Risk factors for injury and illness in youth floorball players - A prospective cohort study.

OBJECTIVES: To investigate risk factors for injury and illness in female and male youth floorball players (12-17 years) during a 26-week floorball season. DESIGN: Prospective cohort study. SETTING: Recreational youth sport. PARTICIPANTS: 471 players (142 females) 12-17 years. MAIN OUTCOME MEASURES: Weekly survey including questions about stress, sleep quality, well-being, sport exposure and average weekly rating of perceived exertion (RPE). Acute:chronic workload ratio (ACWR) was calculated. The Oslo Sports Trauma Research Center questionnaire on health problems was used. Predictors of new injury and illness were examined using multi-level logistic regression models with weekly measures nested within individuals. RESULTS: Higher stress, poorer sleep quality and well-being increased the odds of a new injury in the subsequent week by 8% (2.0-13.5%), 10% (4.2-15.9%) and 8% (2.4-13.5%) per 1 unit increase. Higher stress, and poorer well-being increased the odds of illness by 8% (2.6-12.6%), and 12% (7.2-16.6%). ACWR below 0.8 or above 1.3 increased the odds of illness by 34% (4.9-70.8%). CONCLUSIONS: Perceived stress, well-being, and sleep quality were associated with injury and illness occurrence in the subsequent week. ACWR outside the range 0.8-1.3 was associated with illness the subsequent week. TRIAL REGISTRATION: Clinical Trials registration NCT03309904.

Use of metagenomic microbial source tracking to investigate the source of a foodborne outbreak of cryptosporidiosis.

Cryptosporidium is a protozoan parasite of global public health importance that causes gastroenteritis in a variety of vertebrate hosts, with many human outbreaks reported yearly, often from ingestion of contaminated water or food. Despite the major public health implications, little is typically known about sources of contamination of disease outbreaks caused by Cryptosporidium. Here, we study a national foodborne outbreak resulted from infection with Cryptosporidium parvum via romaine lettuce, with the main goal to trace the source of the parasite. To do so, we combined traditional outbreak investigation methods with molecular detection and characterization methods (i.e. PCR based typing, amplicon and shotgun sequencing) of romaine lettuce samples collected at the same farm from which the contaminated food was produced. Using 18S rRNA typing, we detected C. parvum in two out of three lettuce samples, which was supported by detections in the metagenome analysis. Microbial source tracking analysis of the lettuce samples suggested sewage water as a likely source of the contamination, albeit with some uncertainty. In addition, the high degree of overlap in bacterial species content with a public human gut microbial database corroborated the source tracking results. The combination of traditional and molecular based methods applied here is a promising tool for future source tracking investigations of food- and waterborne outbreaks of Cryptosporidium spp. and can help to control and mitigate contamination risks.

Predators and nutrient availability favor protozoa-resisting bacteria in aquatic systems.

The long co-existence of bacteria and protozoa has led to the development of bacterial protozoa resistance strategies, which are suggested to serve as drivers for the evolution of pathogenic bacteria. However, the ecological mechanisms underpinning selection for protozoa-resistance in aquatic bacteria are poorly known. To assess the role of nutrient availability and predation-pressure on selection for protozoa-resisting bacteria (PRB), an enrichment-dilution experiment was designed using laboratory microcosms containing natural lake water. PRB was monitored by screening 16S rRNA amplicon sequence data for reads assigned to bacteria that previously has been shown to resist degradation by amoebae. To estimate the effects of the microbial food web dynamics (microscopy of; heterotrophic bacteria, phytoplankton, protozoa and rotifers) and physicochemical variables on the PRB abundance in the study system, a joint species distribution modelling approach was used. The predation-pressure (ratio between predator and bacterial biomass) had a positive effect on the abundance of the PRB genus Mycobacterium, while perturbation (enrichment and dilution) favored the PRB genus Pseudomonas that dominated the bacterial community in the disturbed systems. Our results show that PRB with different ecological strategies can be expected in water of high and intermediate nutrient levels and after major disturbances of an aquatic system.

Perspectives in football medicine.

