Normal course of events amongst Swedish soccer players: an 8-year follow-up study

Injury Profile among Elite Youth Male Football Players in a German Academy

Studies that report injuries in elite youth football players are scarce. So far, no such studies have been reported in Germany. The aim of this study is to descriptively and statistically report the incidence of injuries that resulted in time-loss ≥ 4 days in the TSG Hoffenheim football academy by 138 male players aged between 12 and 19 years during one season. A total of 109 injuries were sustained by 76 players: 6.9 injuries occurred per 1000 hours of matches (95% CI, 5.0-9.6) and 0.7 injuries per 1000 hours of training (95% CI, 0.5-0.9) with a ratio of 9.8. Some 66% of all injuries occurred during matches. Injuries involved the lower limb (81%), upper limb (9%), head & neck (5%) and trunk injuries (5%). 21 (19%) of all injuries were regarded as severe and resulted in time-loss > 28 days. U16-U19 teams sustained more injuries (74, 68%) than U12-U15 (35, 32%) (P= 0.032). The most frequent diagnosis was thigh strain (22%). Time-loss ranged from 4-339 days (SD: 40, Average: 23). Many injuries were a result of strain. Available injury prevention programs should be adhered to more strictly. Dedicated epidemiological studies are needed to optimize focused injury prevention programs.

Effect of isolated hip abductor fatigue on single-leg landing mechanics and simulated ACL loading

BACKGROUND

Altered movement biomechanics are a risk factor for ACL injury. While hip abductor weakness has been shown to negatively impact landing biomechanics, the role of this musculature and injury risk is not clear. The aim of this musculoskeletal simulation study was to determine the effect of hip abductor fatigue-induced weakness on ACL loading, force production of lower extremity muscles, and lower extremity biomechanics during single-leg landing.

METHODS

Biomechanical data from ten healthy adults were collected before and after a fatigue protocol and used to derive subject-specific estimates of muscle forces and ACL loading using a 5-degree of freedom (DOF) model.

RESULTS

There were no significant differences in knee joint angles and ACL loading between pre and post-fatigue. However, there were significant differences, due to fatigue, in lateral trunk flexion angle, total excursion of trunk, muscle forces, and joint moments.

CONCLUSION

Altered landing mechanics, due to hip abductor fatigue-induced weakness, may be associated with increased risk of ACL injury during single-leg landings. Clinical assessment or screening of ACL injury risk will benefit from subject-specific musculoskeletal models during dynamic movements. Future study considering the type of the fatigue protocols, cognitive loads, and various tasks is needed to further identify the effect of hip abductor weakness on lower extremity landing biomechanics.

Injectable Ketorolac and Corticosteroid Use in Athletes: A Systematic Review

CONTEXT

The use of injectable medications to help athletes quickly return to the field of play after injury is common. Understanding the effects and risks of these medications will help providers make informed decisions regarding their use in this patient population.

OBJECTIVE

To evaluate the utilization, efficacy, and adverse effects of injectable ketorolac and corticosteroids in athletes.

DATA SOURCES

This systematic review followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. A systematic search of the literature was performed using multiple databases (PubMed, Embase, Cochrane, Web of Science, and ClinicalTrials.gov). Secondary references were appraised for relevant articles. No randomized controlled trials or other prospective studies were identified. Articles included retrospective database reviews and physician survey studies.

STUDY SELECTION

A total of 6 studies met the inclusion and exclusion criteria and were reviewed by 2 independent reviewers with a third consulted in the case of disagreement, which was not needed.

STUDY DESIGN

Systematic review.

LEVEL OF EVIDENCE

Level 5.

DATA EXTRACTION

Two reviewers recorded rate of use, effectiveness of treatment, and reported side effect data.

RESULTS

Most studies centered around the football athlete, either professional or collegiate. Professional football game day use of intramuscular ketorolac declined from 93.3% (28/30) in 2002 to 48% in 2016. Collegiate football game day use of intramuscular ketorolac declined from 62% in 2008 to 26% in 2016. Game day corticosteroid injection was far lower than ketorolac usage. Both medications were reported to be effective with few adverse events.

CONCLUSION

Use of injectable ketorolac is common but declining in professional and college football. Pain control efficacy is good, and risk of adverse events is low. The incidence of injectable corticosteroid use in athletes is unknown. Use of injectable corticosteroids in athletes allows for early return to sport activities with no reported complications.

Anterior cruciate ligament injury risk factors in football

INTRODUCTION

Anterior cruciate ligament (ACL) lesion represents one of the most dramatic injuries in a football (soccer) player's career. There are many injury risk factors related to intrinsic (non-modifiable) and/or extrinsic (modifiable) factors of ACL injury.

