Background and Objectives: Patellar tendinopathy is difficult to treat, and when combined with partial rupture, there are additional challenges. The aim of this study was to evaluate the subjective outcome and return-to-sport status after ultrasound (US)- and colour doppler (CD)-guided wide awake local anaesthetic no tourniquet (WALANT) arthroscopic shaving in elite athletes. Material and Methods: Thirty Swedish and international elite athletes (27 males) with a long duration (>1 year) of persistent painful patellar tendinopathy in 35 patellar tendons, not responding to non-surgical treatment, were included. All patients were treated with the same protocol of arthroscopic shaving, including bone removal and debridement of partial rupture, followed by at least 3 months of structured rehabilitation. The VISA-P score and a study-specific questionnaire evaluating physical activity level and subjective satisfaction with the treatment were used for evaluation. Results: At the 2-year follow-up (mean 23, range 8-38 months), 25/30 patients (29/35 tendons) were satisfied with the treatment result and had returned to their pre-injury sport. The mean VISA-P score increased from 37 (range 7-69) before surgery to 80 (range 44-100) after surgery (p < 0.05). There was one drop-out (one tendon). There were no complications. Conclusions: US- and CD-guided WALANT arthroscopic shaving for persistent painful patellar tendinopathy, including bone removal and debridement of partial rupture, followed by structured rehabilitation showed good clinical results in the majority of the elite-level athletes.

Objectives. Jumper's knee, or proximal patellar tendinopathy, is commonly seen among athletes in leg explosive sports, and for a subgroup surgical treatment is needed. The aim of this study was to identify what type of sports were most frequent among athletes treated surgically for Jumper's knee at an international tendon clinic during a consecutive 13-year period. Methods. The study included 344 consecutive patients (306 males, mean age 27 years, range 17-58; 38 females, mean age 24 years, range 18-44) from 21 different countries seeking help for therapy-resistant jumper's knee. There were 274 elite athletes, 168 being full-time professionals. All were diagnosed to have tendinopathy in the proximal patellar tendon and were operated on with ultrasound- and Doppler-guided arthroscopic shaving surgery. Results. The single most common sport was football (n = 95, 28%), followed by rugby (n = 37, 11%) and handball (n = 32, 9%), with 117 (34%) playing at a professional level. The rest of the athletes participated in 17 other different elite sports and nine recreational sports (running/jogging, padel, squash, biking, gym training, bowling, cheerleading, dancing, and ultimate frisbee). Conclusions. Football was the most common sport among patients requiring surgical treatment for jumper's knee, constituting 28% of all patients, and together with rugby and handball they constituted almost half of all patients. There was a wide sport distribution with 29 different team and individual sports represented.

Purpose: Midportion Achilles tendinopathy is a relatively common condition. This study aimed to investigate the presence of a normal Achilles tendon, but a tendinopathic plantaris tendon, in a large and consecutive prospective sample of patients referred to a specialised tendon clinic for midportion Achilles tendon pain not responding to non-surgical treatment. Patients and Methods: A total of 105 consecutive tendons were operated on in 81 patients (62 males) suffering from painful midportion Achilles tendon pain. Clinical examination, ultrasound (US) and colour Doppler (CD) examination, and wide awake local anaesthetic no tourniquet (WALANT) surgery were performed in all patients. Results: For 19/105 (18%) tendons from 14 patients, clinical examination suspected plantaris tendinopathy alone as there was a distinct tenderness on the medial side, but no thickening of the Achilles tendon. US examination followed by surgery confirmed the diagnosis. Conclusion: Midportion Achilles tendon pain is not always related to Achilles tendinopathy since pain related to the plantaris tendon alone was found in almost every fifth patient. Consequently, there is an obvious need for proper examination to identify the pain source and establish a correct diagnosis before treatment.

Background and Objectives: Chronic painful midportion Achilles combined with plantaris tendinopathy can be a troublesome condition to treat. The objective was to prospectively follow patients subjected to ultrasound (US)- and color doppler (CD)-guided wide awake, local anesthetic, no-tourniquet (WALANT) surgery in a private setting. Material and Methods: Twenty-six Swedish patients (17 men and 9 women, mean age 50 years (range 29-62)) and eight international male patients (mean age of 38 years (range 25-71)) with combined midportion Achilles and plantaris tendinopathy in 45 tendons altogether were included. All patients had had >6 months of pain and had tried non-surgical treatment with eccentric training, without effect. US + CD-guided surgical scraping of the ventral Achilles tendon and plantaris removal under local anesthesia was performed on all patients. A 4-6-week rehabilitation protocol with an immediate full-weight-bearing tendon loading regime was used. The VISA-A score and a study-specific questionnaire evaluating physical activity level and subjective satisfaction with the treatment were used for evaluation. Results: At the 1-year follow-up, 32/34 patients (43 tendons) were satisfied with the treatment result and had returned to their pre-injury Achilles tendon loading activity. There were two dropouts (two tendons). For the Swedish patients, the mean VISA-A score increased from 34 (0-64) before surgery to 93 (61-100) after surgery (p < 0.001). There were two complications, one wound rupture and one superficial skin infection. Conclusions: For patients suffering from painful midportion Achilles tendinopathy and plantaris tendinopathy, US + CD-guided surgical Achilles tendon scraping and plantaris tendon removal showed a high satisfaction rate and good functional results 1 year after surgery.

