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  • 1.
    Bahr, Roald
    et al.
    Norwegian School Sport Science, Norway; Orthopaed and Sports Medical Hospital, Qatar.
    Thorborg, Kristian
    Copenhagen University Hospital, Denmark; Copenhagen University Hospital, Denmark.
    Ekstrand, Jan
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Evidence-based hamstring injury prevention is not adopted by the majority of Champions League or Norwegian Premier League football teams: the Nordic Hamstring survey2015In: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 49, no 22Article in journal (Refereed)
    Abstract [en]

    Background The Nordic hamstring (NH) exercise programme was introduced in 2001 and has been shown to reduce the risk of acute hamstring injuries in football by at least 50%. Despite this, the rate of hamstring injuries has not decreased over the past decade in male elite football. Aim To examine the implementation of the NH exercise programme at the highest level of male football in Europe, the UEFA Champions League (UCL), and to compare this to the Norwegian Premier League, Tippeligaen, where the pioneer research on the NH programme was conducted. Design Retrospective survey. Setting/participants 50 professional football teams, 32 from the UCL and 18 from Tippeligaen. Methods A questionnaire, based on the Reach, Efficacy, Adoption, Implementation and Maintenance framework, addressing key issues related to the implementation of the NH programme during three seasons from 2012 through 2014, was distributed to team medical staff using electronic survey software. Results The response rate was 100%. Of the 150 club-seasons covered by the study, the NH programme was completed in full in 16 (10.7%) and in part in an additional 9 (6%) seasons. Consequently, 125 (83.3%) club-seasons were classified as non-compliant. There was no difference in compliance between the UCL and Tippeligaen in any season (chi(2): 0.41 to 0.52). Conclusions Adoption and implementation of the NH exercise programme at the highest levels of male football in Europe is low; too low to expect any overall effect on acute hamstring injury rates.

  • 2.
    Bak, K
    et al.
    Linkoping Univ Hosp, Dept Orthopaed Surg, Div Sports Traumatol, S-58185 Linkoping, Sweden Gentofte Hosp, Dept Orthopaed Surg, Div Sports Traumatol, Copenhagen, Denmark.
    Jorgensen, U
    Linkoping Univ Hosp, Dept Orthopaed Surg, Div Sports Traumatol, S-58185 Linkoping, Sweden Gentofte Hosp, Dept Orthopaed Surg, Div Sports Traumatol, Copenhagen, Denmark.
    Ekstrand, Jan
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Division of Preventive and Social Medicine and Public Health Science.
    Scavenius, M
    Linkoping Univ Hosp, Dept Orthopaed Surg, Div Sports Traumatol, S-58185 Linkoping, Sweden Gentofte Hosp, Dept Orthopaed Surg, Div Sports Traumatol, Copenhagen, Denmark.
    Reconstruction of anterior cruciate ligament deficient knees in soccer players with an iliotibial band autograft - A prospective study of 132 reconstructed knees followed for 4 (2-7) years2001In: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, E-ISSN 1600-0838, Vol. 11, no 1, p. 16-22Article in journal (Refereed)
    Abstract [en]

    One hundred and thirty-two consecutive soccer players (117 males and 15 females, median age 23, range 16-39 years) underwent primary reconstruction of the anterior cruciate ligament (ACL) with an iliotibial band (ITB) autograft. AU patients were followed prospectively for a minimum of 2 years. One hundred and eighteen patients (89%) attended an independent observer follow-up after a median of 47 (24-92) months. The time before participating in soccer was a median of 7 (5-24) months. At a median of 4 years, 80 (68%) mere still active soccer players, while 38 had changed activity to a lower level. Twenty-five gave up soccer playing for reasons unrelated to the knee, and 13 (11%) gave up due to problems from the reconstructed knee. The Lysholm score improved from a median of 82 (range 42-99, mean [SD] 80.5 [+/-11.9]) points prior to the operation to a median of 99 (range 57-100, mean [SD] 94.6 [+/-8.5]) at followup. The Tegner score improved from a median of 3.5 (0-7) preoperatively to 9 (1-10), Four patients (3%) sustained a rupture of the graft: three ruptures occurred among the 15 females (20%), and one was seen among the 117 males (0.8%) (P=0.01). Eight per cent had predominantly minor cosmetic complaints from the donor-site hernia, while 51% had temporary discomfort from the staples used for graft fixation. Using the ITB autograft for ACL reconstruction, we found excellent and good results in soccer players with ACL deficiency and high demands for optimal knee function. The failure rate in general was comparable with other methods, and the majority was still active in soccer sports at a median of 4 years after surgery, An unacceptably high rerupture rate was registered in female players.

  • 3.
    Bengtsson, Hakan
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Health Sciences.
    Ekstrand, Jan
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Health Sciences.
    Waldén, Markus
    Linköping University, Department of Medical and Health Sciences, Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Hägglund, Martin
    Linköping University, Department of Medical and Health Sciences, Division of Physiotherapy. Linköping University, Faculty of Health Sciences.
    Match Injury Rates in Professional Soccer Vary With Match Result, Match Venue, and Type of Competition2013In: American Journal of Sports Medicine, ISSN 0363-5465, E-ISSN 1552-3365, Vol. 41, no 7, p. 1505-1510Article in journal (Refereed)
    Abstract [en]

    Background: Player activities in soccer matches are influenced by the match result and match venue. It is not known whether injury rates are influenced by these factors. Purpose: To investigate whether there are associations between injury rates and the match result, venue, and type of competition in male soccer. Study Design: Cohort study; Level of evidence, 3. Methods: Twenty-six professional clubs from 10 countries were followed prospectively during 9 seasons (2001-2002 to 2009-2010). All matches, and injuries occurring in these matches, were registered by the teams medical staff. An injury was registered if it resulted in player absence from training or matches. Information about match result, venue, and type of competition for all reported matches was gathered by the authors from online databases. Injury rates in matches with varying match characteristics were compared by use of generalized estimating equations. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Results: A total of 2738 injuries during 6010 matches were registered. There were no associations between odds of 1 injury occurrence and match result or type of competition, whereas the odds were decreased in matches played away compared with home matches (OR, 0.89; 95% CI, 0.80-0.99). The odds of 2 or more injury occurrences in a match were increased in matches resulting in a draw (OR, 1.39; 95% CI, 1.15-1.69) or loss (OR, 1.66; 95% CI, 1.38-1.98) compared with matches won and were decreased in other cup matches compared with league matches (OR, 0.57; 95% CI, 0.39-0.84) and in matches played away compared with home matches (OR, 0.70; 95% CI, 0.60-0.82). Finally, injuries with more than 1 weeks absence occurred more frequently in Champions League matches compared with league matches both for matches with 1 injury (OR, 1.26; 95% CI, 1.09-1.45) and matches with 2 or more injuries (OR, 1.57; 95% CI, 1.13-2.20). Conclusion: The odds of 2 or more injury occurrences in professional soccer were higher in matches resulting in a loss or a draw compared with a win, whereas the odds of injury occurrences were lower in matches played away compared with home matches. The rate of moderate and severe injuries increased with the importance of the match.

  • 4.
    Bengtsson, Håkan
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Physiotherapy. Linköping University, Faculty of Health Sciences.
    Ekstrand, Jan
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Health Sciences.
    Hägglund, Martin
    Linköping University, Department of Medical and Health Sciences, Division of Physiotherapy. Linköping University, Faculty of Health Sciences.
    Muscle injury rates in professional football increase with fixture congestion: an 11-year follow-up of the UEFA Champions League injury study2013In: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 47, no 12, p. 743-747Article in journal (Refereed)
    Abstract [en]

    Background The influence of fixture congestion on injury rates and team performance has only been scarcely investigated.

    Aim To study associations between recovery time and match load and injury rates and team performance in professional football.

    Methods Exposure and time loss injuries were registered prospectively from 27 teams over 11 seasons. Matches were grouped according to recovery days before each match (≤3 vs >3 days, and ≤4 vs ≥6 days). Injury rates and team performance were compared between groups. Match load in match sequences containing five consecutive matches was determined by the number of days separating the first match and the last training session during that match sequence. Linear regression was used to study associations between match load and injury rates and team performance.

    Results Team performance showed no association with match load, or recovery days prior to matches, except for Europa League matches that indicated more matches lost with short recovery (≤3 days) (p=0.048). Total injury rates and muscle injury rates were increased in league matches with ≤4 days compared with ≥6 days’ recovery (RR 1.09, 95% CI 1.00 to 1.18, and RR 1.32, 95% CI 1.15 to 1.51, respectively), specifically hamstring and quadriceps injuries. High match load was associated with increase in muscle injury rate in matches in the same match sequence (p=0.012), and increase in ligament injury rate in training in the subsequent match sequence (p=0.003).

    Conclusions Fixture congestion was associated with increased muscle injury rates but had no, or very limited, influence on team performance.

  • 5.
    Bjorneboe, John
    et al.
    Norwegian School Sport Science, Norway.
    Kristensson, Karolina
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Waldén, Markus
    Linköping University, Department of Medical and Health Sciences, Division of Physiotherapy. Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Bengtsson, Håkan
    Linköping University, Department of Medical and Health Sciences, Division of Physiotherapy. Linköping University, Faculty of Medicine and Health Sciences.
    Ekstrand, Jan
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Hägglund, Martin
    Linköping University, Department of Medical and Health Sciences, Division of Physiotherapy. Linköping University, Faculty of Medicine and Health Sciences.
    Ronsen, Ola
    Aker Solut, Norway.
    Einar Andersen, Thor
    Norwegian School Sport Science, Norway.
    Role of illness in male professional football: not a major contributor to time loss2016In: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 50, no 11, p. 699-702Article in journal (Refereed)
    Abstract [en]

    Background There are limited data on the nature, type and incidence of illness in football. Previous studies indicate that gastrointestinal and respiratory tract illnesses are most common. Aim To describe the incidence and burden of illness in male professional football. Methods Over the 4-year study period, 2011-2014, 73 professional football teams in Europe participated, with a total of 1 261 367 player-days recorded. All time-loss illnesses were recorded by the medical staff of each club. A recordable illness episode was any physical or psychological symptom (not related to injury) that resulted in the player being unable to participate fully in training or match play. Results A total of 1914 illness episodes were recorded. The illness incidence was 1.5 per 1000 player-days, meaning that, on average, a player experienced an illness episode every second season, with a median of 3 days absence per illness episode. Severe illness (absence amp;gt;4 weeks) constituted 2% of all illnesses. Respiratory tract illness was the most common (58%), followed by gastrointestinal illness (38%). Respiratory tract illness, gastrointestinal illness and cardiovascular illness caused the highest illness burden. Conclusions The illness incidence among male professional football players is low compared with the injury incidence. We found that the highest illness burden was caused by illness to the respiratory tract, gastrointestinal tract and cardiovascular system.

  • 6.
    Ekstrand, Jan
    Linköping University, Department of Medical and Health Sciences, Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    A 94% return to elite level football after ACL surgery: a proof of possibilities with optimal caretaking or a sign of knee abuse? in KNEE SURGERY SPORTS TRAUMATOLOGY ARTHROSCOPY2011In: Knee Surgery, Sports Traumatology, Arthroscopy, ISSN 0942-2056, E-ISSN 1433-7347, Vol. 19, no 1, p. 1-2Article in journal (Other academic)
  • 7.
    Ekstrand, Jan
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Medicine and Health Sciences. UEFA Injury Study Lead Expert, Linkoping, Sweden.
    Editorial Material: Preventing injuries in professional football: thinking bigger and working together in BRITISH JOURNAL OF SPORTS MEDICINE, vol 50, issue 12, pp 709-+2016In: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 50, no 12, p. 709-710Article in journal (Other academic)
    Abstract [en]

    n/a

  • 8.
    Ekstrand, Jan
    Linköping University, Department of Medicine and Health Sciences, Division of Preventive and Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Epidemiology of football injuries2008In: Science & sports, ISSN 0765-1597, E-ISSN 1778-4131, Vol. 23, no 2, p. 73-77Article in journal (Refereed)
    Abstract [en]

    Aim

    The overall aim of this on-going injury study is to increase the safety in football.

