Soccer injury in the lower extremities

Foot accelerations are larger than tibia accelerations during sprinting when measured with inertial measurement units

Accelerometers are often placed on the tibia to measure segmental accelerations, and external mechanical load during running. However, in applied sport settings it is sometimes preferable to place accelerometers on the dorsal foot to avoid tibial impact injuries. This study aimed to quantify the differences in accelerations measured at the dorsal foot compared with the distal tibia during running. Sixteen recreationally active participants performed a sprint protocol on a non-motorised treadmill. Accelerometers were positioned bilaterally on the medial tibia (TIB_Left and TIB_Right), and bilateral dorsal foot surfaces (DOR_Left and DOR_Right). Continuous acceleration signal waveform analysis was performed using one-dimensional statistical parametric mapping (1DSPM). Resultant accelerations were greater for DOR_Left than TIB_Left for 60% of the gait cycle (p < 0.001) and greater for DOR_Right than TIB_Right for 50% of the gait cycle (p < 0.003). The larger accelerations at the dorsal foot than the tibia can be explained by movement at the ankle joint, and the placement location relative to the hip. The dorsal foot location can be used to effectively measure accelerations and external mechanical load when it is not feasible to place the accelerometer on the tibia, however results between the two locations should not be compared.

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.

Relative and absolute within-session reliability of the modified Star Excursion Balance Test in healthy elite athletes

Background

The Star Excursion Balance Test (SEBT) is commonly used to assess dynamic postural balance both in clinical practice and research. The aim of our study was to assess the within-session relative and absolute reliability of participants’ performance of the modified SEBT (mSEBT) using a single practice trial in healthy elite athletes who were familiar with the test.

Methods

An intra-session repeated-measures design was used to investigate the relative and absolute reliability of participants’ (healthy athletes partaking in sports at a high-risk of ankle sprain injury) performance of the mSEBT. A total of 122 healthy elite athletes from soccer (n = 73), basketball (n = 15), and volleyball (n = 34) performed one practice trial and three test trials within one session, in three directions (anterior, postero-medial, and postero-lateral), for both legs. Intraclass correlation coefficient (ICC), standard error of measurement (SEM), and smallest detectable change at a 95% confidence were calculated.

Results

We found a good to excellent relative within-session intra-rater reliability between the three trials on specified directions, with an ICC (3,1) from 0.90 to 0.95. SEM and SDC₉₅ for normalized and composite scores, for both legs ranged from 0.91 to 2.86, and 2.54 to 7.94, respectively.

Conclusions

In conclusion, we report good to excellent within-session reliability for the mSEBT. Our results confirm that the test can be reliably used with only one practice trial in healthy elite athletes familiar with the test.

The effect of the change of football turf on knee kinematics of adolescent male football players

BACKGROUND

The aim of this study was to investigate the effect of the change of football turf on knee kinematics of adolescent male football players.

METHODS

Thirteen adolescent male football players were tested by a portable infrared motion analysis system based on markers. The angular displacements of flexion/extension,valgus/varus and internal/external rotation were calculated respectively when players performed 90° shuttle running on artificial turf and natural turf.

RESULTS

The maximum valgus angle and range of valgus/varus were larger when they were changed from artificial turf to natural turf (P<0.05). There were no significant differences in the maximum flexion angle, maximum extension angle, range of flexion/extension, maximum varus angle, maximum internal rotation angle, maximum external rotation angle and range of internal/external rotation (P>0.05).

CONCLUSIONS

The change of football turf has a significant effect on knee kinematics of adolescent male football players. The risk of noncontact anterior cruciate ligament (ACL) injury is increased when players who are changed from artificial turf to natural turf.

Relationship of Pre-season Training Load With In-Season Biochemical Markers, Injuries and Performance in Professional Soccer Players

INTRODUCTION

There is controversy in the literature in regards of the link between training load and injury rate. Thus, the aims of this non-interventional study were to evaluate relationships between pre-season training load with biochemical markers, injury incidence and performance during the first month of the competitive period in professional soccer players.

MATERIALS AND METHODS

Healthy professional soccer players were enrolled in this study over two pre-season periods. Data sets were available from 26 players during the first season (2014-2015) and 24 players during the second season (2015-2016) who completed two pre-season periods (6 weeks each). External training load was assessed from all athletes during training using Global Positioning System (GPS). Internal training load was monitored after each training session using rate of perceived exertion (RPE). Before and after each pre-season, blood samples were taken to determine plasma lactate dehydrogenase (LDH), creatine kinase (CK) and C-reactive protein (CRP). Injury incidence and overall performance (ranking of the team after the first five official games of the championship) were recorded for both seasons separately.

RESULTS

There was no statistically significant difference in mean RPE values of the two-preparation periods (2737 ± 452 and 2629 ± 786 AU, p = 0.492). The correlational analysis did not reveal significant associations between internal and external training load (RPE and GPS data) and biological markers. There was a significant positive correlation between RPE and LDH during the 2015/2016 season (r = 0.974, p = 0.001). In addition, a significant negative correlation was found between total distance >20 km/h and CRP during the 2015-2016 season (r = -0.863, p = 0.027). The injury rates for the two seasons were 1.76 and 1.06 per 1000 h exposure for the 2014-2015 and 2015-2016 seasons, respectively (p = 0.127).

CONCLUSION

Our study showed that pre-season training load is not associated with overall team performance. This association is most likely multifactorial and other factors (e.g., technical and tactical level of the team, opponents, environment) may play an important role for the collective team performance. Our findings may help coaches to better prepare their athletes during pre-season.

Spikes in acute:chronic workload ratio (ACWR) associated with a 5-7 times greater injury rate in English Premier League football players: a comprehensive 3-year study

Objectives

We examined the relation between global positioning system (GPS)-derived workloads and injury in English Premier League football players (n=33) over three seasons.

Methods

Workload and injury data were collected over three consecutive seasons. Cumulative (1-weekly, 2-weekly, 3-weekly and 4-weekly) loads in addition to acute:chronic workload ratios (ACWR) (acute workload (1-week workload)) divided by chronic workload (previous 4-week average acute workload) were classified into discrete ranges by z-scores. Relative risk (RR) for each range was then calculated between injured and non-injured players using specific GPS variables: total distance, low-intensity distance, high-speed running distance, sprint distance, accelerations and decelerations.

Results

The greatest non-contact injury risk was when the chronic exposure to decelerations was low (<1731) and the ACWR was >2.0 (RR=6.7). Non-contact injury risk was also 5–6 times higher for accelerations and low-intensity distance when the chronic workloads were categorised as low and the ACWR was >2.0 (RR=5.4–6.6), compared with ACWRs below this. When all chronic workloads were included, an ACWR >2.0 was associated with a significant but lesser injury risk for the same metrics, plus total distance (RR=3.7–3.9).

Conclusions

We recommend that practitioners involved in planning training for performance and injury prevention monitor the ACWR, increase chronic exposure to load and avoid spikes that approach or exceed 2.0.

The negative impact of anterior cruciate ligament reconstruction in professional male footballers

BACKGROUND

Soccer is one of the most common international sports in which ACL injuries occur, with previous studies reporting high return-to-play rates following ACL reconstruction (ACLR). Return-to-play analysis fails to take into consideration how effective a player remains once returning to competition. The aims of this study are to provide a large-scale international analysis of return-to-play and player performance statistics among professional soccer athletes following ACLR.