EVIDENCE ACQUISITION

Research of the studies was conducted until September 2018 without publication data limitation or language restriction on the following databases: PubMed/MEDLINE, Scopus, ISI, EXCERPTA.

EVIDENCE SYNTHESIS

To date, evidence from the literature suggests that the risk of ACL injury is multifactorial and involves biomechanical, anatomical, hormonal, and neuromuscular factors. Despite this relative complexity, the mechanisms of injury are well known and rationally classified into two categories: mechanisms of injury based on contact or on non-contact with another player, with the non-contact injury mechanisms clearly prevailing over the mechanisms of contact injury. One of the most frequent biomechanical risk factors, associated with ACL non-contact injury, is represented by the valgus knee in the pivoting and cutting movements and in the landing phase after jumping. Gender-related risk factors show female populations to have a higher predisposition to ACL injury than males However, there are still some theoretical and practical aspects that need further investigation such as; genetic risks together with the role of estrogen and progesterone receptors in female populations, and the in-vivo interaction shoe-playing surface. In particular, the genetic risk factors of ACL lesion seem to be an interesting and promising field of investigation, where considerable progress has still to be made.

CONCLUSIONS

This narrative review provides an insight into the risk factors of ACL injury that could be used by practitioners for preventing injury in football (soccer).

Injury profile among elite male youth soccer players in a Swedish first league

This study investigated the injury profile among elite male youth soccer players in a Swedish first league during two seasons. The present cohort study is based on data collected during the 2013–2014 seasons. In total, 43 young elite male soccer players, aged 15 to 19 yr, were prospectively followed regarding injuries, time of exposure, injury location, type of injury, and injury severity. The overall incidence of injury in the present study was estimated to 6.8 injuries per 1,000 exposure hours and 15.5 and 5.6 injuries per 1,000 hr for matches and training, respectively. The single most common injury subtype was muscle strain (53%). The hip and groin were the most common locations for injuries. Thirty-one percent of the injuries were classified as severe injury and caused >28 days absence from training and match play. Both the injury incidence and the number of serious injury seems to be relatively high in youth elite players according to this study. Although the injury incidence seems to be slightly lower than in adult elite players the injuries seem to be more traumatic in youth elite players.

Incidence and risk factors of lower leg fractures in Belgian soccer players

INTRODUCTION

Soccer is the world's most popular sport and one that is physically demanding and highly competitive. Consequently, the rate of injuries resulting from this sport is only increasing. It is estimated that 2-20% of all such injuries are fractures, one-third of which are located in the lower extremities. The aim of this epidemiological study was to investigate the incidence of lower-leg fractures (LLFs) in Belgian soccer players and determine the possible risk factors that lead to them.

METHODS

All injuries of players associated with the Royal Belgium Football Association (RBFA) were reported and collected in a nationwide registry. We retrospectively compared the incidence rate of and risk factors for LLFs in Belgian soccer players during two seasons, 1999-2000 and 2009-2010.

RESULTS

In total, 1600 fractures (3%) were located in the lower leg. After a decade, the number of LLFs remained unchanged. Ankle fractures were the most common (37%), followed by foot and tibia fractures (33% and 22%, respectively). The least common were fibula fractures, which accounted for just 9%. A higher incidence of every type of LLF was observed in older and amateur-level soccer players, when compared with their younger and professional counterparts. Male players experienced more tibia and foot fractures, whereas the incidences of ankle and fibula fractures were comparable with those in female soccer players. The vast majority of fractures occurred during soccer games.

CONCLUSION

Ankle fractures and foot fractures represented two-thirds of all fractures noted in this analysis. Male gender, recreational level and adult age were important risk factors for LLFs. After 10 years, the incidence of LLFs did not decrease. Given the socioeconomic impact of these injuries, improved prevention techniques are required to reduce their incidence, particularly with regard to the frequently occurring ankle and foot fractures in this population.

Optimizing whole-body kinematics to minimize valgus knee loading during sidestepping: implications for ACL injury risk

The kinematic mechanisms associated with elevated externally applied valgus knee moments during non-contact sidestepping and subsequent anterior cruciate ligament (ACL) injury risk are not well understood. To address this issue, the residual reduction algorithm (RRA) in OpenSim was used to create nine subject-specific, full-body (37 degrees of freedom) torque-driven simulations of athletic males performing unplanned sidestep (UnSS) sport tasks. The RRA was used again to produce an optimized kinematic solution with reduced peak valgus knee torques during the weight acceptance phase of stance. Pre-to-post kinematic optimization, mean peak valgus knee moments were significantly reduced by 44.2 Nm (p=0.045). Nine of a possible 37 upper and lower body kinematic changes in all three planes of motion were consistently used during the RRA to decrease peak valgus knee moments. The generalized kinematic strategy used by all nine simulations to reduce peak valgus knee moments and subsequent ACL injury risk during UnSS was to redirect the whole-body center of mass medially, towards the desired direction of travel.

