapted version of the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement and the Newcastle Ottawa Scale (NOS) to assess risk of bias for the quality of external validity. Results (3): The overall incidence of injuries in professional male football players was 7.75 ± 2.28, 95% confidence interval, injuries/1000 h of exposure and that of amateur football players was 7.98 ± 2.95, 95% confidence interval, injuries/1000 h of exposure. The incidence of match injuries (30.64 ± 10.28, 95% confidence interval, injuries/1000 exposure hours) was 7.71 times higher than the training injury incidence rate (3.97 ± 1.35, 95% confidence interval, injuries/1000 h) in professional football players and 5.45 times higher in amateurs (17.56 ± 6.15 vs. 3.22 ± 1.4, 95% confidence interval, injuries/1000 h). Aggregate lower extremity injuries had the highest prevalence in both categories of footballers, being 83.32 ± 4.85% in professional footballers and 80.4 ± 7.04% in amateur footballers: thigh, ankle, and knee injuries predominated. Conclusions (4): Professional and amateur football players are at substantial risk of injury, especially during matches that require the highest level of performance. Injury rates have implications for players, coaches, and sports medicine practitioners. Therefore, information on football injuries can help develop personalized injury risk mitigation strategies that could make football safer for both categories of football players. The current findings have implications for the management, monitoring, and design of training, competition, injury prevention, especially severe injury, and education programs for amateur football players.

Consensus Delphi study on guidelines for the assessment of anterior cruciate ligament injuries in children

Background: Knee examination guidelines in minors are intended to aid decision-making in the management of knee instability. Clinical question: A Delphi study was conducted with a formal consensus process using a validated methodology with sufficient scientific evidence. A group consensus meeting was held to develop recommendations and practical guidelines for use in the assessment of instability injuries in children. Key findings: there is a lack of evidence to analyse anterior cruciate ligament injuries in children and their subsequent surgical management if necessary. Diagnostic guidelines and clinical assessment of the patient based on a thorough examination of the knee are performed and a guide to anterior cruciate ligament exploration in children is developed. Clinical application: In the absence of a strong evidence base, these established guidelines are intended to assist in that decision-making process to help the clinician decide on the most optimal treatment with the aim of benefiting the patient as much as possible. Following this expert consensus, surgical treatment is advised when the patient has a subjective sensation of instability accompanied by a pivot shift test ++, and may include an anterior drawer test + and a Lachman test +. If these conditions are not present, the conservative approach should be chosen, as the anatomical and functional development of children, together with a physiotherapy programme, may improve the evolution of the injury.

Injuries in elite level male beach soccer players: a prospective three year study

OBJECTIVES

The aim of this study was to investigate the incidence and characteristics of match and training injuries in elite-level national male beach soccer players.

METHOD

The incidence, mechanism, location, type, severity, and burden of injuries of the Turkish national beach soccer team were recorded between 2017 and 2019.

RESULTS

A total of 136 injuries occurred during the study period. Total injury incidence was 238.9 injuries/1,000 match hours (MHs) and 37.7 injuries/1,000 training hours (THs) (p < 0.001). Twenty-seven injuries led to time-loss, and the incidences for match and training injuries were 36.7 and 7.9 per 1,000 hours, respectively. Of medical attention injuries (MAI) caused by trauma, 54.6% (n = 53) were due to another player and, 60.9% (n = 14) of time-loss injuries (TLI) caused by trauma were due to non-contact trauma (p < 0.001). While 82% (n = 91) of training injuries occurred in lower extremities, 29% (n = 9) of match injuries occurred in the head/neck region (p < 0.001). Head injury incidence was 45.9 per 1,000 match hours. Of MAI, 50% (n = 57) were contusion, and 32.1% (n = 9) of TLI were strain (p < 0.001). Also, the most common injury subtype was foot/toe contusion during match and training (19.4%; n = 6, 27.9%; n = 31, respectively). The majority of injuries 91.9% (n = 125) had slight severity.

CONCLUSION

Head trauma, tendon injury, and foot/toe contusion are important for clinical practice in beach soccer. Protective measures (rule regulation, use of protective equipment, etc.) should be considered to prevent these injuries.

Sexual Dimorphisms in Anterior Cruciate Ligament Injury: A Current Concepts Review

Background:

Although most anterior cruciate ligament (ACL) injuries occur in male athletes, female athletes are consistently observed to be at a higher risk for sports-specific ACL injury.

Purpose:

To provide a thorough review of what is known about the sexual dimorphisms in ACL injury to guide treatment and prevention strategies and future research.

Study Design:

Narrative review.

Methods:

We conducted a comprehensive literature search for ACL-related studies published between January 1982 and September 2017 to identify pertinent studies regarding ACL injury epidemiology, prevention strategies, treatment outcomes, and dimorphisms. By performing a broad ACL injury search, we initially identified 11,453 articles. After applying additional qualifiers, we retained articles if they were published in English after 1980 and focused on sex-specific differences in any of 8 different topics: sex-specific reporting, difference in sports, selective training, hormonal effects, genetics, neuromuscular and kinematic control, anatomic differences, and outcomes.

Results:

A total of 122 articles met the inclusion criteria. In sum, the literature review indicated that female athletes are at significantly higher risk for ACL injuries than are their male counterparts, but the exact reasons for this were not clear. Initial studies focused on intrinsic differences between the sexes, whereas recent studies have shifted to focus on extrinsic factors to explain the increased risk. It is likely both intrinsic and extrinsic factors contribute to this increased risk, but further study is needed. In addition to female patients having an increased risk for ACL injuries, they are less likely than are male patients to undergo reconstructive surgery, and they experience worse postsurgical outcomes. Despite this, reconstructive surgery remains the gold standard when knee stability, return to sports, and high functional outcome scores are the goal, but further research is needed to determine why there is disparity in surgical rates and what surgical techniques optimize postsurgical outcomes for female patients.

Conclusion:

Male athletes often predominated the research concerning ACL injury and treatment, and although sex-specific reporting is progressing, it has historically been deficient. ACL injuries, prevention techniques, and ACL reconstruction require further research to maximize the health potential of at-risk female athletes.

