Injury incidence and distribution in elite football--a prospective study of the Danish and the Swedish top divisions

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.     

Injuries in Swedish elite football--a prospective study on injury definitions, risk for injury and injury pattern during 2001

The purpose of this study was to study the risk for injury and injury pattern in Swedish male elite football and to compare two different injury definitions. A prospective cohort study was conducted during 2001 on all 14 teams (310 players) in the Swedish top division. Injuries and individual exposure were recorded. Injury was defined as time-lost injury (715 injuries) and for comparison as tissue injury (765 injuries). No significant difference in the risk for injury between tissue injuries and time-lost injuries was found during matches (27.2 vs. 25.9 injuries per 1000 match hours, P=0.66) or training sessions (5.7 vs. 5.2 injuries per 1000 training hours, P=0.65). The risk for injury during training was significantly higher during the pre-season compared with the competitive season (P=0.01). Thigh strain was the single most common injury (14%). Knee sprain was the most common major injury (absence >4 weeks). Overuse injuries and re-injuries were frequent and constituted 37% and 22% of all injuries. Re-injuries caused significantly longer absence than their corresponding initial injuries (P=0.02). The risk for re-injury (P=0.02) and overuse injury (P<0.01) was significantly higher during the pre-season compared with the competitive season.     

Exposure and injury risk in Swedish elite football: a comparison between seasons 1982 and 2001

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.     

Epidemiology and traumatology of injuries in track athletes

During one year 4398 injured athletes were treated at the casualty wards of Aarhus, Denmark; 156 were practicing track and field disciplines. In the same period 54 track athletes of a Danish sport club were followed in order to register any lesion incurred during sports activity. Thirty-one athletes (57%) had 35 injuries, giving an injury incidence of 1.8 per 1000 hours of practice. At follow-up after 1 year, 13% of all athletes still had complaints, and none of them had returned to former sports activity. Jumpers had overuse symptoms correlated to take-off, and sprains or fractures related to downstrokes. Runners had a higher risk of overuse injuries than jumpers, especially involving the Achilles tendon and the plantar aponeurosis. Young athletes had a higher injury incidence per time than older participants; and women had higher injury risk than men.     

Injuries among Swedish female elite football players: a prospective population study

Injury occurrence in all 12 female elite senior football teams in premiere league was registered during 1 year. Of 269 players, 129 (48%) sustained 237 injuries. The total injury incidence was 4.6/1000 h of football. The injury incidence during practice was 2.7 and during the game time was 13.9/1000 h. The highest injury incidence during practice was to the knee (0.8/1000 h) and thigh (0.5/1000 h), and during game time was to the knee (4.4/1000 h) and head (2.2/1000 h). In total, the location for the highest injury incidence was the knee with 1.5 injuries/1000 h of football. The majority of injuries (82%) were localized to the lower extremities. Sixty-six injuries (28%) were re-occurring injuries (re-injuries). The incidence of traumatic injuries was 3.3/1000 h of football and for overuse injuries 1.3/1000 h. Overuse injuries occurred mainly during the preseason and at the beginning of the spring season. Thirty-nine percent of the injuries were slight or minor causing absence from practice or game time of less than 1 week, 39% were moderate (absence 7-28 days) and 22% were major (absence more than 28 days). The major injuries occurred often owing to trauma and were mainly to the knee.     

Long-term outcome of knee and ankle injuries in elite football

To estimate the risk and evaluate the long-term outcome of knee and ankle injuries in former national team elite football, 69 players were randomly selected, followed by clinical and stress radiographic examinations. Thirty-nine players (49 knees) had had knee injuries and 29 ankle injuries (35 ankles). The median time from injury until study examination was 25 years. The knee injuries were tears of the medial collateral ligament (MCL) in 24 cases combined with rupture of the anterior cruciate ligament (ACL) and meniscus lesions in three. Meniscus lesions had occurred in 17 cases including three combined with ACL and MCL and another two with ACL ruptures. Isolated rupture of the ACL had occurred in four cases. The ankle lesions were in 26 of 35 cases ruptures of the lateral ligaments. In all, 12 players had completely stopped football and three had changed occupation. Signs of arthritis were present in 63% of the injured knees and in 33% of the injured ankles. The incidence of arthritis in the group of 17 uninjured players was 26% in the knee and 18% the ankle. In elite football players knee and ankle injuries seem to have a serious long-term outcome, but also uninjured players have a higher risk of developing arthritis than the normal population.     