Background: A cruciate ligament (CL) injury is a severe injury in soccer. Neuromuscular training programs have a well-documented preventive effect, but there are few studies on the effectiveness of such a program at a national level. The Swedish Knee Control Program (KCP) was found to be effective in preventing CL injuries in youth female soccer players. The KCP was implemented nationwide in Sweden in 2010. Purpose: To evaluate the effectiveness of the Swedish KCP in reducing acute knee injuries in soccer players at a nationwide level. Study Design: Descriptive epidemiology study. Methods: All licensed soccer players in Sweden are covered by the same insurance company. Using this insurance database, around 17,500 acute knee injuries that were reported to the insurance company between 2006 and 2015 were included in the study. By matching the number of licensed soccer players with the number of reported injuries each year, the annual incidence of knee and CL injuries was able to be calculated. To evaluate the spread of the KCP nationally, a questionnaire was sent to all 24 Swedish district football associations (FAs) with questions regarding KCP education. The number of downloads of the KCP mobile application (app) was obtained. Results: The incidence of CL injuries decreased during the study period for both male (from 2.9 to 2.4 per 1000 player-years) and female players (from 4.9 to 3.9 per 1000 player-years). The overall incidence of knee injuries decreased in both male (from 5.6 to 4.6 per 1000 player-years) and female players (from 8.7 to 6.4 per 1000 player-years). Comparing before and after the nationwide implementation of the KCP, there was a decrease in the incidence of CL injuries by 6% (rate ratio [RR], 0.94 [95% CI, 0.89-0.98]) in male players and 13% (RR, 0.87 [95% CI, 0.81-0.92]) in female players and a decrease in the incidence of knee injuries by 8% (RR, 0.92 [95% CI, 0.89-0.96]) and 21% (RR, 0.79 [95% CI, 0.75-0.83]), respectively (P amp;lt; .01 for all). This trend corresponded to a reduction of approximately 100 CL injuries each year in Sweden. A total of 21 of 24 district FAs held organized KCP educational courses during the study period. The percentage of district FAs holding KCP courses was between 46% and 79% each year. There were 101,236 downloads of the KCP app. Conclusion: The KCP can be considered partially implemented nationwide, and the incidence of knee and CL injuries has decreased in both sexes at a nationwide level.

Background: The literature on upper extremity injuries in professional soccer players is scarce, and further insight into the onset and cause of these injuries as well as potential differences between goalkeepers and outfield players is important. Purpose: To investigate the epidemiology of hand, wrist, and forearm injuries in male professional soccer players between 2001 and 2019. Study Design: Descriptive epidemiology study. Methods: Between the 2001-2002 and 2018-2019 seasons, 120 European male soccer teams were followed prospectively for a varying number of seasons (558 team-seasons in total). Time-loss injuries and player-exposures to training sessions and matches were recorded on an individual basis in 6754 unique players. Injury incidence was reported as the number of injuries per 1000 player-hours, and between-group differences were analyzed using Z statistics and rate ratios (RRs) with 95% CIs. Between-group differences in layoff time were analyzed. Results: In total, 25,462 injuries were recorded, with 238 (0.9%) of these affecting the hand (71.4%; n = 170), wrist (16.8%; n = 40), and forearm (11.8%; n = 28), producing an incidence of 0.065 injuries per 1000 hours. A majority of the injuries were traumatic with an acute onset (98.7%; n = 235). Fractures were the most common injuries recorded (58.8%; n = 140), often involving the metacarpal bones (25.2%; n = 60) and phalanges (10.1%; n = 24). The injury incidence was significantly higher for goalkeepers (115 injuries; 0.265 per 1000 hours) compared with outfield players (123 injuries; 0.038 per 1000 hours) (RR, 7.0 [95% CI, 5.4-9.0]). Goalkeepers also had a significantly longer mean layoff time than outfield players (23 +/- 27 vs 15 +/- 27 days; P = .016). Conclusion: Injuries to the hand, wrist, and forearm constituted less than 1% of all time-loss injuries in male professional soccer players. Fractures were most common and constituted more than half of all injuries. Goalkeepers had a 7-fold higher incidence and an over 1-week longer mean layoff time compared with outfield players.

Pneumatic wound compression does not reduce the need for transfusion after hip fracture surgery.