METHODS

Using publicly available sources, professional soccer athletes who have undergone ACLR between the 1996 and 2015 seasons were identified. Player metrics including statistical performance, recovery time, and return-to-play rates were analyzed both before and after reconstruction. Furthermore, player performance statistics during each of three consecutive seasons post-ACLR were compared.

RESULTS

A total of 176 athletes who underwent ACLR were included in this study. The return-to-play rate was 93.2% (164 athletes). Cumulative post-surgical statistical analysis of ACLR players demonstrated fewer games/season, minutes/season, minutes/game, goals/season, and more fouls/season following ACLR (p < 0.04). Analysis of player performance statistics suggests that athletes do not return to their baseline number of games/season and minutes/game until two and three seasons post-ACLR, respectively. At three seasons post-ACLR, athletes are still starting fewer games/season and scoring fewer goals/90 min (p < 0.04).

CONCLUSION

Return-to-play rate is high following ACLR; however, athletes exhibit poorer statistical performance, especially in the first few seasons upon return. Our data shows that athletes continue to start fewer games/season and score fewer goals/90 min at three seasons post-ACLR.

Epidemiology of injuries among Italian footballers: the role of the playing field

Background

Football has a higher injury rate compared with other team sports such as rugby, in terms of two main categories: intrinsic (individual) and extrinsic (environmental) factors. The playing field is an extrinsic risk factor which has been poorly investigated in the literature.

Purpose

The aim of our study was to define the incidence and risk factors of injuries in a cohort of footballers comparing the role of three different types of playing field (hard court, natural grass or synthetic grass).

Study design

This was a cross sectional prevalence study.

Methods

The population comprised footballers recruited by a convenience sample; the instrument used for the survey was an anonymous self-administered questionnaire.

Results

267 football players were enrolled (average age 23.4±4.8 years), of whom 33.7% (n=90/267) played on hard court, 33.0% (n=88/267) on natural grass and 33.3% (n=89/267) on synthetic grass. The overall incidence of injury was 40.1 (95% CI 34.1 to 46.8) ×1000 person-years of training, with higher values for ankle and knee injuries. Ankle injuries (aOR 0.4; P=0.021) were associated with playing on natural grass as a protective factor, while playing on natural grass seemed to be a risk factor for muscular injuries (aOR 2.3; P=0.026).

Conclusion

Our study showed a high lifetime prevalence of injury among footballers (57%), in particular among athletes who play and train on a hard court. We have studied a topic poorly investigated previously and provide the opportunity to understand interventions to increase the capacity of stakeholders in preventing injuries.

Lower limb injury prevention programs in youth soccer: a survey of coach knowledge, usage, and barriers

Background

Participation in youth soccer carries a significant risk of injury, most commonly non-contact injuries of the lower extremity. A growing body of research supports the use of neuromuscular interventions by teams to prevent such injuries, yet the uptake of these recommendations by soccer teams remains largely unexplored. The purposes of the study were to determine (1) the level of awareness by youth coaches of injury prevention programs and their efficacy; (2) the number of youth coaches that use these interventions; and (3) barriers and potential facilitators to implementing a sustainable injury prevention program.

Methods

Four hundred eighteen coaches of male and female youth soccer teams were emailed an online blinded survey. This survey consisted of 26 questions covering coaches’ demographics, level of training, experience with injuries among players, and use of injury prevention programs. Question development was guided by the RE-AIM Sports Setting Matrix in combination with findings from the literature review and expert experience from orthopaedic surgeons specializing in sport medicine.

Results

Of the 418 coaches contacted, 101 responded. Only 29.8% of respondents used an injury prevention program in the prior soccer season. Coaches that had completed one or more coaching courses were more likely to use an intervention. Of those that did not already use an intervention, coaches agreed or strongly agreed that they would consider using one if it could be used in place of the warm up and take no more than 20 min (74.0%), if they could access information about the exercises (84.0%), and if the exercises could be properly demonstrated (84.0%). Additionally, 84% of coaches that did not already use an intervention agreed or strongly agreed that knowing that interventions may reduce a player’s risk of injury by 45% would affect whether they would use one.

Conclusion

This study suggests that the current use and awareness of injury prevention programs is limited by a lack of communication and education between sporting associations and coaches, as well as perceived time constraints. The results also suggest that improving coaching education of injury prevention could increase the frequency of intervention use.

Electronic supplementary material

The online version of this article (10.1186/s40634-018-0160-6) contains supplementary material, which is available to authorized users.

Foot typology, body weight distribution, and postural stability of adolescent elite soccer players: A 3-year longitudinal study

Objective

The unique foot morphology and distinctive functions facilitate complex tasks and strategies such as standing, walking, and running. In those weight-bearing activities, postural stability (PS) plays an important role. Correlations among foot type, PS, and other musculoskeletal problems that increase sport injury risk are known. However, long-term associations among the foot type, the PS, and body weight (BW) distribution are lacking. Thus, the purpose of this study was to longitudinally identify changes in foot morphology, PS, and symmetry in BW distribution during adolescence among elite male soccer players.

Methods

Thirty-five Czech elite male soccer players (age, 15.49 ± 0.61 years; BW, 64.11 ± 6.16 kg; body height, 174.62 ± 5.71 cm) underwent foot type, PS, and BW distribution measurements during 3 consecutive years (T1, T2, T3). The Chippaux-Smirak index (CSI), BW distribution, and centre of pressure (COP) displacement (total traveled way [TTW]) of each player for the preferred (PL) and non-preferred leg (NL) were acquired. Repeated-measures analysis of variance (RM ANOVA), Bonferroni´s post hoc tests, and partial eta-squared (η_p²) coefficient were used for investigating the effect of time on selected variables and effect size evaluation.

Results

Statistically significant effect of time on CSI values (PL: F_2,68 = 5.08, p < 0.01, η_p² = 0.13 and NL: F_2,68 = 10.87, p < 0.01, η_p² = 0.24) and COP displacement values (PL: F_2,68 = 5.07, p <0.01, η_p² = 0.13; NL: F_2,68 = 3.53, p <0.05, η_p² = 0.09) for both legs over 3-years period was identified. Furthermore, the Bonferroni´s post hoc analysis revealed a significant improvement of PS values in the PL (TTW_T1 = 1617.11 ± 520.22 mm vs. TTW_T2 = 1405.29 ± 462.76, p < 0.05; and between TTW_T1 = 1617.11 ± 520.22 mm vs. TTW_T3 = 1370.46 ± 373.94, p < 0.05). Only BW distribution parameter showed no significant differences, although slightly improved over time.

Conclusions

We observed changes in foot typology, PS, and BW distribution in young elite male soccer players during 3 consecutive years. Results demonstrated that changes in PS and body weight distribution under the high-load sport conditions during adolescence may improve with aging, except for foot morphology. Therefore, foot morphology should be carefully monitored to minimize sport injury risk in professional young soccer players during adolescence. Further research is necessary to determine more clear associations between these parameters, soccer-related injuries, and sport performances.

