Risk of injury in elite football played on artificial turf versus natural grass: a prospective two-cohort study

Comparison of the incidence, nature and cause of injuries sustained on dirt field and artificial turf field by amateur football players

Background

Data on the incidence, nature, severity and cause of match football injuries sustained on dirt field are scarce. The objectives of this study was to compare the incidence, nature, severity and cause of match injuries sustained on dirt field and artificial turf field by amateur male football players.

Methods

A prospective two-cohort design was employed. Participants were 252 male football players (mean age 27 years, range 18-43) in 14 teams who participated in a local championship carried on a dirt field and 216 male football players (mean age 28 years, range 17-40) in 12 teams who participated in a local championship carried on a artificial turf field in the same zone of the city. Injury definitions and recording procedures were compliant with the international consensus statement for epidemiological studies of injuries in football.

Results

The overall incidence of match injuries for men was 36.9 injuries/1000 player hours on dirt field and 19.5 on artificial turf (incidence rate ratio 1.88; 95% CI 1.19-3.05).

Most common injured part on dirt field was ankle (26.7%) and on artificial turf was knee (24.3%). The most common injury type in the dirt field was skin injuries (abrasion and laceration) and in the artificial turf was sprain and ligament injury followed by haematoma/contusion/bruise.

Most injuries were acute (artificial turf 89%, dirt field 91%) and resulted from player-to-player contact (artificial turf 59.2%, dirt field 51.4%).

Most injuries were slight and minimal in dirt field cohort but in artificial turf cohort the most injuries were mild.

Conclusions

There were differences in the incidence and type of football match injuries sustained on dirt field and artificial turf.

Anterior cruciate ligament injury in elite football: a prospective three-cohort study

Anterior cruciate ligament (ACL) injury causes long lay-off time and is often complicated with subsequent new knee injury and osteoarthritis. Female gender is associated with an increased ACL injury risk, but few studies have adjusted for gender-related differences in age although female players are often younger when sustaining their ACL injury. The objective of this three-cohort study was to describe ACL injury characteristics in teams from the Swedish men's and women's first leagues and from several European men's professional first leagues. Over a varying number of seasons from 2001 to 2009, 57 clubs (2,329 players) were followed prospectively and during this period 78 ACL injuries occurred (five partial). Mean age at ACL injury was lower in women compared to men (20.6 ± 2.2 vs. 25.2 ± 4.5 years, P = 0.0002). Using a Cox regression, the female-to-male hazard ratio (HR) was 2.6 (95% CI 1.4-4.6) in all three cohorts studied and 2.6 (95% CI 1.3-5.3) in the Swedish cohorts; adjusted for age, the HR was reduced to 2.4 (95% CI 1.3-4.2) and 2.1 (95% CI 1.0-4.2), respectively. Match play was associated with a higher ACL injury risk with a match-to-training ratio of 20.8 (95% CI 12.4-34.8) and 45 ACL injuries (58%) occurred due to non-contact mechanisms. Hamstrings grafts were used more often in Sweden than in Europe (67 vs. 34%, P = 0.028), and there were no differences in time to return to play after ACL reconstruction between the cohorts or different grafts. In conclusion, this study showed that the ACL injury incidence in female elite footballers was more than doubled compared to their male counterparts, but also that they were significantly younger at ACL injury than males. These findings suggest that future preventive research primarily should address the young female football player.

Countrywide campaign to prevent soccer injuries in Swiss amateur players

BACKGROUND

In Switzerland, the national accident insurance company registered a total of 42 262 soccer injuries, resulting in costs of approximately 145 million Swiss francs (~US$130 million) in 2003. Research on injury prevention has shown that exercise-based programs can reduce the incidence of soccer injuries.

PURPOSE

This study was conducted to assess the implementation and effects of a countrywide campaign to reduce the incidence of soccer injuries in Swiss amateur players.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

All coaches of the Schweizerischer Fussballverband (SFV) received information material and were instructed to implement the injury prevention program "The 11" in their training of amateur players. After the instruction, the coaches were asked to rate the quality and the feasibility of "The 11." Before the start of the intervention and 4 years later, a representative sample of about 1000 Swiss soccer coaches were interviewed about the frequency and characteristics of injuries in their teams. Teams that did or did not practice "The 11" were compared with respect to the incidence of soccer injuries.

