Kathrin Steffen

Comprehensive warm-up programme to prevent injuries in young female footballers: cluster randomised controlled trial

Objective To examine the effect of a comprehensive warm-up programme designed to reduce the risk of injuries in female youth football. Design Cluster randomised controlled trial with clubs as the unit of randomisation. Setting 125 football clubs from the south, east, and middle of Norway (65 clusters in the intervention group; 60 in the control group) followed for one league season (eight months). Participants 1892 female players aged 13-17 (1055 players in the intervention group; 837 players in the control group). Intervention A comprehensive warm-up programme to improve strength, awareness, and neuromuscular control during static and dynamic movements. Main outcome measure Injuries to the lower extremity (foot, ankle, lower leg, knee, thigh, groin, and hip). Results During one season, 264 players had relevant injuries: 121 players in the intervention group and 143 in the control group (rate ratio 0.71, 95% confidence interval 0.49 to 1.03). In the intervention group there was a significantly lower risk of injuries overall (0.68, 0.48 to 0.98), overuse injuries (0.47, 0.26 to 0.85), and severe injuries (0.55, 0.36 to 0.83). Conclusion Though the primary outcome of reduction in lower extremity injury did not reach significance, the risk of severe injuries, overuse injuries, and injuries overall was reduced. This indicates that a structured warm-up programme can prevent injuries in young female football players. Trial registration ISRCTN10306290.

Preventing injuries in female youth football--a cluster-randomized controlled trial.

A set of exercises – the “11”– have been selected to prevent football injuries. The purpose of this cluster‐randomized controlled trial was to investigate the effect of the “11” on injury risk in female youth football. Teams were randomized to an intervention (n=59 teams, 1091 players) or a control group (n=54 teams, 1001 players). The intervention group was taught the “11,” exercises for core stability, lower extremity strength, neuromuscular control and agility, to be used as a 15‐min warm‐up program for football training over an 8‐month season. A total of 396 players (20%) sustained 483 injuries. No difference was observed in the overall injury rate between the intervention (3.6 injuries/1000 h, confidence interval (CI) 3.2–4.1) and control group (3.7, CI 3.2–4.1; RR=1.0, CI 0.8–1.2; P=0.94) nor in the incidence for any type of injury. During the first 4 months of the season, the training program was used during 60% of the football training sessions, but only 14 out of 58 intervention teams completed more than 20 prevention training sessions. In conclusion, we observed no effect of the injury prevention program on the injury rate, most likely because the compliance with the program was low.

The IOC consensus statement: beyond the Female Athlete Triad—Relative Energy Deficiency in Sport (RED-S)

Protecting the health of the athlete is a goal of the International Olympic Committee (IOC). The IOC convened an expert panel to update the 2005 IOC Consensus Statement on the Female Athlete Triad. This Consensus Statement replaces the previous and provides guidelines to guide risk assessment, treatment and return-to-play decisions. The IOC expert working group introduces a broader, more comprehensive term for the condition previously known as ‘Female Athlete Triad’. The term ‘Relative Energy Deficiency in Sport’ (RED-S), points to the complexity involved and the fact that male athletes are also affected. The syndrome of RED-S refers to impaired physiological function including, but not limited to, metabolic rate, menstrual function, bone health, immunity, protein synthesis, cardiovascular health caused by relative energy deficiency. The cause of this syndrome is energy deficiency relative to the balance between dietary energy intake and energy expenditure required for health and activities of daily living, growth and sporting activities. Psychological consequences can either precede RED-S or be the result of RED-S. The clinical phenomenon is not a ‘triad’ of the three entities of energy availability, menstrual function and bone health, but rather a syndrome that affects many aspects of physiological function, health and athletic performance. This Consensus Statement also recommends practical clinical models for the management of affected athletes. The ‘Sport Risk Assessment and Return to Play Model’ categorises the syndrome into three groups and translates these classifications into clinical recommendations.