Comparison of Thigh Muscle Strain Occurrence and Injury Patterns Between Male and Female High School Soccer Athletes

Context: Thigh muscle strains are among the most common injuries in high school soccer for both males and females. Similar results have been reported among college soccer players, specifically for hamstring strains. In college soccer, males have a higher injury rate than women, although they share common injury characteristics. Currently, no studies exist comparing the injury rate or injury characteristics of thigh muscle strains between sexes playing high school soccer. Objective: To compare thigh muscle strain injury rates and injury event characteristics among sexes participating in high school soccer. Design: Descriptive epidemiology study. Setting: A total of 100 nationally representative high schools that participated in the High School Sports-Related Injury Surveillance System, Reporting Information Online. Participants: High school soccer athletes who had a thigh muscle strain. Main Outcome Measures: Injury rates of thigh muscle strains were calculated between sexes. The occurrence of the following variables during a thigh muscle injury was compared between sexes: grade level, age, level of play, event type, time of practice, time of competition, basic injury mechanism, soccer activity, player position, field location, practice type, and time of season. Results: Males had a lower injury rate of thigh muscle strains during competition than females (rate ratio = 0.66; 95% confidence interval, 0.47–0.93). No differences between sexes existed in the distribution of first-time or recurrent event characteristics. When combining sexes, recurrent strains (93%) occurred more frequently on the offensive side of the field than first-time strains (59%), P < .001. The majority of strains occurred among the varsity players (71%), during running activities (60%) and practices (58%). Conclusions: Males were less likely to sustain a thigh muscle strain during competitions, but no other differences existed between sexes. The events surrounding all thigh muscle strains may be described with some common properties. Consideration of these characteristics may assist in the development of preventive and rehabilitative programs as well as direct future research on thigh muscle strains among high school soccer players.

Pre-season Fitness Level and Injury Rate in Professional Soccer - A Prospective Study

The aim of the present study was to assess prospectively the effect of pre-season fitness on injury rate during the competitive season among professional soccer players. Thirty-one players participated in the study during two consecutive competitive seasons (2015-16 and 2016-17; a squad of 22 players in each season). During the 6-week pre-season training period (8 training sessions and a friendly match every week, 14-18 training hours/week) there was a significant improvement in VO ₂ max, a significant increase in ideal and total sprint time and no change in vertical jump, flexibility and repeated sprint-test performance decrement. During the two consecutive seasons, 28 injuries were recorded. Ten injuries were classified as mild (missing 3-7 days of practice/match), 8 as moderate (missing 8-28 days) and 10 as severe (missing >28 days). The rate of match injuries was higher (9.4 per 1000 match hours) compared to practice injuries (4.7 per 1000 training hours). Most injuries were overuse injuries (72%) of the lower limbs (71%). Most of match injuries occurred during the last 15 min of each half. There were no differences in fitness characteristics in the beginning of pre-season training between injured and non-injured players. However, improvements in VO ₂ max during the pre-season training period were significantly lower among injured players (0.9±5.5%) compared to non-injured players (10.4±6.5%, p<0.05). Our results emphasize the importance of pre-season training in professional soccer players not only for improvement in fitness but also for injury prevention during the following competitive season.

Effect of balance taping using kinesiology tape for a hamstring muscle injury and traumatic knee pain in an amateur university football player: A case report

RATIONALE

Football players are at high risk for lower extremity injuries because they turn on an axis of rotation, turn while decelerating, and repeatedly jump and land. One of the most common sites of injury is the knee.

PATIENT CONCERNS

A 25-year-old amateur university football player with pain in the knee medial area (Visual Analog Scale [VAS] score of 6/10), a hamstring muscle injury (VAS of 5/10), and a Tegner Activity Scale level of 3.

DIAGNOSES

He was diagnosed as hamstring muscle injury and traumatic knee pain.

INTERVENTIONS

Balance taping was used for 1.5 months (average, 16 h/d).

OUTCOMES

The Tegner Activity Scale level increased from 3 to 9 after balance taping, indicating increased activity ability. VAS scores for pain in the medial area of the knee and hamstring muscle during knee flexion decreased from 6 and 5 to 0 and 0, respectively. Based on these improvements, the patient was able to resume playing.

LESSONS

Balance taping is an effective treatment for football players with a hamstring muscle injury and traumatic knee pain.

The incidence of injury in elite camogie, an in-season prospective study

Background

Camogie is a stickhandling, high-velocity, multidirectional field sport for females which is native to Ireland, but is also played internationally.

Aim

To establish the incidence, nature and severity of injuries in elite camogie players.

Methods

A prospective, observational cohort study was carried out during the Provincial Championships and extending into the All-Ireland Championship until a participating team was eliminated (11 weeks). A purposive sample of 62 players from 3 of the total 11 senior intercounty teams participated to generate geographical representation. Injury data were recorded and classified by team physiotherapists using a time loss definition, consistent with consensus statements. A concurrent measure of exposure to matches and training was recorded.

Results

Twenty-one incidents of injury were recorded with 14 players injured. Injury incidence rate was 26.4 (95% CI 13.44 to 47.16) per 1000 match hours and 4.2 (95% CI 2.12 to 7.46) per 1000 training hours. There were 11 contact and 10 non-contact injuries. The lower limb accounted for 71.4% (n=15), the upper limb 9.5% (n=2) and the trunk and head 19.1% (n=4) of injuries. The main tissues injured were both muscle and ligament, representing 57.2% (n=6 each). The mean duration time loss from sport per injury was 12.14 days.

Conclusion

These results provide data on the incidence, nature and severity of camogie injuries using definitions that reflect international consensus statements. Further study of injury incidence over a full season or multiple seasons is recommended.

[Biomechanical screening for injury prevention : The importance of 3D-motion analysis in high performance sports]

Standardized clinical diagnostic procedures cannot assess the functionality of the anatomical structures in sport-specific movement. Biomechanical screening is able to detect deficits but is not sufficiently and objectively precise with the current clinical examination tools including conventional imaging techniques. The fields of use of functional testing methods are versatile and range from injury prevention analysis, screening during rehabilitation phases up to the return-to-play decision. Using simple musculoskeletal function analysis it is difficult to assess the risk of injuries. The main advantage of instrumented 3D-motion analysis is its potential to generate objective, reliable and reproducible data with exact joint angles, muscle activity, as well as loading inside the joints during movement. These marker-based motion analysis procedures are more time-consuming and more cost intensive and necessitate in particular biomechanical and medical knowledge to assess the analytical data in terms of clinical relevance. In the absence of scientific studies on biomechanical analyses in professional sports, this study shows preliminary approaches to this topic.

