| 1. |
- Ekstrand, Jan, et al.
(author)
-
Risk of injury in elite football played on artificial turf versus natural grass : a prospective two-cohort study.
- 2006
-
In: British journal of sports medicine. - : BMJ. - 1473-0480 .- 0306-3674. ; 40:12, s. 975-80
-
Journal article (peer-reviewed)abstract
- 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.
|
|
| 2. |
- Fuller, C.W., et al.
(author)
-
Consensus statement on injury definitions and data collection procedures in studies of football (soccer) injuries
- 2006
-
In: Scandinavian Journal of Medicine and Science in Sports. - : Wiley. - 0905-7188 .- 1600-0838. ; 16:2, s. 97-106
-
Research review (peer-reviewed)abstract
- 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.
|
|
| 3. |
- Hägglund, Martin, 1976-
(author)
-
Epidemiology and prevention of football injuries
- 2007
-
Doctoral thesis (other academic/artistic)abstract
- The aims of this thesis were to study the incidence, severity and pattern of injury in male and female elite football players; to study time trends in injury risk; to identify risk factors for injury; and to test the effectiveness of an intervention programme aimed at preventing re-injury.All studies followed a prospective design using standardised definitions and data collection forms. Individual training and match exposure was registered for all players participating. Time loss injuries were documented by each team’s medical staff.The amount of training increased by 68% between the 1982 and 2001 Swedish top male division seasons, reflecting the shift from semi-professionalism to full professionalism. No difference in injury incidence or injury severity was found between seasons. The injury incidence was 4.6 vs. 5.2/1000 training hours and 20.6 vs. 25.9/1000 match hours. The incidence of severe injury (absence >4 weeks) was 0.8/1000 hours in both seasons.The Swedish and Danish top male divisions were followed during the spring season of 2001. A higher risk for training injury (11.8 vs. 6.0/1000 hours, p<0.01) and severe injury (1.8 vs. 0.7/1000 hours, p=0.002) was observed among the Danish players. Re-injury accounted for 30% and 24% of injuries in Denmark and Sweden respectively.The Swedish top male division was studied over two consecutive seasons, 2001 and 2002, and comparison of training and match injury incidences between seasons showed similar results. Players who were injured in the 2001 season were at greater risk for injury in the following season compared to non-injured players (relative risk 2.7; 95% CI 1.7-4.3). Players with a previous hamstring injury, groin injury and knee joint trauma were two to three times more likely to suffer an identical injury to the same limb in the following season, but no such relationship was found for ankle sprain. Age was not associated with an increased injury risk.The effectiveness of a coach-controlled rehabilitation programme on the rate of re-injury was studied in a randomised controlled trial at amateur male level. In the control group, 23 of 79 injured players suffered a recurrence during the season compared to 10 of 90 players in the intervention group. There was a 75% lower re-injury risk in the intervention group for lower limb injuries (relative risk 0.25; 95% CI 0.11-0.57). The preventive effect was greatest during the first weeks after return to play.Both the male and female Swedish top divisions were followed during the 2005 season. Male elite players had a higher risk for training injury (4.7 vs. 3.8/1000 hours, p<0.05) and match injury (28.1 vs. 16.1/1000 hours, p<0.001) than women. However, no difference was observed in the rate of severe injury (0.7/1000 hours in both groups). The thigh was the most common site of injury in both men and women, while injury to the hip/groin was more frequent in men and to the knee in women. Knee sprain accounted for 31% and 37% of the time lost from training and match play in men and women respectively.
|
|
| 4. |
- Hägglund, Martin, et al.
(author)
-
Injuries among male and female elite football players
- 2009
-
In: SCANDINAVIAN JOURNAL OF MEDICINE and SCIENCE IN SPORTS. - : Wiley. - 0905-7188 .- 1600-0838. ; 19:6, s. 819-827
-
Journal article (peer-reviewed)abstract
- 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.
|
|
| 5. |
- Hägglund, Martin, et al.
(author)
-
Injury incidence and distribution in elite football - a prospective study of the Danish and the Swedish top divisions
- 2005
-
In: Scandinavian Journal of Medicine and Science in Sports. - : Wiley. - 0905-7188 .- 1600-0838. ; 15:1, s. 21-28
-
Journal article (peer-reviewed)abstract
- 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.
|
|
| 6. |
- Hägglund, Martin, et al.