    Study design

    Prospective cohort survey

    Methods.

    The study population consisted of two cohorts: The UEFA Champions League (UCL) cohort and the Swedish Superleague cohort. The UEFA Champions League (UCL) cohort with 17 teams from 9 countries was followed over five consecutive seasons (2001 to 2006). The Swedish Super-league with 14 teams was followed for two full consecutive seasons (2001 and 2002). Exposure for training and matches in the club and in national teams was registered in minutes for each player. The team doctor reported all injuries causing the player to miss at least one match or training session. The study follows the consensus on methods for studies on football injuries agreed upon by FIFA and UEFA.

    Results.

    Totally 6300 injuries have been registered during 800.000 hours of exposure. The incidence of injury at top level football is 6-9 injuries/1000 hours of total exposure (3-5 injuries/1000 training hours and 24-30 injuries/1000 matchhours). As a mean, a team of 25 players can expect 40-50 injuries per season, half of them causing absence less than a week but 6-p of them causing absence more than a month. The risk of injury has not increased during the 5-year period. Thigh muscle injury is the most common injury at top level with an injury incidence of 1.6/1000 hours of exposure, which means that a team can expect 10 such injuries each season.  The risk of ankle sprain has been reduced by 50%, probably due to the thorough knowledge in top-level teams about optimal treatment and prevention. A correlation has been found between major injuries (causing absence > 4 weeks) and performance. There is a considerable variation in the number of matches played per season in European professional leagues. Top level players are obliged to play many matches, especially during the final period of the season. A correlation was found between many matches at the end of a season and  an increased injury risk and/or underperformance during subsequent world tournaments

    Conclusion

    The injury risk has not increased in male professional football during recent years.  At elite level, the risk of ankle sprain has been lowered and thigh muscle strain is the most common injury. A period with a congested match calendar can lead to fatigue, increasing the risk of injury and poor performance during the following period.

     

  • 9.
    Ekstrand, Jan
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Health Sciences.
    Keeping your top players on the pitch: the key to football medicine at a professional level2013In: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 47, no 12, p. 723-724Article in journal (Refereed)
    Abstract [en]

    n/a

  • 10.
    Ekstrand, Jan
    Linköping University, Department of Medical and Health Sciences, Division of Preventive and Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Playing too Many Matches is Negative for both Performance and Player Availability - Results from the On-Going UEFA Injury Study2013In: Deutsche Zeitschrift für Sportmedizin, ISSN 0344-5925, Vol. 64, no 1, p. 5-9Article, review/survey (Refereed)
    Abstract [en]

    Objective: To present some results from the on-going survey on male professional football players in Europe, the UEFA Champions League (UCL) injury study. Methods: A total of 27 clubs from ten countries and 1500 players have been followed prospectively during eleven seasons between 2001 and 2012. The design harmonizes with the FIFA-UEFA consensus statement on injury definitions and data collection procedures. Results: In total, 8000 time-loss injuries were recorded. The mean incidence of injury at top level football is 3-5 injuries per 1000 training hours and 25 per 1000 match hours. On average, a team of 25 players can expect about 50 injuries each season. The injury risk has not increased during the eleven year period. The injury risk varies between countries in Europe with a higher risk of ACL (anterior cruciate ligament) injuries but less overall injury risk in countries with a Mediterranean climate. Hamstring muscle injury is the most common single injury Radiological grading by MRI or ultrasonography is associated with lay-off times. Seventy per cent of hamstring injuries seen in professional football are of radiological grade 0 or 1, meaning no fibre disruption on imaging but still cause the majority of absence days. Almost all male top level footballers with ACL injuries return to full football play, but it takes 6-7 months. Stress fractures are not common in footballers but take long time to heal. The injury risk is similar when playing on football turf as when playing on natural grass. Playing too many matches is negative for both performance and player availability

  • 11.
    Ekstrand, Jan
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Health Sciences.
    Askling, Carl
    Swedish School Sport and Health Science, Sweden .
    Magnusson, Henrik
    Linköping University, Department of Medical and Health Sciences, Division of Physiotherapy. Linköping University, Faculty of Health Sciences.
    Mithoefer, Kai
    Harvard University, MA USA .
    Return to play after thigh muscle injury in elite football players: implementation and validation of the Munich muscle injury classification2013In: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 47, no 12, p. 769-774Article in journal (Refereed)
    Abstract [en]

    Background Owing to the complexity and heterogeneity of muscle injuries, a generally accepted classification system is still lacking. less thanbrgreater than less thanbrgreater thanAims To prospectively implement and validate a novel muscle injury classification and to evaluate its predictive value for return to professional football. less thanbrgreater than less thanbrgreater thanMethods The recently described Munich muscle injury classification was prospectively evaluated in 31 European professional male football teams during the 2011/2012 season. Thigh muscle injury types were recorded by team medical staff and correlated to individual player exposure and resultant time-loss. less thanbrgreater than less thanbrgreater thanResults In total, 393 thigh muscle injuries occurred. The muscle classification system was well received with a 100% response rate. Two-thirds of thigh muscle injuries were classified as structural and were associated with longer lay-off times compared to functional muscle disorders (pandlt;0.001). Significant differences were observed between structural injury subgroups (minor partial, moderate partial and complete injuries) with increasing lay-off time associated with more severe structural injury. Median lay-off time of functional disorders was 5-8 days without significant differences between subgroups. There was no significant difference in the absence time between anterior and posterior thigh injuries. less thanbrgreater than less thanbrgreater thanConclusions The Munich muscle classification demonstrates a positive prognostic validity for return to play after thigh muscle injury in professional male football players. Structural injuries are associated with longer average lay-off times than functional muscle disorders. Subclassification of structural injuries correlates with return to play, while subgrouping of functional disorders shows less prognostic relevance. Functional disorders are often underestimated clinically and require further systematic study.

  • 12.
    Ekstrand, Jan
    et al.
    Linköping University, Department of Medical and Health Sciences, Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Healy, Jeremiah C
    University of London Imperial Coll Science Technology and Med.
    Waldén, Markus
    Linköping University, Department of Medical and Health Sciences, Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Lee, Justin C
    University of London Imperial Coll Science Technology and Med.
    English, Bryan
    University of London.
    Hägglund, Martin
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medical and Health Sciences, Division of Physiotherapy.
    Hamstring muscle injuries in professional football: the correlation of MRI findings with return to play2012In: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 46, no 2, p. 112-117Article in journal (Refereed)
    Abstract [en]

    Background Hamstring injury is the single most common injury in professional football. MRI is commonly used to confirm the diagnosis and provide a prognosis of lay-off time. less thanbrgreater than less thanbrgreater thanObjective To evaluate the use of MRI as a prognostic tool for lay-off after hamstring injuries in professional football players and to study the association between MRI findings and injury circumstances. less thanbrgreater than less thanbrgreater thanMethods Prospective cohort study where 23 European professional teams, were followed between 2007 and 2011. Team medical staffs recorded individual player exposure and time-loss injuries. Radiological grading was performed using a modified Peetrons classification into four grades where grades 2 and 3 represent fibre disruption. less thanbrgreater than less thanbrgreater thanResults In total, 516 hamstring injuries occurred and 58% of these were examined by MRI. Thirteen per cent were grade 0 injuries, 57% grade 1, 27% of grade 2 and 3% of grade 3. Grade 0 and 1 injuries accounted for 56% (2141/3830 days) of the total lay-off. The layoff time differed between all four radiological grades of injury (8 +/- 3, 17 +/- 10, 22 +/- 11 and 73 +/- 60 days, p andlt; 0.0001). Eighty-three per cent of injuries affected the biceps femoris while 11% and 5% occurred to the semimembranosus and semitendinosus, respectively. Re-injuries (N=34/207) constituted 16% of injuries. All re-injuries occurred to the biceps femoris. less thanbrgreater than less thanbrgreater thanConclusion MRI can be helpful in verifying the diagnosis of a hamstring injury and to prognosticate layoff time. Radiological grading is associated with lay-off times after injury. Seventy per cent of hamstring injuries seen in professional football are of radiological grade 0 or 1, meaning no signs of fibre disruption on MRI, but still cause the majority of absence days.

  • 13.
    Ekstrand, Jan
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Preventive and Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Hägglund, Martin
    Linköping University, Department of Medical and Health Sciences, Physiotherapy. Linköping University, Faculty of Health Sciences.
    Fuller, C.W
    Centre for Sports Medicine, University of Nottingham, UK.
    Comparison of injuries sustained on artificial turf and grass by male and female elite football players. 2011In: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, E-ISSN 1600-0838, Vol. 21, no 6, p. 824-832Article in journal (Refereed)
    Abstract [en]

    The objective of this study was to compare incidences and patterns of injury for female and male elite teams when playing football on artificial turf and grass. Twenty teams (15 male, 5 female) playing home matches on third-generation artificial turf were followed prospectively; their injury risk when playing on artificial turf pitches was compared with the risk when playing on grass. Individual exposure, injuries (time loss) and injury severity were recorded by the team medical staff. In total, 2105 injuries were recorded during 246 000 h of exposure to football. Seventy-one percent of the injuries were traumatic and 29% overuse injuries. There were no significant differences in the nature of overuse injuries recorded on artificial turf and grass for either men or women. The incidence (injuries/1000 player-hours) of acute (traumatic) injuries did not differ significantly between artificial turf and grass, for men (match 22.4 v 21.7; RR 1.0 (95% CI 0.9–1.2); training 3.5 v 3.5; RR 1.0 (0.8–1.2)) or women [match 14.9 v 12.5; RR 1.2 (0.8–1.8); training 2.9 v 2.8; RR 1.0 (0.6–1.7)]. During matches, men were less likely to sustain a quadriceps strain (P=0.031) and more likely to sustain an ankle sprain (P=0.040) on artificial turf.