Effect of the 11+ injury prevention programme on fundamental movement patterns in soccer players

No studies have assessed whether changes in an individual’s fundamental movement patterns can be achieved with the 11+ prevention programme in soccer players. The aim of this study was to assess the effect of the 11+ compared with a standard warm-up on fundamental movement patterns using the Functional Movement Screen (FMS) in amateur male soccer players. Twenty-three male soccer players (age: 24.7±.3.8 years; height: 1.77±0.58 m; body mass: 73.9±6.2 kg) were randomly assigned to the 11+ (n= 12) or control (n= 11) group. The intervention programme had to be carried out 3 times a week over 6 weeks. The 11+ warm-up lasted ~25 minutes and was conducted before starting regular practice, replacing the team’s standard warm-up. The control group warmed up with standard jogging, ball exercises, and active stretching to match the duration of the 11+. Within-group analysis revealed significant improvements in the FMS total score in the 11+ (+10.51%; d= 0.83) and control group (+7.99%; d= 0.68) from pre-test to post-test. In the between-group analysis, there were no significant differences between groups. At the post-test a significantly greater number of players in the 11+ group exhibited a score that improved to above the injury threshold (≤14) (p= 0.046). This study suggests that regular implementation of the 11+ injury prevention programme may not produce additional improvements in fundamental movement patterns other than those produced by a standard warm-up.

Inferior heel pain in soccer players: a retrospective study with a proposal for guidelines of treatment

Background

The cause of heel pain among soccer players is multifactorial and is related to repetitive microtrauma due to impact forces involving technical moves, but also the playground, the exercise mode, the recovery time, the climatic conditions and the footwear used.

Aim

To investigate the aetiology of plantar heel pain of soccer players with the objective of proposing an example of guidelines for treatment.

Methods

We investigated the prevalence and characteristics of inferior heel pain of 1473 professional, semiprofessional and amateur players. All evaluated subjects were submitted to a specific rehabilitation protocol that involved advanced physical therapies and viscoelastic insoles depending on the aetiology of pain.

Results

Clinical and instrumental examinations revealed that 960 of 1473 athletes had inferior heel pain. These patients were divided into seven groups based on aetiology: sural nerve compression, abductor digiti minimi compression, atrophy and inflammation of the fat pad, plantar fasciitis, stress injury of the heel spur, stress fracture of the heel bone and heel spur. The proposed rehabilitation treatment aims for a reduction of pain and an early return to sports, with excellent results.

Conclusions

According to what was observed in the present study, related also to the specific treatment of inferior heel pain, and considering the technological progress achieved in recent years, we can now propose an integrated therapeutic approach to treatment of heel pain, properly differentiated according to specific aetiology.

Return to Play After Hip Arthroscopic Surgery for Femoroacetabular Impingement in Professional Soccer Players

BACKGROUND

Arthroscopic hip surgery has been shown to be effective in returning professional athletes back to play at a high level of performance in different sports. Limited information exists regarding professional soccer players and their return to play.

PURPOSE

To determine the rate and time to return to sport for professional soccer players after hip arthroscopic surgery for the treatment of femoroacetabular impingement (FAI) and to identify possible risk factors associated with a delay in returning to play.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Professional soccer players who underwent hip arthroscopic surgery for FAI by a single surgeon between 2005 and 2015 were evaluated. Data retrieved from www.mlssoccer.com , www.fifa.com , www.transfermarkt.co.uk , and www.wikipedia.org included information on each player's professional career, participation on the national team, length of professional career before surgery, number of appearances (games) before surgery, time between surgery and first appearance in a professional game, and number of appearances after surgery. Other data were obtained from the patient's medical records.

RESULTS

Twenty-four professional soccer players (26 hips) were included. The mean age at surgery was 25.0 ± 4.0 years (range, 19-32 years). A total of 96% of patients were able to return to play at the professional level. The mean time between surgery and the first professional game played was 9.2 months (range, 1.9-24.0 months). On average, players played in 70 games after surgery (range, 0-224). National team players were able to return to play significantly earlier than the rest of the players (median, 5.7 months vs 11.6 months, respectively; P = .018). Severe chondral damage and microfracture did not interfere with return to play.

CONCLUSION

The arthroscopic management of FAI in symptomatic professional soccer players allowed 96% of them to return to play. Players with national team experience were able to return to play earlier than those without it. Severe chondral damage and microfracture did not interfere with return to play.

Impact of a Soccer Game on Cardiac Biomarkers in Adolescent Players

PURPOSE

Biochemical markers such as cardiac troponin I (cTnI) and N-terminal pro B-type natriuretic peptide (NT-proBNP) have become indispensable tools for the diagnosis of myocardial injury, providing highly sensitive and specific information about cardiac cell damage and wall stress. The purpose of the present research was to examine the response of cardiac biomarkers to a soccer game in adolescent male soccer players.

METHODS

Twenty-two trained adolescent male soccer players (14-16 y) were selected in a purposive manner. Blood samples were taken before, immediately after, and 2 and 24 hours after the game for the determination of cTnI and NT-proBNP.

RESULTS

Serum concentration of cTnI and NT-proBNP increased immediately and 2 hours after the soccer game (P < .001). After 24 hours, the levels of cTnI dropped but remained above baseline (P = .002), whereas serum NT-proBNP levels returned to baseline. At no time point did any of the values exceed the upper reference value.

CONCLUSIONS

This is the first study to investigate the acute responses of cardiac biomarkers to a soccer game in adolescent male players. The postgame elevation of cardiac biomarkers and their rapid recovery are indicative of a physiological rather than a pathological response.

Traumatic posterior tibial artery occlusion in a soccer player: A case report

A 24-year-old male professional soccer player sustained a right ankle contusion due to blunt kick toward the medial malleolus level during a soccer game. He stopped playing due to pain, coldness, and paresthesia on his right foot. Computed tomography angiography revealed a 4.5 cm occlusion on the posterior tibial artery at the right ankle level of which the distal segment was filled with collateral arteries. After the diagnosis of the traumatic occlusion, the patient underwent angiography for recanalization with thrombolysis in an external center, which was unsuccessful. Crural artery injuries after blunt sport traumas are very rare. In knee and ankle traumas with ischemic symptoms, vascular injuries should be excluded with prompt examination.

Effects of lower extremity injuries on aerobic exercise capacity, anaerobic power, and knee isokinetic muscular function in high school soccer players

[Purpose] The study investigated the effects of lower extremity injuries on aerobic exercise capacity, anaerobic power, and knee isokinetic muscular function in high school soccer players. [Subjects and Methods] The study assessed U High School soccer players (n=40) in S area, South Korea, divided into 2 groups: a lower extremity injury group (n=16) comprising those with knee and ankle injuries and a control group (n=24) without injury. Aerobic exercise capacity, anaerobic power, and knee isokinetic muscular function were compared and analyzed. [Results] Regarding the aerobic exercise capacity test, significant differences were observed in maximal oxygen uptake and anaerobic threshold between both groups. For the anaerobic power test, no significant difference was observed in peak power and average power between the groups; however, a significant difference in fatigue index was noted. Regarding the knee isokinetic muscular test, no significant difference was noted in knee flexion, extension, and flexion/extension ratio between both groups. [Conclusion] Lower extremity injury was associated with reduced aerobic exercise capacity and a higher fatigue index with respect to anaerobic exercise capacity. Therefore, it seems necessary to establish post-injury training programs that improve aerobic and anaerobic exercise capacity for soccer players who experience lower extremity injury.