Objective To assess the evidence for risk factors and prevention measures for shoulder injuries in overhead sports. Design Systematic review with best-evidence synthesis. Data sources Medline (Ovid), PubMed (complementary search), Embase (Elsevier), Cochrane (Wiley), SPORTDiscus (Ebsco) and Web of Science Core Collection (Thomson Reuters), from 1 January 1990 to 15 May 2017. Eligibility criteria for selecting studies Randomised controlled trials, cohort studies and case-control studies on risk factors or prevention measures for shoulder injuries in overhead sports. The eligible studies were quality assessed using the Scottish Intercollegiate Guidelines Network criteria. Results Of 4778 studies identified, 38 were eligible for quality review and 17 met the quality criteria to be included in the evidence synthesis. One additional quality study presented a shoulder injury prevention programme. Most studies focused on baseball, lacrosse or volleyball (n = 13). The risk factors examined included participation level (competition vs training) (n = 10), sex (n = 4), biomechanics (n = 2) and external workload (n = 2). The evidence for all risk factors was limited or conflicting. The effect of the prevention programme within the subgroup of uninjured players at baseline was modest and possibly lacked statistical power. Conclusions All investigated potential risk factors for shoulder injury in overhead sports had limited evidence, and most were non-modifiable (eg, sex). There is also limited evidence for the effect of shoulder injury prevention measures in overhead sports.

Shoulder problems are frequent among senior elite handball players. The objective of this study was to assess the prevalence of shoulder problems among adolescent elite handball players and to investigate potential differences in gender, school grade, playing position and playing level. During the 2014 and 2015 pre-season periods, 471 players (age 15-18 years, 54% female) completed a comprehensive baseline questionnaire regarding history of any shoulder pain and shoulder problems experienced during the past season. The players were monitored weekly for one competition season (September-April) regarding shoulder problems and the amount of match and training. Generalised linear models with a binomial link function were used to calculate a prevalence ratio (PR) with 95% confidence interval (CI) to compare the subgroups of players. In total, 110 players (23%) reported having substantial shoulder problems (defined as moderate/severe reduction in training volume, or moderate/severe reduction in performance, or complete inability to participate) at some point during the follow-up season, of which almost half reported complete inability to participate. Of those players reporting substantial problems, 43% (95% CI 39-48) did so for at least 3 consecutive weeks during the season. The prevalence was significantly higher in female players (PR 1.46, 95% 1.04-2.06) and in backcourt players (PR 1.58, 95% CI 1.08-2.32), but no differences were found for school grade (PR 1.21 95% CI 0.88-1.67) or playing level (PR 1.09 95% CI 0.76-1.56). The prevalence of substantial shoulder problems in adolescent elite handball players is high, especially among females, and this warrants further studies on risk factors for shoulder injury and the development of prevention strategies in handball players already before the age of 15. These findings also highlight the importance of introducing a clinical monitoring programme on a routine basis and improving the medical support, taking gender-related aspects into consideration, at handball-profiled secondary schools. II.

Background The risk of injury in adolescent handball is high, and shoulder and knee injuries are among the most frequent and burdensome. The Swedish Knee Control programme reduced the risk of anterior cruciate ligament injuries in female youth football players and traumatic knee injuries in male and female youth floorball players. However, to date, Knee Control has not been evaluated in an elite youth sport setting. The literature on the prevention of shoulder injuries in sport is scarce, and there are to our knowledge no previous studies evaluating the preventative efficacy of injury prevention exercise programmes (IPEPs) on shoulder injuries in adolescent handball players. Objectives To study the preventive efficacy of IPEPs on shoulder and knee injuries in adolescent elite handball players. Methods Eighteen Swedish handball-profiled secondary schools (clusters) with players aged 15-19 years, 54% males were randomised into either the Shoulder Group or Knee Group (interventions) or a Control Group. Players in the Shoulder Group were instructed to perform the Shoulder Control programme, and players in the Knee Group to perform the Knee Control programme, three times per week during May 2018 to May 2019. Control Group players continued their usual training. Outcomes were shoulder and knee injuries defined by the Oslo Sports Trauma Research Center Overuse Injury Questionnaire. Intention-to-treat analyses were performed using Cox regression models with hazard rate ratios (HRRs) with corresponding 95% confidence intervals (CI). Results Six clusters (199 players) in the Shoulder Group, six clusters (216 players) in the Knee Group and six clusters (212 players) in the Control Group were included. There were 100 shoulder injuries and 156 knee injuries. The Shoulder Group had a 56% lower shoulder injury rate, HRR 0.44 (95% CI 0.29 to 0.68), and the Knee Group had a 31% lower knee injury rate, HRR 0.69 (95% CI 0.49 to 0.97) than the Control Group. The absolute risk reduction was 11% and 8%, and the number needed to treat was 9 and 13, respectively. Conclusions Adolescent elite handball players who performed the Shoulder Control and the Knee Control programmes had a lower risk of shoulder and knee injuries, respectively, than players who continued their usual training. Further research on how these two programmes can be combined to reduce knee and shoulder injuries in a time effective way is warranted. Trial registration ISRCTN15946352.