  • 14.
    Ekstrand, Jan
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Health Sciences.
    Hägglund, Martin
    Linköping University, Department of Medical and Health Sciences, Division of Physiotherapy. Linköping University, Faculty of Health Sciences.
    Kristenson, Karolina
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Health Sciences.
    Magnusson, Henrik
    Linköping University, Department of Medical and Health Sciences, Division of Physiotherapy. Linköping University, Faculty of Health Sciences.
    Walden, Markus
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Health Sciences.
    Fewer ligament injuries but no preventive effect on muscle injuries and severe injuries: an 11-year follow-up of the UEFA Champions League injury study2013In: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 47, no 12, p. 732-+Article in journal (Refereed)
    Abstract [en]

    Background less thanbrgreater than less thanbrgreater thanLimited information is available on the variation in injury rates over multiple seasons of professional football. less thanbrgreater than less thanbrgreater thanAim less thanbrgreater than less thanbrgreater thanTo analyse time-trends in injury characteristics of male professional football players over 11 consecutive seasons. less thanbrgreater than less thanbrgreater thanMethods less thanbrgreater than less thanbrgreater thanA total of 1743 players comprising 27 teams from 10 countries were followed prospectively between 2001 and 2012. Team medical staff recorded individual player exposure and time loss injuries. less thanbrgreater than less thanbrgreater thanResults less thanbrgreater than less thanbrgreater thanA total of 8029 time loss injuries were recorded. The match unavailability due to injury was 14% and constant over the study period. On average, a player sustained two injuries per season, resulting in approximately 50 injuries per team and season. The ligament injury rate decreased during the study period (R-2=0.608, b=-0.040, 95% CI -0.065 to -0.016, p=0.005), whereas the rate of muscle injury (R-2=0.228, b=-0.013, 95% CI -0.032 to 0.005, p=0.138) and severe injury (R-2=0.141, b=0.015, 95% CI -0.013 to 0.043, p=0.255) did not change over the study period. In addition, no changes in injury rates over the 11-year period were found for either training (R-2=0.000, b=0.000, 95% CI -0.035 to 0.034, p=0.988) or match play (R-2=0.282, b=-0.015, 95% CI -0.032 to 0.003, p=0.093). less thanbrgreater than less thanbrgreater thanConclusions less thanbrgreater than less thanbrgreater thanThe injury rate has decreased for ligament injuries over the last 11years, but overall training, match injury rates and the rates of muscle injury and severe injury remain high.

  • 15.
    Ekstrand, Jan
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Health Sciences.
    Hägglund, Martin
    Linköping University, Department of Medical and Health Sciences, Division of Physiotherapy. Linköping University, Faculty of Health Sciences.
    Tornqvist, Henrik
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Health Sciences.
    Kristenson, Karolina
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Health Sciences.
    Bengtsson, Håkan
    Linköping University, Department of Electrical Engineering, Electronic Devices. Linköping University, The Institute of Technology.
    Magnusson, Henrik
    Linköping University, Department of Medical and Health Sciences, Division of Physiotherapy. Linköping University, Faculty of Health Sciences.
    Waldén, Markus
    Linköping University, Department of Medical and Health Sciences, Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Upper extremity injuries in male elite football players2013In: Knee Surgery, Sports Traumatology, Arthroscopy, ISSN 0942-2056, E-ISSN 1433-7347, Vol. 21, no 7, p. 1626-1632Article in journal (Refereed)
    Abstract [en]

    To investigate the epidemiology of upper extremity injuries in male elite football players and to describe their characteristics, incidence and lay-off times. less thanbrgreater than less thanbrgreater thanBetween 2001 and 2011, 57 male European elite football teams (2,914 players and 6,215 player seasons) were followed prospectively. Time-loss injuries and exposure to training and matches were recorded on individual basis. less thanbrgreater than less thanbrgreater thanIn total, 11,750 injuries were recorded, 355 (3 %) of those affected the upper extremities giving an incidence of 0.23 injuries/1,000 h of football. The incidence in match play was almost 7 times higher than in training (0.83 vs. 0.12 injuries/1,000 h, rate ratio 6.7, 95 % confidence interval 5.5-8.3). As much as 32 % of traumatic match injuries occurred as a result of foul play situations. Goalkeepers had a significantly higher incidence of upper extremity injuries compared to outfield players (0.80 vs. 0.16 injuries/1,000 h, rate ratio 5.0, 95 % confidence interval 4.0-6.2). The average absence due to an upper extremity injury was 23 +/- A 34 days. less thanbrgreater than less thanbrgreater thanUpper extremity injuries are uncommon among male elite football players. Goalkeepers, however, are prone to upper extremity injury, with a five times higher incidence compared to outfield players. less thanbrgreater than less thanbrgreater thanII.

  • 16.
    Ekstrand, Jan
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Preventive and Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Hägglund, Martin
    Linköping University, Department of Medical and Health Sciences, Physiotherapy. Linköping University, Faculty of Health Sciences.
    Waldén, Markus
    Linköping University, Department of Medical and Health Sciences, Division of Preventive and Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Epidemiology of Muscle Injuries in Professional Football (Soccer)2011In: American Journal of Sports Medicine, ISSN 0363-5465, E-ISSN 1552-3365, Vol. 39, no 6, p. 1226-1232Article in journal (Refereed)
    Abstract [en]

    Background: Muscle injuries constitute a large percentage of all injuries in football.

    Purpose: To investigate the incidence and nature of muscle injuries in male professional footballers.

    Study Design: Cohort study; Level of evidence, 2.

    Methods: Fifty-one football teams, comprising 2299 players, were followed prospectively during the years 2001 to 2009. Team medical staff recorded individual player exposure and time-loss injuries. The first-team squads of 24 clubs selected by the Union of European Football Associations as belonging to the best European teams, 15 teams of the Swedish First League, and another 15 European teams playing their home matches on artificial turf pitches were included. A muscle injury was defined as “a traumatic distraction or overuse injury to the muscle leading to a player being unable to fully participate in training or match play.”

    Results: In total, 2908 muscle injuries were registered. On average, a player sustained 0.6 muscle injuries per season. A squad of 25 players can thus expect about 15 muscle injuries per season. Muscle injuries constituted 31% of all injuries and caused 27% of the total injury absence. Ninety-two percent of all muscle injuries affected the 4 major muscle groups of the lower limbs: hamstrings (37%), adductors (23%), quadriceps (19%), and calf muscles (13%). Sixteen percent of the muscle injuries were reinjuries. These reinjuries caused significantly longer absences than did index injuries. The incidence of muscle injury increased with age. When separated into different muscle groups, however, an increased incidence with age was found only for calf muscle injuries and not for hamstring, quadriceps, or hip/groin strains.

    Conclusion: Muscle injuries are a substantial problem for players and their clubs. They constitute almost one third of all time-loss injuries in men’s professional football, and 92% of all injuries affect the 4 big muscle groups in the lower limbs.

  • 17.
    Ekstrand, Jan
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Preventive and Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Hägglund, Martin
    Linköping University, Department of Medical and Health Sciences, Physiotherapy. Linköping University, Faculty of Health Sciences.
    Waldén, Markus
    Linköping University, Department of Medical and Health Sciences, Division of Preventive and Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Injury incidence and injury patterns in professional football - the UEFA injury study2011In: British journal of sports medicine, ISSN 1473-0480, Vol. 45, no 7, p. 553-558Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE: To study the injury characteristics in professional football and to follow the variation of injury incidence during a match, during a season and over consecutive seasons. DESIGN: Prospective cohort study where teams were followed for seven consecutive seasons. Team medical staff recorded individual player exposure and time-loss injuries from 2001 to 2008. SETTING: European professional men's football. PARTICIPANTS: The first team squads of 23 teams selected by UEFA as belonging to the 50 best European teams. Main outcome measurement: Injury incidence. RESULTS: 4,483 injuries occurred during 566,000 hours of exposure, giving an injury incidence of 8.0 injuries/1,000 hours. The injury incidence during matches was higher than in training (27.5 v 4.1, p<0.0001). A player sustained on average 2.0 injuries per season and a team with typically 25 players can thus expect about 50 injuries each season. The single most common injury subtype was thigh strain, representing 17% of all injuries. Re-injuries constituted 12% of all injuries and they caused longer absences than non re-injuries (24 v 18 days, p<0.0001). The incidence of match injuries showed an increasing injury tendency over time in both the first and second halves (p<0.0001). Traumatic injuries and hamstring strains were more frequent during the competitive season, while overuse injuries were common during the pre-season. Training and match injury incidences were stable over the period with no significant differences between seasons. CONCLUSIONS: The training and match injury incidences were stable over seven seasons. The risk of injury increased with time in each half of matches.

  • 18.
    Ekstrand, Jan
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Department of Health and Society, Division of Preventive and Social Medicine and Public Health Science.
    Karlsson, J
    The risk for injury in football. There is a need for a consensus about definition of the injury and the design of studies2003In: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, E-ISSN 1600-0838, Vol. 13, no 3, p. 147-149Article in journal (Refereed)
    Abstract [en]

    [No abstract available]

  • 19.
    Ekstrand, Jan
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Lee, Justin C.
    University of London Imperial Coll Science Technology and Med, England.
    Healy, Jeremiah C.
    University of London Imperial Coll Science Technology and Med, England.
    MRI findings and return to play in football: a prospective analysis of 255 hamstring injuries in the UEFA Elite Club Injury Study2016In: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 50, no 12, p. 738-743Article in journal (Refereed)
    Abstract [en]

    Aim The present study evaluated whether the MRI parameters of hamstring injuries in male professional football players correlate with time to return to play (RTP). Methods 46 elite European football teams were followed prospectively for hamstring injuries between 2007 and 2014. Club medical staff recorded individual player exposure and time-loss after hamstring injury. MRI parameters were evaluated by two independent radiologists and correlated with the RTP data. Results A total of 255 grade 1 and 2 injuries were evaluated in this study. RTP was longer for grade 2 than grade 1 injuries (24 +/- 13, 95% CI 21 to 26 days vs 18 +/- 15, 95% CI 16 to 20 days; mean difference: 6, 95% CI 2 to 9 days, p=0.004, d=0.39). 84% of injuries affected the biceps femoris (BF) muscle, whereas 12% and 4% affected the semimembranosus (SM) and semitendinosus (ST), respectively. No difference in lay-off time was found for injuries to the three different muscles (BF 20 +/- 15 days, SM 18 +/- 11 days, ST 23 +/- 14 days; p=0.83). The recurrence rate was higher for BF injuries than for SM and ST injuries combined (18% vs 2%, p=0.009). The size of the oedema weakly correlated with time to RTP (r(2)=6-12%). No correlation was found between location of injury and time to RTP. The majority of the intramuscular injuries affected the MT junction (56% in grade 1 and 2 injuries), but no difference in lay-off time was found between the different types of injuries. Conclusions The radiological grade and size of the oedema correlate with time to RTP for both, grade 1 and 2 injuries. No correlations were found between time to RTP and the location and type of injury.

  • 20.
    Ekstrand, Jan
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Lundqvist, Daniel
    Linköping University, Department of Behavioural Sciences and Learning, Education and Sociology. Linköping University, Faculty of Arts and Sciences. Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Lagerbäck, Lars
    Linköping University.
    Vouillamoz, Marc
    UEFA, Switzerland.
    Papadimitiou, Niki
    UEFA, Switzerland.
    Karlsson, Jon
    Linköping University. Gothenburg University, Gothenburg, Sweden.
    Is there a correlation between coaches leadership styles and injuries in elite football teams?: A study of 36 elite teams in 17 countries2018In: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 52, no 8, p. 527-531Article in journal (Refereed)
    Abstract [en]

    Background Do coaches’ leadership styles affect injury rates and the availability of players in professional football? Certain types of leadership behaviour may cause stress and have a negative impact on players’ health and well-being.

    Aim To investigate the transformational leadership styles of head coaches in elite men’s football and to evaluate the correlation between leadership styles, injury rates and players’ availability.

    Methods Medical staff from 36 elite football clubs in 17 European countries produced 77 reports at four postseason meetings with a view to assessing their perception of the type of leadership exhibited by the head coaches of their respective teams using the Global Transformational Leadership scale. At the same time, they also recorded details of individual players’ exposure to football and time-loss injuries.

    Results There was a negative correlation between the overall level of transformational leadership and the incidence of severe injuries (rho=−0.248; n=77; p=0.030); high levels of transformational leadership were associated with smaller numbers of severe injuries. Global Transformational Leadership only explained 6% of variation in the incidence of severe injuries (r2=0.062). The incidence of severe injuries was lower at clubs where coaches communicated a clear and positive vision, supported staff members and gave players encouragement and recognition. Players’ attendance rates at training were higher in teams where coaches gave encouragement and recognition to staff members, encouraged innovative thinking, fostered trust and cooperation and acted as role models.