Osteoarthritis in Football

Football is currently the most popular sporting activity in the world. Multiple reports have shown that a high incidence of osteoarthritis is found in football players. Evidence clearly shows that traumatic injury significantly predisposes players for such pathophysiology. Injuries are frequent in amateur as well as professional football players, with knee and ankle accounting for the most severe injuries. Many professional athletes lose playing time due to injuries and many are forced into early retirement. Posttraumatic osteoarthritis is a common finding among ex-football players with numbers well above the normal population. Today's surgical techniques are advanced and capable of restoring the joint to a certain extent. However, a restitution ad integrum is reached only in very rare cases. Professional football players that return to play after serious injuries perform their extremely strenuous activity on morphologically compromised joints. Incomplete rehabilitation and pressure to return to play after an injurious event clearly put the athlete at an even higher risk for joint degeneration. Prevention strategies, improved surgical management, strict rehabilitation, as well as future aspects such as early suppression of inflammation, personalized medicine, and predictive genomics DNA profiling are needed to reduce incidence and improve the health perspectives of football players.

Incidence, Mechanisms, and Severity of Match-Related Collegiate Men's Soccer Injuries on FieldTurf and Natural Grass Surfaces: A 6-Year Prospective Study

BACKGROUND

Numerous injuries have been attributed to playing on artificial turf. More recently, newer generations of artificial turf have been developed to duplicate the playing characteristics of natural grass. Although artificial turf has been deemed safer than natural grass in some studies, few long-term studies have been conducted comparing match-related collegiate soccer injuries between the 2 playing surfaces.

HYPOTHESIS

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

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Male soccer athletes from 11 universities were evaluated over 6 seasons. Demographic features and predictors included player position, cleat design, player weight, turf age, and environmental factors. Outcomes of interest included injury incidence, injury category, time loss, injury mechanism and situation, type of injury, injury grade and anatomic location, injury severity, head and lower extremity trauma, and elective medical procedures. All match-related injuries were evaluated by the attending head athletic trainer and team physicians on site and subsequently in the physician's office when further follow-up and treatment were deemed necessary. In sum, 765 collegiate games were evaluated for match-related soccer injuries sustained on FieldTurf or natural grass during 6 seasons.

RESULTS

Overall, 380 team games (49.7%) were played on FieldTurf versus 385 team games (50.3%) played on natural grass. A total of 722 injuries were documented, with 268 (37.1%) occurring on FieldTurf and 454 (62.9%) on natural grass. Multivariate analysis per 10 team games indicated a significant playing surface effect: F_2,720 = 7.260, P = .001. A significantly lower total injury incidence rate (IIR) of 7.1 (95% CI, 6.6-7.5) versus 11.8 (95% CI, 11.3-12.2; P < .0001) and lower rate of substantial injuries, 0.7 (95% CI, 0.5-1.0) versus 1.9 (95% CI, 1.5-2.3; P < .03), were documented on FieldTurf versus natural grass, respectively. Analyses also indicated significantly less trauma on FieldTurf when comparing injury category, time loss, player position, injury mechanism and situation, injuries under various environmental conditions, cleat design, turf age, anatomic location, and elective medical procedures. No significant difference (F_11,710 = 0.822, P = .618) between surfaces by knee injury was observed, with the majority of knee injuries involving patellar tendinopathies/syndromes followed by medial collateral ligament injuries on both surfaces.

CONCLUSION

Although similarities existed between FieldTurf and natural grass during competitive match play, FieldTurf is, in many cases, safer than natural grass when comparing injuries in collegiate men's soccer. The findings of this study, however, may not be generalizable to other levels of competition or to other artificial surfaces.

Sports injuries in soccer according to tactical position: a retrospective survey

Abstract Introduction: In soccer, the players’ positions have been associated with specific functional overload, which may cause sports injuries. Objective: To investigate the occurrence and characterize sport injuries according to soccer player position. Methods: 232 male soccer players (129 professionals and 103 amateurs) from different sport teams in Mato Grosso do Sul, Brazil, were distributed in groups according to their soccer player position. Besides anthropometric characteristics, sports injuries were registered by using a referred morbidity survey. The occurrence of injuries was analyzed by means of the Goodman Test. Logistic regression models were used to investigate the relationship between different risk factors and the occurrence/-recurrence of sports injuries. Results: Forwards showed higher occurrence rates of sport injuries than other soccer position groups. Joint injuries in lower limbs constituted the most frequent registered cases. Muscle injuries in the back region were the most registered sports injuries among midfielders, while muscle damages in lower limbs were the primary injuries registered for other line positions. In the etiologic context, contact was the main cause of sports injuries in all groups. Most athletes (195) reported recurrence of sports injuries. Conclusion: The occurrence of sports injuries was higher among forwards. Traumatic joint and muscle injuries were the most prevalent registers in all line positions.

Anterior Cruciate Ligament Injuries in Baseball Players

PURPOSE

To determine common mechanisms of anterior cruciate ligament (ACL) injury in baseball players and to quantify the rate of return to play after primary surgical reconstruction and review intermediate clinical outcomes.

METHODS

Surgical injuries involving the ACL in youth, high school, collegiate, and professional baseball players were queried for an 11-year period (2001 to 2011). Over the study period, 42 baseball players were identified who had undergone arthroscopically assisted primary ACL reconstruction by 1 of 3 attending surgeons. Retrospective chart review was performed for all 42 patients to evaluate variables of age, level of competition, position, mechanism of injury, graft choice, and associated meniscal injuries. Twenty-six patients were reached for telephone survey and International Knee Documentation Committee questionnaire and they answered questions about their original injury and playing history.

RESULTS

The most common mechanism of injury was fielding, followed by base running. Infielders and outfielders (32% each) were the most commonly injured position, followed by pitchers (29%). Among the 32 players for whom it could be determined, 30 (94%) were able to return to playing baseball at a mean follow-up of 4.2 years (range 1.0 to 9.9 years). The mean International Knee Documentation Committee score was 84.0 (range 63 to 91). Among the 26 patients contacted for telephone interview, no one required revision ACL surgery, but 3 required a subsequent procedure for meniscal tear. Twenty-five patients (96%) denied any episodes of instability in the knee after reconstruction.

CONCLUSIONS

The overwhelming majority of baseball players that sustain ACL injuries do so while fielding or base running. Outfielders are significantly more likely than infielders to suffer ACL injuries while fielding versus base running. The results with respect to return to play are promising, as nearly all patients were able to return to baseball and none required a revision ACL surgery at a mean follow-up of 4.2 years.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Mobility, proprioception, strength and FMS as predictors of injury in professional footballers

Background

The premise of this study was to investigate if anthropometric variables such as mobility, proprioception, strength and modified Functional Movement Screen (mFMS) could be used as primary indicators of injury risk in an English Championship division football team. This study focused on moderate injuries occurring in the lower extremities, during the 2014/2015 competitive season.

Methods

To differentiate between minor, moderate and severe injuries, this study classified moderate injuries as an injury with an average injury severity of 2–28 days. This study is composed of 4 individual investigations. Each variable was assessed against 2 groups: injured (n=6) and non-injured (n=10). The 2 groups were compiled from the first team, with the criteria that each participant of this study required: full preseason assessment and injury history for the time period, 1 July 2014 to 19 March 2015. A Mann-Whitney U test (0.05% significance) was applied to statistically analyse if each variable showed any variation across the 2 groups. Effect size was estimated with Cliff's d.