The high injury rate among men's professional football players is well-known. Therefore, the Union of European Football Associations (UEFA) launched an injury study already in 2001. This study, the UEFA Elite Club Injury Study (ECIS), currently includes data from a total of 51 clubs from 18 European countries with more than 14,000 registered injuries. With the 21st World Cup (WC) in Russia just around the corner, we have from our study identified a higher match injury rate and a higher proportion of severe injuries in the European Championships compared to the preceding club competitive seasons. Moreover, we have also recently showed that the muscle injury rate is higher when players are given a recovery window of five days or less between two matches. Considering the congested match schedule of the upcoming WC, it is therefore likely that injuries and fatigue once again will be a topic of discussion this summer.

Adoption and use of an injury prevention exercise program in female football: A qualitative study among coaches.

This study focuses on an injury prevention exercise program (IPEP), Knee Control, which has been shown to reduce the incidence of acute knee injury in female adolescent football players. The aim was to explore the factors influencing coaches' adoption and use of Knee Control within female football in Sweden. This was a qualitative study involving interviews with 20 strategically selected coaches for female football teams, predominantly adolescent teams. The semi-structured interview guide was influenced by the Health Belief Model, and an ecological perspective was adopted during the interviews. Interviews were analyzed with qualitative content analysis. The results illustrate the different influences that interact on adoption and use of Knee Control by coaches. The coaches described themselves as crucial for Knee Control adoption and use, but external facilitators and barriers such as resources for training, social support from other coaches, clubs and football associations and player buy-in were also described as important. Knee Control characteristics, such as how well the program fit the team, also influenced use of Knee Control. Many coaches modified the program to improve player buy-in and Knee Control fit. Such modifications may risk compromising the preventive effect but may increase feasibility, that is the ease of using Knee Control, and thereby long-term use. These findings may guide the design and delivery of future IPEPs, and improve use of Knee Control, for example, by expanding the program to fit different target groups and supporting coaches and players in the use of Knee Control.

Severe musculoskeletal time-loss injuries and symptoms of common mental disorders in professional soccer: a longitudinal analysis of 12-month follow-up data.

PURPOSE: Psychological factors have shown to be predictors of injury in professional football. However, it seems that this is a two-way relationship, as severe musculoskeletal time-loss injuries have shown to be associated with the onset of symptoms of common mental disorders (CMD). There is no longitudinal study performed exploring this interaction between symptoms of CMD and injuries. The purpose of this study was to explore the interaction between severe musculoskeletal time-loss injuries and symptoms of CMD in professional football players over a 12-month period. METHODS: Players were recruited by their national players' unions in five European countries. Symptoms of CMD included in the study were related to distress, anxiety/depression, sleep disturbance and adverse alcohol use. RESULTS: A total of 384 professional football players were enrolled in the study, of whom 262 (68%) completed the 12-month follow-up period. The mean age of the participants at baseline was 27 ± 5 years, and they had played professional football for 8 ± 5 years on average. Symptoms of CMD at baseline were not associated with the onset of severe musculoskeletal time-loss injuries during the follow-up period with relative risks (and 95% CI) ranging from 0.6 (0.3-1.0) to 1.0 (0.5-2.2). In contrast, severe musculoskeletal time-loss injuries reported at baseline were associated with the onset of symptoms of CMD during the follow-up period with relative risks ranging from 1.8 (0.8-3.7) to 6.9 (4.0-11.9). CONCLUSION: No relationship was found between symptoms of CMD and the onset of severe musculoskeletal time-loss injuries. However, professional football players who suffered from severe musculoskeletal time-loss injuries are likely to develop subsequent symptoms of CMD. This study emphasizes the need for an interdisciplinary medical approach, which not only focuses on the physical but also on the mental health of professional football players. An early identification of players at risk of symptoms of CMD, such as those suffering from severe musculoskeletal injuries, creates the opportunity for an interdisciplinary clinical medical team to treat the players timely and adequately. LEVEL OF EVIDENCE: Prospective cohort study, Level II.

Factors associated with playing football after anterior cruciate ligament reconstruction in female football players.