    Conclusions There is an association between injury rates and players’ availability and the leadership style of the head coach.

  • 21.
    Ekstrand, Jan
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Division of Preventive and Social Medicine and Public Health Science.
    Ringborg, S
    Hlth Univ, Linkoping, Sweden.
    Surgery versus conservative treatment in soccer players with chronic groin pain: A prospective randomised study in soccer players2001In: European journal of sports traumatology and related research (Testo stampato), ISSN 1592-3894, E-ISSN 1720-836X, Vol. 23, no 4, p. 141-145Article in journal (Refereed)
    Abstract [en]

    J. Ekstrand, and S Ringborg: Surgery versus conservative treatment in soccer players with chronic groin pain: A prospective randomised study in soccer players. Eur.J. Sports Traumatol. rel, res. 23:141-145,2001. We compared surgery with conservative treatment in 66 soccer players with chronic groin pain and verified pathology in the form of incipient hernia at hemiography and/or positive nerve block test of the ilioinguinal or iliohypogastric nerves. The patients were randomised into 4 groups: surgery, individual training, physiotherapy and controls. All were evaluated preoperatively and postoperatively at 3 and 6 months using a Visual Analogue Scale (VAS) regarding pain on coughing, jogging, sprinting, kicking and sit-ups. The patients in the non-surgery groups were offered crossover to surgery after 3-6 months if their symptoms persisted. The control-group in our study did not show any change in their symptoms during the six-month follow-up period. This would imp v that expectation alone does not help these patients since the chronic groin pain did not disappear spontaneously. Conventional conservative treatment had little or no effect on the symptoms. Neither individual training nor treatment with NSAID and physiotherapy had effect on the pain apart from a minor decrease in pain on jogging, sprinting and kicking at 3 months. At 6 months there was no difference in any variable between the controls and the groups who received conservative treatment. The patients who underwent surgery had significantly less pain in all variables throughout the follow-up period. The superiority of surgery over conservative or no treatment was further emphasised in the crossover test. (C)2001, Editrice Kurtis.

  • 22.
    Ekstrand, Jan
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medical and Health Sciences, Social Medicine and Public Health Science.
    Timpka, Toomas
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medical and Health Sciences, Social Medicine and Public Health Science.
    Hägglund, Martin
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medical and Health Sciences, Division of Physiotherapy.
    Risk of injury in elite football played on artificial turf versus natural grass: a prospective two-cohort study.2006In: British journal of sports medicine, ISSN 1473-0480, Vol. 40, no 12, p. 975-80Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE: To compare injury risk in elite football played on artificial turf compared with natural grass.

    DESIGN: Prospective two-cohort study.

    SETTING: Male European elite football leagues.

    PARTICIPANTS: 290 players from 10 elite European clubs that had installed third-generation artificial turf surfaces in 2003-4, and 202 players from the Swedish Premier League acting as a control group.

    MAIN OUTCOME MEASURE: Injury incidence.

    RESULTS: The incidence of injury during training and match play did not differ between surfaces for the teams in the artificial turf cohort: 2.42 v 2.94 injuries/1000 training hours and 19.60 v 21.48 injuries/1000 match hours for artificial turf and grass respectively. The risk of ankle sprain was increased in matches on artificial turf compared with grass (4.83 v 2.66 injuries/1000 match hours; rate ratio 1.81, 95% confidence interval 1.00 to 3.28). No difference in injury severity was seen between surfaces. Compared with the control cohort who played home games on natural grass, teams in the artificial turf cohort had a lower injury incidence during match play (15.26 v 23.08 injuries/1000 match hours; rate ratio 0.66, 95% confidence interval 0.48 to 0.91).

    CONCLUSIONS: No evidence of a greater risk of injury was found when football was played on artificial turf compared with natural grass. The higher incidence of ankle sprain on artificial turf warrants further attention, although this result should be interpreted with caution as the number of ankle sprains was low.

  • 23.
    Ekstrand, Jan
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Preventive and Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Torstveit, M. K.
    University of Agder.
    Stress fractures in elite male football players2012In: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, E-ISSN 1600-0838, Vol. 22, no 3, p. 341-346Article in journal (Refereed)
    Abstract [en]

    The objective was to investigate the incidence, type and distribution of stress fractures in professional male football players. Fifty-four football teams, comprising 2379 players, were followed prospectively for 189 team seasons during the years 2001–2009. Team medical staff recorded individual player exposure and time-loss injuries. The first team squads of 24 clubs selected by UEFA as belonging to the 50 best European teams, 15 teams of the Swedish Super League and 15 teams playing their home matches on artificial turf pitches were included. In total, 51 stress fractures occurred during 1 180 000 h of exposure, giving an injury incidence of 0.04 injuries/1000 h. A team of 25 players can therefore expect one stress fracture every third season. All fractures affected the lower extremities and 78% the fifth metatarsal bone. Stress fractures to the fifth metatarsal bone, tibia or pelvis caused absences of 3–5 months. Twenty-nine percent of the stress fractures were re-injuries. Players that sustained stress fractures were significantly younger than those that did not. Stress fractures are rare in men's professional football but cause long absences. Younger age and intensive pre-season training appear to be risk factors.

  • 24.
    Ekstrand, Jan
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Health Sciences.
    van Dijk, Niek C.
    University of Amsterdam, Netherlands .
    Fifth metatarsal fractures among male professional footballers: a potential career-ending disease2013In: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 47, no 12, p. 754-+Article in journal (Refereed)
    Abstract [en]

    Background less thanbrgreater than less thanbrgreater thanThere is little information about Metatarsal Five (MT-5) fractures for specific sports. less thanbrgreater than less thanbrgreater thanObjective less thanbrgreater than less thanbrgreater thanTo study the occurrence, the imaging characteristics, the lay-off times and healing problems of MT-5 fractures among male footballers. less thanbrgreater than less thanbrgreater thanMethods less thanbrgreater than less thanbrgreater thanSixty-four European elite teams were monitored from 2001 to 2012. x-Rays were collected and classified by the Torg criteria. less thanbrgreater than less thanbrgreater thanResults less thanbrgreater than less thanbrgreater thanOf 13754 injuries, 0.5% (67) proved to be MT-5 fractures. Their incidence was 0.04 injuries/1000h of exposure. A team of 25 players might thus expect an MT-5 fracture every fifth season. Of these fractures, 67% (38) were primary and 33% were refractures. One of the 38 primary fractures was an avulsion of the tuberosity; all the others (97%) located towards the base. In total, 32% of the players with MT-5 fracture were younger than 21years, 40% of the fractures occurred during the preseason and 45% of the players had prodromal symptoms. In total, 54% of the initial x-rays were classified as Torg type II (stress fractures), and 46% were classified as Torg type I (acute type). After surgical treatment the fractures healed faster, compared with conservative treatment (75% vs 33%, pandlt;0.05). There was no significant difference in lay-off days between players that had been operated, and those that had not (80 vs 74days, p=0.67). less thanbrgreater than less thanbrgreater thanConclusions less thanbrgreater than less thanbrgreater thanThe majority of MT-5 fractures are stress fractures, and mainly occur among young players. There are frequent healing problems, which might be explained by the stress nature of the injury. After surgery there are less healing problems, compared with those in conservative treatment.

  • 25.
    Ekstrand, Jan
    et al.
    Linköping University, Department of Medicine and Health Sciences, Division of Preventive and Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Waldén, Markus
    Linköping University, Department of Medicine and Health Sciences, Division of Preventive and Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Hägglund, Martin
    Linköping University, Department of Medicine and Health Sciences, Division of Preventive and Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    A congested football calendar and the wellbeing of players: The correlation between exposure to match play for football players in European clubs during the months prior to the World Cup 2002 and the injuries and performance of these players during the World Cup2004In: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 38, p. 493-497Article in journal (Refereed)
    Abstract [en]

    Abstract

    Objectives: To investigate the correlation between exposure to match play for football players in European clubs during the months prior to the World Cup 2002 and the injuries and performance of these players during the World Cup.

    Methods: The team doctors at eleven of the best football clubs in Europe prospectively recorded player’s exposure and injuries during the 2001-2002 season (July 2001-May 2002). Sixty-five  players  participated in the World Cup in Korea/Japan (June 2002). During the World Cup, the clubs reported injuries sustained by these players, and their performance was evaluated by three international experts.

    Results: The number of  team matches during the season varied between 40 and 76 for the different countries involved. The individual player had a mean of 36 matches during the season. Top players played more matches, especially during the final period of the season. Players that participated in the World Cup (WC players) played more matches during the season compared to players who did not participate in the World Cup (46 vs 33 matches).

    WC players did not show an increased risk for injury during the season. Twenty-nine per cent of the WC players incurred injuries during the World Cup and 32% performed below their normal standard. The players who under-performed in the World Cup played more matches during the 10 weeks prior to the World Cup compared to those who performed better than expected (12.5 vs 9, p< 0.05). Twenty-three (60%) of the 38 players who had played more than 1 match/week prior to the World Cup incurred injuries or underperformed during the World Cup.

    Conclusions: There is a considerable variation in the number of matches played per season in European professional leagues. Top-level players are obliged to play many matches especially during the final period of the season.

  • 26.
    Ekstrand, Jan
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Medicine and Health Sciences. UEFA Medical Comm, Switzerland.
    Waldén, Markus
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Hägglund, Martin
    Linköping University, Department of Medical and Health Sciences, Division of Physiotherapy. Linköping University, Faculty of Medicine and Health Sciences.
    Hamstring injuries have increased by 4% annually in mens professional football, since 2001: a 13-year longitudinal analysis of the UEFA Elite Club injury study2016In: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 50, no 12, p. 731-737Article in journal (Refereed)
    Abstract [en]

    Background There are limited data on hamstring injury rates over time in football. Aim To analyse time trends in hamstring injury rates in male professional footballers over 13 consecutive seasons and to distinguish the relative contribution of training and match injuries. Methods 36 clubs from 12 European countries were followed between 2001 and 2014. Team medical staff recorded individual player exposure and time-loss injuries. Injuries per 1000 h were compared as a rate ratio (RR) with 95% CI. Injury burden was the number of lay off days per 1000 h. Seasonal trend for injury was analysed using linear regression. Results A total of 1614 hamstring injuries were recorded; 22% of players sustained at least one hamstring injury during a season. The overall hamstring injury rate over the 13-year period was 1.20 injuries per 1000 h; the match injury rate (4.77) being 9 times higher than the training injury rate (0.51; RR 9.4; 95% CI 8.5 to 10.4). The time-trend analysis showed an annual average 2.3% year on year increase in the total hamstring injury rate over the 13-year period (R-2=0.431, b=0.023, 95% CI 0.006 to 0.041, p=0.015). This increase over time was most pronounced for training injuries-these increased by 4.0% per year (R-2=0.450, b=0.040, 95% CI 0.011 to 0.070, p=0.012). The average hamstring injury burden was 19.7 days per 1000 h (annual average increase 4.1%) (R-2=0.437, b=0.041, 95% CI 0.010 to 0.072, p=0.014). Conclusions Training-related hamstring injury rates have increased substantially since 2001 but match-related injury rates have remained stable. The challenge is for clubs to reduce training-related hamstring injury rates without impairing match performance.