Soccer-related injuries utilization of U.S. emergency departments for concussions, intracranial injuries, and other-injuries in a national representative probability sample: Nationwide Emergency Department Sample, 2010 to 2013

Soccer participation in the United States (U.S.) has increased over time, and injuries as well as interest to prevent injuries has become more common. This study described Emergency Department (ED) visits related to concussions, intracranial injuries (ICI), and all-other injuries attributed to soccer play; described healthcare cost and length of hospital stay of soccer-related injuries; and determined independent predictors of concussions, ICI, and all-other soccer injuries leading to ED visits. The study examined soccer-related weighted discharge data from the Nationwide Emergency Department Sample, Healthcare Cost and Utilization Project, Agency for Healthcare Research and Quality. Weighted tabular analysis of univariate and bivariate analyses and weighted and adjusted logistic regression models were conducted. A total of 480,580 of U.S. ED visits related to soccer injuries were available for analysis between 2010 to 2013. Generally, 98% of soccer-related ED visits resulted in routine (treat-and-release) visits. However, the odds of transfer to a short-term hospital following ED evaluation and treatment was more than 37-fold higher for soccer-injured youth and adults diagnosed with ICI when compared to all-other soccer injuries; additionally, these patients showed 28-fold higher odds of being admitted for inpatient care at the ED-affiliated hospital. For concussion, soccer-injured patients with concussion showed nearly 1.5-fold higher odds of being transferred to a short-term hospital than did those with any other soccer injury. Soccer-related ED visits cost more than 700 million in U.S. dollars from 2010 to 2013. Notable differences were noted between concussions, ICI, and all-other soccer injuries presenting to U.S. ED. Albeit underestimated given that this study excludes other forms of health care and treatment for injuries, such as outpatient clinics, over the counter medications and treatment, and rehabilitation, healthcare cost associated with soccer-related injuries presenting to ED is high, and remarkably costly in those with an ICI diagnosis.

Anterior cruciate ligament injury: towards a gendered environmental approach

BACKGROUND

The anterior cruciate ligament (ACL) injury rate for girls/women has not changed in over 20 years, and they remain 3-6 times more likely to experience injury compared with boys/men. To date, ACL injury prevention and management has been approached from a sex-based biological point of view which has furthered our understanding of injury risk factors, mechanisms, and prevention and rehabilitation programmes. However, the traditional sex-based approach does not take into account the growing recognition of how sex and gender (a social construct) are 'entangled' and influence each other.

OBJECTIVE

This paper discusses the curious absence of gender as an influencer in the dialogue surrounding ACL injuries. We propose adding gender as a pervasive developmental environment as a new theoretical overlay to an established injury model to illustrate how gender can operate as an extrinsic determinant from the presport, training and competition environments through to ACL injury and the treatment environment.

APPROACH

We draw on social epidemiological theories of the embodiment of gender and health to provide plausible examples of how gender may influence ACL injury, and demonstrate the opportunity for new, interdisciplinary research in the field.

CONCLUSION

Over 20 years of research has failed to decrease the ACL injury rate disparity between girls/women and boys/men. Embedding gender in the study of ACL injury will heighten awareness of possible influences outside the traditional biological elements, challenge us to think about the inextricable 'entanglement' of sex and gender, and inform more effective approaches to ACL injury prevention and treatment.

Sex differences in the knee orthopaedic injury patterns among recreational alpine skiers

Background

Although studies have reported the sex differences in injury patterns among recreational skiers, the findings are still conflicting. This study aims to analyse the sex differences of orthopaedic knee injuries that occurred during alpine skiing.

Methods

A total of 306 recreational alpine skiers (125 females and 181 males) who sustained knee surgeries between June 2016 and December 2018 participated in this study. Age, height, weight, and physical activity level of the patients were recorded. The orthopaedic knee injury patterns were analysed based on the diagnosis given by the physicians.

Results

Male skiers (17.13%) had a higher proportion of multiple knee ligament injuries than females (6.40%). The combined anterior cruciate ligament (ACL) and medial collateral ligament injury were the most common injury types in both females and males, with ACL injury being more prevalent for females (79.20%) than that in males (56.35%). The proportion of female skiers (17.6%) with vigorous-intensity activity level was significantly lower than that of males (30.9%). Female skiers had lower body height, body weight, and body mass index than male skiers (P <  0.001).

Conclusions

ACL injury is the most common orthopaedic injury among both female and male knee-injured recreational skiers. The proportion of females with an ACL injury is higher than that of males, but the proportion of multiple knee ligament injuries is lower than that of males. More male recreational skiers have vigorous-intensity activity level habits in daily life than females.

ACL Injuries Aren't Just for Girls: The Role of Age in Predicting Pediatric ACL Injury

BACKGROUND

Female athletes have a higher rate of anterior cruciate ligament (ACL) injuries than male athletes; however, the role of age in mediating this injury risk has not been explored. The purpose of this study was to characterize the relationship between age and sex in predicting ACL injury in the pediatric population.

HYPOTHESIS

Prepubescent boys are more likely to sustain an ACL injury than prepubescent girls.

STUDY DESIGN

Descriptive epidemiological study.

LEVEL OF EVIDENCE

Level 4.

METHODS

Data were collected from the Statewide Planning and Research Cooperative System database for the state of New York from 1996 to 2016. The database was queried for patients aged ≤19 years who had been diagnosed with an ACL tear using the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) code 844.2 or the ICD-10 (10th Revision) codes S83.512A/S83.511A/S83.519A. Patient age and sex at time of ACL injury diagnosis were recorded. Chi-square analysis was used to compare the frequency of ACL injury between groups, with statistical significance set atP < 0.05.

RESULTS

A total of 20,128 patients aged ≤19 years were diagnosed with an ACL tear (10,830 males, 9298 females; male:female, 1.16:1). In all, 129 patients aged <12 years sustained an ACL tear (85 boys, 44 girls; male:female, 1.93:1), and 19,999 of those patients were aged 12 to 19 years (10,745 males, 9254 females; male:female, 1.16:1). Chi-square analysis demonstrated a significant relationship between sex and age group (P < 0.006). Additional analysis revealed that female athletes were most at risk for ACL injury from ages 12 to 16 years, with 4025 male and 5095 female athletes sustaining ACL injuries in this group (male:female, 1:1.27; P < 0.0001).

CONCLUSION

Prepubescent boys (aged <12 years) are more likely to sustain an ACL injury than same-aged female peers.

CLINICAL RELEVANCE

This study demonstrates that the risk of ACL injury varies with age and sex throughout childhood and adolescence, further guiding treatment and prevention for these pediatric athletes.

Epidemiology of Anterior Cruciate Ligament Injury in Italian First Division Soccer Players

BACKGROUND

The burden of anterior cruciate ligament (ACL) injury in professional soccer players is particularly relevant as it represents a potentially career-threatening injury.

HYPOTHESIS

Our hypotheses were that (1) injury incidence rate would be similar to that reported in the literature, (2) we would identify a uniform distribution of the injuries along the season, and (3) injury incidence rate would be similar in high-ranked and lower ranked teams, based on final placement in the league.

STUDY DESIGN

Descriptive epidemiological study.

LEVEL OF EVIDENCE

Level 4.

METHODS

Professional male soccer players participating in the Serie A championship league in 7 consecutive seasons (2011-2012 to 2017-2018) were screened to identify ACL injuries through the online football archive transfermarkt.com . Exposure in matches and training were calculated.