Background: Handball is a physical contact sport that includes frequent overhead throwing, and this combination leads to a high rate of shoulder injuries. Several factors have been associated with shoulder injuries in overhead athletes, but strong scientific evidence is lacking for most suggested risk factors. We therefore designed the Karolinska Handball Study (KHAST) with the aim to identify risk factors for shoulder injuries in adolescent male and female elite handball players studying at handball-profiled secondary schools in Sweden. Secondary objectives are to investigate whether shoulder function changes during the competition season and whether the physical profile of the players changes during their time in secondary school. Methods: Players aged 15 to 19 years were included during the pre-season period of the 2014-2015 and the 2015-2016 seasons. At inclusion, players signed informed consent and filled in a questionnaire regarding playing position, playing level, previous handball experience, history of shoulder problems and athletic identity. Players also completed a detailed test battery at baseline evaluating the shoulder, neck and trunk. Players were then prospectively monitored weekly during the 2014-2015 and/or 2015-2016 competitive seasons regarding injuries and training/match workload. Results from the annual routine physical tests in the secondary school curriculum including bench press, deep squat, hand grip strength, clean lifts, squat jumps, counter movement jumps, amp;lt;30 m sprints, chins, dips and Coopers test will be collected until the end of the competitive season 2017-2018. The primary outcome is the incidence of shoulder injuries and shoulder problems. The secondary outcome is the prevalence of shoulder injuries and shoulder problems. Discussion: Shoulder problems are frequent among handball players and a reduction of these injuries is therefore warranted. However, in order to introduce appropriate preventive measures, a detailed understanding of the underlying risk factors is needed. Our study has a high potential to identify important risk factors for shoulder injuries in adolescent elite handball players owing to a large study sample, a high response rate, data collection during consecutive seasons, and recording of potential confounding factors.

OBJECTIVE: To investigate whether adolescent elite female and male handball players with shoulder muscle weakness, deficits in shoulder rotation range of motion (ROM) or in joint position sense (JPS), or scapular dyskinesis in the preseason had a higher rate of new shoulder injuries compared to players without these characteristics. DESIGN: Prospective cohort study. METHODS: We studied 344 uninjured players (452 player-seasons, 50% female). We measured their shoulder strength in isometric external rotation (IER), isometric internal rotation (IIR), isometric abduction, and eccentric external rotation, as well as their shoulder ROM, JPS, and scapular dyskinesis, during the preseason. Players were monitored weekly regarding match and training hours and shoulder injuries during 1 or 2 seasons. We used multivariable Cox proportional hazard models to calculate hazard rate ratios related to the first injury and 95% confidence intervals (CIs). RESULTS: During 2 seasons, the participants reported 48 new shoulder injuries. In female players, the hazard ratio was 2.37 (95% CI: 103, 5.44) for IER weakness and 2.44 (95% CI: 106, 5.61) for IIR weakness. The hazard rate ratio was 0.85 (95% CI: 0.39,183) for an IER/IIR ratio of less than 0.75 and 1.53 (95% CI: 0.36, 6.52) for scapular dyskinesis. In male players, the hazard rate ratio was 1.02 (95% CI: 0.44, 2.36) for ER weakness, 0.74 (95% CI: 0.31,1.75) for IIR weakness, 2.0 (95% CI: 0.68, 5.92) for an IER/IIR rati of less than 0.75, and 3.43 (95% CI: 1.49, 7.92) for scapular dyskinesis. There were no associations between new shoulder injuries and deficits in ROM or JPS. CONCLUSION: In adolescent elite handball, male players with preseason scapular dyskinesis and female players with preseason IIR or IER shoulder weakness had an increased shoulder injury rate.

Background and purpose - Treatment of Dupuytrens contracture (DC) with collagenase Clostridium histolyticum (CCH) consists of injection followed by finger manipulation. We used a modified method, injecting a higher dose than recommended on the label into several parts of the cord, which allows treatment of multiple joint contractures in 1 session and may increase efficacy. We studied the occurrence of skin tears and short-term outcome with this procedure. Patients and methods - We studied 164 consecutive hands with DC, palpable cord, and extension deficit of greater than= 20 degrees in the metacarpophalangeal (MCP) and/or proximal interphalangeal (PIP) joint (mean patient age 70 years, 82% men). A hand surgeon injected all the content of 1 CCH vial (approximately 0.80 mg) into multiple spots in the cord and performed finger extension under local anesthesia after 1 or 2 days. A nurse recorded skin tears on a diagram and conducted a standard telephone follow-up within 4 weeks. A hand therapist measured joint contracture before injection and at a median of 23 (IQR: 7-34) days after finger extension. Results - A skin tear occurred in 66 hands (40%). The largest diameter of the tear was less than= 5 mm in 30 hands and greater than 10 mm in 14 hands. Hands with skin tear had greater mean pretreatment MCP extension deficit than those without tear: 59 degrees (SD 26) as opposed to 32 degrees (SD 23). Skin tear occurred in 21 of 24 hands with MCP contracture of greater than= 75 degrees. All tears healed with open-wound treatment. No infections occurred. Mean improvement in total (MCP + PIP) extension deficit was 55 degrees (SD 28). Interpretation - Skin tears occurred in 40% of hands treated with collagenase injections, but only a fifth of them were larger than 1 cm. Tears were more likely in hands with severe MCP joint contracture. All tears healed without complications. Short-term contracture reduction was good.