RESULTS

A total of 5549 coaches for amateur players were instructed to perform "The 11" in the training with their teams. The ratings of the teaching session and the prevention program were overall very positive. In 2008, 80% of all SFV coaches knew the prevention campaign "The 11" and 57% performed the program or most parts of it. Teams performing "The 11" had an 11.5% lower incidence of match injuries and a 25.3% lower incidence of training injuries than other teams; noncontact injuries in particular were prevented by the program.

CONCLUSION

"The 11" was successfully implemented in a countrywide campaign and proved effective in reducing soccer injuries in amateur players. An effect of the prevention program was also observed in the population-based insurance data and health-care costs.

Revision, uptake and coding issues related to the open access Orchard Sports Injury Classification System (OSICS) versions 8, 9 and 10.1

The Orchard Sports Injury Classification System (OSICS) is one of the world's most commonly used systems for coding injury diagnoses in sports injury surveillance systems. Its major strengths are that it has wide usage, has codes specific to sports medicine and that it is free to use. Literature searches and stakeholder consultations were made to assess the uptake of OSICS and to develop new versions. OSICS was commonly used in the sports of football (soccer), Australian football, rugby union, cricket and tennis. It is referenced in international papers in three sports and used in four commercially available computerised injury management systems. Suggested injury categories for the major sports are presented. New versions OSICS 9 (three digit codes) and OSICS 10.1 (four digit codes) are presented. OSICS is a potentially helpful component of a comprehensive sports injury surveillance system, but many other components are required. Choices made in developing these components should ideally be agreed upon by groups of researchers in consensus statements.

Incidence, mechanisms, and severity of game-related college football injuries on FieldTurf versus natural grass: a 3-year prospective study

BACKGROUND

Numerous injuries have been attributed to playing on artificial turf. More recently, FieldTurf was developed to duplicate the playing characteristics of natural grass. No long-term studies have been conducted comparing game-related collegiate football injuries between the 2 playing surfaces.

HYPOTHESIS

Collegiate athletes do not experience any difference in the incidence, mechanisms, and severity of game-related injuries between FieldTurf and natural grass.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Twenty-four universities were evaluated over 3 competitive seasons for injury incidence, injury category, time of injury, injury time loss, player position, injury mechanism, primary type of injury, grade and anatomical location of injury, type of tissue injured, trauma (head, knee, and shoulder), and environmental factors.

RESULTS

In sum, 465 collegiate games were evaluated for game-related football injuries sustained on FieldTurf or natural grass during 3 seasons. Overall, 230 team games (49.5%) were played on FieldTurf versus 235 team games (50.5%) played on natural grass. A total of 2253 injuries were documented, with 1050 (46.6%) occurring during play on FieldTurf, and 1203 (53.4%) on natural grass. Multivariate analysis per 10 team games indicated significantly lower total injury incidence rates, F(3, 2249) = 3.468, P = .016, n - beta = 0.778, on FieldTurf, 45.7 (95% confidence interval [CI], 44.2-46.3), versus natural grass, 51.2 (95% CI, 49.8-51.7). Significantly lower minor injury incidence rates, 38.0 (95% CI, 36.9-38.5) versus 39.9 (95% CI, 39.1-40.0, P = .001), substantial injury incidence rates, 5.0 (95% CI, 4.3-5.6) versus 7.2 (95% CI, 6.6-7.7, P = .020), and severe injury incidence rates, 2.7 (95% CI, 2.1-3.3) versus 4.1 (95% CI, 3.5-4.1; P = .049), were documented on FieldTurf versus natural grass, respectively. Multivariate analyses also indicated significantly less trauma on FieldTurf when comparing injury time loss, injury situation, grade of injury, injuries under various field conditions, and temperature. No significant differences in head, knee, or shoulder trauma were observed between playing surfaces.

CONCLUSION

FieldTurf is in many cases safer than natural grass. It must be reiterated, however, that the findings of this study may be generalizable to only this level of competition. Because this study is still in the early stages, investigation is ongoing.