RESULTS

There were 84 ACL injuries found (mean player age, 25.3 ± 4.2 years). Overall, 25% of ACL injuries were reruptures (15%) or contralateral injuries (10%). ACL incidence rate was 0.4215 per 1000 hours of play during Serie A matches, 0.0305 per 1000 hours of training (rate ratio [RR], 13.8; 95% CI, 8.4-22.7; P < 0.0001), and 0.0618 per 1000 hours of total play. Injury distribution had a bimodal peak, with the highest number of events in October and March. Alternatively, training injuries peaked in June and July. A significantly higher incidence rate was found for the teams ranked from 1st to 4th place compared with those ranked 5th to 20th (0.1256 vs 0.0559 per 1000 hours of play; RR, 2.2; 95% CI, 1.4-3.6; P = 0.0003). A similar finding was found for injury incidence proportion (3.76% vs 1.64%; P = 0.0003).

CONCLUSION

The overall incidence rate of ACL injuries in Italian Serie A was 0.062 per 1000 hours, with a 14-fold risk in matches compared with training. Relevantly, 25% were second injuries. Most injuries occurred in October and March, and an almost 2-fold incidence rate and incidence proportion were noted in those teams ranked in the first 4 positions of the championship league.

CLINICAL RELEVANCE

Knowing the precise epidemiology of ACL injury in one of the most competitive professional football championship leagues could help delineate fields of research aimed to investigate its risk factors.

Soccer Injuries in Children and Adolescents

Participation in youth soccer in the United States continues to increase steadily, with a greater percentage of preadolescent participants than perhaps any other youth sport. Despite the wide-ranging health benefits of participation in organized sports, injuries occur and represent a threat to the health and performance of young athletes. Youth soccer has a greater reported injury rate than many other contact sports, and recent studies suggest that injury rates are increasing. Large increases in the incidence of concussions in youth soccer have been reported, and anterior cruciate ligament injuries remain a significant problem in this sport, particularly among female athletes. Considerable new research has identified a number of modifiable risk factors for lower-extremity injuries and concussion, and several prevention programs have been identified to reduce the risk of injury. Rule enforcement and fair play also serve an important role in reducing the risk of injury among youth soccer participants. This report provides an updated review of the relevant literature as well as recommendations to promote the safe participation of children and adolescents in soccer.

Comparison of anatomical risk factors for noncontact anterior cruciate ligament injury using magnetic resonance imaging

PURPOSE

To compare the significance of the tibio-femoral geometrical indices (notch width index, medial and lateral tibial slopes) and patellar tendon- tibial shaft angle in predicting non-contact ACL injuries and to compare these factors between genders.

METHODS

Retrospective case control study evaluating 66 MRI knee of patients of age group of 18-60 years with 33 cases of noncontact ACL injury and 33 age matched controls. Notch width index, medial and lateral tibial slopes and patellar tendon tibial shaft angles were calculated and compared for statistical significance and was also compared between the genders. ROC curve was for plotted for the significant factors.

RESULTS

Statistically significant difference was seen in notch width index and patellar tendon tibial shaft angles with cases showing a narrow notch width index and an increased patellar tendon tibial shaft angle. Gender comparative results showed no statistically significant differences. ROC curve plotted for NWI showed an optimal cut off value of 0.263 with a sensitivity of 88% and a specificity of 52%. ROC curve plotted for PTTS angle showed a cut off value of 26.7 degrees with a sensitivity of 67% and a specificity of 49%.

CONCLUSION

Narrow Notch width index and increased Patellar tendon tibial shaft angle are predictors of ACL injury. PTTS angle which has been studied as a function of knee flexion angle, can itself be an independent predictor of ACL injury (at a constant knee flexion angle).

Differences in neuromuscular activity of ankle stabilizing muscles during postural disturbances: A gender-specific analysis

The purpose was to examine gender differences in ankle stabilizing muscle activation during postural disturbances. Seventeen participants (9 females: 27 ± 2yrs., 1.69 ± 0.1 m, 63 ± 7 kg; 8 males: 29 ± 2yrs., 1.81 ± 0.1 m; 83 ± 7 kg) were included in the study. After familiarization on a split-belt-treadmill, participants walked (1 m/s) while 15 right-sided perturbations were randomly applied 200 ms after initial heel contact. Muscle activity of M. tibialis anterior (TA), peroneus longus (PL) and gastrocnemius medialis (GM) was recorded during unperturbed and perturbed walking. The root mean square (RMS; [%]) was analyzed within 200 ms after perturbation. Co-activation was quantified as ratio of antagonist (GM)/agonist (TA) EMG-RMS during unperturbed and perturbed walking. Time to onset was calculated (ms). Data were analyzed descriptively (mean ± SD) followed by three-way-ANOVA (gender/condition/muscle; α = 0.05). Perturbed walking elicited higher EMG activity compared to normal walking for TA and PL in both genders (p < 0.000). RMS amplitude gender comparisons revealed an interaction between gender and condition (F = 4.6, p = 0.049) and, a triple interaction among gender, condition and muscle (F = 4.7, p = 0.02). Women presented significantly higher EMG-RMS [%] PL amplitude than men during perturbed walking (mean difference = 209.6%, 95% confidence interval = -367.0 to -52.2%, p < 0.000). Co-activation showed significant lower values for perturbed compared to normal walking (p < 0.000), without significant gender differences for both walking conditions. GM activated significantly earlier than TA and PL (p < 0.01) without significant differences between the muscle activation onsets of men and women (p = 0.7). The results reflect that activation strategies of the ankle encompassing muscles differ between genders. In provoked stumbling, higher PL EMG activity in women compared to men is present. Future studies should aim to elucidate if this specific behavior has any relationship with ankle injury occurrence between genders.

Prevention, treatment, and rehabilitation of anterior cruciate ligament injuries in children

As more children and adolescents participate in competitive organized sports, there has been an increase in the reported incidence of anterior cruciate ligament (ACL) injuries in these age groups. ACL injuries in skeletally immature athletes present a challenge, as reconstruction must preserve the physis of the distal femur and of the proximal tibia to avoid growth disturbances. Historically, a skeletally immature athlete with an ACL injury was treated with a brace and activity modification until skeletal maturity, with ACL reconstruction being performed at that time in the “non-copers” who experienced instability. More recently, evidence has shown that delayed reconstruction may lead to increased damage to the meniscus and articular cartilage. As a result, early reconstruction is favored to protect the meniscus and allow continued physical activity. While adolescents at or those near skeletal maturity may be treated with standard reconstruction techniques, they may result in growth disturbances in younger athletes with significant growth remaining. In response to the growing need for ACL reconstruction techniques in skeletally immature individuals, physeal-sparing and physeal-respecting reconstruction techniques have been developed. In addition to the advancements in surgical technique, ACL injury prevention has also gained attention. This growing interest in ACL prevention is in part related to the high risk of ACL re-tear, either of the ACL graft or of the contralateral ACL, in children and adolescents. Recent reports indicate that well-designed neuromuscular training programs may reduce the risk of primary and subsequent ACL injuries.