OBJECTIVES:

To compare collagenase injections and surgery (fasciectomy) for Dupuytren's contracture (DC) regarding actual total direct treatment costs and short-term outcomes.

DESIGN:

Retrospective cohort study.

SETTING:

Orthopaedic department of a regional hospital in Sweden.

PARTICIPANTS:

Patients aged 65 years or older with previously untreated DC of 30° or greater in the metacarpophalangeal (MCP) and/or proximal interphalangeal (PIP) joints of the small, ring or middle finger. The collagenase group comprised 16 consecutive patients treated during the first 6 months following the introduction of collagenase as treatment for DC at the study centre. The controls were 16 patients randomly selected among those operated on with fasciectomy at the same centre during the preceding 3 years.

INTERVENTIONS:

Treatment with collagenase was given during two standard outpatient clinic visits (injection of 0.9 mg, distributed at multiple sites in a palpable cord, and next-day finger extension under local anaesthesia) followed by night-time splinting. Fasciectomy was carried out in the operating room (day surgery) under general or regional anaesthesia using standard technique, followed by therapy and splinting.

PRIMARY AND SECONDARY OUTCOME MEASURES:

Actual total direct costs (salaries of all medical personnel involved in care, medications, materials and other relevant costs), and total MCP and PIP extension deficit (degrees) measured by hand therapists at 6-12 weeks after the treatment.

RESULTS:

Collagenase injection required fewer hospital outpatient visits to a therapist and nurse than fasciectomy. Total treatment cost for collagenase injection was US$1418.04 and for fasciectomy US$2102.56. The post-treatment median (IQR) total extension deficit was 10 (0-30) for the collagenase group and 10 (0-34) for the fasciectomy group.

CONCLUSIONS:

Treatment of DC with one collagenase injection costs 33% less than fasciectomy with equivalent efficacy at 6 weeks regarding reduction in contracture.

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.

Background It has been hypothesised that injury risk after return to play following an injury absence is influenced by the amount of training completed before return to competition. Aim To analyse if the number of completed training sessions between return to play and the first subsequent match appearance was associated with the odds of injury in men's professional football. Methods From a cohort study, including 303 637 individual matches, 4805 first match appearances after return to play following moderate to severe injuries (≥8 days absence) were analysed. Rate ratios (RRs) were used to compare injury rates in the first match appearances with the average seasonal match injury rate. Odds ratios (ORs) were used to analyse associations between the number of completed training sessions and general (all injuries), muscle, and non-muscle injury odds. Results Injury rate in the first match after return to play was increased by 87% compared with the average seasonal match injury rate (46.9 vs 25.0/1000 hours, RR=1.87; 95% CI 1.64 to 2.14). The odds of injury dropped 7% with each training session before the first match (OR 0.93; 95% CI 0.87 to 0.98). The same association was found for muscle injuries (OR 0.87; 95% CI 0.79 to 0.95) but not for non-muscle injuries (OR 0.99; 95% CI 0.91 to 1.07). Conclusions Injury rates in the first match after injury are higher than the average seasonal match injury rate, but the propensity for player injury is decreased when players complete more training sessions before their first match. 

Background The association between match congestion and injury rates in professional football has yielded conflicting results. Aim To analyse associations between match congestion on an individual player level and injury rates during professional football matches. Methods Data from a prospective cohort study of professional football with 133 170 match observations were analysed with Poisson regressions. Associations between short-term match congestion, defined as number of days between two match exposures (3, 4, 5, 6 and 7-10 days) and injury rates were analysed. To analyse the influence of long-term match congestion, defined as individual match exposure hours in the 30 days preceding a match, observations were categorised into three groups (low, 4.5; medium, amp;gt;4.5to 7.5; and high, amp;gt;7.5hours). Results No differences in total match injury rates were found between the reference category (3 days) and the other categories of short-term congestion. Muscle injury rates were significantly lower in matches preceded by 6 (rate ratio (RR) 0.79; 95%CI 0.65 to 0.95) or 7-10 days (RR 0.81; 95%CI 0.71 to 0.93) compared with 3 days since the last match exposure. No differences in total and muscle injury rates between the three long-term match congestion groups were found. Conclusions In this study of male professional football players, there were no match congestion-related differences in total match injury rates, but muscle injury rates during matches were lower when players were given at least 6days between their match exposures.

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.

Background Studies on subsequent anterior cruciate ligament (ACL) ruptures and career length in male professional football players after ACL reconstruction (ACLR) are scarce. Aim To investigate the second ACL injury rate, potential predictors of second ACL injury and the career length after ACLR. Study design Prospective cohort study. Setting Mens professional football. Methods 118 players with index ACL injury were tracked longitudinally for subsequent ACL injury and career length over 16.9 years. Multivariable Cox regression analysis with HR was carried out to study potential predictors for subsequent ACL injury. Results Median follow-up was 4.3 (IQR 4.6) years after ACLR. The second ACL injury rate after return to training (RTT) was 17.8% (n=21), with 9.3% (n=11) to the ipsilateral and 8.5% (n=10) to the contralateral knee. Significant predictors for second ACL injury were a non-contact index ACL injury (HR 7.16, 95% CI 1.63 to 31.22) and an isolated index ACL injury (HR 2.73, 95% CI 1.06 to 7.07). In total, 11 of 26 players (42%) with a non-contact isolated index ACL injury suffered a second ACL injury. RTT time was not an independent predictor of second ACL injury, even though there was a tendency for a risk reduction with longer time to RTT. Median career length after ACLR was 4.1 (IQR 4.0) years and 60% of players were still playing at preinjury level 5 years after ACLR. Conclusions Almost one out of five top-level professional male football players sustained a second ACL injury following ACLR and return to football, with a considerably increased risk for players with a non-contact or isolated index injury.

