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The aim of this study was to describe complication rates and long-term functional outcomes among patients with amputated versus reconstructed limb after high-energy open tibial fractures. Patients treated operatively for a high-energy open tibial fracture, classified as Gustilo–Anderson (GA) grade 3, at our hospital in the time period 2004–2013 were invited to a clinical and radiographic follow-up at minimum 2 years after injury. Eighty-two patients with 87 GA grade 3 fractures were included. There were 39 type GA 3A, 34 GA 3B, and 14 GA 3C. The GA 3A reconstruction group had the lowest complication rate and the best long-term outcome scores at mean 5 years (range 2–8 years) after injury. Within the group of GA 3B and 3C fractures, we found no significant differences in long-term outcomes among patients with reconstructed versus amputated limbs. The mean physical component summary score of the SF-36 in the reconstruction versus amputation group was 54.2 (95% CI 46.3–62.1) versus 47.7 (95% CI 32.6–62.2), respectively (p = 0.524), while the mean mental component summary score was 63.7 (95% CI 50.6–71.8) versus 59.2 (95% CI 48.8–68.0), respectively (p = 0.603). On the 6-minute walk test, the reconstruction group walked on average 493 m (95% CI 447–535 m) versus 449 m (95% CI 384–518 m) in the amputation group. The return to work rate was 73% (16 of 22) in the reconstruction group versus 50% (7 of 14) in the amputation group (p = 0.166). The mean patient satisfaction score (VAS 0–100) was 67 (95% CI 67–77) in the reconstruction group versus 65 (95% CI 51–76) in the amputation group (p = 0.795). Regardless of the treatment strategy, the complication rate was high. Amputation should be considered as a viable treatment option, equal to limb salvage, after high-energy open tibial fracture with severe vascular damage or soft tissue loss.

Introduction Isolated iliac wing fracture is a rare pelvic fracture that is considered benign in the literature. As there is a complete lack of information on function and quality of life in patients with this injury, the primary aim of this study was to evaluate the long-term functional results, and secondly to evaluate the patients’ clinical function and fracture healing. Patients and Methods All patients treated in Oslo University Hospital, Ullevaal (OUH-U), the Norwegian National Pelvic Service, in the time period 2006–2016 were included. Nine of 13 eligible patients (69%) were evaluated by the Patient Reported Outcome Measures (PROM); EQ-5D-3L and Majeed Score. For the secondary outcomes, the patients were clinically examined for Range of Motion (ROM) in the hips, pain, muscular function and nerve deficiencies. Finally, the patients underwent X-rays (AP-view and iliac and obturator oblique views). Results All patients were injured in high-energy trauma with severe associated injuries. Five patients were operated and four received conservative treatment. At the time of follow-up (median seven years after injury), the mean EQ-5D VAS was 84, and the mean Majeed score was 87. Two out of nine reported moderate level of pain, three reported mild pain, and the rest reported no pain. Six patients were still working, two were retired, and the last one was receiving disability benefit of other reasons than the iliac fracture. One patient had difference in range of external rotation of >10° between the hips, while the rest had no differences in ROM. The follow-up X-rays showed healed fractures in all the patients. Conclusion Patients with isolated iliac wing fractures seem to have a good general state of health, scoring high on the PROMs, with minor and insignificant clinical sequela. This original finding is in accordance with the general assumption amongst pelvic surgeons that the injury is a benign one.

IntroductionPeriacetabular osteotomy (PAO) is an established treatment for adolescent and adult patients with hip dysplasia. However, the efficacy of PAO has not been tested against another surgical intervention or conservative treatment in a randomised controlled trial before. We suggest that progressive resistance training (PRT) could be an alternative to PAO. The primary aim of this trial is therefore to examine the efficacy of PAO followed by 4 months of usual care followed by 8 months of PRT compared to 12 months of solely PRT in patients with hip dysplasia eligible for PAO in terms of patient-reported pain measured by The Copenhagen Hip and Groin Outcome Score (HAGOS).Methods and analysisThis trial is a single-blinded multicentre randomised controlled clinical trial, where patients with hip dysplasia, who are eligible for PAO, will be randomised to either PAO followed by usual care and PRT or PRT only. Primary outcome is patient-reported pain, measured on the subscale pain on the HAGOS questionnaire 12 months after initiation of PAO or PRT. The key secondary outcomes are the other subscales of the HAGOS, adverse and serious adverse events, usage of painkillers (yes/no) and type of analgesics. Based on the sample size calculation, the trial needs to include 96 patients.Ethics and disseminationThe trial is approved by the Central Denmark Region Committee on Biomedical Research Ethics (Journal No 1-10-72-234-18) and by the Danish Data Protection Agency (Journal No 1-16-02-120-19). The trial is also approved by The Regional Committee for Medical and Health Research Ethics, Region South-East Norway (Ref. 2018/1603). All results from this trial will be published in international peer-reviewed scientific journals regardless of whether the results are positive, negative or inconclusive.Trial registration numberNCT03941171