Preseason Aerobic Capacity Is an Independent Predictor of In-Season Injury in Collegiate Soccer Players

PURPOSE

To determine whether preseason aerobic capacity is independently associated with in-season injury among collegiate soccer players.

DESIGN

Prospective cohort study.

SETTING

University athletic department.

PARTICIPANTS

Forty-three NCAA Division I soccer athletes (male = 23).

INDEPENDENT VARIABLES

Gender and preseason lean body mass (LBM), body fat percentage (BF%), and maximal aerobic capacity (V[Combining Dot Above]O2max).

MAIN OUTCOME MEASURES

In-season injuries were recorded during the season, and body composition and fitness variables were compared between injured and uninjured players. Multivariate regression models were developed to predict injury during the entire season and during the first 4 weeks of the season.

RESULTS

Thirty-five injuries among 25 players were recorded during the season. Players injured at any point during the season had lower V[Combining Dot Above]O2max (57.7 vs 63.4 mL·kg·min, P = 0.014) and Tmax (15.8 vs 17.2 minutes, P = 0.035), compared with uninjured players, but no differences were noted in age, gender, LBM, or BF%. Players injured during the first 4 weeks of the season had lower LBM (49.7 vs 56.0 kg, P = 0.038) and Tmax (15.1 vs 16.7 minutes, P = 0.043) than uninjured players. For injuries occurring throughout the entire season, V[Combining Dot Above]O2max was an independent predictor of injury (P = 0.043), whereas gender, LBM, and BF% were not. During the first 4 weeks of the season, V[Combining Dot Above]O2max (P = 0.035) and LBM (P = 0.049) were related to injury, whereas gender and BF% were not.

CONCLUSIONS

Aerobic fitness is an independent predictor of in-season injury. Early-season injuries are related to aerobic fitness and LBM.

CLINICAL RELEVANCE

Efforts to increase aerobic capacity and LBM among soccer players in the off-season may help reduce in-season injury.

Rehabilitation Principles of the Anterior Cruciate Ligament Reconstructed Knee: Twelve Steps for Successful Progression and Return to Play

The rehabilitation process begins immediately after injury to the anterior cruciate ligament (ACL). The goal of preoperative rehabilitation is to prepare the patient for surgery. Current rehabilitation programs focus on strengthening exercises and proprioceptive and neuromuscular control drills to provide a neurologic stimulus. It is also important to address preexisting factors, especially for the female athlete, that may predispose to future injury, such as hip and hamstring weakness. Our goal in the rehabilitation program is to restore full, unrestricted function and to assist the patient to return to 100% of the preinjury level while achieving excellent long-term outcomes.

Epidemiology of injuries in the Spanish national futsal male team: a five-season retrospective study

Background

Futsal started being played in 1930 and the number of futsal players has increased all over the world ever since. Nonetheless, despite the fact that Spain is one of the most relevant national teams worldwide, information on the incidence of injuries and their anthropometric characteristics is sparse in this country.

Aim

To analyse medical assistance provided to players in their prematch concentration camps with the Spanish national team over five seasons, from 2010–2011 to 2014–2015, and also to collect data regarding anthropometric characteristics.

Materials and methods

This is a retrospective and detailed study of injuries players suffered over these five seasons. All variables were registered on an Excel spreadsheet and later analysed statistically.

Results

411 injuries were studied in total. The dominant somatotype was mesomorph and the injured pivots were both the most endomorphic and the most mesomorphic. The most injured body structure was the hamstring muscles, occurring due to training and intrinsic mechanisms, where fatigue was the most frequent diagnosis. Only a few complementary examinations were carried out and prematch withdrawal was rare.

Discussion

The skinfold test total sum was lower than that of the Spanish 11-a-side players or than that in the lower category futsal Spanish players. In various research studies analysing exclusively injuries occurring in matches, the most frequent injury is ligament injury by extrinsic mechanism. The body mass index was not a useful parameter when assessing players’ appropriate weight. Most injuries occurred in training sessions, mostly by intrinsic mechanism; the highest percentage of traumatic injuries occurred in official matches.

Prophylactic knee bracing alters lower-limb muscle forces during a double-leg drop landing

Anterior cruciate ligament (ACL) injury can be a painful, debilitating and costly consequence of participating in sporting activities. Prophylactic knee bracing aims to reduce the number and severity of ACL injury, which commonly occurs during landing maneuvers and is more prevalent in female athletes, but a consensus on the effectiveness of prophylactic knee braces has not been established. The lower-limb muscles are believed to play an important role in stabilizing the knee joint. The purpose of this study was to investigate the changes in lower-limb muscle function with prophylactic knee bracing in male and female athletes during landing. Fifteen recreational athletes performed double-leg drop landing tasks from 0.30m and 0.60m with and without a prophylactic knee brace. Motion analysis data were used to create subject-specific musculoskeletal models in OpenSim. Static optimization was performed to calculate the lower-limb muscle forces. A linear mixed model determined that the hamstrings and vasti muscles produced significantly greater flexion and extension torques, respectively, and greater peak muscle forces with bracing. No differences in the timings of peak muscle forces were observed. These findings suggest that prophylactic knee bracing may help to provide stability to the knee joint by increasing the active stiffness of the hamstrings and vasti muscles later in the landing phase rather than by altering the timing of muscle forces. Further studies are necessary to quantify whether prophylactic knee bracing can reduce the load placed on the ACL during intense dynamic movements.

Acute Lower Extremity Injury Rates Increase after Concussion in College Athletes

Dynamic postural control deficits and disrupted cortical pathways have been reported to persist beyond an athlete's return to activity after concussion, potentially increasing the risk of acute lower extremity musculoskeletal injury.

PURPOSE

This study aimed to investigate acute lower extremity musculoskeletal injury rates before and after concussion in athletes with concussion and their matched control.

METHODS

College athletes with concussion (n = 44; age, 20.0 ± 1.2 yr) were physician-diagnosed. Nonconcussed college athletes (n = 58; age, 20.5 ± 1.3 yr) were matched to individuals with concussion. Acute lower extremity musculoskeletal injury data were collected for 2 yr (±1 yr of the diagnosed concussion) using electronic medical records. Control participants' 2-yr window for exposure and musculoskeletal injury data were anchored to their match's concussion injury date. Pre- and postconcussion musculoskeletal injury rates were calculated for 90-, 180-, and 365-d periods for both study cohorts. Risk ratios were calculated to determine differences within and between groups for all periods.