Purpose To study the epidemiology and return to play characteristics of anterior and posterior ankle impingement syndromes (AAIS and PAIS) over 18 consecutive seasons in male professional soccer players. Methods Between the 2001-2002 and 2018-2019 seasons, 120 European soccer teams were followed prospectively for various seasons. Time loss injuries and player exposures were recorded individually in 6754 unique players. Injury incidence and burden were reported as the number of injuries and days absence per 1000 h with 95% confidence intervals (CIs). Injury severity was reported as median absence in days with the interquartile range (IQR). Results Out of 25,462 reported injuries, 93 (0.4%) were diagnosed as AAIS (38%) or PAIS (62%) in 77 players. AAIS and PAIS were similar regarding injury characteristics except for a greater proportion of AAIS having a gradual onset (69% vs.47%; P = 0.03) and being re-injuries (31% vs. 9%; P = 0.01). Impingement syndromes resulted in an overall incidence of 0.03 injuries (95% CI 0.02-0.03) per 1000 h and an injury burden of 0.4 absence days per 1000 h. PAIS incidence was significantly higher than that for AAIS [0.02 (95% CI 0.002-0.03) vs. 0.01 (95% CI 0.005-0.01) injuries per 1000 h (RR = 1.7). The absence was significantly longer in AAIS than in PAIS [10 (22) vs. 6 (11) days; P = 0.023]. Impingement syndromes that presented with a gradual onset had longer absences in comparison to impingement with an acute onset [8 (22) vs. 5 (11) days; P = 0.014]. Match play was associated with a higher incidence and greater injury burden than training: 0.08 vs. 0.02 injuries per 1000 h (RR 4.7), respectively, and 0.9 vs. 0.3 days absence per 1000 h (RR 2.5). Conclusion Ankle injuries are frequent in mens professional soccer and ankle impingement is increasingly recognized as a common source of pain, limited range of motion, and potential time loss. In our study, ankle impingement was the cause of time loss in less than 0.5% of all injuries. PAIS was more frequently reported than AAIS, but AAIS was associated with more absence days and a higher re-injury rate than PAIS. The findings in this study can assist the physician in best practice management on ankle impingment syndromes in professional football.

Objectives The primary objective was to study the adoption of the NHE programme in European football teams in the 2020/21 season and to compare it to the previous study. A second objective was to compare hamstring injury rates between teams that used the NHE programme in the team training and teams that used the NHE only for players with previous or current hamstring injuries. Methods Data about the implementation of the NHE programme and injury rates were included for 17 teams participating in the Elite Club Injury Study during the 2020/2021 season. Results One team (6%) used the full original NHE programme, and another four teams used it for all or most players in the team (team training group, n=5). Eleven teams used NHE only for players with a previous or current hamstring injury (individual training group), and one team did not use NHE. The team training group had fewer hamstring injuries (5 vs 11 per team, p=0.008) and a lower injury burden (12 vs 35 lay-off days per 1000 hours, p=0.003) than the individual training group. Conclusion Similar to previous reports, low adoption of the NHE programme was seen in the 2020/2021 season. The low adoption rate (13%) relates to the number of teams fully or partly using NHE programmes. Teams that used NHE for the whole team or most players had a lower hamstring injury burden than teams that used NHE only for individual players.

ObjectivesTo: (1) describe hamstring injury incidence and burden in male professional football players over 21 seasons (2001/02 to 2021/22); (2) analyse the time-trends of hamstring muscle injuries over the most recent eight seasons (2014/15 to 2021/22); and (3) describe hamstring injury location, mechanism and recurrence rate. Methods3909 players from 54 teams (in 20 European countries) from 2001/02 to 2021/22 (21 consecutive seasons) were included. Team medical staff recorded individual player exposure and time-loss injuries. Time-trend analyses were performed with Poisson regression using generalised linear models. Results2636 hamstring injuries represented 19% of all reported injuries, with the proportion of all injuries increasing from 12% during the first season to 24% in the most recent season. During that same period, the percentage of all injury absence days caused by hamstring injuries increased from 10% to 20%. Between 2014/15 and 2021/22, training hamstring injury incidence increased (6.7% annually, 95% CI 1.7% to 12.5%) as did burden (9.0% annually, 95% CI 1.2% to 18.3%). During those years, the match hamstring injury incidence also increased (3.9% annually, 95% CI 0.1% to 7.9%) and with the same trend (not statistically significant) for match hamstring injury burden (6.2% annually, 95% CI -0.5% to 15.0%). ConclusionsHamstring injury proportions-in number of injuries and total absence days-doubled during the 21-year period of study. During the last eight seasons, hamstring injury rates have increased both in training and match play.