Incidence of injury among adolescent soccer players: a comparative study of artificial and natural grass turfs

OBJECTIVE

To investigate the incidence of acute injuries and soccer-related chronic pain from long-term training and during matches in adolescent players using natural grass turfs (NT) and artificial turfs (AT).

DESIGN

Case-controlled prospective study.

SETTING

Institutional-level Fédération Internationale de Football Association Medical Centre of Excellence.

PARTICIPANTS

Youth soccer players (12-17 years of age) from 6 teams, with a predominant tendency to train on either NT or AT, were included. Of 332 players enrolled in this study, 301 remained to completion.

INTERVENTIONS

Medically diagnosed acute injuries and chronic pain were recorded daily by team health care staff throughout 2005, and reports were provided monthly to the authors.

ASSESSMENT OF RISK FACTORS

Noninvasive prospective study.

INDEPENDENT VARIABLES

Age and turf type.

MAIN OUTCOME MEASURES

Acute injuries per 1000 player hours on each surface and chronic complaints per 1000 player hours were evaluated according to frequency of surface used > or = 80% of the time. Incidence rate ratio (IRR) of acute injuries and chronic complaints during play on NT and AT was calculated.

RESULTS

There was no significant difference in the incidence of acute injuries between the 2 surfaces during training and competition. However, the AT group showed a significantly higher incidence of low back pain during training (IRR, 1.62; 95% confidence interval, 1.06-2.48). Early adolescence and prolonged training hours were factors associated with an increased incidence of chronic pain in the AT group.

CONCLUSION

Adolescent players routinely training on AT for prolonged periods should be carefully monitored, even on AT conforming to new standards.

Prevention of non-contact anterior cruciate ligament injuries in soccer players. Part 1: Mechanisms of injury and underlying risk factors

Soccer is the most commonly played sport in the world, with an estimated 265 million active soccer players by 2006. Inherent to this sport is the higher risk of injury to the anterior cruciate ligament (ACL) relative to other sports. ACL injury causes the most time lost from competition in soccer which has influenced a strong research focus to determine the risk factors for injury. This research emphasis has afforded a rapid influx of literature defining potential modifiable and non-modifiable risk factors that increase the risk of injury. The purpose of the current review is to sequence the most recent literature that reports potential mechanisms and risk factors for non-contact ACL injury in soccer players. Most ACL tears in soccer players are non-contact in nature. Common playing situations precluding a non-contact ACL injury include: change of direction or cutting maneuvers combined with deceleration, landing from a jump in or near full extension, and pivoting with knee near full extension and a planted foot. The most common non-contact ACL injury mechanism include a deceleration task with high knee internal extension torque (with or without perturbation) combined with dynamic valgus rotation with the body weight shifted over the injured leg and the plantar surface of the foot fixed flat on the playing surface. Potential extrinsic non-contact ACL injury risk factors include: dry weather and surface, and artificial surface instead of natural grass. Commonly purported intrinsic risk factors include: generalized and specific knee joint laxity, small and narrow intercondylar notch width (ratio of notch width to the diameter and cross sectional area of the ACL), pre-ovulatory phase of menstrual cycle in females not using oral contraceptives, decreased relative (to quadriceps) hamstring strength and recruitment, muscular fatigue by altering neuromuscular control, decreased "core" strength and proprioception, low trunk, hip, and knee flexion angles, and high dorsiflexion of the ankle when performing sport tasks, lateral trunk displacement and hip adduction combined with increased knee abduction moments (dynamic knee valgus), and increased hip internal rotation and tibial external rotation with or without foot pronation. The identified mechanisms and risk factors for non-contact ACL injuries have been mainly studied in female soccer players; thus, further research in male players is warranted. Non-contact ACL injuries in soccer players likely has a multi-factorial etiology. The identification of those athletes at increased risk may be a salient first step before designing and implementing specific pre-season and in-season training programs aimed to modify the identified risk factors and to decrease ACL injury rates. Current evidence indicates that this crucial step to prevent ACL injury is the only option to effectively prevent the sequelae of osteoarthritis associated with this traumatic injury.