Serum concentrations of two biochemical markers of brain tissue damage S-100B and neurone specific enolase are increased in elite female soccer players after a competitive game

BACKGROUND

It is a matter of debate whether or not ordinary heading of the ball in soccer causes injury to brain tissue.

OBJECTIVE

To analyse concentrations of the biochemical markers of brain tissue damage S-100B and neurone specific enolase (NSE) in serum of female elite soccer players in association with a competitive game.

METHODS

Venous blood samples were obtained from 44 female soccer players before and after a competitive game for analysis. The number of headers and trauma events (falls, collisions, etc) was assessed from videotape recordings for each player.

RESULTS

Concentrations of both brain damage markers were increased after the game (S-100B, 0.18 (0.11) v 0.11 (0.05) microg/l (p = 0.000); NSE, 10.14 (1.74) v 9.05 (1.59) microg/l (p = 0.001)). There was a significant correlation between changes in S-100B concentrations and both the number of headers (r = 0.430, p = 0.004) and the number of other trauma events (r = 0.517, p < 0.001).

CONCLUSION

The concentrations of both S-100B and NSE were increased by game associated activities and events. The increases in S-100B concentration were significantly related to the number of headers and other trauma events, which indicates that both these factors may have contributed to these increases.

High risk of new knee injury in elite footballers with previous anterior cruciate ligament injury

BACKGROUND

Anterior cruciate ligament (ACL) injury is a severe event for a footballer, but it is unclear if the knee injury rate is higher on returning to football after ACL injury.

OBJECTIVE

To study the risk of knee injury in elite footballers with a history of ACL injury compared with those without.

METHOD

The Swedish male professional league (310 players) was studied during 2001. Players with a history of ACL injury at the study start were identified. Exposure to football and all time loss injuries during the season were recorded prospectively.

RESULTS

Twenty four players (8%) had a history of 28 ACL injuries in 27 knees (one rerupture). These players had a higher incidence of new knee injury of any type than the players without ACL injury (mean (SD) 4.2 (3.7) v 1.0 (0.7) injuries per 1000 hours, p = 0.02). The risk of suffering a knee overuse injury was significantly higher regardless of whether the player (relative risk 4.8, 95% confidence interval 2.0 to 11.2) or the knee (relative risk 7.9, 95% confidence interval 3.4 to 18.5) was used as the unit of analysis. No interactive effects of age or any other anthropometric data were seen.

CONCLUSION

The risk of new knee injury, especially overuse injury, was significantly increased on return to elite football after ACL injury regardless of whether the player or the knee was used as the unit of analysis.

Injury incidence and prevalence among elite weight and power lifters

The purpose of this study was to investigate the incidence and prevalence of injuries among elite weight lifters and power lifters, with a special focus on shoulder injuries and possible injury-provoking exercises. In 1995, a questionnaire was administered to 110 male and female elite lifters to evaluate injuries and training characteristics. A follow-up of the athletes from 1995 was conducted in 2000, and a new 2000 elite group was also queried. In 1995 and again in 2000, the athletes sustained, on average, 2.6 injuries per 1000 hours of activity. Most common in 1995 were low back injuries, with an injury rate of 0.43 per 1000 hours, and shoulder injuries, with a rate of 0.42 per 1000 hours. Shoulder injuries dominated in 2000, with an injury rate of 0.51 per 1000 hours of activity. There was a difference in injury pattern between weight lifters, who mostly sustained low back and knee injuries, and power lifters, in whom shoulder injuries were most common. No correlation was found between shoulder injuries and any specific exercise. Although the total injury rate was the same during the two periods of study, the rate of shoulder injuries had increased.