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.

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.

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.

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.

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.

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.

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.

Objective: To study normative values of range of motion (ROM), strength, and functional performance and investigate changes over 1 year in adolescent female football players.Design: Cross-sectional.Participants: 418 adolescent female football players aged 12-17 years.Main outcome measures: The physical characteristic assessments included (1) ROM assessment of the trunk, hips, and ankles; (2) strength measures (maximal isometric and eccentric strength for the trunk, hips, and knees, and strength endurance for the neck, back, trunk and calves), and (3) functional per-formance (the one-leg long box jump test and the square hop test).Results: Older players were stronger, but not when normalized to body weight. Only small differences in ROM regarding age were found. ROM increased over 1 year in most measurements with the largest change in hip external rotation, which increased by 6-7 degrees (Cohens d = 0.83-0.87). Hip (d = 0.28-1.07) and knee (d = 0.38-0.53) muscle strength and the square hop test (d = 0.71-0.99) improved over 1 year.Conclusions: Normative values for ROM and strength assessments of neck, back, trunk, hips, knees, calves and ankles are presented for adolescent female football players. Generally, fluctuations in ROM were small with little clinical meaning, whereas strength improved over 1 year.(c) 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Background: Normative values of lifestyle characteristics in adolescent female football players may be used by clinicians and coaches to take actions because the potential important for well-being, performance on the pitch, and risk of injury. The aim was to report descriptive characteristics of lifestyle factors in adolescent female football players and potential changes over 1 year. Methods: We included 419 adolescent competitive female football players from 12 clubs and 27 teams (age 14 & PLUSMN; 1 years, range 12-17 years) and 286 were followed over 1 year. The players completed an extensive questionnaire regarding demographics, football-related factors, and lifestyle factors including tobacco consumption, alcohol use, medicine intake, eating and sleeping habits, well-being, stress, coping, and passion. Baseline data are presented for the total cohort and separately for 4 age groups (12, 13, 14, and 15-17 years). Results: 12% skipped breakfast, 8% skipped lunch and 11% used protein supplements several days per week. 16% slept less than 8 h/night, 8% had impaired sleep with daytime consequences, and 22% stated that they were tired in daily activities several days per week. 32% experienced stress some or most days/week and 24% were classified as having psychological distress. Medicine intake (23% vs. 34%), skipping breakfast or lunch several days per week (10% vs. 47% and 20 vs. 33%), tiredness (20% vs. 27%), stress (26% vs. 40%), and psychological distress (27% vs. 37%) increased significantly (P = 0.031 to &lt; 0.001) at the 1-year follow-up. Conclusion: Many adolescent female football players skip breakfast and lunch, have insufficient sleep, experience stress and are classified as having psychological distress. These factors increased over 1 year.

BACKGROUND: "When will I be able to play again?" is the most frequent question asked by injured athletes. Due to the complex nature of sports injury, deciding when an injured athlete may safely return to training is a critical and difficult decision. OBJECTIVE: To study if the Safe Multidimensional Algorithm for Return to Training (SMART) scores, applied before the release to full return to training after injury differs between football players who suffer a subsequent re-injury and football players who do not. METHOD: Seventy one male professional football players were prospectively monitored for injuries during two seasons. The SMART tool was applied in injured players with an absence amp;gt; 10 days. The injured player had to carry out 17 multidimensional tests included in the algorithm in his final days of the planned rehabilitation. The results of the SMART were compared between players who sustained re-injuries and those who did not. RESULTS: Fifty-five injuries with absence amp;gt; 10 days were recorded and re-injuries occurred in 12 of these cases (22%). There was a lower re-injury rate in players who presented a better recovery in pain (p amp;lt; 0.001), agility (RR 21.0, 95% CI: 2.0 to 213.2), advanced agility (RR 26.7, 95% CI: 4.9 to 142.8), anxiety (RR 8.6, 95% CI: 2.0 to 36.2), depression (RR 10.3, 95% CI: 1.5 to 65.7), self-perception (p amp;lt; 0.001), advanced skills mode (RR 20.5, 95% CI: 3.3 to 125.9) and group skills mode (p amp;lt; 0.001). CONCLUSIONS: A multidimensional approach of Return to Training that includes objective measures may indicate potential deficiencies in the recovery of injured players.

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.