Epidemiology and traumatology of injuries in soccer

A prospective investigation of soccer injuries among 123 players participating at various competition levels was undertaken in a Danish soccer club. The injury incidence during games was highest at division level (18.5/1000 hours) and lowest at series level (11.9/1000 hours), whereas the distribution of the incidences during practice was reversed. The youth section (16 to 18 years) had incidences that could be compared to the highest senior level. The lower extremity was involved in 84% of the injuries, including 34% of overuse injuries. Ankle sprains were most common (36%) and equally found at all levels, whereas half of all overuse injuries were seen among division players. Contact injuries during tackling occurred most often in lower series and youths (45%). Players participating at high levels had only 30% of the injuries during tackling and 54% during running. More than half of 20 knee injuries were caused by tackling. Thirty-five percent of injured players were absent from soccer for more than 1 month; 28% had complaints 12 months after the end of the season with knee injuries the most serious. The study shows that the injury incidence, the pattern of injury, and the traumatology varied between players participating at different levels of soccer competition.     

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.     

Epidemiology of injuries in Portuguese senior male rugby union sevens: a cohort prospective study

Objectives: To assess the incidence, type and location of injuries sustained during the Portuguese rugby union sevens circuit. To investigate the influence of players’ training loads on injury risk.

Methods: A prospective cohort study recording time-loss injuries was conducted with all teams competing in the Portuguese national rugby sevens circuit (eight from the top-tier and seven from the second-tier). Main outcome measures included: incidence rate, anatomical location, type, injury incident and severity. Data were also collected regarding players’ training loads. Fisher’s exact test was used to estimate the relative risk of suffering an injury during the sevens season and training sevens during the fifteens season.

Results: A total of 27 injuries were recorded corresponding to an incidence rate of 133.9 injuries per 1000 player match-hours. The average severity was 22.22 days. Contact events preceded 81.5% of injuries. Most injuries occurred in the lower limb (66.7%) and were joint/ligament or muscle/tendon injuries (85.1%). The association between injuries and lower volume of training during the sevens season was identified for the second-tier (p = 0.021). For the same level, an inverse relation between training hours and injury severity was also found (p = 0.008). Top-tier players training sevens and fifteens simultaneously during the year presented a significant increase of injury risk (relative risk = 3.2; p = 0.011).

Conclusions: Injury incidence in our study is similar to that reported for international sevens, although severity is lower. An association between training loads and the occurrence of injuries was found for both tiers, although with differential results, thus reinforcing the need to customize players’ preparation. Further studies at non-elite competitions are needed to gather significant data to accurately formulate future injury prevention protocols or recommend modifications to game laws or competition formats, aiming at players’ welfare.     

Epidemiology of injuries during the Wheelchair Basketball World Championships 2018: A prospective cohort study

Several international sports federations have implemented a standardized injury reporting system during their championships. However, very few studies have investigated athletes with disabilities during major championships apart from the Paralympic Games. Therefore, the aim of this study was to assess the rate and characteristics of injuries during the Wheelchair Basketball World Championships 2018 (WBWC). This prospective cohort study was conducted during the WBWC held in Hamburg, Germany, from August 16 to August 26, 2018. Physicians or physiotherapists of all 28 participating teams (total 336 players) were asked to report all newly incurred injuries (with location, diagnosis, cause, and estimated duration of absence) daily on a standardized injury report form. Prevalence and incidence rates were calculated. Medical staff of 11 teams (132 players) reported 100 injuries, equivalent to 75.8 per 100 players (95% CI: 60.9-90.7) or 68.9 per 1000 player-days (55.4-82.4). Eight time-loss injuries were reported (6.1 injuries per 100 players [95% CI: 1.9-10.3] or 5.5 injuries per 1000 player-days [1.7-9.3]). More injuries were incurred during matches (n = 68) than during training. Most injuries affected the neck/cervical spine (16%), thoracic spine/upper back (15%), and shoulder (14%). The most frequent diagnosis was muscle spasms (25%), the most frequent cause was overuse (52%). A high rate of non–time-loss injuries compared to Paralympic Games was reported. Future studies should focus on the etiology of muscle spasms and further identify injury mechanisms of traumatic and overuse injuries in wheelchair basketball players to develop adequate preventive measures.     