Sports injuries and illnesses during the London Summer Olympic Games 2012

Background The Olympic Movement Medical Code encourages all stakeholders to ensure that sport is practised without danger to the health of the athletes. Systematic surveillance of injuries and illnesses is the foundation for developing preventive measures in sport. Aim To analyse the injuries and illnesses that occurred during the Games of the XXX Olympiad, held in London in 2012. Methods We recorded the daily occurrence (or non-occurrence) of injuries and illnesses (1) through the reporting of all National Olympic Committee (NOC) medical teams and (2) in the polyclinic and medical venues by the London Organising Committee of the Olympic and Paralympic Games’ (LOCOG) medical staff. Results In total, 10 568 athletes (4676 women and 5892 men) from 204 NOCs participated in the study. NOC and LOCOG medical staff reported 1361 injuries and 758 illnesses, equalling incidences of 128.8 injuries and 71.7 illnesses per 1000 athletes. Altogether, 11% and 7% of the athletes incurred at least one injury or illness, respectively. The risk of an athlete being injured was the highest in taekwondo, football, BMX, handball, mountain bike, athletics, weightlifting, hockey and badminton, and the lowest in archery, canoe slalom and sprint, track cycling, rowing, shooting and equestrian. 35% of the injuries were expected to prevent the athlete from participating during competition or training. Women suffered 60% more illnesses than men (86.0 vs 53.3 illnesses per 1000 athletes). The rate of illness was the highest in athletics, beach volleyball, football, sailing, synchronised swimming and taekwondo. A total of 310 illnesses (41%) affected the respiratory system and the most common cause of illness was infection (n=347, 46%). Conclusions At least 11% of the athletes incurred an injury during the games and 7% of the athletes’ an illness. The incidence of injuries and illnesses varied substantially among sports. Future initiatives should include the development of preventive measures tailored for each specific sport and the continued focus among sport bodies to institute and further develop scientific injury and illness surveillance systems.

High adherence to a neuromuscular injury prevention programme (FIFA 11+) improves functional balance and reduces injury risk in Canadian youth female football players: A cluster randomised trial

Background A protective effect on injury risk in youth sports through neuromuscular warm-up training routines has consistently been demonstrated. However, there is a paucity of information regarding the quantity and quality of coach-led injury prevention programmes and its impact on the physical performance of players. Objective The aim of this cluster-randomised controlled trial was to assess whether different delivery methods of an injury prevention programme (FIFA 11+) to coaches could improve player performance, and to examine the effect of player adherence on performance and injury risk. Method During the 2011 football season (May–August), coaches of 31 tiers 1–3 level teams were introduced to the 11+ through either an unsupervised website or a coach-focused workshop with and without additional on-field supervisions. Playing exposure, adherence to the 11+, and injuries were recorded for female 13-year-old to 18-year-old players. Performance testing included the Star Excursion Balance Test (SEBT), single-leg balance, triple hop and jumping-over-a-bar tests. Results Complete preseason and postseason performance tests were available for 226 players (66.5%). Compared to the unsupervised group, single-leg balance (OR=2.8; 95% CI 1.1 to 4.6) and the anterior direction of the SEBT improved significantly in the onfield supervised group of players (OR=4.7; 95% CI 2.2 to 7.1), while 2-leg jumping performance decreased (OR=−5.1; 95% CI −9.9 to −0.2). However, significant improvements in 5 of 6 reach distances in the SEBT were found, favouring players who highly adhered to the 11+. Also, injury risk was lower for those players (injury rate ratio, IRR=0.28, 95% CI 0.10 to 0.79). Conclusions Different delivery methods of the FIFA 11+ to coaches influenced players’ physical performance minimally. However, high player adherence to the 11+ resulted in significant improvements in functional balance and reduced injury risk.

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

Background: Artificial turf is becoming increasingly popular, although the risk of injury on newer generations of turf is unknown. Aim: To investigate the risk of injury on artificial turf compared with natural grass among young female football players. Study design: Prospective cohort study. Methods: 2020 players from 109 teams (mean (SD) 15.4 (0.8) years) participated in the study during the 2005 football season. Time-loss injuries and exposure data on different types of turf were recorded over an eight-month period. Results: 421 (21%) players sustained 526 injuries, leading to an injury incidence of 3.7/1000 playing hours (95% CI 3.4 to 4.0). The incidence of acute injuries on artificial turf and grass did not differ significantly with respect to match injuries (rate ratio (RR) 1.0, 95% CI 0.8 to 1.3; p = 0.72) or training injuries (RR 1.0, 95% CI 0.6 to 1.5, p = 0.93). In matches, the incidence of serious injuries was significantly higher on artificial turf (RR 2.0, 95% CI 1.3 to 3.2; p = 0.03). Ankle sprain was the most common type of injury (34% of all acute injuries), and there was a trend towards more ankle sprains on artificial turf than on grass (RR 1.5, 95% CI 1.0 to 2.2; p = 0.06). Conclusion: In the present study among young female football players, the overall risk of acute injuries was similar between artificial turf and natural grass.