Ankle instability in sports

Ankle stability is integral to normal motion and to minimizing the risk of ankle sprain during participation in sport activities. The ability of the dynamic and static stabilizers of the ankle joint to maintain their structural integrity is a major component of the normal gait cycle. In sports, this quality assumes even greater importance given the range of movement and stresses imposed on the ankle during various sporting disciplines. In the general population, the incidence of ankle sprain is very high. In several studies, injuries to the lateral ankle ligaments have been shown to be the most common sports-related injuries, accounting for approximately 25% of all sports-related injuries. Furthermore, up to 80% of all ankle sprains involve the lateral ligament complex. Other studies have estimated their incidence as approximately 5000 injuries per day in the United Kingdom and 23 000 in the United States. Aggressive treatment of the sprained ankle is essential to maintain foot and ankle mobility and prevent prolonged disability and subsequent overuse injuries among athletes, both professional and "weekend warriors" alike.

Natural turf surfaces: the case for continued research

It is well documented that health and social benefits can be attained through participation in sport and exercise. Participation, particularly in sports, benefits from appropriate surface provisions that are safe, affordable and high quality preferably across the recreational to elite continuum. Investment, construction and research into artificial sports surfaces have increased to meet this provision. However, not all sports (e.g. golf, rugby and cricket) are suited to training and match-play on artificial turf without compromising some playing characteristics of the games. Therefore, full sport surface provision cannot be met without the use of natural turf surfaces, which also have an important role as green spaces in the built environment. Furthermore, a significant number of people participate in outdoor sport on natural turf pitches, although this is a declining trend as the number of synthetic turf surfaces increases. Despite natural turf being a common playing surface for popular sports such as soccer, rugby and cricket, few biomechanical studies have been performed using natural turf conditions. It is proposed that if natural turf surfaces are to help meet the provision of sports surfaces, advancement in the construction and sustainability of natural turf surface design is required. The design of a natural turf surface should also be informed by knowledge of surface-related overuse injury risk factors. This article reviews biomechanical, engineering, soil mechanics, turfgrass science, sports medicine and injury-related literature with a view to proposing a multidisciplinary approach to engineering a more sustainable natural turf sport surface. The present article concludes that an integrated approach incorporating an engineering and biomechanical analysis of the effects of variations in natural turf media on human movement and the effects of variations in human movement on natural turf is primarily required to address the longer-term development of sustainable natural turf playing surfaces. It also recommends that the use of 'natural turf' as a catch-all categorization in injury studies masks the spatial and temporal variation within and among such surfaces, which could be important.

Prevenção de lesões do ligamento cruzado anterior em futebolistas

A lesão do joelho é a mais comum entre as lesões graves apresentadas por futebolistas, destacando-se o ligamento cruzado anterior como um dos ligamentos do joelho mais frequentemente lesados. Assim, a prevenção de lesões do ligamento cruzado anterior em futebolistas deve ser encarada como uma preocupação constante para todos os agentes ligados à modalidade, independentemente do nível competitivo, idade e sexo dos praticantes. OBJETIVOS: O objetivo deste trabalho é a análise da importância do trabalho de prevenção de lesões do LCA em futebolistas que possa ser incorporado no treino de futebol. METODOLOGIA: A metodologia utilizada neste trabalho foi uma revisão da literatura. CONCLUSÕES: Propõe-se um programa de prevenção de lesões do ligamento cruzado anterior em futebolistas, com três sessões de treino semanais, englobando treino neuromuscular e treino proprioceptivo.

Epidemiology of knee injuries among boys and girls in US high school athletics

BACKGROUND

The knee joint is the second most commonly injured body site and the leading cause of high school sports-related surgeries. Knee injuries are among the most economically costly sports injuries and may require subsequent surgery or extensive and expensive rehabilitation.

PURPOSE

To report the incidence, risk, and severity of high school knee injuries across sports, genders, and type of exposure.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

During the 2005-2006 and 2006-2007 school years, 100 US high schools were randomly selected for a nationally representative sample. Certified athletic trainers tracked injuries using an online injury surveillance system, High School RIO, in 9 high school sports.