A one‐season prospective study of injuries and illness in elite junior tennis

The objective of this study was to estimate the incidence and prevalence of injury and illness among elite junior tennis players. A cohort of 73 players (11–14 years) in the 2012–2013 Dutch national high‐performance program was followed for 32 weeks; all participants completed the study. The OSTRC Questionnaire on Health Problems was used to record self‐reported injuries and illnesses and to record training and match exposure. Main outcome measures were average prevalence of overuse injury and illness and incidence density of acute injury. On average, players practiced 9.1 h/week (SD 0.6; range 2.3–12.0) and had 2.2 h of match play (SD 0.6; range 2.3–12.0). During the course of the study, 67 players reported a total of 187 health problems. The average weekly prevalence of all health problems was 21.3% (95% CI: 19.2–22.9), of which 12.1% (95% CI: 10.9–13.3) constituted overuse injuries and 5.8% (95% CI: 4.6–6.9) illnesses. The incidence of acute injuries was 1.2/1000 h of tennis play (95% CI: 0.7–1.7). The high occurrence of overuse injuries among elite junior tennis players suggests that an early focus on preventative measures is warranted, with a particular focus on the monitoring and management of workload.     

Soccer injuries in Iceland

We investigated the frequency, cause and location of injuries in Icelandic elite soccer in 1991. The incidence of injuries for the individual player was 34.8 ± 5.7 per 1000 game-hours and 5.9 ± 1.1 per 1000 practice-hours. The most common types of injuries were muscle strains (29%), ligament sprains (22%), contusions (20%), and other injuries (29%). The frequency of reinjury was markedly high, where 44% of the strains and 58% of the sprains were registered as reinjuries. Strains occurred mainly during sprinting, sprains by tackling, and contusion during other contact. Significantly more injuries occurred on artificial turf than on grass or gravel in correlation to number of hours in games and practices. Teams who had the longest pre-season preparation period obtained significantly fewer injuries during the season.     

Soccer injuries in childhood

A prospective study of soccer injuries, involving 287 male youth players, from the ages of 12-15 was conducted in 24 Greek soccer clubs, during the course of one year. A total of 193 players sustained 209 injuries. The incidence of injuries was 4.0 injuries per 1000 h of soccer time per player, and the most common types of injuries were sprains and strains. Surprisingly, it was found that an increase of injury incidences occurred during practice. Fifty-eight injuries required medical assistance. The majority of injuries (80%) were located in the lower extremities. Collision with other players was the most common activity at the time of injury, accounting for 40% of all injuries. The conclusion of this study and the evidence from other studies suggests that youth soccer is a relatively low risk sport. However, a substantial amount of injuries could be prevented. It is necessary to identify the risk factors, which are associated with these types of injuries.     

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.     

Musculoskeletal injuries in the Norwegian National Ballet: a prospective cohort study

The purpose of the present study was to determine the incidence of musculoskeletal injuries among professional ballet dancers in the Norwegian National Ballet. A 19 weeks prospective study with registration and clinical assessment of dancers with injuries was conducted. Medical staff working for the National Ballet registered incidence of injuries. In addition the dancers filled out a questionnaire about previous injuries, their work situation, and factors they believed increased the risk of injuries. Of the 41 dancers (80% response rate), 31 dancers experienced one injury or more. The majority of injuries involved foot and ankle. Twenty-two per cent of the injuries were acute injuries. Seventy-five per cent of the injuries were soft tissue injuries. Most injuries were of mild to moderate severity. Sixteen per cent of the injuries resulted in absence from work. Factors, the dancers believed were associated with risk of injuries were related to training, organizational factors and environmental factors. Seventy-eight per cent of the dancers experienced "negative" stress at work. Sixty-four per cent experienced that they had little influence on their work conditions. This study showed, however, no significant association between these psychological factors and musculoskeletal injuries. It is concluded that there is a high incidence of musculoskeletal injuries in the Norwegian National Ballet.     