RESULTS

Within 1 yr after concussion, the group with concussion was 1.97 (95% confidence interval (CI), 1.19-3.28; P = 0.01) times more likely to have experienced an acute lower extremity musculoskeletal injury after concussion than before concussion and 1.64 times (95% CI, 1.07-2.51; P = 0.02) more likely to have experienced an acute lower extremity musculoskeletal injury after concussion than their matched nonconcussed cohort over the same period. Up to 180 d after concussion, the group with concussion was 2.02 (95% CI, 1.08-3.78; P = 0.02) times more likely to have experienced an acute lower extremity musculoskeletal injury after concussion than before concussion.

CONCLUSIONS

Previous literature has identified dynamic postural control deficits along with increased motor evoked potential latency and decreased amplitude after concussion, suggesting that the brain may be unable to effectively coordinate movement. Our findings underscore the need to explore functional movement and dynamic postural control assessments in postconcussion injury assessment protocols.

Effects of Prophylactic Knee Bracing on Lower Limb Kinematics, Kinetics, and Energetics During Double-Leg Drop Landing at 2 Heights

BACKGROUND

Anterior cruciate ligament (ACL) injuries commonly occur during landing maneuvers. Prophylactic knee braces were introduced to reduce the risk of ACL injuries, but their effectiveness is debated.

HYPOTHESES

We hypothesized that bracing would improve biomechanical factors previously related to the risk of ACL injuries, such as increased hip and knee flexion angles at initial contact and at peak vertical ground-reaction force (GRF), increased ankle plantar flexion angles at initial contact, decreased peak GRFs, and decreased peak knee extension moment. We also hypothesized that bracing would increase the negative power and work of the hip joint and would decrease the negative power and work of the knee and ankle joints.

STUDY DESIGN

Controlled laboratory study.

METHODS

Three-dimensional motion and force plate data were collected from 8 female and 7 male recreational athletes performing double-leg drop landings from 0.30 m and 0.60 m with and without a prophylactic knee brace. GRFs, joint angles, moments, power, and work were calculated for each athlete with and without a knee brace.

RESULTS

Prophylactic knee bracing increased the hip flexion angle at peak GRF by 5.56° (P < .001), knee flexion angle at peak GRF by 4.75° (P = .001), and peak hip extension moment by 0.44 N·m/kg (P < .001). Bracing also increased the peak hip negative power by 4.89 W/kg (P = .002) and hip negative work by 0.14 J/kg (P = .001) but did not result in significant differences in the energetics of the knee and ankle. No differences in peak GRFs and peak knee extension moment were observed with bracing.

CONCLUSION

The application of a prophylactic knee brace resulted in improvements in important biomechanical factors associated with the risk of ACL injuries.

CLINICAL RELEVANCE

Prophylactic knee braces may help reduce the risk of noncontact knee injuries in recreational and professional athletes while playing sports. Further studies should investigate different types of prophylactic knee braces in conjunction with existing training interventions so that the sports medicine community can better assess the effectiveness of prophylactic knee bracing.

Effects of plyometric training on soccer players

Plyometric training (PT) is a technique used to increase strength and explosiveness. It consists of physical exercises in which muscles exert maximum force at short intervals to increase dynamic performances. In such a training, muscles undergo a rapid elongation followed by an immediate shortening (stretch-shortening contraction), utilizing the elastic energy stored during the stretching phase. There is consensus on the fact that when used, PT contributes to improvement in vertical jump performance, acceleration, leg strength, muscular power, increase of joint awareness and overall sport-specific skills. Consequently, PT which was primarily used by martial artists, sprinters and high jumpers to improve performances has gained in popularity and has been used by athletes in all types of sports. However, although PT has been shown to increase performance variables in many sports, little scientific information is currently available to determine whether PT actually enhances skill performance in soccer players, considering that soccer is an extremely demanding sport. Soccer players require dynamic muscular performance for fighting at all levels of training status, including rapid movements such as acceleration and deceleration of the body, change of direction, vertical and horizontal jumps, endurance, speed as well as power for kicking and tackling. In this review we discussed the effects of PT on soccer players by considering gender and age categories.

Foot and Ankle Injuries in Professional Soccer Players: Diagnosis, Treatment, and Expectations

Soccer is one of the most popular sports in the world. It has undergone many changes in recent years, mainly because of increased physical demands, and this has led to an increased injury risk. Direct contact accounts for half of all injuries in both indoor and outdoor soccer and ankle sprains are the most common foot and ankle injury. There is a spectrum of foot and ankle injuries and their treatment should be individualized in these high-demand patients. An injury prevention program is also important and should the players, the trainer, responsible physician, and physical therapists.

ACL injuries in men's professional football: a 15-year prospective study on time trends and return-to-play rates reveals only 65% of players still play at the top level 3 years after ACL rupture

BACKGROUND

Studies investigating the development of ACL injuries over time in football are scarce and more data on what happens before and after return to play (RTP) are needed.

AIM

To investigate (1) time trends in ACL injury rates, (2) complication rates before return to match play following ACL reconstruction, and (3) the influence of ACL injury on the subsequent playing career in male professional football players.

METHODS

78 clubs were followed between 2001 and 2015. Time trend in ACL injury rate was analysed using linear regression. ACL-injured players were monitored until RTP and tracked for 3 years after RTP.

RESULTS

We recorded 157 ACL injuries, 140 total and 17 partial ruptures, with a non-significant average annual increase in the ACL injury rate by 6% (R(2)=0.13, b=0.059, 95% CI -0.04 to 0.15, p=0.20). The match ACL injury rate was 20-fold higher than the training injury rate (0.340 vs 0.017 per 1000 h). 138 players (98.6%) with a total rupture underwent ACL reconstruction; all 134 players with RTP data (4 players still under rehabilitation) were able to return to training, but 9 of them (6.7%) suffered complications before their first match appearance (5 reruptures and 4 other knee surgeries). The median layoff after ACL reconstruction was 6.6 months to training and 7.4 months to match play. We report 3-year follow-up data for 106 players in total; 91 players (85.8%) were still playing football and 60 of 93 players (65%) with ACL reconstruction for a total rupture played at the same level.

CONCLUSIONS

The ACL injury rate has not declined during the 2000s and the rerupture rate before return to match play was 4%. The RTP rate within a year after ACL reconstruction was very high, but only two-thirds competed at the highest level 3 years later.

Risk factors for acute knee injury in female youth football

PURPOSE

To prospectively evaluate risk factors for acute time-loss knee injury, in particular ACL injury, in female youth football players.

METHODS

Risk factors were studied in 4556 players aged 12-17 years from a randomised controlled trial during the 2009 season. Covariates were both intrinsic (body mass index, age, relative age effect, onset of menarche, previous acute knee injury or ACL injury, current knee complaints, and familial disposition of ACL injury) and extrinsic (no. of training sessions/week, no. of matches/week, match exposure ratio, match play with other teams, and artificial turf exposure). Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated from individual variable and multiple Cox regression analyses.