This study investigated whether player-related factors (demographic, personality, or psychological factors) or the characteristics of the anterior cruciate ligament (ACL) injury were associated with the return to playing football in females after ACL reconstruction (ACLR). We also compared current knee function, knee related quality of life and readiness to return to sport between females who returned to football and those who had not returned. Females who sustained a primary ACL rupture while playing football and underwent ACLR 6-36 months ago were eligible. Of the 460 contacted, 274 (60%) completed a battery of questionnaires, and 182 were included a median of 18 months (IQR 13) after ACLR. Of these, 94 (52%) returned to football and were currently playing, and 88 (48%) had not returned. Multiple logistic regression analysis identified two factors associated with returning to football: short time between injury and ACLR (0-3 months, OR 5.6; 3-12 months OR 4.7 vs reference group > 12 months) and high motivation. Current players showed higher ratings for current knee function, knee-related quality of life, and psychological readiness to return to sport (P < 0.001). Undergoing ACLR sooner after injury and high motivation to return to sports may impact a player's return to football after ACLR.

Injuries in male professional football: A prospective comparison between individual and team-based exposure registration.

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 categorization 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 IBE recording, and inter-agreement in injury categorization was very high.

Cartilage repair of experimentally 11 induced osteochondral defects in New Zealand White rabbits.

Articular cartilage has a limited capacity for self-repair in adult humans, and methods used to stimulate regeneration often result in re-growth of fibrous cartilage, which has lower durability. No current treatment option can provide complete repair. The possibility of growth factor delivery into the joint for cartilage regeneration after injury would be an attractive treatment option. A full thickness osteochondral defect of 4 mm in diameter and 2 mm deep was created by mechanical drilling in the medial femoral condyle in 20 female adult New Zealand White rabbits. In an attempt to improve regeneration a hyaluronic hydrogel system, with or without bone morphogenetic protein-2 (BMP-2) was delivered intraarticularly. The contralateral joint defect was treated with saline as control. Throughout the study, rabbits were clinically examined and after 12 (n = 6) or 24 (n = 9) weeks, the rabbits were euthanized and the joints evaluated by histology. The defects healed with fibrocartilage like tissue, and the filling of the defects ranged from less than 25% to complete. The healing of the defects varied both inter- and intra-group wise. Treatment with hyaluronan gel with or without BMP-2 had no effect on cartilage regeneration compared with controls. Instead, severe ectopic bone formation was found in seven joints treated with BMP-2. In conclusion, the present study shows that neither treatment with hyaluronic gel alone, nor in combination with BMP-2, improves the healing of an induced cartilage defect in rabbits. It further shows that BMP-2 can induce ectopic bone formation, which severely affects the functionality of the joint.

Regional differences in injury incidence in European professional football.

The objective of this study was to investigate regional differences in injury incidence in men's professional football in Europe. A nine-season prospective cohort study was carried out between 2001-2002 and 2009-2010 involving 1357 players in 25 teams from nine countries. Teams were categorized into different regions according to the Köppen-Geiger climate classification system. Teams from the northern parts of Europe (n = 20) had higher incidences of injury overall [rate ratio 1.12, 95% confidence interval (CI) 1.06 to 1.20], training injury (rate ratio 1.16, 95% CI 1.05 to 1.27), and severe injury (rate ratio 1.29, 95% CI 1.10 to 1.52), all statistically significant, compared to teams from more southern parts (n = 5). In contrast, the anterior cruciate ligament injury incidence was lower in the northern European teams with a statistically significant difference (rate ratio 0.43, 95% CI 0.25 to 0.77), especially for noncontact anterior cruciate ligament injury (rate ratio 0.19, 95% CI 0.09 to 0.39). In conclusion, this study suggests that there are regional differences in injury incidence of European professional football. However, further studies are needed to identify the underlying causes.

Injury incidence and injury patterns in professional football: the UEFA injury study.

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 the Union of European Football Associations as belonging to the 50 best European teams. MAIN OUTCOME MEASUREMENT: Injury incidence. RESULTS: 4483 injuries occurred during 566 000 h of exposure, giving an injury incidence of 8.0 injuries/1000 h. The injury incidence during matches was higher than in training (27.5 vs 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 vs 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 preseason. 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.