RESULTS

There were 1383 knee injuries reported during 3,551131 athlete exposures for a rate of 3.89 knee injuries per 10,000 athlete exposures. Although boys had a higher overall rate of knee injury (rate ratio, 1.38; confidence interval, 1.22-1.55), girls were twice as likely to sustain knee injuries requiring surgery (major knee injuries) than were boys (injury proportion ratio, 1.98; confidence interval, 1.45-2.70) and twice as likely to incur noncontact major knee injuries (injury proportion ratio, 1.98; confidence interval, 1.23-3.19) as were boys. Although illegal play was identified as a contributing factor in only 5.7% of all knee injuries, 20% of knee injuries resulting from illegal play required surgery.

CONCLUSION

Knee injury rates and patterns varied by sport, gender, and type of exposure. Identified gender differences included differences in injury rates, injury severity, and basic injury mechanism. Further surveillance is crucial for the development of targeted, evidence-based injury prevention strategies to reduce the morbidity and economic impact of knee surgeries.

Elite football on artificial turf versus natural grass: Movement patterns, technical standards, and player impressions

The aim of the present study was to examine the movement patterns, ball skills, and the impressions of Swedish elite football players during competitive games on artificial turf and natural grass. Time - motion analyses (36 observations) and technical analyses (16 team observations) were performed and 72 male and 21 female players completed a questionnaire. No differences were observed between artificial turf and natural grass in terms of total distance covered (mean 10.19 km, s = 0.19 vs. 10.33 km, s = 0.23), high-intensity running (1.86 km, s = 0.10 vs. 1.87 km, s = 0.14), number of sprints (21, s = 1 vs. 22, s = 2), standing tackles (10, s = 1 vs. 11, s = 1) or headers per game (8, s = 1 vs. 8, s = 1), whereas there were fewer sliding tackles (P < 0.05) on artificial turf than natural grass (2.1, s = 0.5 vs. 4.3, s = 0.6). There were more short passes (218, s = 14 vs. 167, s = 12) and midfield-to-midfield passes (148, s = 11 vs. 107, s = 8) (both P < 0.05) on artificial turf than natural grass. On a scale of 0-10, where 0 = "better than", 5 = "equal to", and 10 = "worse than", the male players reported a negative overall impression (8.3, s = 0.2), poorer ball control (7.3, s = 0.3), and greater physical effort (7.2, s = 0.2) on artificial turf than natural grass. In conclusion, the running activities and technical standard were similar during games on artificial turf and natural grass. However, fewer sliding tackles and more short passes were performed during games on artificial turf. The observed change in playing style could partly explain the male players' negative impression of artificial turf.

Comparison of the incidence, nature and cause of injuries sustained on grass and new generation artificial turf by male and female football players. Part 1: match injuries

OBJECTIVE

To compare the incidence, nature, severity and cause of match injuries sustained on grass and new generation artificial turf by male and female footballers.

METHODS

The National Collegiate Athletic Association Injury Surveillance System was used for a two-season (August to December) prospective study of American college and university football teams (2005 season: men 52 teams, women 64 teams; 2006 season: men 54 teams, women 72 teams). Injury definitions and recording procedures were compliant with the international consensus statement for epidemiological studies of injuries in football. Athletic trainers recorded details of the playing surface and the location, diagnosis, severity and cause of all match injuries. The number of days lost from training and match play was used to define the severity of an injury. Match exposures (player hours) were recorded on a team basis.

RESULTS

The overall incidence of match injuries for men was 25.43 injuries/1000 player hours on artificial turf and 23.92 on grass (incidence ratio 1.06; p = 0.46) and for women was 19.15 injuries/1000 player hours on artificial turf and 21.79 on grass (incidence ratio = 0.88; p = 0.16). For men, the mean severity of non-season ending injuries was 7.1 days (median 5) on artificial turf and 8.4 days (median 5) on grass and, for women, 11.2 days (median 5) on artificial turf and 8.9 days (median 5) on grass. Joint (non-bone)/ligament/cartilage and contusion injuries to the lower limbs were the most common general categories of match injury on artificial turf and grass for both male and female players. Most injuries were acute (men: artificial turf 24.60, grass 22.91; p = 0.40; women: artificial turf 18.29, grass 20.64; p = 0.21) and resulted from player-to-player contact (men: artificial turf 14.73, grass 13.34; p = 0.37; women: artificial turf 10.72; grass 11.68; p = 0.50).

CONCLUSIONS

There were no major differences in the incidence, severity, nature or cause of match injuries sustained on new generation artificial turf and grass by either male or female players.