Injury and illness definitions and data collection procedures for use in epidemiological studies in Athletics (track and field): Consensus statement

Background Movement towards sport safety in Athletics through the introduction of preventive strategies requires consensus on definitions and methods for reporting epidemiological data in the various populations of athletes. Objective To define health-related incidents (injuries and illnesses) that should be recorded in epidemiological studies in Athletics, and the criteria for recording their nature, cause and severity, as well as standards for data collection and analysis procedures. Methods A 1-day meeting of 14 experts from eight countries representing a range of Athletics stakeholders and sport science researchers was facilitated. Definitions of injuries and illnesses, study design and data collection for epidemiological studies in Athletics were discussed during the meeting. Two members of the group produced a draft statement after this meeting, and distributed to the group members for their input. A revision was prepared, and the procedure was repeated to finalise the consensus statement. Results Definitions of injuries and illnesses and categories for recording of their nature, cause and severity were provided. Essential baseline information was listed. Guidelines on the recording of exposure data during competition and training and the calculation of prevalence and incidences were given. Finally, methodological guidance for consistent recording and reporting on injury and illness in athletics was described. Conclusions This consensus statement provides definitions and methodological guidance for epidemiological studies in Athletics. Consistent use of the definitions and methodological guidance would lead to more reliable and comparable evidence.

Performance aspects of an injury prevention program: a ten-week intervention in adolescent female football players

The injury rate in football is high, and effective injury prevention methods are needed. An exercise program, the “11,” has been designed to prevent the most common injury types in football. However, the effect of such a program on performance is not known. The aim of this randomized‐controlled trial was to investigate the effect of the “11” on performance after a 10‐week training period. Thirty‐four adolescent female football players were randomly assigned to either an intervention (n=18) or a control group (n=16). The “11” is a 15‐min program consisting of ten exercises for core stability, lower extremity strength, balance and agility. Performance tests included isokinetic and isometric strength protocols for the quadriceps and hamstrings, isometric hip adduction and abduction strength, vertical jump tests, sprint running and soccer skill tests. There was no difference between the intervention and control groups in the change in performance from the pre‐ to post‐test for any of the tests used. In conclusion, no effect was observed on a series of performance tests in a group of adolescent female football players using the “11” as a structured warm‐up program.

Evaluation of how different implementation strategies of an injury prevention programme (FIFA 11+) impact team adherence and injury risk in Canadian female youth football players: a cluster-randomised trial

Background Injury prevention programme delivery on adherence and injury risk, specifically involving regular supervisions with coaches and players on programme execution on field, has not been examined. Aim The objective of this cluster-randomised study was to evaluate different delivery methods of an effective injury prevention programme (FIFA 11+) on adherence and injury risk among female youth football teams. Method During the 4-month 2011 football season, coaches and 13-year-old to 18-year-old players from 31 tier 1–3 level teams were introduced to the 11+ through either an unsupervised website (‘control’) or a coach-focused workshop with (‘comprehensive’) and without (‘regular’) additional supervisions by a physiotherapist. Team and player adherence to the 11+, playing exposure, history and injuries were recorded. Results Teams in the comprehensive and regular intervention groups demonstrated adherence to the 11+ programme of 85.6% and 81.3% completion of total possible sessions, compared to 73.5% for teams in the control group. These differences were not statistically significant, after adjustment for cluster by team, age, level and injury history. Compared to players with low adherence, players with high adherence to the 11+ had a 57% lower injury risk (IRR 0.43, 95% CI 0.19 to 1.00). However, adjusting for covariates, this between-group difference was not statistically significant (IRR=0.44, 95% CI 0.18 to 1.06). Conclusion Following a coach workshop, coach-led delivery of the FIFA 11+ was equally successful with or without the additional field involvement of a physiotherapist. Proper education of coaches during an extensive preseason workshop was more effective in terms of team adherence than an unsupervised delivery of the 11+ programme to the team. Trial registration ISRCTN67835569.

Self-reported psychological characteristics as risk factors for injuries in female youth football

Identifying and understanding injury risk factors are necessary to target the injury‐prone athlete and develop injury prevention measurements. The influence of psychological factors on injuries in football is poorly documented. The purpose of this 8‐month prospective cohort study therefore was to examine whether psychological player characteristics assessed by a self‐administered questionnaire represent risk factors for injury. At baseline, female football players (14–16 years) were asked to complete a detailed questionnaire covering player history, previous injuries, perception of success and motivational climate, life stress, anxiety and coping strategies. During the 2005 season, a total of 1430 players were followed up to record injuries. A history of a previous injury [odds ratio (OR)=1.9 (1.4; 2.5), P<0.001] increased the risk of a new injury to the same region. There were significant differences in disfavor for previously injured compared with non‐injured players for ego orientation (P=0.007), perception of a performance climate (P=0.003) and experienced stressful life events (P<0.001). However, only high life stress (P=0.001) and perception of a mastery climate (P=0.03) were significant risk factors for new injuries. In conclusion, a perceived mastery climate and a high level of life stress were significant predictors for new injuries in a cohort of young female football players.