(author)
-
Lower re-injury rate with a coach-controlled rehabilitation program in amateur male soccer : A randomized controlled trial
- 2007
-
In: American Journal of Sports Medicine. - : SAGE Publications. - 0363-5465 .- 1552-3365. ; 35:9, s. 1433-1442
-
Journal article (peer-reviewed)abstract
- 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.
|
|
| 7. |
|
|
| 8. |
- Hägglund, Martin, et al.
(author)
-
Preventing knee injuries in adolescent female football players - design of a cluster randomized controlled trial [NCT00894595]
- 2009
-
In: BMC Musculoskeletal Disorders. - : Springer Science and Business Media LLC. - 1471-2474. ; 10:75
-
Journal article (peer-reviewed)abstract
- Background: Knee injuries in football are common regardless of age, gender or playing level, but adolescent females seem to have the highest risk. The consequences after severe knee injury, for example anterior cruciate ligament (ACL) injury, are well-known, but less is known about knee injury prevention. We have designed a cluster randomized controlled trial (RCT) to evaluate the effect of a warm-up program aimed at preventing acute knee injury in adolescent female football. Methods: In this cluster randomized trial 516 teams (309 clusters) in eight regional football districts in Sweden with female players aged 13-17 years were randomized into an intervention group (260 teams) or a control group (256 teams). The teams in the intervention group were instructed to do a structured warm-up program at two training sessions per week throughout the 2009 competitive season (April to October) and those in the control group were informed to train and play as usual. Sixty-eight sports physical therapists are assigned to the clubs to assist both groups in data collection and to examine the players acute knee injuries during the study period. Three different forms are used in the trial: (1) baseline player data form collected at the start of the trial, (2) computer-based registration form collected every month, on which one of the coaches/team leaders documents individual player exposure, and (3) injury report form on which the study therapists report acute knee injuries resulting in time loss from training or match play. The primary outcome is the incidence of ACL injury and the secondary outcomes are the incidence of any acute knee injury (except contusion) and incidence of severe knee injury (defined as injury resulting in absence of more than 4 weeks). Outcome measures are assessed after the end of the 2009 season. Discussion: Prevention of knee injury is beneficial for players, clubs, insurance companies, and society. If the warm-up program is proven to be effective in reducing the incidence of knee injury, it can have a major impact by reducing the future knee injury burden in female football as well as the negative long-term disabilities associated with knee injury.
|
|
| 9. |
- Hägglund, Martin, et al.
(author)
-
Previous injury as a risk factor for injury in elite football: a prospective study over two consecutive seasons
- 2006
-
In: British Journal of Sports Medicine. - : BMJ. - 0306-3674 .- 1473-0480. ; 40, s. 767-772
-
Journal article (peer-reviewed)abstract
- 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.
|
|
| 10. |
- Johansson, Martin, 1973, et al.
(author)
-
Approximate boundary conditions for a fluid-loaded elastic plate
- 2005
-
In: Journal of the Acoustical Society of America. - : Acoustical Society of America (ASA). - 1520-8524 .- 0001-4966. ; 118:6, s. 3436-3446
-
Journal article (peer-reviewed)abstract
- Approximate boundary conditions for an infinite elastic layer immersed in a fluid are derived. By using series expansions in the thickness coordinate of the plate fields, the displacements fields are eliminated, adopting the three-dimensional equations of motion. The sums and differences of the boundary pressure fields and their normal derivatives are related through a set of approximate boundary conditions, one symmetric and one antisymmetric. These equations involve powers in the layer thickness together with partial derivatives with respect to time as well as the spatial variables in the plate plane. The approximate boundary conditions can be truncated to an arbitrary order, and explicit relations are presented including terms of order five. Comparisons are made with effective boundary conditions using classical plate theories. The numerical examples involve reflection and transmission of plane waves incident on the plate at different angles, as well as the pressure fields due to a line force. Three fluid-loading cases are studied: modest, heavy, and light loadings. The results using truncated approximate boundary conditions are compared to exact and classical plate solutions. The examples show that the accuracies of the power series approximations of order three and higher are very good in the frequency interval considered.
|
|