A 1‐year prospective analysis of injuries in amateur and elite fistball

The purpose of this study was to examine the incidence and mechanisms of acute injuries in the sport of fistball. No scientific studies on injury characteristics have yet been conducted in this traditional sport game. The study was conducted prospectively over the course of 12 months. During a total of 40.308 h of sport‐specific exposure, 240 players reported 492 injuries, representing an overall injury rate of 12.2 injuries/1000 h of exposure. Most injuries were classified as bagatelle injuries (67.8%). The majority of the injuries were located in the knee (23.5%) followed by the elbow (11.9%) and the hip (11.5%). Ankle injuries resulted in the longest impairment from sports participation. The most common types of injury were abrasions (38.2%), contusions (21.1%), distortions (7.5%) and muscle strains (6.9%). Wrong or insufficient equipment (15.0%) was the most commonly mentioned causes of injury. The data indicate that the injury risk in fistball is rather high; however, the sport should not be considered a high‐risk sport because most of the injuries are slight and do not prevent the players from training or competition. Injury prevention strategies should include the development of fistball‐specific protective equipment with focus on the knee and elbow joint.     

Recording injuries among World Cup skiers and snowboarders: a methodological study

No long‐term injury surveillance programs exist for competitive skiing or snowboarding. The objective of this study was, therefore, to compare different methods to record injuries among World Cup athletes in alpine, freestyle, and cross‐country skiing, snowboarding, ski jumping and Nordic combined. Information regarding injuries sustained during the 2006–2007 winter season was recorded through three separate and independent systems: prospective injury reports by technical delegates (TD) from the International Ski Federation, prospective medical team registration by selected teams, and retrospective athlete interviews at the end of the season. A total of 100 unique injuries to 602 World Cup athletes were identified from any of the three recording methods. Of these, 91% were registered through the athlete interviews, 47% by the medical team registration and 27% by the TD reports. Only 20 injuries (20%) were captured by all three methods. A total of 64 time‐loss injuries were registered. The interviews captured 60 (94%), the medical team registration 39 (61%), and the TD reports 23 (36%) time‐loss injuries, while 18 (28%) were registered by all three systems. Retrospective interviews with athletes/coaches regarding injuries during the last 6 months gave the most complete picture of injuries to World Cup skiers and snowboarders.     

Intrinsic risk factors for acute ankle injuries among male soccer players: a prospective cohort study

This prospective cohort study was conducted to identify risk factors for acute ankle injuries among male soccer players. A total of 508 players representing 31 amateur teams were tested during the 2004 pre‐season through a questionnaire on previous injury and function score (foot and ankle outcome score; FAOS), functional tests (balance tests on the floor and a balance mat) and a clinical examination of the ankle. Generalized estimating equations were used in univariate analyses to identify candidate risk factors, and factors with a P‐value <0.10 were then examined in a multivariate model. During the season, 56 acute ankle injuries, affecting 46 legs (43 players), were registered. Univariate analyses identified a history of previous acute ankle injuries [odds ratio (OR) per previous injury: 1.25, 95% confidence interval (CI) 1.09–1.43] and the FAOS sub‐score “Pain” (OR for a 10‐point difference in score: 0.81, 95% CI 0.62–1.04) as candidate risk factors. In a multivariate analysis, only the number of previous acute ankle injuries proved to be a significant (adjusted OR per previous injury: 1.23; 95% CI 1.06–1.41, P=0.005) predictor of new injuries. Function scores, functional tests and clinical examination could not independently identify players at an increased risk in this study.