  • 27.
    Ekstrand, Jan
    et al.
    Linköping University, Department of Medicine and Health Sciences, Division of Preventive and Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Waldén, Markus
    Linköping University, Department of Medicine and Health Sciences, Division of Preventive and Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Hägglund, Martin
    Linköping University, Department of Medicine and Health Sciences, Division of Preventive and Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Risk for injury when playing in a national football team.2004In: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, E-ISSN 1600-0838, Vol. 14, no 1, p. 34-38Article in journal (Refereed)
    Abstract [en]

    The Swedish male senior national football team was followed prospectively between 1991 and 1997. During these 6 years, the team played 73 official matches and had three training camps. The senior author (J. E.) attended 57 of these matches and the three training camps and these matches and training camps, are included in the present study. Exposure to football was recorded individually for each player. The team physician examined all injuries. Total exposure was 7245 h (6235 training and 1010 match hours) and there were 71 injuries (40 training and 31 match injuries). Five (16%) of the match injuries were major, with more than 4 weeks of absence from football. The injury incidence during training was 6.5/1000 h and the injury risk during matchplay was 30.3/1000 h. A significantly higher injury incidence was found for matches lost compared to matches won or drawn (52.5 vs. 22.7/1000 h, P=0.026). No statistically significant difference for injury was found between competitive matches and friendly matches. No difference was found between home and away matches or matches on neutral ground. The risk for injury when playing in a national team compares with previously reported figures for professional football at a high level.

  • 28.
    Fuller, Colin W
    et al.
    University of Nottingham.
    Ekstrand, Jan
    Linköping University, Department of Medicine and Health Sciences, Division of Preventive and Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Junge, Astrid
    FIFA-Medical Assessment and Research Centre.
    Andersen, Thor E
    Oslo Sports Trauma Research Center.
    Bahr, Roald
    Oslo Sports Trauma Research Center.
    Dvorak, Jiri
    FIFA-Medical Assessment and Research Centre.
    Hägglund, Martin
    Linköping University, Department of Medicine and Health Sciences, Division of Preventive and Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    McCrory, Paul
    University of Melbourne.
    Meeuwisse, Willem H
    University of Calgary.
    Consensus statement on injury definitions and data collection procedures in studies of football (soccer) injuries.2006In: Clinical Journal of Sports Medicine, ISSN 1050-642X, E-ISSN 1536-3724, Vol. 16, no 2, p. 97-106Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Variations in definitions and methodologies have created differences in the results and conclusions obtained from studies of football (soccer) injuries; this has made interstudy comparisons difficult. PROCEDURE: An Injury Consensus Group was established under the auspices of Fédération Internationale de Football Association Medical Assessment and Research Centre. Using a nominal group consensus model approach, a working document that identified the key issues related to definitions, methodology, and implementation was discussed by members of the group during a 2-day meeting. After this meeting, iterative draft statements were prepared and circulated to the members of the group for comment before the final consensus statement was produced. RESULTS: Definitions of injury, recurrent injury, severity, and training and match exposures in football, together with criteria for classifying injuries in terms of location, type, diagnosis, and causation are proposed. Proforma for recording players' baseline information, injuries, and training and match exposures are presented. Recommendations are made on how the incidence of match and training injuries should be reported and a checklist of issues and information that should be included in published reports of studies of football injuries is presented. CONCLUSIONS: The definitions and methodology proposed in the consensus statement will ensure that consistent and comparable results will be obtained from studies of football injuries.

  • 29.
    Fuller, C.W.
    et al.
    Centre for Sports Medicine, University of Nottingham, Nottingham, United Kingdom, Centre for Sports Medicine, University of Nottingham, Nottingham NG7 2UH, United Kingdom.
    Ekstrand, Jan
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Division of Preventive and Social Medicine and Public Health Science.
    Junge, A.
    FIFA-Medical Assessment and Research Centre, Schulthess Clinic, Zurich, Switzerland.
    Andersen, T.E.
    Oslo Sports Trauma Research Center, Oslo, Norway.
    Bahr, R.
    Oslo Sports Trauma Research Center, Oslo, Norway.
    Dvorak, J.
    FIFA-Medical Assessment and Research Centre, Schulthess Clinic, Zurich, Switzerland.
    Hagglund, M.
    McCrory, P.
    Centre for Health, Exercise and Sports Medicine, University of Melbourne, Melbourne, Vic., Australia.
    Meeuwisse, W.H.
    Sport Injury Prevention Research Centre, University of Calgary, Calgary, Alta., Canada.
    Consensus statement on injury definitions and data collection procedures in studies of football (soccer) injuries2006In: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, E-ISSN 1600-0838, Vol. 16, no 2, p. 83-92Article, review/survey (Refereed)
    Abstract [en]

    Variations in definitions and methodologies have created differences in the results and conclusions obtained from studies of football injuries, this has made inter-study comparisons difficult. An Injury Consensus Group was established under the auspices of FIFA Medical Assessment and Research Centre. Using a nominal group consensus model approach, a working document that identified the key issues related to definitions, methodology and implementation was discussed by members of the group during a 2-day meeting. Following this meeting, iterative draft statements were prepared and circulated to members of the group for comment before the final consensus statement was produced. Definitions of injury, recurrent injury, severity and training and match exposures in football together with criteria for classifying injuries in terms of location, type, diagnosis and causation are proposed. Proforma for recording players' baseline information, injuries and training and match exposures are presented. Recommendations are made on how the incidence of match and training injuries should be reported and a checklist of issues and information that should be included in published reports of studies of football injuries is presented. The definitions and methodology proposed in the consensus statement will ensure that consistent and comparable results will be obtained from studies of football injuries. Copyright © Blackwell Munksgaard 2006.

  • 30.
    Fuller, C.W.
    et al.
    Centre for Sports Medicine, University of Nottingham, Nottingham NG7 2UH, United Kingdom.
    Ekstrand, Jan
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Division of Preventive and Social Medicine and Public Health Science.
    Junge, A.
    FIFA Medical Assessment and Research Centre, Schulthess Clinic, Zurich, Switzerland.
    Andersen, T.E.
    Oslo Sports Trauma Research Center, Oslo, Norway.
    Bahr, R.
    Oslo Sports Trauma Research Center, Oslo, Norway.
    Dvorak, J.
    FIFA Medical Assessment and Research Centre, Schulthess Clinic, Zurich, Switzerland.
    Hagglund, M.
    McCrory, P.
    Centre for Health, Exercise and Sports Medicine, University of Melbourne, Melbourne, Vic., Australia.
    Meeuwisse, W.H.
    Sport Injury Prevention Research Centre, University of Calgary, Calgary, Alta., Canada.
    Consensus statement on injury definitions and data collection procedures in studies of football (soccer) injuries2006In: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 40, no 3, p. 193-201Article, review/survey (Refereed)
    Abstract [en]

    Variations in definitions and methodologies have created differences in the results and conclusions obtained from studies of football (soccer) injuries, making interstudy comparisons difficult. Therefore an Injury Consensus Group was established under the auspices of Federation Internationale de Football Association Medical Assessment and Research Centre. A nominal group consensus model approach was used. A working document on definitions, methodology, and implementation was discussed by the group. Iterative draft statements were prepared and circulated to members of the group for comment before the final consensus statement was produced. Definitions of injury, recurrent injury, severity, and training and match exposures in football together with criteria for classifying injuries in terms of location, type, diagnosis, and causation are proposed. Proforma for recording players' baseline information, injuries, and training and match exposures are presented. Recommendations are made on how the incidence of match and training injuries should be reported and a checklist of issues and information that should be included in published reports of studies of football injuries is presented.

  • 31.
    Gajhede-Knudsen, Mariann
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Health Sciences.
    Ekstrand, Jan
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Health Sciences.
    Magnusson, Henrik
    Linköping University, Department of Medical and Health Sciences, Division of Physiotherapy. Linköping University, Faculty of Health Sciences.
    Maffulli, Nicola
    University of Salerno, Italy .
    Recurrence of Achilles tendon injuries in elite male football players is more common after early return to play: an 11-year follow-up of the UEFA Champions League injury study2013In: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 47, no 12, p. 763-768Article in journal (Refereed)
    Abstract [en]

    Background There is limited information about Achilles tendon disorders in professional football. less thanbrgreater than less thanbrgreater thanAims To investigate the incidence, injury circumstances, lay-off times and reinjury rates of Achilles tendon disorders in male professional football. less thanbrgreater than less thanbrgreater thanMethods A total of 27 clubs from 10 countries and 1743 players have been followed prospectively during 11 seasons between 2001 and 2012. The team medical staff recorded individual player exposure and time-loss injuries. less thanbrgreater than less thanbrgreater thanResults A total of 203 (2.5% of all injuries) Achilles tendon disorders were registered. A majority (96%) of the disorders were tendinopathies, and nine were partial or total ruptures. A higher injury rate was found during the preseason compared with the competitive season, 0.25 vs 0.18/1000 h (rate ratio (RR) 1.4, 95% CI 1.1 to 2.0; p=0.027). The mean lay-off time for Achilles tendinopathies was 23 +/- 37 (median=10, Q(1)=4 and Q(3)=24) days, while a rupture of the Achilles tendon, on average, caused 161 +/- 65 (median=169, Q(1)=110 and Q(3)=189) days of absence. Players with Achilles tendon disorders were significantly older than the rest of the cohort, with a mean age of 27.2 +/- 4 years vs 25.6 +/- 4.6 years (pandlt;0.001). 27% of all Achilles tendinopathies were reinjuries. A higher reinjury risk was found after short recovery periods (31%) compared with longer recovery periods (13%) (RR 2.4, 95% CI 2.1 to 2.8; pandlt;0.001). less thanbrgreater than less thanbrgreater thanConclusions Achilles tendon disorders account for 3.8% of the total lay-off time and are more common in older players. Recurrence is common after Achilles tendinopathies and the reinjury risk is higher after short recovery periods.

  • 32.
    Gouttebarge, Vincent
    et al.
    ACES, Academic Medical Center, Amsterdam / Amsterdam Collaboration for Health and Safety in Sports / Dept. of Orthopaedic Surgery, Academic Medical Center, Amsterdam / World Players Union, Hoofddorp .
    Aoki, Haruhito
    St. Marianna University School of Medicine, Kawasaki, Japan.
    Ekstrand, Jan
    Linköping University, Faculty of Medicine and Health Sciences. Linköping University, Department of Medical and Health Sciences, Division of Community Medicine.
    Verhagen, Evert A L M
    Amsterdam Collaboration for Health and Safety in Sports / Dept. of Public and Occupational Health, VU, University Medical Center, Amsterdam.
    Kerkhoffs, Gino M M J
    ACES, Academic Medical Center, Amsterdam / Amsterdam Collaboration for Health and Safety in Sports / Dept. of Orthopaedic Surgery, Academic Medical Center, Amsterdam .
    Are severe musculoskeletal injuries associated with symptoms of common mental disorders among male European professional footballers?2016In: Knee Surgery, Sports Traumatology, Arthroscopy, ISSN 0942-2056, E-ISSN 1433-7347, Vol. 24, no 12, p. 3934-3942Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To explore the associations of severe musculoskeletal injuries (joint and muscles) and surgeries with symptoms of common mental disorders (distress, anxiety/depression, sleeping disturbance, adverse alcohol behaviour , smoking, adverse nutrition behaviour) among male European professional footballers.

    METHODS: Cross-sectional analyses were conducted on electronic questionnaires completed by professional footballers recruited from the national players' unions of Finland, France, Norway, Spain or Sweden. The number of severe (time loss of more than 28 days) musculoskeletal injuries (total, joint, muscle) and surgeries during a professional football career was examined through four questions, while symptoms of common mental disorders were evaluated through validated scales.