RESULTS

Ninety-six acute knee injuries were recorded, 21 of them ACL injuries. Multiple Cox regression showed a fourfold higher ACL injury rate for players with familial disposition of ACL injury (HR 3.57; 95% CI 1.48-8.62). Significant predictor variables for acute knee injury were age >14 years (HR 1.97; 95% CI 1.30-2.97), knee complaints at the start of the season (HR 1.98; 95% CI 1.30-3.02), and familial disposition of ACL injury (HR 1.96; 95% CI 1.22-3.16). No differences in injury rates were seen when playing on artificial turf compared with natural grass.

CONCLUSION

Female youth football players with a familial disposition of ACL injury had an increased risk of ACL injury and acute knee injury. Older players and those with knee complaints at pre-season were more at risk of acute knee injury. Although the predictive values were low, these factors could be used in athlete screening to target preventive interventions.

LEVEL OF EVIDENCE

II.

Young Females Exhibit Decreased Coronal Plane Postural Stability Compared to Young Males

BACKGROUND

Female athletes are at significantly higher risk of noncontact ACL injury than males, particularly in pivoting sports such as soccer and basketball. Sex-based differences in proprioception and core stability may contribute to this elevated risk.

QUESTIONS/PURPOSE

This study evaluates a novel method of assessing dynamic stability to test the hypothesis that healthy adolescent controls have sex-based differences in postural stability.

METHODS

Seventy-nine male and 72 female subjects completed three rounds of dynamic postural stability testing. During the assessment, subjects attempted to stabilize their torso and upper body in response to random movements of the platform. The total time a subject lasted on the platform and dynamic motion analysis (DMA) score, a summation of motion in five planes throughout testing, was calculated for each subject. The average score for each subject was included in the analysis.

RESULTS

Males lasted longer on the platform (98 ± 14 s) than females (94 ± 13 s) (p = 0.04). Coronal plane and rotation stability differed significantly between genders (323 ± 126 vs. 365 ± 128, p = 0.04) and (318 ± 82 vs. 403 ± 153, p = 0.0002), respectively. No statistically significant difference was seen in the other planes of motion.

CONCLUSIONS

Females have less dynamic postural stability than their male counterparts in the coronal plane based on a novel assessment tool. This finding may contribute to better understanding of sex-based differences in rates of injury such as noncontact ACL tears.

Randomized comparison of tape versus semi-rigid and versus lace-up ankle support in the treatment of acute lateral ankle ligament injury

PURPOSE

Functional treatment is the optimal non-surgical treatment for acute lateral ankle ligament injury (ALALI) in favour of immobilization treatment. There is no single most effective functional treatment (tape, semi-rigid brace or lace-up brace) based on currently available randomized trials.

METHODS

This study is designed as a randomized controlled trial to evaluate the difference in functional outcome after treatment with tape versus semi-rigid versus lace-up ankle support (brace) for grades II and III ALALIs. The Karlsson score and the FAOS were evaluated at 6-month follow-up.

RESULTS

One hundred and ninety-three patients (52% males) were randomized, 66 patients were treated with tape, 58 patients with a semi-rigid brace and 62 patients with a lace-up brace. There were no significant differences in any baseline characteristics between the three groups. Mean age of the patients was 37.3 years (35.1-39.5; SD 15.3). Ninety-five males (49%) were included. One hundred and sixty-one (59 + 50 + 52) patients completed the study through final follow-up; 32% lost at follow-up. In two patients treated with tape support, the treatment was changed to a semi-rigid brace because of dermatomal blisters. Except for the difference in Foot and Ankle Outcome Score sport between the lace-up and the semi-rigid brace, there are no differences in any of the outcomes after 6-month follow-up.

CONCLUSION

The most important finding of current study was that there is no difference in outcome 6 months after treatment with tape, semi-rigid brace and a lace-up brace.

LEVEL OF EVIDENCE

I.

Validation of porcine knee as a sex-specific model to study human anterior cruciate ligament disorders

BACKGROUND

Animal models have long been considered an important modality for studying ACL injuries. However, to our knowledge, the value of these preclinical models to study sex-related phenomena associated with ACL injury and recovery has not been evaluated.

QUESTIONS/PURPOSES

We asked whether (1) prominent anatomic and (2) biomechanical factors differ between female and male porcine knees, particularly those known to increase the risk of ACL injury.

METHODS

Eighteen intact minipig knees (nine males, nine females) underwent MRI to determine the femoral bicondylar width, intercondylar notch size (width, area and index), medial and lateral tibial slope, ACL size (length, cross-sectional area, and volume), and medial compartment tibiofemoral cartilage thickness. AP knee laxity at 30°, 60°, and 90° flexion and ACL tensile structural properties were measured using custom-designed loading fixtures in a universal tensile testing apparatus. Comparisons between males and females were performed for all anatomic and biomechanical measures. The findings then were compared with published data from human knees.

RESULTS

Female pigs had smaller bicondylar widths (2.9 mm, ratio=0.93, effect size=-1.5) and intercondylar notches (width: 2.0 mm, ratio=0.79, effect size=-2.8; area: 30.8 mm2, ratio=0.76, effect size=-2.1; index: 0.4, ratio=0.84, effect size=-2.0), steeper lateral tibial slope (4.3°, ratio=1.13, effect size=1.1), smaller ACL (length: 2.7 mm, ratio=0.91, effect size=-1.1; area: 6.8 mm2, ratio=0.74, effect size=-1.5; volume: 266.2 mm3, ratio=0.68, effect size=-1.5), thinner medial femoral cartilage (0.4 mm, ratio=0.8, effect size=-1.1), lower ACL yield load (275 N, ratio=0.81, effect size=-1.1), and greater AP knee laxity at 30° (0.7 mm, ratio=1.32, effect size=1.1) and 90° (0.5 mm, ratio=1.24, effect size=1.1) flexion compared with their male counterparts. These differences were significant for all parameters (p≤0.04). Observed sex-related differences were similar to those reported for the human knee.

CONCLUSIONS

Significant differences exist between knees of male and female pigs with respect to prominent anatomic and biomechanical factors. Our findings strongly agreed with published data regarding human knees.

CLINICAL RELEVANCE

The findings highlight the use of the porcine large animal model to study the role of sex on ACL injuries and surgical outcome. This validated preclinical model may facilitate the development of novel, sex-specific interventions to prevent and treat ACL injuries for male and female patients.

Injuries in iran futsal national teams: a comparative study of incidence and characteristics

Background:

Futsal is a growing sport with lots of fans in many countries including Iran, but there are few papers in the literature which report injuries in top level futsal.

Objectives:

The aim of this study is to record and analyze the incidence and characteristics of injuries in Iran futsal national teams from March 2011 to September 2012.