Comparison of the incidence, nature and cause of injuries sustained on grass and new generation artificial turf by male and female football players. Part 2: training injuries

OBJECTIVE

To compare the incidence, nature, severity and cause of training injuries sustained on new generation artificial turf and grass by male and female footballers.

METHODS

The National Collegiate Athletic Association Injury Surveillance System was used for a two-season (August to December) prospective study involving American college and university football teams (2005 season: men 52 teams, women 64 teams; 2006 season: men 54 teams, women 72 teams). Injury definitions and recording procedures were compliant with the international consensus statement for epidemiological studies of injuries in football. Athletic trainers recorded details of the playing surface and the location, diagnosis, severity and cause of all training injuries. The number of days lost from training and match play was used to define the severity of an injury. Training exposures (player hours) were recorded on a team basis.

RESULTS

The overall incidence of training injuries for men was 3.34 injuries/1000 player hours on artificial turf and 3.01 on grass (incidence ratio 1.11; p = 0.21) and for women it was 2.60 injuries/1000 player hours on artificial turf and 2.79 on grass (incidence ratio 0.93; p = 0.46). For men, the mean severity of injuries that were not season ending injuries was 9.4 days (median 5) on artificial turf and 7.8 days (median 4) on grass and, for women, 10.5 days (median 4) on artificial turf and 10.0 days (median 5) on grass. Joint (non-bone)/ligament/cartilage and muscle/tendon injuries to the lower limbs were the most common general categories of injury on artificial turf and grass for both male and female players. Most training injuries were acute (men: artificial turf 2.92, grass 2.63, p = 0.24; women: artificial turf 1.94, grass 2.23, p = 0.21) and resulted from player-to-player contact (men: artificial turf 1.08, grass 0.85, p = 0.10; women: artificial turf 0.47, grass 0.56; p = 0.45).

CONCLUSIONS

There were no major differences between the incidence, severity, nature or cause of training injuries sustained on new generation artificial turf and on grass by either men or women.

Stress fracture risk factors in female football players and their clinical implications

A stress fracture represents the inability of the skeleton to withstand repetitive bouts of mechanical loading, which results in structural fatigue, and resultant signs and symptoms of localised pain and tenderness. Reports of stress fractures in female football players are not prevalent; however, they are probably under-reported and their importance lies in the morbidity that they cause in terms of time lost from participation. By considering risk factors for stress fractures in female football players it may be possible to reduce the impact of these troublesome injuries. Risk factors for stress fractures in female football players include intrinsic risk factors such as gender, endocrine, nutritional, physical fitness and neuromusculoskeletal factors, as well as extrinsic risk factors such as training programme, equipment and environmental factors. This paper discusses these risk factors and their implications in terms of developing prevention and management strategies for stress fractures in female football players.

Risk of injury on artificial turf and natural grass in young female football players

BACKGROUND

Artificial turf is becoming increasingly popular, although the risk of injury on newer generations of turf is unknown.

AIM

To investigate the risk of injury on artificial turf compared with natural grass among young female football players.

STUDY DESIGN

Prospective cohort study.

METHODS

2020 players from 109 teams (mean (SD) 15.4 (0.8) years) participated in the study during the 2005 football season. Time-loss injuries and exposure data on different types of turf were recorded over an eight-month period.

RESULTS

421 (21%) players sustained 526 injuries, leading to an injury incidence of 3.7/1000 playing hours (95% CI 3.4 to 4.0). The incidence of acute injuries on artificial turf and grass did not differ significantly with respect to match injuries (rate ratio (RR) 1.0, 95% CI 0.8 to 1.3; p = 0.72) or training injuries (RR 1.0, 95% CI 0.6 to 1.5, p = 0.93). In matches, the incidence of serious injuries was significantly higher on artificial turf (RR 2.0, 95% CI 1.3 to 3.2; p = 0.03). Ankle sprain was the most common type of injury (34% of all acute injuries), and there was a trend towards more ankle sprains on artificial turf than on grass (RR 1.5, 95% CI 1.0 to 2.2; p = 0.06).

CONCLUSION

In the present study among young female football players, the overall risk of acute injuries was similar between artificial turf and natural grass.