    RESULTS: A total of 540 professional footballers (mean age of 27 years; 54 % playing in the highest leagues) participated in the study. Sixty-eight per cent of the participants had already incurred one or more severe joint injuries and 60 % one or more severe muscle injuries. Prevalence of symptoms of common mental disorders ranged from 3 % for smoking to 37 % for anxiety/depression and 58 % for adverse nutrition behaviour. The number of severe musculoskeletal injuries during a football career was positively correlated with distress, anxiety and sleeping disturbance, while the number of surgeries was correlated with adverse alcohol behaviour and smoking. Professional footballers who had sustained one or more severe musculoskeletal injuries during their career were two to nearly four times more likely to report symptoms of common mental disorders than professional footballers who had not suffered from severe musculoskeletal injuries.

    CONCLUSION: It can be concluded that the number of severe musculoskeletal injuries and surgeries during a career is positively correlated and associated with symptoms of common mental disorders among male European professional footballers. This study emphasises the importance of applying a multidisciplinary approach to the clinical care and support of professional footballers, especially when a player faces lengthy periods without training and competition as a consequence of recurrent severe joint or muscle injuries.

    LEVEL OF EVIDENCE: III.

  • 33.
    Hagglund, Martin
    et al.
    Linköping University, Department of Medicine and Health Sciences, Division of Preventive and Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Waldén, Marcus
    Linköping University, Department of Medicine and Health Sciences, Division of Preventive and Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Ekstrand, Jan
    Linköping University, Department of Medicine and Health Sciences, Division of Preventive and Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    UEFA injury study-an injury audit of European Championships 2006 to 20082009In: BRITISH JOURNAL OF SPORTS MEDICINE, ISSN 0306-3674, Vol. 43, no 7, p. 483-489Article in journal (Refereed)
    Abstract [en]

    Objective: To study the incidence and nature of injuries at European Championships, to compare training and match injury characteristics and to study differences in injury incidence between tournaments. Design: Team physicians prospectively recorded individual player exposure and time loss injuries during 12 European Championships (mens EURO n = 1, mens Under-21 n = 2, mens Under-19 n = 3, mens Under-17 n = 3, womens Under-19 n = 3) from 2006 to 2008. Setting: International football tournaments Participants: 1594 men and 433 women Main outcome measurement: Injury incidence Results: 224 injuries (45 training, 179 match play) were registered among 208 (10%) players. No differences in training injury incidence were seen between tournaments (range 1.3-3.9 injuries/1000 hours). The mens EURO had the highest match injury incidence (41.6 injuries/1000 hours) followed by the mens Under-21 tournaments (33.9). The lowest match injury incidence was seen in the womens Under-19 tournaments (20.5). Training injuries constituted 20% of all injuries and caused 26% of all match unavailability. A greater proportion of match injuries were due to trauma (83 vs 47%, p less than 0.001) and occurred from player contact (75 vs 48%, p = 0.018) compared to training injuries. A higher frequency of reinjury was found among training injuries than match injuries (20 vs 6%, p = 0.009). Conclusions: Match injury incidence increased with age, indicating greater risk with higher intensity of play. Training injury incidence was relatively low, but training injuries were responsible for a quarter of all match unavailability and may thus have a profound impact on team performance and should be the object of preventive measures.

  • 34.
    Hallen, Anna
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Health Sciences.
    Ekstrand, Jan
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Health Sciences.
    Return to play following muscle injuries in professional footballers2014In: Journal of Sports Sciences, ISSN 0264-0414, E-ISSN 1466-447X, Vol. 32, no 13, p. 1229-1236Article in journal (Refereed)
    Abstract [en]

    This prospective cohort study described return-to-play (RTP) data for different types of muscle injuries in male elite-level football players in Europe. Eighty-nine European professional teams were followed between 2001 and 2013. Team medical staff recorded individual player exposure and time-loss injuries. A total of 17,371 injuries occurred, including 5603 (32%) muscle injuries. From 2007, we received results from 386 magnetic resonance imaging (MRI) examinations, and radiological grading was performed. A negative MRI was associated with shorter recovery time (6 +/- 7 days). Lay-off days were correlated with MRI grading of thigh muscle injuries (P less than 0.001). Among hamstring injuries, 83% occurred to the biceps femoris, 12% affected the semimembranosus and 5% the semitendinosus. Recurrence rate was higher among biceps femoris injuries (18%) compared with semitendinosus and semimembranosus injuries (2% together). Groin muscle injuries caused shorter median absence (9 days) than hamstring (13 days; P less than 0.001), quadriceps (12 days; P less than 0.001) and calf muscle (13 days; P less than 0.001) injuries. Overall, we found that MRI was valuable for prognosticating RTP, with radiological grading associated with lay-off times after injury. Re-injuries were common in biceps femoris injuries but rare in semitendinosus and semimembranosus injuries.

  • 35.
    Hägglund, Martin
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Physiotherapy. Linköping University, Faculty of Health Sciences.
    Walden, Markus
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Health Sciences.
    Magnusson, Henrik
    Linköping University, Department of Medical and Health Sciences, Division of Physiotherapy. Linköping University, Faculty of Health Sciences.
    Kristenson, Karolina
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Health Sciences.
    Bengtsson, Hakan
    Football Research Group, Linköping University, Linköping, Sweden.
    Ekstrand, Jan
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Health Sciences.
    Injuries affect team performance negatively in professional football: an 11-year follow-up of the UEFA Champions League injury study2013In: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 47, no 12, p. 738-742Article in journal (Refereed)
    Abstract [en]

    Background The influence of injuries on team performance in football has only been scarcely investigated.

    Aim To study the association between injury rates and team performance in the domestic league play, and in European cups, in male professional football.

    Methods 24 football teams from nine European countries were followed prospectively for 11 seasons (2001–2012), including 155 team-seasons. Individual training and match exposure and time-loss injuries were registered. To analyse the effect of injury rates on performance, a Generalised Estimating Equation was used to fit a linear regression on team-level data. Each team's season injury rate and performance were evaluated using its own preceding season data for comparison in the analyses.

    Results 7792 injuries were reported during 1 026 104 exposure hours. The total injury incidence was 7.7 injuries/1000 h, injury burden 130 injury days lost/1000 h and player match availability 86%. Lower injury burden (p=0.011) and higher match availability (p=0.031) were associated with higher final league ranking. Similarly, lower injury incidence (p=0.035), lower injury burden (p<0.001) and higher match availability (p<0.001) were associated with increased points per league match. Finally, lower injury burden (p=0.043) and higher match availability (p=0.048) were associated with an increase in the Union of European Football Association (UEFA) Season Club Coefficient, reflecting success in the UEFA Champions League or Europa League.

    Conclusions Injuries had a significant influence on performance in the league play and in European cups in male professional football. The findings stress the importance of injury prevention to increase a team's chances of success.

  • 36.
    Hägglund, Martin
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Department of Health and Society, Division of Preventive and Social Medicine and Public Health Science.
    Waldén, Markus
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Department of Health and Society, Division of Preventive and Social Medicine and Public Health Science.
    Bahr, R
    Sports and psysical education Norwegian university, Oslo.
    Ekstrand, Jan
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Department of Health and Society, Division of Preventive and Social Medicine and Public Health Science.
    Methods for epidemiological study of injuries to prfessional football players: developing the UEFA model2005In: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 39, p. 340-346Article in journal (Refereed)
  • 37.
    Hägglund, Martin
    et al.
    Linköping University, Department of Medical and Health Sciences, Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Waldén, Markus
    Linköping University, Department of Medical and Health Sciences, Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Ekstrand, Jan
    Linköping University, Department of Medical and Health Sciences, Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Exposure and injury risk in Swedish elite football: a comparison between seasons 1982 and 20012003In: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, Vol. 13, no 6, p. 364-370Article in journal (Refereed)
    Abstract [en]

    The long-term development of injury risk in Swedish male elite football was studied. Two prospective cohort studies from seasons 1982 and 2001 were compared with respect to exposure to football, injury incidence and injury severity.

    The mean number of training sessions during the season had increased by 68% between 1982 and 2001 (142 vs. 238, P<0.001), whereas teams played more matches in 1982 (49 vs. 41, P=0.02). The total exposure to football had increased by 27%. Three out of four players incurred an injury in both seasons. In 2001, players suffered more training injuries due to an increased training exposure. Accounting for risk exposure, there was no difference in injury incidence or severity between the two seasons. The incidence was 8.3 injuries/ 1000 h of total exposure (4.6 in training and 20.6 in matches) in 1982, compared to 7.8 1000 h−1 (5.2 in training and 25.9 in matches) in 2001. Major injuries accounted for 9% of all injuries, corresponding to an incidence of 0.8 /1000 h of football, in both seasons.

    A trend from semi-professionalism to full professionalism in Swedish elite football was seen during the last two decades. The injury risk did not change over the same period.

  • 38.
    Hägglund, Martin
    et al.
    Linköping University, Department of Medicine and Health Sciences, Division of Preventive and Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Waldén, Markus
    Linköping University, Department of Medicine and Health Sciences, Division of Preventive and Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Ekstrand, Jan
    Linköping University, Department of Medicine and Health Sciences, Division of Preventive and Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Injuries among male and female elite football players2009In: SCANDINAVIAN JOURNAL OF MEDICINE and SCIENCE IN SPORTS, ISSN 0905-7188, Vol. 19, no 6, p. 819-827Article in journal (Refereed)
    Abstract [en]

    All 12 female football clubs (228 players) and 11 of 14 male clubs (239 players) in the Swedish premier league were followed prospectively during the 2005 season. Individual exposure (playing time), injuries (time loss), and injury severity (days lost due to injury) were recorded by the team medical staffs. Injury incidence was higher for male players during both training (4.7 vs 3.8 injuries/1000 h, P=0.018) and match play (28.1 vs 16.1, P andlt; 0.001). However, no difference was found in the incidence of severe injury (absence andgt; 4 weeks) (0.7/1000 h in both groups). The thigh, especially the hamstrings, was the overall most commonly injured region in both sexes, while the hip/groin was more commonly injured in male players and the knee in female players. Knee ligament injuries accounted for 31% and 37% of the total time lost from football for male and female players, respectively. In conclusion, male elite players had a higher injury incidence than their female counterparts although no difference was observed in the incidence of moderate to severe injury. We recommend that preventive measures should be focused on hamstring and knee ligament injury in order to reduce the overall injury burden.

  • 39.
    Hägglund, Martin
    et al.
    Linköping University, Department of Medicine and Health Sciences, Division of Preventive and Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Waldén, Markus
    Linköping University, Department of Medicine and Health Sciences, Division of Preventive and Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Ekstrand, Jan
    Linköping University, Department of Medicine and Health Sciences, Division of Preventive and Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Injuries among male and female elite football playersManuscript (Other (popular science, discussion, etc.))
  • 40.
    Hägglund, Martin
    et al.
    Linköping University, Department of Medical and Health Sciences, Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Waldén, Markus
    Linköping University, Department of Medical and Health Sciences, Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Ekstrand, Jan
    Linköping University, Department of Medical and Health Sciences, Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Injury incidence and distribution in elite football - a prospective study of the Danish and the Swedish top divisions2005In: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, Vol. 15, no 1, p. 21-28Article in journal (Refereed)
    Abstract [en]

    The Danish and Swedish male top football divisions were studied prospectively from January to June 2001. Exposure to football and injury incidence, severity and distribution were compared between the countries.