Results

Strength asymmetry displayed significant difference (p=0.007), mobility, proprioception and mFMS did not (p=0.263, p=0.792 and p=0.181, respectively). Mean scores for mobility, proprioception, strength asymmetry and mFMS for injured versus non-injured players (effect size) were: 40.00 vs 38.00 (0.37), 10.33 vs 10.20 (0.10), 61.13 vs 30.40 (0.80) and 7.33 vs 8.90 (−0.4), respectively.

Conclusions

This study found no relationship between mobility/proprioception and injury risk; however, strength asymmetry was statistically significant in predicting injury and mFMS exhibited enough positive difference for recommendation of further investigation.

Injuries in professional male football players in Kosovo: a descriptive epidemiological study

BACKGROUND

The incidence and severity of football-related injuries has been found to differ strongly between professional leagues from different countries. The aims of this study were to record the incidence, type and severity of injuries in Kosovarian football players and investigate the relationship between injury incidence rates (IRs), players' age and playing positions.

METHODS

Players' age, anthropometric characteristics and playing positions, training and match exposure as well as injury occurrences were monitored in 11 teams (143 players) of Kosovo's top division during the 2013/14 season. The exact type, severity and duration of football-related injuries were documented following International Federation of Football Associations (FIFA) recommendations.

RESULTS

A total of 272 injuries were observed, with traumatic injuries accounting for 71 %. The overall injury IR was 7.38 (CI: 7.14, 7.63) injuries per 1,000 exposure hours and ~11x lower during training as opposed to matches. Strains and ruptures of thigh muscles, ligamentous injuries of the knee as well as meniscus or other cartilage tears represented the most frequent differential diagnoses. While no statistical differences were found between players engaged in different playing positions, injury IR was found to be higher by 10-13 % in younger (IR = 7.63; CI: 7.39, 7.87) as compared to middle-aged (IR = 6.95; CI: 6.41, 7.54) and older players (IR = 6.76; CI: 5.71, 8.00).

CONCLUSIONS

The total injury IR in elite football in Kosovo is slightly lower than the international average, which may be related to lesser match exposure. Typical injury patterns agree well with previously reported data. Our finding that injury IR was greater in younger players is related to a higher rate of traumatic injuries and may indicate a more aggressive and risky style of play in this age group.

Accumulated workloads and the acute:chronic workload ratio relate to injury risk in elite youth football players

Aim

The purpose of this study was to investigate the relationship between physical workload and injury risk in elite youth football players.

Methods

The workload data and injury incidence of 32 players were monitored throughout 2 seasons. Multiple regression was used to compare cumulative (1, 2, 3 and 4-weekly) loads and acute:chronic (A:C) workload ratios (acute workload divided by chronic workload) between injured and non-injured players for specific GPS and accelerometer-derived variables:total distance (TD), high-speed distance (HSD), accelerations (ACC) and total load. Workloads were classified into discrete ranges by z-scores and the relative risk was determined.

Results

A very high number of ACC (≥9254) over 3 weeks was associated with the highest significant overall (relative risk (RR)=3.84) and non-contact injury risk (RR=5.11). Non-contact injury risk was significantly increased when a high acute HSD was combined with low chronic HSD (RR=2.55), but not with high chronic HSD (RR=0.47). Contact injury risk was greatest when A:C TD and ACC ratios were very high (1.76 and 1.77, respectively) (RR=4.98).

Conclusions

In general, higher accumulated and acute workloads were associated with a greater injury risk. However, progressive increases in chronic workload may develop the players' physical tolerance to higher acute loads and resilience to injury risk.

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.

Analysis of Injury Incidences in Male Professional Adult and Elite Youth Soccer Players: A Systematic Review

CONTEXT

The incidence of injury for elite youth and professional adult soccer players is an important concern, but the risk factors for these groups are different.

OBJECTIVE

To summarize and compare the injury incidences and injury characteristics of male professional adult and elite youth soccer players.

DATA SOURCES

We searched MEDLINE and Web of Science using the search terms elite, international, European, soccer, football, injury, injuries, epidemiology, incidence, prevalence, not female, not American football, and not rugby. We also used the search terms professional for studies on professional adult soccer players and high-level, soccer academy, youth, adolescent, and young for studies on elite youth soccer players.

STUDY SELECTION

Eligible studies were published in English, had a prospective cohort design, and had a minimum study period of 6 months. To ensure that injury data were assessed in relationship to the athlete's individual exposure, we included only studies that reported on injuries and documented exposure volume.

DATA EXTRACTION

Two independent reviewers applied the selection criteria and assessed the quality of the studies.

DATA SYNTHESIS

A total of 676 studies were retrieved from the literature search. Eighteen articles met the inclusion criteria: 6 for elite youth and 12 for professional adult soccer players.

CONCLUSIONS

Injury rates were higher for matches than for training for both youth and adult players. Youth players had a higher incidence of training injuries than professionals. Efforts must be made to reduce the overall injury rate in matches. Therefore, preventive interventions, such as adequately enforcing rules and focusing on fair play, must be analyzed and developed to reduce match-related injury incidences. Reducing training injuries should be a particular focus for youth soccer players.

Five-week sensory motor training program improves functional performance and postural control in young male soccer players - A blind randomized clinical trial

Sensory motor training programs are used in the rehabilitation and prevention of injuries among soccer players. Inconsistencies are found in the literature regarding the duration of the protocols and the exercises and equipment used.

OBJECTIVE

To evaluate the benefits of a five-week sensory motor training program on the functional performance and postural control of young soccer players.

METHODS

The study sample comprised 22 young male soccer players who were evaluated using: the Figure-of-Eight Test (F8), Side Hop Test (SHT), Star Excursion Balance Test (SEBT), and a force platform. The players were randomly divided into a control group (N = 10), who continued their soccer practice sessions and an intervention group (N = 12), who continued their soccer practice sessions and were also enrolled in a supervised five-week sensory motor training program.

RESULTS

After the five-week training program, the intervention group obtained significant results in the F8, SHT and SEBT, as well as in the following parameters: area of pressure of sway center (COP), mean velocity and mean frequency of COP.

CONCLUSION

The five-week sensory motor training program, carried out with easily available and low cost equipment, was effective at improving functional performance and postural control in young soccer players.

M. J. Kerkhoffs G. Injuries, Matches Missed and the Influence of Minimum Medical Standards in the A-League Professional Football: A 5-Year Prospective Study

BACKGROUND

Epidemiological data on the occurrence of time-loss injuries over several A-League seasons remains lacking, while the effect of the mandatory implementation of 'Minimum Medical Standards' as a part of the collective bargaining agreement (CBA) needs to be explored.

OBJECTIVES

To explore the 5 year evolution of hamstring, groin, knee, ankle and total time-loss injuries among professional footballers in the A-League; to evaluate the consequences of these time-loss injuries in terms of total matches missed and costs incurred; and to explore whether the mandatory implementation of 'Minimum Medical Standards' in the A-League had led to a decrease in the occurrence of total time-loss injuries and total matches missed.

PATIENTS AND METHODS

An observational prospective study has been carried out since 2008. Data were collected weekly during the seasons 2008 - 2009 to 2012 - 2013 through official match previews/reviews, official media releases, official websites and/or self-reports by players. Total and specific (hamstring, groin, knee and ankle) numbers of time-loss injuries and matches missed were obtained for each season and the related financial costs calculated.