An examination of injuries in major league soccer. The inaugural season

We analyzed the injury data collected from the 10 teams (237 players) that constituted Major League Soccer during its inaugural season. The overall injury rate was 6.2 per 1000 hours of participation. An injury rate of 2.9 per 1000 hours was noted for practice and 35.3 per 1000 hours was found for games. The difference was statistically significant. With regard to severity, 36% of injuries (143 of 399) were categorized as an incident (no time lost from competition). Of the 256 injuries that caused the player to lose playing time, 59% were classified as minor (<7 days lost), 28% as moderate (7 to 29 days lost), and 13% as major (>30 days lost). Seventy-seven percent of the injuries (197 of 256) were to the lower extremity; most frequently affected were the knee (N = 54) and ankle (N = 46). Neither the player's age nor playing position was found to be associated with prevalence or severity of injury. We believe that this information serves to underscore the notion that soccer, as it is played at the professional level, is a sport with a relatively low incidence of injury.

Functional properties of adhesive ankle taping: neuromuscular and mechanical effects before and after exercise

The purpose of the study was to investigate effects of adhesive ankle taping. Using electromyographic, goniometric, and thermologic methods, different ankle tapes were tested before and after athletic exercise in simulated inversion trauma. Twelve subjects with stable ankle joints performed five trials: with two different materials, with two taping techniques, and one trial without tape as control. After the simulated inversion trauma, approximately 35% of the initial maximum inversion amplitude was decreased by ankle taping. Depending on the technique, there was a loss of tape stability < or =14% after 30 min of athletic exercise. Thermologic analysis revealed a postexercise 6 degrees C temperature increase in the foot, especially under the tape. Initially, interpreted as the primary effect, the improved joint stabilization is based on mechanical stiffness caused by the adhesive tape. Joint stability was influenced positively by neuromuscular proprioceptive and physiological processes, characterized by relatively increased electromyographic activation.

The incidence and differential diagnosis of acute groin injuries in male soccer players

This prospective cohort study evaluated the incidence of acute groin injuries and estimated the distribution of differential diagnoses in male soccer players. Two senior male soccer divisions (21 teams, 326 players) were followed for 1 year. Patients with groin injuries were examined clinically as well as by herniography, sonography and by plain x-ray of the pelvic bones. Groin injuries accounted for 8% of all injuries. The incidence of groin injury was 0.8/1000 h of exposure. Thirteen (52%) of the 25 patients were clinically considered to have a muscle/tendon injury. However, when using sonography, muscle/tendon injury was only verified in 1 patient. Clinical suspicion of hernia or incipient hernia was evident in 4 (16%) of the patients, while 14 (56%) had a pathological finding at herniography. Clinical and paraclinical (i.e. diagnostic methods using imaging and other advanced techniques) diagnoses do not correspond very well in acute groin injury.

The footballer's fracture

OBJECTIVE

To describe the typical tibial diaphyseal fracture ("footballer's fracture") and to clarify the circumstances and mechanism of the injury.

METHODS

In an attempt to obtain a detailed analysis of the types of injury suffered, and thereby highlight areas for prevention, 100 consecutive adult football players with a tibial diaphyseal fracture were studied prospectively. Details of the circumstances and mechanism of injury were collected using a questionnaire (response rate 85%). Treatments depended on the Gustilo classification, displacement, and axial stability. Long term follow up was performed until clinical healing to define the overall prognosis.

RESULTS

61% of players suffered a fracture of both the tibia and the fibula. Ninety five percent of the tibial fractures were transverse or short oblique and were caused by impact during a tackle. Radiographic evidence of bridging callus was better than a classification of the bony injury for predicting weeks to clinical healing. The delayed union and non-union incidence following this injury is low. One patient suffered symptomatic shortening. One patient suffered symptomatic angulation and two patients with nonunion required bone grafting.

CONCLUSIONS

Tibial fracture is an expensive injury. It prevents a young population from being employed and takes up valuable NHS resources. As 85% of players were wearing shin guards, it is likely that improvements in shin guard design could reduce the rate of tibial fracture.

Soccer after anterior cruciate ligament injury--an incompatible combination? A national survey of incidence and risk factors and a 7-year follow-up of 310 players

All players in Swedish soccer teams are required to have insurance in the same company. From the archives of the insurance company, all 3,735 injuries reported in 1986 in 188,152 Swedish soccer players were reviewed. Of these, 937 were knee injuries. All players were asked by mail to fill in a questionnaire and 83 percent replied. The patient records from the different hospitals were requested. The anterior cruciate injuries represented one third of the reported knee injuries. The relative risk of sustaining an anterior cruciate ligament injury was increased in female players, in elite players, and in players in the forward position. The odds ratios were 1.6 (1.3-2.1), 3.3 (1.7-6.1) and 1.8 (1.4-2.5), respectively. The injuries occurred at a younger age in females than in males. 50 percent of the injured players were treated with anterior cruciate ligament surgery, predominantly as a reconstructive procedure, with use of a patellar tendon transplant. 30 (20) percent of the players with anterior cruciate ligament injury were active in soccer after 3 (7) years, compared to 80 (50) percent of an injured control population of soccer players. None of the elite players was active at the same level after 7 years. A comparison of anterior cruciate ligament-injured players, whether treated by surgical reconstruction or not, revealed no difference with regard to the proportion of players still playing soccer after 7 years.