Patients and Methods:

55 Iranian national futsal players participated in this prospective cohort study. Before entering the study, all players took part in Pre-Competition Medical Assessment (PCMA) in accordance with FIFA protocol. Team physicians recorded the injuries throughout the match and trainings in a special form which was designed for this purpose. Finally, data analysis was done with the SPSS software.

Results:

The total exposure time for all players was 24326 hours (21138 hours during training and 3188 hours during matches). During the study period, 32 of the 55 national players (58.2%) incurred 54 injuries (incidence rate = 2.22 injuries per 1000 players-hours). The incidence rate of injury in female players was significantly higher than male players (P = 0.001). The majority of injuries (85.2%) were located on the lower extremities. The ankle was the most frequent injury location (40.7%) and sprain was the most frequent type of injury.

Conclusions:

Injuries are common among futsal players and female players are more prone to injuries than male players. The ankle is the most frequent site and sprain is the most frequent type of injury among futsal players.

Cruciate ligament reconstruction and risk of knee osteoarthritis: the association between cruciate ligament injury and post-traumatic osteoarthritis. a population based nationwide study in Sweden, 1987-2009

Objective

To study the association between Cruciate Ligament (CL) injury and development of post-traumatic osteoarthritis in the knee in patients treated operatively with CL reconstruction compared with patients treated non-operatively.

Design

Population based cohort study; level of evidence II-2.

Setting

Sweden, 1987–2009.

Participants

All patients aged between 15–60 years being diagnosed and registered with a CL injury in The National Swedish Patient Register between 1987 and 2009.

Main Outcome Measures

Knee osteoarthritis.

Results

A total of 64,614 patients diagnosed with CL injury during 1987 to 2009 in Sweden were included in the study. Seven percent of the patients were diagnosed with knee OA in specialized healthcare during the follow-up (mean 9 years). Stratified analysis by follow-up showed that while those with shorter follow-up had a non-significant difference in risk (0.99, 95%CI 0.90–1.09 for follow-up less than five years compared with the non-operated cohort), those with longer follow-up had an increased risk of knee OA after CL reconstruction (HR = 1.42, 95%CI 1.27–1.58 for follow-up more than ten years compared with non-operated cohort). The risk to develop OA was not affected by sex.

Conclusion

CL reconstructive surgery does not seem to have a protective effect on long term OA in either men or women.

Understanding the Acute Skin Injury Mechanism Caused by Player-Surface Contact During Soccer: A Survey and Systematic Review

Background:

Superficial skin injuries are considered minor, and their incidence is probably underestimated. Insight into the incidence and mechanism of acute skin injury can be helpful in developing suitable preventive measures and safer playing surfaces for soccer and other field sports.

Purpose:

To gain insight into the incidence and severity of skin injuries related to soccer and to describe the skin injury mechanism due to player-surface contact.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

The prevention model by van Mechelen et al (1992) combined with the injury causation model of Bahr and Krosshaug (2005) were used as a framework for the survey to describe the skin injury incidence and mechanism caused by player-surface contact.

Results:

The reviewed literature showed that common injury reporting methods are mainly based on time lost from participation or the need for medical attention. Because skin abrasions seldom lead to absence or medical attention, they are often not reported. When reported, the incidence of abrasion/laceration injuries varies from 0.8 to 6.1 injuries per 1000 player-hours. Wound assessment techniques such as the Skin Damage Area and Severity Index can be a valuable tool to obtain a more accurate estimation of the incidence and severity of acute skin injuries.

Conclusion:

The use of protective equipment, a skin lubricant, or wet surface conditions has a positive effect on preventing abrasion-type injuries from artificial turf surfaces. The literature also shows that essential biomechanical information of the sliding event is lacking, such as how energy is transferred to the area of contact. From a clinical and histological perspective, there are strong indications that a sliding-induced skin lesion is caused by mechanical rather than thermal injury to the skin.

Football injuries in children and adolescent players: are there clues for prevention?

Football (soccer) is the world's most popular sport with most players being younger than 18 years. Playing football can induce beneficial health effects, but there is also a high risk of injury. Therefore, it is necessary to implement measures for preventing injuries. The present review analyzes and summarizes published scientific information on the incidence and characteristics of football injuries in children and adolescent players to arrive at sound conclusions and valid considerations for the development of injury-prevention programs. A literature search was conducted up to November 2012. Fifty-three relevant scientific publications were detected. Thirty-two studies fulfilled the inclusion criteria for pooled analysis. Additional information from the remaining 21 studies was considered where appropriate to obtain a broader perspective on the injury problem in children and youth football. Training injury incidence was nearly constant for players aged 13-19 years, ranging from 1 to 5 injuries per 1,000 h training. Match injury incidence tended to increase with age through all age groups, with an average incidence of about 15 to 20 injuries per 1,000 match hours in players older than 15 years. Between 60 and 90 % of all football injuries were classified as traumatic and about 10-40 % were overuse injuries. Most injuries (60-90 %) were located at the lower extremities with the ankle, knee, and thigh being mostly affected. The frequency of upper-extremity and head/face injuries was higher in those studies that analyzed match injuries only. The most common injury types were strains, sprains, and contusions (10 up to 40 % each). There is some evidence that the risk of traumatic injuries and, in particular, of sustaining a fracture, contusion, or concussion was higher during match play than in practice sessions. Fractures were more frequent in children younger than 15 years than in older players. About half of all time-loss injuries led to an absence from sport of less than 1 week, one third resulted in an absence between 1 and 4 weeks, and 10 to 15 % of all injuries were severe. Separate data for players under the age of 11 years are almost absent. Maturation status seems to have an influence on injury characteristics, although evidence is not conclusive at this time. Three main areas seem to be of particular relevance for future prevention research in young football players: (1) the substantial number of severe contact injuries during matches, (2) the high number of fractures in younger players, and (3) the influence of maturation status and growth spurts.

Incidence and characteristics of injuries during the 2010 FELDA/FAM National Futsal League in Malaysia

Objective

In Malaysia, futsal is a popular sport played by individuals across all ages and genders. Despite its popularity, information on futsal related injury in Malaysia is not available. The purpose of this study is to examine the injury incidence and injury patterns among amateur men and women futsal players in Malaysia.

Methods

Players reported injury to the tournament medical team during the FELDA/FAM National Futsal League 2010 were interviewed and assessed by a Sports Medicine registrar. Player's socio-demographic profiles and information about the injury were documented in the injury report form adapted from medical report form used by FIFA: Medical Assessment and Research Centre (F-Marc).

Results

A total of 86 injuries were reported from 141 matches, equivalent to an incidence of 91.5 injuries per 1000 player hours (95% CI 72.2 to 110.8), or 61.0 injuries per 1000 player matches (95% CI 48.1 to 73.9). Most were minor injuries resulted from contact with another player. Injuries often involved the lower extremity (44%) followed by the trunk (14%) and the upper limb (13%). Ankle (n = 7; 39%) and knee (n = 6; 33%) sprains were the most prevalent diagnoses of time-loss injuries. A significant association between time-loss and type of injury was found χ² (1,N = 86) = 3.99, p = 0.04. In addition, time-loss injury was significantly associated with playing surface χ² (1,N = 86) = 10.11, p = 0.018.