Comparison of injuries sustained on artificial turf and grass by male and female elite football players.

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.

UEFA injury study: a prospective study of hip and groin injuries in professional football over seven consecutive seasons.

BACKGROUND: Groin injury is a common injury in football and a complicated area when it comes to diagnosis and therapy. There is a lack of comprehensive epidemiological data on groin injuries in professional football. OBJECTIVE: To investigate the incidence, pattern and severity of hip and groin injuries in professional footballers over seven consecutive seasons. STUDY DESIGN: Prospective cohort study. SETTING: European professional football. METHODS: During the 2001/2 to 2007/8 seasons, between nine and 17 clubs per season (23 clubs in total) were investigated, accounting for 88 club seasons in total. Time loss injuries and individual exposure during club and national team training sessions and matches were recorded. MAIN OUTCOME MEASURE: Injury incidence. RESULTS: A total of 628 hip/groin injuries were recorded, accounting for 12-16% of all injuries per season. The total injury incidence was 1.1/1000 h (3.5/1000 match hours vs 0.6/1000 training hours, p<0.001) and was consistent over the seasons studied. Eighteen different diagnostic entities were registered, adductor (n = 399) and iliopsoas (n = 52) related injuries being the most common. More than half of the injuries (53%) were classified as moderate or severe (absence of more than a week), the mean absence per injury being 15 days. Reinjuries accounted for 15% of all registered injuries. In the 2005/6 to 2007/8 seasons, 41% of all diagnoses relied solely on clinical examination. CONCLUSIONS: Hip/groin injuries are common in professional football, and the incidence over consecutive seasons is consistent. Hip/groin injuries are associated with long absences. Many hip/groin diagnoses are based only on clinical examination.

UEFA injury study--an injury audit of European Championships 2006 to 2008.

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 (men's EURO n = 1, men's Under-21 n = 2, men's Under-19 n = 3, men's Under-17 n = 3, women's 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 men's EURO had the highest match injury incidence (41.6 injuries/1000 hours) followed by the men's Under-21 tournaments (33.9). The lowest match injury incidence was seen in the women's 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<0.001) and occurred from player contact (75 vs 48%, p = 0.018) compared to training injuries. A higher frequency of re-injury 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.

Injuries among male and female elite football players.

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<0.001). However, no difference was found in the incidence of severe injury (absence >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.

From user needs to system specifications: multi-disciplinary thematic seminars as a collaborative design method for development of health information systems.

This paper presents a new multi-disciplinary method for user needs analysis and requirements specification in the context of health information systems based on established theories from the fields of participatory design and computer supported cooperative work (CSCW). Whereas conventional methods imply a separate, sequential needs analysis for each profession, the "multi-disciplinary thematic seminar" (MdTS) method uses a collaborative design process. Application of the method in elderly homecare resulted in prototypes that were well adapted to the intended user groups. Vital information in the points of intersection between different care professions was elicited and a holistic view of the entire care process was obtained. Health informatics-usability specialists and clinical domain experts are necessary to apply the method. Although user needs acquisition can be time-consuming, MdTS was perceived to efficiently identify in-context user needs, and transformed these directly into requirements specifications. Consequently the method was perceived to expedite the entire ICT implementation process.

Usability laboratory test of a novel mobile homecare application with experienced home help service staff.

Using participatory design, we developed and deployed a mobile Virtual Health Record (VHR) on a personal digital assistant (PDA) together with experienced homecare staff. To assess transferability to a second setting and usability when used by novice users with limited system education the application was tested in a usability lab. Eight participants from another homecare district performed tasks related to daily homecare work using the VHR. Test protocols were analyzed with regard to effectiveness, potential usability problems and user satisfaction. Usability problems having impact on system performance and contextual factors affecting system transferability were uncovered. Questionnaires revealed that the participants frequently used computers, but never PDAs. Surprisingly there were only minor differences in input efficiency between novice and experienced users. The participants were overall satisfied with the application. However, transfer to another district can not be performed, unless by means of careful field observations of contextual differences.

Risk of injury in elite football played on artificial turf versus natural grass: a prospective two-cohort study.

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.