A fivefold reduction in the incidence of recurrent ankle sprains in soccer players using the Sport-Stirrup orthosis

A study was undertaken to evaluate the effect of a semi-rigid ankle orthosis (Sport-Stirrup) on the incidence of ankle sprains in soccer players during 1 playing season. Senior soccer players were divided into 2 groups: players with previous ankle sprains (N = 258) and players without such history (N = 246). The players in these groups were each randomly allocated to either a semi-rigid orthosis or a control group at the start of the playing season. All subsequent injuries during the season and the total number of playing hours were documented. There was a significant reduction in the incidence of ankle sprains (injuries/1000 playing hours) by ankles in the orthosis group with previous sprains (0.14) compared with the nonbraced group with previous sprains (0.86). The incidence of ankle sprains was significantly higher in the nonbraced group with previous sprains (0.86) compared with the nonbraced group without previous sprains (0.46). Thus, in this study, a semirigid orthosis significantly reduced the incidence of recurrent ankle sprains in soccer players with previous history of ankle sprains.

Health and healthcare costs and benefits of exercise

To assess the value of promoting health through exercise, we review what is known about the medical and medical care resource costs and benefits of exercise. Literature searches were undertaken to derive estimates of the relative risk, in individuals who exercise regularly compared with those who do not, of each of the major disease groups for which there is good evidence that the disease can be ameliorated by exercise (coronary heart disease, stroke, diabetes, hip fracture, and mental illness). These relative risks were used to estimate the incidence of hospital admissions and mortality, and associated healthcare costs, which could be prevented if the whole population exercised. Literature on the incidence and costs of exercise-related morbidity and mortality was also reviewed to derive estimates of both the costs to health and also the healthcare resource implications of exercise in total population. Indirect costs and benefits, and also quality-of-life effects associated with exercise were not included in this assessment. The results show that in younger adults (ages 15 to 44 years) the average annual medical care costs per person that might be incurred as a result of full participation in sport and exercise (approximately 30 pounds British sterling) exceed the costs that might be avoided by the disease-prevention effects of exercise ( less than 5 pounds British sterling per person). However, in older adults ( greater than or equal to 45) the estimated costs avoided ( greater than 30 pounds British sterling per person) greatly outweigh the costs that would be incurred ( less than 10 pounds British sterling). There was little evidence that exercise leads to deferred health or health service resource benefits. We conclude that with regard to health and medical care costs, there are strong economic arguments in favour of exercise in adults aged greater than or equal to 45 but not in younger adults. Estimates derived from the international scientific literature and routine UK data sources may have limited direct application in the healthcare systems of other countries. Nevertheless, the result that exercise costs exceed the benefits in younger adults but vice versa in older people is likely to be generally true. Indeed, a similar result has been found in a study of a Dutch population.

Factors related to the incidence of running injuries. A review

The term incidence is interpreted in many different ways in the literature. Running injury epidemiology should include denominator-based incidence rates, in which the number of new injuries observed during 1 year is related to the population of runners at risk. In 10 studies with denominator-based incidences selected from the literature, the annual incidence rates of injured runners vary from 24 to 65%. Comparison of denominator-based incidence rates from different studies requires a discussion of the denominator and of the numerator; i.e. the study population and the definition of running injury. Injury definitions differ from one study to another. Study populations are particular subgroups of the total running population and they differ from one study to another. Subgroups may differ in origin: volunteers, runners from a mailing list or entrants of a road race. Incidence rates are higher among supervised volunteers than among listed runners, and higher among both these groups than among race-entrants. The choice from the universe of the running population and the used injury definition are methodological issues. Incidence is dependently associated with the prevalence of predisposing running injury factors. There is consistent epidemiological support for the role of a few aetiological factors; i.e. higher mileage per week, previous running injury, higher running speed and lesser running experience. Higher mileage per week is probably the strongest predictor. In the selected injury studies, mileage per week differs from one study population to another. Differences in mileage per week do not explain differences in incidence rate between these studies. In conclusion, caution must be taken when comparing annual incidence rates of different studies. Methodological issues are at least as important as aetiological factors. Study populations may refer to different selections of the universe of the running population. The lengths of observation periods and 'running injury' definitions may differ from one study to another.