Conclusion

The injury rate during the FELDA/FAM National Amateur Futsal Men's League in Malaysia was lower compared with previous Futsal World Cups competition. Most injuries resulted from contact with another player were minor and did not lead to time-loss from participation. Time-loss injury was significantly associated with type of injury and playing surface.

Effects of knee extension constraint training on knee flexion angle and peak impact ground-reaction force

BACKGROUND

Low compliance with training programs is likely to be one of the major reasons for inconsistency of the data regarding the effectiveness of current anterior cruciate ligament (ACL) injury prevention programs. Training methods that reduce training time and cost could favorably influence the effectiveness of ACL injury prevention programs. A newly designed knee extension constraint training device may serve this purpose.

HYPOTHESIS

(1) Knee extension constraint training for 4 weeks would significantly increase the knee flexion angle at the time of peak impact posterior ground-reaction force and decrease peak impact ground-reaction forces during landing of a stop-jump task and a side-cutting task, and (2) the training effects would be retained 4 weeks after completion of the training program.

STUDY DESIGN

Controlled laboratory study.

METHODS

Twenty-four recreational athletes were randomly assigned to group A or B. Participants in group A played sports without wearing a knee extension constraint device for 4 weeks and then played sports while wearing the device for 4 weeks, while participants in group B underwent a reversed protocol. Both groups were tested at the beginning of week 1 and at the ends of weeks 4 and 8 without wearing the device. Knee joint angles were obtained from 3-dimensional videographic data, while ground-reaction forces were measured simultaneously using force plates. Analyses of variance were performed to determine the training effects and the retention of training effects.

RESULTS

Participants in group A significantly increased knee flexion angles and decreased ground-reaction forces at the end of week 8 (P ≤ .012). Participants in group B significantly increased knee flexion angles and decreased ground-reaction forces at the ends of weeks 4 and 8 (P ≤ .007). However, participants in group B decreased knee flexion angles and increased ground-reaction forces at the end of week 8 in comparison with the end of week 4 (P ≤ .009).

CONCLUSION

Knee extension constraint training for 4 weeks significantly altered lower extremity movement patterns and transferred these changes in lower extremity movement patterns to stop-jump and side-cutting tasks in which ACL injuries frequently occur. Training effects were retained 4 weeks after the training was completed but were diminished in magnitude.

CLINICAL RELEVANCE

A knee extension constraint device may be a useful training tool in future ACL injury prevention programs to alter movement patterns without extra training time.

Differences in injury risk and characteristics between Dutch amateur and professional soccer players

OBJECTIVES

To compare the incidence and characteristics of injuries between Dutch amateur and professional male soccer players during one entire competition season.

DESIGN

A prospective two-cohort design.

METHODS

During the 2009-2010 season, 456 Dutch male amateur soccer players and 217 professional players were prospectively followed. Information on injuries and individual exposure to all soccer activities were recorded in both cohorts. Injuries were recorded using the time-loss definition.

RESULTS

In total, 424 injuries were recorded among 274 of the amateur players (60.1% injured players) and 286 injuries were sustained by 136 (62.7% injured players) of the professional players (p=0.52). Compared to the professionals, the injury incidence during training sessions was higher among amateurs (p=0.01), but the injury incidence among professionals was higher during matches (p<0.001). Professional players also had a higher incidence of minimal injuries (p<0.001), whereas the incidence of moderate and severe injuries was higher for amateurs (all p<0.001). Lastly, professional players sustained more overuse injuries (p=0.02), whereas amateurs reported more recurrent injuries (p<0.001).

CONCLUSIONS

The above-mentioned differences in injury rates between amateur and professional players in the Netherlands might be explained by the difference in the level at which they play, since factors like the availability of medical support and/or the team size may influence the injury risk and characteristics.

Basic science of anterior cruciate ligament injury and repair

Injury to the anterior cruciate ligament (ACL) is one of the most devastating and frequent injuries of the knee. Surgical reconstruction is the current standard of care for treatment of ACL injuries in active patients. The widespread adoption of ACL reconstruction over primary repair was based on early perception of the limited healing capacity of the ACL. Although the majority of ACL reconstruction surgeries successfully restore gross joint stability, post-traumatic osteoarthritis is commonplace following these injuries, even with ACL reconstruction. The development of new techniques to limit the long-term clinical sequelae associated with ACL reconstruction has been the main focus of research over the past decades. The improved knowledge of healing, along with recent advances in tissue engineering and regenerative medicine, has resulted in the discovery of novel biologically augmented ACL-repair techniques that have satisfactory outcomes in preclinical studies. This instructional review provides a summary of the latest advances made in ACL repair. Cite this article: Bone Joint Res 2014;3:20-31.

Neuromuscular retraining intervention programs: do they reduce noncontact anterior cruciate ligament injury rates in adolescent female athletes?

PURPOSE

The purpose of this study was to identify neuromuscular training intervention programs that significantly reduced the incidence of noncontact anterior cruciate ligament (ACL) injury rates in female adolescent athletes.

METHODS

A systematic search of PubMed was conducted to determine the outcome of ACL neuromuscular retraining programs in a specific population. The inclusion criteria were English language, published from 1994-2013, original clinical trials, all evidence levels, female athletes aged 19 years or younger, and noncontact ACL injury incidence rates determined by athlete-exposures.

RESULTS

Of 694 articles identified, 8 met the inclusion criteria. Three training programs significantly reduced noncontact ACL injury incidence rates in female adolescent athletes. These were the Sportsmetrics, Prevent Injury and Enhance Performance, and Knee Injury Prevention programs. The estimated number of athletes who needed to train to prevent 1 ACL injury in these 3 studies ranged from 70 to 98, and the relative risk reduction ranged from 75% to 100%. Five programs did not significantly reduce noncontact ACL injury incidence rates. The ACL injury incidence rates for control subjects were lower in these studies (0.03 to 0.08 per 1,000 athlete-exposures) than in those investigations that had a significant effect (0.21 to 0.49 per 1,000 athlete-exposures). There was wide variability among all programs in the frequency, duration, and timing of training; how training was conducted, supervised, or controlled; the components of the program; how exposure data were calculated; noncontact ACL injury incidence rates in the control groups; and compliance with training.

CONCLUSIONS

Three ACL intervention programs successfully reduced noncontact ACL injury incidence rates in female adolescent athletes. Pooling of data of all ACL intervention programs is not recommended because of numerous methodologic differences among studies.

LEVEL OF EVIDENCE

Level II, systematic review of Level I and II studies.