    Swedish players had greater exposure to training (171 vs. 123 h per season, P<0.001), whereas exposure to matches did not differ between the countries. There was a higher risk for injury during training in Denmark than in Sweden (11.8 vs. 6.0 per 1000 h, P<0.01), whereas for match play there was no difference (28.2 vs. 26.2 per 1000 h). The risk for incurring a major injury (absence from football more than 4 weeks) was greater in Denmark (1.8 vs. 0.7 per 1000 h, P=0.002). The distribution of injuries according to type and location was similar in both countries. Of all injuries in Denmark and Sweden, overuse injury accounted for 39% and 38% (NS), and re-injury for 30% and 24% (P=0.032), respectively.

    The greater training exposure and the long pre-season period in Sweden may explain some of the reported differences.

  • 41.
    Hägglund, Martin
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Physiotherapy. Linköping University, Faculty of Medicine and Health Sciences.
    Waldén, Markus
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Ekstrand, Jan
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Injury recurrence is lower at the highest professional football level than at national and amateur levels: does sports medicine and sports physiotherapy deliver?2016In: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 50, no 12, p. 751-758Article in journal (Refereed)
    Abstract [en]

    Background Previous injury is a well-documented risk factor for football injury. The time trends and patterns of recurrent injuries at different playing levels are not clear. Aim To compare recurrent injury proportions, incidences and patterns between different football playing levels, and to study time trends in recurrent injury incidence. Methods Time-loss injuries were collected from injury surveillance of 43 top-level European professional teams (240 team-seasons), 19 Swedish premier division teams (82 team-seasons) and 10 Swedish amateur teams (10 team-seasons). Recurrent injury was defined as an injury of the same type and at the same site as an index injury within the preceding year, with injury amp;lt;2 months defined as an early recurrence, and amp;gt;2 months as a delayed recurrence. Seasonal trend for recurrent injury incidence, expressed as the average annual percentage of change, was analysed using linear regression. Results 13 050 injuries were included, 2449 (18.8%) being recurrent injuries, with 1944 early (14.9%) and 505 delayed recurrences (3.9%). Recurrence proportions were highest in the second half of the competitive season for all cohorts. Recurrence proportions differed between playing levels, with 35.1% in the amateur cohort, 25.0% in the Swedish elite cohort and 16.6% in the European cohort (chi(2) overall effect, pamp;lt;0.001). A decreasing trend was observed in recurrent injury incidence in the European cohort, a -2.9% average annual change over the 14-year study period (95% CI -5.4% to -0.4%, p=0.026). Similarly, a decreasing tendency was also seen in the Swedish premier division. Conclusions Recurrence proportions showed an inverse relationship with playing level, and recurrent injury incidence has decreased over the past decade.

  • 42.
    Hägglund, Martin
    et al.
    Linköping University, Department of Medical and Health Sciences, Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Waldén, Markus
    Linköping University, Department of Medical and Health Sciences, Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Ekstrand, Jan
    Linköping University, Department of Medical and Health Sciences, Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Lower re-injury rate with a coach-controlled rehabilitation program in amateur male soccer: A randomized controlled trial2007In: American Journal of Sports Medicine, ISSN 0363-5465, E-ISSN 1552-3365, Vol. 35, no 9, p. 1433-1442Article in journal (Refereed)
    Abstract [en]

    Background: Soccer injuries are common, and athletes returning to play after injury are especially at risk. Few studies have investigated how to prevent reinjury.

    Hypothesis: The rate of reinjury is reduced using a coach-controlled rehabilitation program.

    Study Design: Randomized controlled trial; Level of evidence, 1.

    Methods: Twenty-four male amateur soccer teams were randomized into an intervention (n = 282) and control group (n = 300). The intervention was implemented by team coaches and consisted of information about risk factors for reinjury, rehabilitation principles, and a 10-step progressive rehabilitation program including return to play criteria. During the 2003 season, coaches reported individual exposure and all time loss injuries were evaluated by a doctor and a physiotherapist. Four teams (n = 100) withdrew from the study after randomization, leaving 10 teams with 241 players for analysis in both groups.

    Results: There were 90 injured players (132 injuries) in the intervention group, and 10 of these (11%) suffered 14 reinjuries during the season. In the control group, 23 of 79 injured players (29%) had 40 recurrences (134 injuries). A Cox regression analysis showed a 66% reinjury risk reduction in the intervention group for all injury locations (hazard ratio [HR] 0.34, 95% confidence interval [CI] 0.16–0.72, P = .0047) and 75% for lower limb injuries (HR 0.25, 95% CI 0.11–0.57, P < .001). The preventive effect was greatest within the first week of return to play. Injured players in the intervention group complied with the intervention for 90 of 132 injuries (68%).

    Conclusion: The reinjury rate in amateur male soccer players was reduced after a controlled rehabilitation program implemented by coaches.

  • 43.
    Hägglund, Martin
    et al.
    Linköping University, Department of Medical and Health Sciences, Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Waldén, Markus
    Linköping University, Department of Medical and Health Sciences, Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Ekstrand, Jan
    Linköping University, Department of Medical and Health Sciences, Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Previous injury as a risk factor for injury in elite football: a prospective study over two consecutive seasons2006In: British Journal of Sports Medicine, ISSN 0306-3674, Vol. 40, p. 767-772Article in journal (Refereed)
    Abstract [en]

    Background: Previous injury is often proposed to be a risk factorfor football injury, but most studies rely on players reportingtheir own medical history and are thus potentially subject torecall bias. Little is known about the natural variation ininjury pattern between seasons.

    Objectives: To study whether prospectively recorded injuriesduring one season are associated with injuries sustained duringthe following season, and to compare injury risk and injurypattern between consecutive seasons.

    Methods: The medical staffs of 12 elite Swedish male footballteams prospectively recorded individual exposure and time lossinjuries over two full consecutive seasons (2001 and 2002).A multivariate model was used to determine the relation betweenprevious injury, anthropometric data, and the risk of injury.

    Results: The training and match injury incidences were similarbetween seasons (5.1 v 5.3 injuries/1000 training hours and25.9 v 22.7/1000 match hours), but analysis of injury severityand injury patterns showed variations between seasons. Playerswho were injured in the 2001 season were at greater risk ofany injury in the following season compared with non-injuredplayers (hazard ratio 2.7; 95% confidence interval 1.7 to 4.3,p<0.0001). Players with a previous hamstring injury, groininjury, and knee joint trauma were two to three times more likelyto suffer an identical injury in the following season, whereasno such relation was found for ankle sprain. Age was not associatedwith an increased injury risk.

    Conclusions: This study confirmed previous results showing thatprevious injury is an important risk factor for football injury.Overall injury incidences were similar between consecutive seasons,indicating that an injury surveillance study covering one fullseason can provide a reasonable overview of the injury problemamong elite football players in a specific environment. However,a prolonged study period is recommended for analyses of specificinjury patterns.

  • 44.
    Hägglund, Martin
    et al.
    Linköping University, Department of Medical and Health Sciences, Physiotherapy. Linköping University, Faculty of Health Sciences.
    Waldén, Markus
    Linköping University, Department of Medical and Health Sciences, Division of Preventive and Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Ekstrand, Jan
    Linköping University, Department of Medical and Health Sciences, Division of Preventive and Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Risk Factors for Lower Extremity Muscle Injury in Professional Soccer: The UEFA Injury Study2013In: American Journal of Sports Medicine, ISSN 0363-5465, E-ISSN 1552-3365, Vol. 41, no 2, p. 327-335Article in journal (Refereed)
    Abstract [en]

    Background: Muscle injury is the most common injury type in professional soccer players. Despite this, risk factors for common lower extremity injuries remain elusive.

    Purpose: To evaluate the effects of various player- and match-related risk factors on the occurrence of lower extremity muscle injury in male professional soccer.

    Study Design: Cohort study; Level of evidence, 2.

    Methods: Between 2001 and 2010, 26 soccer clubs (1401 players) from 10 European countries participated in the study. Individual player exposure and time loss muscle injuries in the lower extremity were registered prospectively by the club medical staffs during 9 consecutive seasons. Hazard ratios (HRs) were calculated for player-related factors from simple and multiple Cox regression, and odds ratios (ORs) were calculated for match-related variables from simple and multiple logistic regression, presented with 95% confidence intervals (CIs).

    Results: There were 2123 muscle injuries documented in the major lower extremity muscle groups: adductors (n = 523), hamstrings (n = 900), quadriceps (n = 394), and calf (n = 306). Injuries to the adductors (56%; P = .015) and quadriceps (63%; P< .001) were more frequent in the kicking leg. Multiple analysis indicated that having a previous identical injury in the preceding season increased injury rates significantly for adductor (HR, 1.40; 95% CI, 1.00-1.96), hamstring (HR, 1.40; 95% CI, 1.12-1.75), quadriceps (HR, 3.10; 95% CI, 2.21-4.36), and calf injuries (HR, 2.33; 95% CI, 1.52-3.57). Older players (above mean age) had an almost 2-fold increased rate of calf injury (HR, 1.93; 95% CI, 1.38-2.71), but no association was found in other muscle groups. Goalkeepers had reduced injury rates in all 4 muscle groups. Match play on away ground was associated with reduced rates of adductor (OR, 0.56; 95% CI, 0.43-0.73) and hamstring injuries (OR, 0.76; 95% CI, 0.63-0.92). Quadriceps injuries were more frequent during preseason, whereas adductor, hamstring, and calf injury rates increased during the competitive season.

    Conclusion: Intrinsic factors found to increase muscle injury rates in professional soccer were previous injury, older age, and kicking leg. Injury rates varied during different parts of the season and also depending on match location.

  • 45.
    Hägglund, Martin
    et al.
    Linköping University, Department of Medical and Health Sciences, Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Zwerver, Johannes
    University Medical Center Groningen.
    Ekstrand, Jan
    Linköping University, Department of Medical and Health Sciences, Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Epidemiology of Patellar Tendinopathy in Elite Male Soccer Players2011In: American Journal of Sports Medicine, ISSN 0363-5465, E-ISSN 1552-3365, Vol. 39, no 9, p. 1906-1911Article in journal (Refereed)
    Abstract [en]

    Background: Patellar tendinopathy is common among athletes in jumping sports and in sports with prolonged repetitive stress of the knee extensor apparatus. The epidemiology in soccer is not well described. less thanbrgreater than less thanbrgreater thanPurpose: This study was undertaken to investigate and describe the epidemiology of patellar tendinopathy in elite male soccer players and evaluate potential risk factors. less thanbrgreater than less thanbrgreater thanStudy Design: Cohort study; Level of evidence, 2. less thanbrgreater than less thanbrgreater thanMethods: Between 2001 and 2009, the authors followed 51 European elite soccer clubs (2229 players) from 3 different cohorts: the Swedish First League cohort (SWE) and Union of European Football Associations (UEFA) Champions League cohort (UCL), both playing on natural grass; and the Artifical Turf cohort (ART), playing on third-generation artificial turf. Individual player exposure in training and matches and time-loss injuries were recorded. less thanbrgreater than less thanbrgreater thanResults: In total, 137 patellar tendinopathies were recorded, comprising 1.5% of all injuries and corresponding to an incidence of 0.12 injuries/1000 hours. Each season, 2.4% of players were affected, with most injuries (61%) resulting in absence up to 1 week or less. Twenty percent of tendinopathies were recurrent complaints. No significant difference in season prevalence (odds ratio [OR], 0.93; 95% confidence interval [CI], 0.60-1.44; P = .74) or incidence (rate ratio [RR] 1.20; 95% CI, 0.82-1.75; P = .36) was observed between teams playing on artificial turf and natural grass, respectively. Multivariate logistic regression showed that a high total exposure hours (OR, 1.02 per 10-hour increase; 95% CI, 1.00-1.04; P = .033) was a significant risk factor for patellar tendinopathy, and increased body mass was borderline significant (OR, 1.15 per 5-kg increase; 95% CI, 1.00-1.33; P = .055). In addition, 2 acute partial tendon ruptures were recorded, but no total rupture. less thanbrgreater than less thanbrgreater thanConclusion: Although mainly mild in nature, patellar tendinopathy is a fairly common condition in elite soccer and the recurrence rate is high. Exposure to artificial turf did not increase the prevalence or incidence of injury. High total amount of exposure was identified as a risk factor for patellar tendinopathy.