RESULTS

The total number of time-loss injuries and matches missed rose from 129 and 506 respectively in 2008 - 2009 to 202 and 1110 in 2010 - 2011. Following the introduction of 'Minimum Medical Standards', both categories decreased (significantly for matches missed). These time-loss injuries and matches missed led to high costs of up to AUD$ 37,317,029.29 (2012 - 2013 season). The same trend was found for knee injuries, while hamstring and ankle injuries remained almost the same. However, time-loss due to groin injuries increased despite the introduction of "Minimum Medical Standards".

CONCLUSIONS

The introduction of "Minimum Medical Standards" in the A-League had a favorable effect on the number of total, hamstring, knee and ankle injuries and on the number of matches missed due to these injuries, but not on the number of groin injuries. The costs related to time-loss injuries and related matches missed remained high.

Epidemiology of injuries in female high school soccer players

BACKGROUND

Sport is a compulsory activity in schools in South Africa. Female learners participating in soccer are more vulnerable to injuries than males.

OBJECTIVE

This study determined the epidemiology of injuries in female high school soccer players.

METHODS

A cross sectional survey captured the epidemiology of injuries in the players. The population included 200 players from 27 high schools in one district between the ages of 14 to 19 years. A self-administered questionnaire was used to collect data.

RESULTS

Only 85 scholars from 8 schools participated. From the 85 respondents, 31 (36.5%) sustained injuries. Only 61 injuries were reported by the injured players. The injury prevalence for the season was 36.5%. The rate of injury was 90 per 1000 athlete exposure hours during the season. The defenders and midfielders sustained the most injuries. Most injuries reported were contact in nature. More injuries occurred during training than during matches. The lower extremity (77.8%) was injured more than the upper extremity (22.2%). The knee (22.2%) and ankle (15.9%) were the most frequently injured body parts. Muscle injury was the most commonly reported followed by bruising.

CONCLUSION

Prevalence of injuries was high with the lower limb, specifically the knee and ankle being commonly injured.

Pubic apophysitis: a previously undescribed clinical entity of groin pain in athletes

Background

Sport-related pubalgia is often a diagnostic challenge in elite athletes. While scientific attention has focused on adults, there is little data on adolescents. Cadaveric and imaging studies identify a secondary ossification centre located along the anteromedial corner of pubis beneath the insertions of symphysial joint capsule and adductor longus tendon. Little is known about this apophysis and its response to chronic stress.

Aim

We report pubic apophysitis as a clinically relevant entity in adolescent athletes.

Methods

The clinical and imaging findings in 26 highly trained adolescent football players (15.6 years±1.3) who complained of adductor-related groin pain were reviewed. The imaging features (X-ray 26/26, US 9/26, MRI 11/26, CT 7/26) of the pubic apophyses in this symptomatic group were compared against those of a comparison group of 31 male patients (age range 9–30 years) with no known history of groin pain or pelvic trauma, who underwent pelvic CT scans for unrelated medical reasons.

Results

All symptomatic subjects presented with similar history and physical findings. The CT scans of these patients demonstrated open pubic apophyses with stress-related physeal changes (widening, asymmetry and small rounded cyst-like expansions) that were not observed in the comparison group. No comparison subject demonstrated apophyseal maturity before 21 years of age, and immaturity was seen up to the age of 26 years.

Conclusions

This retrospective case series identifies pubic apophyseal stress (or ‘apophysitis’) as an important differential consideration in the adolescent athlete who presents with groin pain.

Football injuries of the ankle: A review of injury mechanisms, diagnosis and management

Football is the most popular sport worldwide and is associated with a high injury rate, most of which are the result of trauma from player contact. Ankle injuries are among the most commonly diagnosed injuries in the game. The result is reduced physical activity and endurance levels, lost game time, and considerable medical cost. Sports medicine professionals must employ the correct diagnostic tools and effective treatments and rehabilitation protocols to minimize the impact of these injuries on the player. This review examines the diagnosis, treatment, and postoperative rehabilitation for common football injuries of the ankle based on the clinical evidence provided in the current literature.

Analysis of Jumping-Landing Manoeuvers after Different Speed Performances in Soccer Players

Purpose

Running at high speed and sudden change in direction or activity stresses the knee. Surprisingly, not many studies have investigated the effects of sprinting on knee’s kinetics and kinematics of soccer players. Hence, this study is aimed to investigate indices of injury risk factors of jumping-landing maneuvers performed immediately after sprinting in male soccer players.

Methods

Twenty-three collegiate male soccer players (22.1±1.7 years) were tested in four conditions; vertical jump (VJ), vertical jump immediately after slow running (VJSR), vertical jump immediately after sprinting (VJFR) and double horizontal jump immediately after sprinting (HJFR). The kinematics and kinetics data were measured using Vicon motion analyzer (100Hz) and two Kistler force platforms (1000Hz), respectively.

Results

For knee flexion joint angle, (p = 0.014, η = 0.15) and knee valgus moment (p = 0.001, η = 0.71) differences between condition in the landing phase were found. For knee valgus joint angle, a main effect between legs in the jumping phase was found (p = 0.006, η = 0.31), which suggests bilateral deficit existed between the right and left lower limbs.

Conclusion

In brief, the important findings were greater knee valgus moment and less knee flexion joint angle proceeding sprint (HJFR & VJFR) rather than no sprint condition (VJ) present an increased risk for knee injuries. These results seem to suggest that running and sudden subsequent jumping-landing activity experienced during playing soccer may negatively change the knee valgus moment. Thus, sprinting preceding a jump task may increase knee risk factors such as moment and knee flexion joint angle.

Sports injuries profile of a first division Brazilian soccer team: a descriptive cohort study

Objective:

To establish the injury profile of soccer players from a first division Brazilian soccer team. In addition, we investigated the association between the characteristics of the injuries and the player's age and position.

Method:

Forty-eight players from a Brazilian first division soccer team were followed during one season. Descriptive statistics were used to characterize the injury profile. Spearman's tests were used to verify the association between the number and severity of injuries and the player's age. Chi-square test was used to verify the association between type of injury and player's position. Fisher's exact test was used to verify the association between the severity of injuries and player's position.

Results:

The incidence of injuries was 42.84/1000 hours in matches and 2.40/1000 hours in training. The injury severity was 19.5±34.4 days off competition or training. Lower limb was the most common location of injury and most injuries were muscular/tendinous, overuse, non-recurrent, and non-contact injuries. Player's age correlated with the amount and severity of muscle and tendon injuries. Defenders had more minimal injuries (1-3 days lost), while forwards had more moderate (8-28 days lost) and severe injuries (>28 days lost). Furthermore, wingbacks had more muscle and tendon injuries, while midfielders had more joint and ligament injuries.

Conclusion:

The injury profile of the Brazilian players investigated in this study reflected regional differences in soccer practices. Results confirm the influence of the player's age and position on the soccer injuries profile.