ObjectiveInjuries in women's football (soccer) have scarcely been investigated, and no study has been conducted in the highest competitive level involving club teams from different countries. Our aim was to investigate the time-loss injury epidemiology and characteristics among women's elite football players over four seasons.Methods596 players from 15 elite women's teams in Europe were studied prospectively during the 2018/2019 to 2021/2022 seasons (44 team seasons). Medical staff recorded individual player exposure and time-loss injuries. Injury incidence was calculated as the number of injuries per 1000 playing hours and injury burden as the number of days lost per 1000 hours.Results1527 injuries were recorded in 463 players with an injury incidence of 6.7 (95% CI 6.4 to 7.0) injuries per 1000 hours and a nearly fourfold higher incidence during match play compared with training (18.4, 95% CI 16.9 to 19.9 vs 4.8, 95% CI 4.5 to 5.1; rate ratio 3.8, 95% CI 3.5 to 4.2). Thigh muscle injuries (hamstrings 12%, 188/1527, and quadriceps 11%, 171/1527) were the most frequent injury, while anterior cruciate ligament (ACL) injury had the highest burden (38.0 days lost per 1000 hours, IQR 29.2-52.1) with median days lost of 292 (IQR 246-334) days. Concussions constituted 3% (47/1527) of all injuries, with more than half of them (55%, 26/47) due to ball-related impact.ConclusionAn elite women's football team can expect approximately 35 time-loss injuries per season. Thigh muscle injury was the most common injury and ACL injury had the highest injury burden.

Purpose: To prospectively evaluate risk factors for acute time-loss knee injury, in particular ACL injury, in female youth football players.andlt;br /andgt;Methods: Risk factors were studied in 4556 players aged 12-17 years from a randomised controlled trial during the 2009 season. Covariates were both intrinsic (body mass index, age, relative age effect, onset of menarche, previous acute knee injury or ACL injury, current knee complaints, and familial disposition of ACL injury) and extrinsic (no. of training sessions/week, no. of matches/week, match exposure ratio, match play with other teams, and artificial turf exposure). Hazard ratios (HRs) and 95 % confidence intervals (CIs) were calculated from individual variable and multiple Cox regression analyses.andlt;br /andgt;Results: Ninety-six acute knee injuries were recorded, 21 of them ACL injuries. Multiple Cox regression showed a fourfold higher ACL injury rate for players with familial disposition of ACL injury (HR 3.57; 95 % CI 1.48-8.62). Significant predictor variables for acute knee injury were age andgt;14 years (HR 1.97; 95 % CI 1.30-2.97), knee complaints at the start of the season (HR 1.98; 95 % CI 1.30-3.02), and familial disposition of ACL injury (HR 1.96; 95 % CI 1.22-3.16). No differences in injury rates were seen when playing on artificial turf compared with natural grass.andlt;br /andgt;Conclusion: Female youth football players with a familial disposition of ACL injury had an increased risk of ACL injury and acute knee injury. Older players and those with knee complaints at pre-season were more at risk of acute knee injury. Although the predictive values were low, these factors could be used in athlete screening to target preventive interventions.andlt;br /andgt;Level Of Evidence: II.

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.

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.

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.

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.

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.

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.

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.

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.

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The aim of the study was to examine how players perceptions of sociocultural factors and intra- and interpersonal aspects of sporting experiences may have influenced the emotions, cognitions, and behaviours of elite female soccer players prior to the occurrence of ACL injuries. The research questions guiding the study were: (a) how did female elite soccer players perceive that their psychosocial experiences were related to their cognitive, physiological, and emotional states prior to their ACL injuries, and (b) how did the players feel their perceived states influenced their behaviours prior to injury occurrence. The participants consisted of the total population of female players (N = 18) competing in the Swedish womens elite league, who incurred a total ACL tear during the 2012 season. Using a semi-structured interview guide, all players were interviewed post-season. We represented the data using a storytelling approach of aggregated creative nonfiction. The aggregated stories showed sociocultural rules and expectations of overtraining and placing pressure on athletes to play even if they were not physically or psychologically fit. Responding to pressures with potentially risk-increasing behaviours might raise the probability of becoming injured through a number of pathways. Team managers, coaches, and members of the medical team are recommended to develop environments that stimulate the players to engage in adaptive stress-recovery and risk-decreasing behaviours.

BACKGROUND: Most of the research in the area of psychosocial factors in rehabilitation after sports injuries has focused on risk behaviors, while relatively few studies have focused on behaviors that facilitate rehabilitation. The objective of our study was to understand the psychosocial features that characterize elite female football players who express a resilient behaviour during rehabilitation after a first-time anterior cruciate ligament (ACL) injury and reconstruction.

METHODS: A qualitative method was used based on individual in-person interviews and video communication of players who incurred a first-time ACL tear during the 2012 season of the Swedish Women's Elite Football League. In total, 13 players had a first-time ACL and were interviewed post-season. The interviews were followed by a thematic content analysis. Based on this, eight players were identified as showing resilient behaviors during their rehabilitation and were included in the final analysis.

RESULTS: Three core themes representing psychosocial factors that help players cope successfully with rehabilitation were identified: (I) constructive communication and rich interaction with significant others; (II) strong belief in the importance and efficacy of one's own actions; and (III) the ability to set reasonable goals.

CONCLUSIONS: The findings suggest three core themes of psychosocial factors that characterize first-time ACL-injured elite female football players showing resilience during rehabilitation after ACL reconstruction. Suggestions for medical teams about ways to support communication, self-efficacy, and goal-setting during the rehabilitation process, are provided.