  • 46.
    Jorgensen, U.
    et al.
    Jørgensen, U., Department of Orthopedic Surgery, Gentofte Hospital, University of Copenhagen, 2900 Hellerup, Denmark.
    Bak, K.
    Department of Orthopedic Surgery, Gentofte Hospital, University of Copenhagen, 2900 Hellerup, Denmark.
    Ekstrand, Jan
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Division of Preventive and Social Medicine and Public Health Science.
    Scavenius, M.
    Department of Orthopedic Surgery, Gentofte Hospital, University of Copenhagen, 2900 Hellerup, Denmark.
    Reconstruction of the anterior cruciate ligament with the iliotibial band autograft in patients with chronic knee instability2001In: Knee Surgery, Sports Traumatology, Arthroscopy, ISSN 0942-2056, E-ISSN 1433-7347, Vol. 9, no 3, p. 137-145Article in journal (Refereed)
    Abstract [en]

    We performed combined internal and external anterior cruciate ligament (ACL) reconstruction with the iliotibial band autograft in 169 consecutive patients with chronic ACL insufficiency who were followed up for 24-61 months. Of these, 155 (91%) agreed to an additional independent observer follow-up after 24-92 months. Eight patients (5%) had sustained a rerupture/elongation of the graft and were operated on again, nine (6%) had sustained a tear of the contralateral ACL. Knee function and activity increased after the reconstruction. Lysholm scores improved from median 81 preoperatively to 99 at follow-up and Tegner scores from median 4 to 7. At follow-up 97 (71%) were active at the same level as prior to injury. In 17 of the 40 patients (12%) dropping to a lower activity level this was due to knee problems. The side-to-side difference in anterior-posterior knee laxity was more than 3 mm in 18 knees (13%) and more than 5 mm in 3 knees (2%). Including eight reruptures, this results in a "stability" failure rate of 8.8%. The overall IKCD rating showed normal knee function in 88 (73%) and nearly normal knee function in 30 (25%). Anterior knee pain was present in 14 (10%) of the patients at follow-up. Patients with isolated ACL injury had higher Lysholm scores and Tegner scores than patients with associated injuries. No clinical signs of varus knee development were seen. Of the 155 patients 94% would have the procedure repeated if necessary with the knowledge that they have today. The combined internal and external iliotibial band procedure can restore knee stability and function in the majority of chronic ACL-insufficient knees.

  • 47.
    Kerkhoffs, Gino M M J
    et al.
    University of Amsterdam, Netherlands .
    van Es, Nick
    University of Amsterdam, Netherlands .
    Wieldraaijer, Thijs
    University of Amsterdam, Netherlands .
    Sierevelt, Inger N.
    University of Amsterdam, Netherlands .
    Ekstrand, Jan
    Linköping University, Department of Medical and Health Sciences, Division of Preventive and Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Niek van Dijk, C
    University of Amsterdam, Netherlands .
    Diagnosis and prognosis of acute hamstring injuries in athletes2013In: Knee Surgery, Sports Traumatology, Arthroscopy, ISSN 0942-2056, E-ISSN 1433-7347, Vol. 21, no 2, p. 500-509Article in journal (Refereed)
    Abstract [en]

    Identification of the most relevant diagnostic and prognostic factors of physical examination and imaging of hamstring injuries in (elite) athletes. less thanbrgreater than less thanbrgreater thanA literature search was conducted in MEDLINE and EMBASE for articles between 1950 and April 2011. A survey was distributed among the members of the European Society of Sports Traumatology, Knee Surgery and Arthroscopy, which focused on physical examination, prognosis, imaging and laboratory tests of hamstring injuries in (elite) athletes. less thanbrgreater than less thanbrgreater thanMedical history, inspection and palpation of the muscle bellies and imaging are most valuable at the initial assessment according to the literature. Experts considered medical history, posture and gait inspection, inspection and palpation of muscle bellies, range of motion tests, manual muscle testing, referred pain tests and imaging to be most important in the initial assessment of hamstring injuries. Magnetic resonance imaging (MRI) is preferred over ultrasonography and should take place within 3 days post-trauma. Important prognostic factors are injury grade, length of the muscle tear on MR images, MRI-negative injuries and trauma mechanism. less thanbrgreater than less thanbrgreater thanPosture and gait inspection, inspection and palpation of muscle bellies, range of motion tests, manual muscle testing and referred pain tests within 2 days post-trauma were identified as the most relevant diagnostic factors. less thanbrgreater than less thanbrgreater thanLiterature review and expert opinion, Level V.

  • 48.
    Kristenson, Karolina
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Medicine and Health Sciences. Football Research Group, Linköping, Sweden.
    Bjørneboe, John
    Department of Sports Medicine, Oslo Sports Trauma Research Center, Norwegian School of Sport Sciences, Oslo, Norway.
    Waldén, Markus
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Medicine and Health Sciences. Football Research Group, Linköping, Sweden.
    Andersen, Thor Einar
    Department of Sports Medicine, Oslo Sports Trauma Research Center, Norwegian School of Sport Sciences, Oslo, Norway.
    Ekstrand, Jan
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Medicine and Health Sciences. Football Research Group, Linköping, Sweden.
    Hägglund, Martin
    Linköping University, Department of Medical and Health Sciences, Division of Physiotherapy. Linköping University, Faculty of Medicine and Health Sciences. Football Research Group, Linköping, Sweden.
    Injuries in male professional football: a prospective comparison between individual and team-based exposure registration2016In: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, E-ISSN 1600-0838, Vol. 26, no 10, p. 1225-1232Article in journal (Refereed)
    Abstract [en]

    Methodological considerations of football injury epidemiology have only scarcely been described. The aim of this study was to evaluate the inter-rater agreement in injury capture rate and injury categorisation for data registered in two different prospective injury surveillance audits studying the same two Norwegian male professional football clubs for two consecutive seasons, 2008-2009. One audit used team-based exposure (TBE) recording and the other individual-based exposure (IBE). The number of injuries recorded and corresponding injury rates (injuries/1000 h exposure) were compared between audits. Cohen’s Kappa and Prevalence Adjusted Bias Adjusted Kappa (PABAK) coefficients were calculated for injury variables. Of 323 injuries included, the IBE audit captured 318 (overall capture rate 98.5%, training 98.9%, match 97.8%) and the TBE audit 303 injuries (overall capture rate 93.8%, training 91.4%, match 97.1%). Agreement analysis showed Kappa and PABAK coefficients regarded as almost perfect (> 0.81) for 8 of 9 injury variables, and substantial (ƙ 0.75) for the variable injury severity. In conclusion, the capture rate for training injuries was slightly higher with individual-based exposure recording, and inter-agreement in injury categorisation was very high.

  • 49.
    Kristenson, Karolina
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Health Sciences.
    Bjørneboe, John
    Norwegian School Sport Science, Norway.
    Waldén, Markus
    Linköping University, Department of Medical and Health Sciences, Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Andersen, Thor Einar
    Norwegian School Sport Science, Norway.
    Ekstrand, Jan
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Health Sciences.
    Hägglund, Martin
    Linköping University, Department of Medical and Health Sciences, Division of Physiotherapy. Linköping University, Faculty of Health Sciences.
    The Nordic Football Injury Audit: higher injury rates for professional football clubs with third-generation artificial turf at their home venue2013In: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 47, no 12, p. 775-781Article in journal (Refereed)
    Abstract [en]

    Background Previously, no difference in acute injury rate has been found when playing football on artificial turf (AT) compared with natural grass (NG).

    Aim To compare acute injury rates in professional football played on AT and NG at the individual player level; and to compare, at club level, acute and overuse injury rates between clubs that have AT at their home venue (AT clubs) and clubs that have NG (NG clubs).

    Methods 32 clubs (AT, n=11; NG, n=21) in the male Swedish and Norwegian premier leagues were followed prospectively during the 2010 and 2011 seasons. Injury rate was expressed as the number of time loss injuries/1000 h and compared with rate ratio (RR) and 99% CI.

    Results No statistically significant differences were found in acute injury rates on AT compared with NG during match play (RR 0.98, 99% CI 0.79 to 1.22) or training (RR 1.14, 99% CI 0.86 to 1.50) when analysing at the individual player level. When analysing at the club level, however, AT clubs had a significantly higher acute training injury rate (RR 1.31, 99% CI 1.04 to 1.63) and overuse injury rate (RR 1.38, 99% CI 1.14 to 1.65) compared with NG clubs.

    Conclusions At the individual player level, no significant differences were found in acute injury rates when playing on AT compared with NG. However, clubs with AT at their home venue had higher rates of acute training injuries and overuse injuries compared with clubs that played home matches on NG.

  • 50.
    Kristenson, Karolina
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Bjørneboe, John
    Norwegian School Sport Science, Norway.
    Waldén, Markus
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Ekstrand, Jan
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Andersen, Thor Einar
    Norwegian School Sport Science, Norway.
    Hägglund, Martin
    Linköping University, Department of Medical and Health Sciences, Division of Physiotherapy. Linköping University, Faculty of Medicine and Health Sciences.
    No association between surface shifts and time-loss overuse injury risk in male professional football: a prospective cohort study2016In: Journal of Science and Medicine in Sport, ISSN 1440-2440, E-ISSN 1878-1861, Vol. 19, no 3, p. 218-221Article in journal (Refereed)
    Abstract [en]

    Objectives: To investigate frequent surface shifts, match play on an unaccustomed surface, and climate type as potential risk factors for injury in Scandinavian male professional football.

    Design: Prospective cohort study.

    Methods: 32 clubs from two climate zones, warm temperate (n=19) and snow climates (n=13), were followed during seasons 2010 and 2011. The association between number of surface shifts during fivematch sequences and subsequent overuse injury risk was evaluated with generalized estimating equations. Injury rate was expressed as time loss injuries/1000 hours, and compared between groups with a rate ratio and 95% confidence interval (CI).

    Results: No association was found between the number of surface shifts and subsequent overuse injury risk (risk ratio 1.01, 95% CI 0.91-1.12). Grass clubs (grass installed at home venue) had a lower match injury rate when playing away matches on artificial turf vs. away matches on grass (rate ratio 0.66, 95% CI 0.40-0.89). Analyses on the total cohort showed no difference in injury rates between clubs in the two climate zones, but sub-analyses revealed that grass clubs from the snow climate zone had lower training and match injury rates than grass clubs from the warm temperate zone (rate ratio 0.69, 95% CI 0.55-0.87).

    Conclusions: No influence on injury risk was seen from frequent surface shifts or from playing matches on an unaccustomed surface. Climate type at club home venue had minimal influence on injury rates.

12 1 - 50 of 73
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