Relation between performance in side bridge and injuries in amateur soccer

AbstractIntroduction Central instability is associated with insufficient endurance and strength of the stabilizer muscles, and it can lead to muscle imbalance and injuries.Objective Relate side bridge performance with the presence of injuries in amateur soccer athletes.Materials and methods A cross-sectional study with a sample of 188 male athletes, aged between 11 and 17 years. To identify the injuries, a questionnaire developed by researchers was applied and the players’ clinical records were reviewed. The time of the side bridge test was used to identify muscle imbalance. For statistical analysis, the following tests were used: chi-square test; Pearson’s chi-square test; Fisher’s exact test; Yates’s correction for continuity; two-way ANOVA; one-way ANOVA; and t-test. The significance level (α) of 5% was adopted.Results Injuries were reported by 59.6% of the athletes: sprain (31.3%); muscle strain (28.6%) and fracture; luxation and subluxation (19.6%) were the most frequently reported injuries. Athletes that reported any injury corresponded to 73.2% of the sample. The presence of injuries was not associated with muscle imbalance (p = 0.565), as it prevailed in athletes with both balance (64%) and imbalance (58%). Injury type and prevalence were not significant when compared with the presence of imbalance (p > 0.05).Final considerations No significant relation between muscle imbalance and injury was observed in the studied sample.

Core stability training on lower limb balance strength

This study aimed to assess the effects of core stability training on lower limbs' muscular asymmetries and imbalances in team sport. Twenty footballers were divided into two groups, either core stability or control group. Before each daily practice, core stability group (n = 10) performed a core stability training programme, while control group (n = 10) did a standard warm-up. The effects of the core stability training programme were assessed by performing isokinetic tests and single-leg countermovement jumps. Significant improvement was found for knee extensors peak torque at 3.14 rad · s(-1) (14%; P < 0.05), knee flexors peak torque at 1.05 and 3.14 rad · s(-1) (19% and 22% with P < 0.01 and P < 0.01, respectively) and peak torque flexors/extensors ratios at 1.05 and 3.14 rad · s(-1) (7.7% and 8.5% with P < 0.05 and P < 0.05, respectively) only in the core stability group. The jump tests showed a significant reduction in the strength asymmetries in core stability group (-71.4%; P = 0.02) while a concurrent increase was seen in the control group (33.3%; P < 0.05). This study provides practical evidence in combining core exercises for optimal lower limbs strength balance development in young soccer players.

Injury characteristics in the German professional male soccer leagues after a shortened winter break

CONTEXT

The winter break in the top 2 German professional soccer leagues was shortened from 6.5 to 3.5 weeks in the 2009-2010 season.

OBJECTIVE

To investigate whether this change affected injury characteristics by comparing the second half of the 2008-2009 (long winter break) with the equivalent period in the 2009-2010 season (short winter break).

DESIGN

Prospective cohort study.

SETTING

German male professional soccer leagues.

PATIENTS OR OTHER PARTICIPANTS

Seven professional German male soccer teams (184 players in the 2008-2009 season, 188 players in the 2009-2010 season).

MAIN OUTCOME MEASURE(S)

Injury incidences and injury characteristics (cause of injury, location, severity, type, diagnosis), including their monthly distribution, were recorded.

RESULTS

A total of 300 time-loss injuries (2008-2009 n = 151, 2009-2010 n = 149) occurred. The overall injury incidence per 1000 soccer hours was 5.90 (95% confidence interval = 5.03, 6.82) in 2008-2009 and 6.55 (5.58, 7.69) in 2009-2010. Match injuries per 1000 hours were 31.5 (25.0, 38.0) in the first season and 26.5 (20.2, 32.7) in the second season; the corresponding training values were 2.67 (2.08-3.44) and 3.98 (3.19-4.95), respectively. The training injury incidence (incidence rate ratio = 1.49 [95% confidence interval = 1.07, 2.08], P = .02) and the risk of sustaining a knee injury (incidence rate ratio = 1.66 [1.00, 2.76], P = .049) were higher in 2009-2010 after the short winter break; the incidence of moderate and severe injuries (time loss >7 days) trended higher (incidence rate ratio = 1.34 [0.96, 1.86], P = .09).

CONCLUSIONS

Shortening the winter break from 6.5 to 3.5 weeks did not change the overall injury incidence; however, a higher number of training, knee, and possibly more severe injuries (time loss >7 days) occurred.

Quality of functional movement patterns and injury examination in elite-level male professional football players

The purpose of this study is to examine the quality of functional movement patterns among one of Hungary's first league soccer clubs, where the elite male football players (N = 20) utilize the well-established Functional Movement Screen™ (FMS) system; a comprehensive functional program designed to determine and identify the quality of movement and the greatest risk factors for non-contact injuries. Furthermore, an additional purpose of this program is to examine injuries over the course of 6 competitive months. Focusing on the mechanisms of injuries and their causes in the lower extremities during this period is one of the key objectives. Over the course of 6 months we found significant differences between ankle injuries and the FMS Hurdle Step exercise (p < 0.05), and the FMS Deep Squat exercise and knee and hip injuries (p < 0.05). The FMS pre-screening system found lower limb asymmetry present in 40% of the participants. The authors believe that the importance of preventative measures and structural sport specific pre-screening cannot be overemphasized, and that there is a growing need for further transparent research in this field in order to be more effective with regard to programs dedicated to injury prevention and the enhancement players' physical performance.

The preventive effect of the nordic hamstring exercise on hamstring injuries in amateur soccer players: a randomized controlled trial

BACKGROUND

Hamstring injuries are the most common muscle injuries in soccer, and they have a high rate of recurrence. Eccentric hamstrings strength is recognized as an important modifiable risk factor. This led to the development of prevention exercises such as the nordic hamstring exercise (NHE). The effectiveness of the NHE on hamstring injury prevention has never been investigated in amateur soccer.

PURPOSE

To investigate the preventive effect of the NHE on the incidence and severity of hamstring injuries in male amateur soccer players.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

Male amateur soccer players (age, mean ± SD, 24.5 ± 3.8 years) from 40 teams were randomly allocated to an intervention (n = 20 teams, 292 players) or control group (n = 20 teams, 287 players). The intervention group was instructed to perform 25 sessions of NHE in a 13-week period. Both the intervention and control groups performed regular soccer training and were followed for hamstring injury incidence and severity during the 2013 calendar year. At baseline, personal characteristics (eg, age, injury history, field position) were gathered from all participants via a questionnaire. Primary outcome was injury incidence. Secondary outcomes were injury severity and compliance with the intervention protocol.

RESULTS

A total of 38 hamstring injuries were recorded, affecting 36 of 579 players (6.2%). The overall injury incidence rate was 0.7 (95% CI, 0.6-0.8) per 1000 player hours, 0.33 (95% CI, 0.25-0.46) in training, and 1.2 (95% CI, 0.82-1.94) in matches. Injury incidence rates were significantly different between the intervention (0.25; 95% CI, 0.19-0.35) and control groups (0.8; 95% CI, 0.61-1.15), χ(2)(1, n = 579) = 7.865; P = .005. The risk for hamstring injuries was reduced in the intervention group compared with the control group (odds ratio, 0.282; 95% CI, 0.110-0.721) and was statistically significant (P = .005). No statistically significant differences were identified between the intervention and control groups regarding injury severity. Compliance with the intervention protocol was 91%.

CONCLUSION

Incorporating the NHE protocol in regular amateur training significantly reduces hamstring injury incidence, but it does not reduce hamstring injury severity. Compliance with the intervention was excellent.