Although handball is a contact sport with a high risk of acute match injuries, their mechanisms have not yet been investigated. We aimed to describe the mechanisms of acute match injuries in elite male handball and evaluate referee performance in injury situations. Based on injury surveillance from the 24th Men's Handball World Championship 2015 in Qatar, injury situations and the referee decisions were identified on video footage. A total of 55 injury situations and 37 referee decisions were included for analysis. The injury situations were analyzed individually by five handball experts, followed by a consensus meeting. An expert referee panel performed individual blinded evaluation of the referee decisions, followed by an online consensus meeting. Injuries were evenly distributed among attackers (n = 29) and defenders (n = 26). The most frequent injury cause was contact trauma due to a tackle (n = 27). At the time of injury, attackers were most frequently performing a jump shot (n = 9), while defenders were completing a tackle (n = 10). Defenders most commonly tackled the throwing arm (n = 7) or toward the head/face region (n = 6) of injured attackers, while attackers most frequently hit injured defenders with the knee during jump shots (n = 5). Agreement between the referees and the expert panel was weak (kappa: 0.22, 95% CI 0.07 to 0.36), with substantially more lenient rule interpretation by the referees. Our results suggest that stricter refereeing and rule amendments should be considered to prevent acute match injuries in elite handball, especially in relation to tackling episodes when an attacker is performing a jump shot.

BackgroundThe 9+ screening battery test consists of 11 tests to assess limitations in functional movement.AimTo examine the association of the 9+ with lower extremity injuries and to identify a cut-off point to predict injury risk.MethodsProfessional male football players in Qatar from 14 teams completed the 9+ at the beginning of the 2013/2014 and 2014/2015 seasons. Time-loss injuries and exposure in training and matches were registered prospectively by club medical staff during these seasons. Univariate and multivariate Cox regression analyses were used to calculate HR and 95% CI. Receiver operating characteristic (ROC) curves were calculated to determine sensitivity and specificity and identify the optimal cut-off point for risk assessment.Results362 players completed the 9+ and had injury and exposure registration. There were 526 injuries among 203 players (56.1%) during the two seasons; injuries to the thigh were the most frequent. There was no association between 9+ total score and the risk of lower extremity injuries (HR 1.02, 95% CI 0.99 to 1.05, p=0.13), even after adjusting for other risk factors in a multivariate analysis (HR 1.01, 95% CI 0.98 to 1.04, p=0.37). ROC curve analysis revealed an area under the curve of 0.48, and there was no cut-off point that distinguished injured from non-injured players.ConclusionThe 9+ was not associated with lower extremity injury, and it was no better than chance for distinguishing between injured and uninjured players. Therefore, the 9+ test cannot be recommended as an injury prediction tool in this population.

Background The Nine Plus screening battery test (9+) is a functional movement test intended to identify limitations in fundamental movement patterns predisposing athletes to injury. However, the interseason variability is unknown. Aim To examine the variability of the 9+ test between 2 consecutive seasons in professional male football players. Methods Asymptomatic Qatar Star League players (n= 220) completed the 9+ at the beginning of the 2013 and 2014 seasons. Time-loss injuries in training and matches were obtained from the Aspetar Injury and Illness Surveillance Program. No intervention was initiated between test occasions. Results A significant increase in the mean total score of 1.6 points (95% CI 1.0 to 2.2, p

The primary role of the pre-participation assessment (PPA) is to allow the team medical staff to get to know the current health status of the handball players in their team. This will usually include reviewing the player’s current medical problems and injuries, endeavouring to pick up unreported medical problems or symptoms, checking family history and reviewing medications and/or supplements.

Background: Lower extremity muscle strength tests are commonly used to screen for injury risk in professional soccer. However, there is limited evidence on the ability of such tests in predicting future injuries. Purpose: To examine the association between hip and thigh muscle strength and the risk of lower extremity injuries in professional male soccer players. Study Design: Case-control study; Level of evidence, 3. Methods: Professional male soccer players from 14 teams in Qatar underwent a comprehensive strength assessment at the beginning of the 2013/2014 and 2014/2015 seasons. Testing consisted of concentric and eccentric quadriceps and hamstring isokinetic peak torques, eccentric hip adduction and abduction forces, and bilateral isometric adductor force (squeeze test at 45°). Time-loss injuries and exposure in training and matches were registered prospectively by club medical staff throughout each season. Univariate and multivariate Cox regression analyses were used to calculate hazard ratios (HRs) with 95% CIs. Results: In total, 369 players completed all strength tests and had registered injury and exposure data. Of these, 206 players (55.8%) suffered 538 lower extremity injuries during the 2 seasons; acute muscle injuries were the most frequent. Of the 20 strength measures examined, greater quadriceps concentric peak torque at 300 deg/s (HR, 1.005 [95% CI, 1.00-1.01]; P = .037) was the only strength measure identified as significantly associated with a risk of lower extremity injuries in multivariate analysis. Greater quadriceps concentric peak torque at 60 deg/s (HR, 1.004 [95% CI, 1.00-1.01]; P = .026) was associated with the risk of overuse injuries, and greater bilateral adductor strength adjusted for body weight (HR, 0.75 [95% CI, 0.57-0.97; P = .032) was associated with a lower risk for any knee injury. Receiver operating characteristic curve analyses indicated poor predictive ability of the significant strength variables (area under the curve, 0.45-0.56). Conclusion: There was a weak association with the risk of lower extremity injuries for 2 strength variables: greater quadriceps concentric muscle strength at (1) high and (2) low speeds. These associations were too small to identify an “at-risk” player. Therefore, strength testing, as performed in the present study, cannot be recommended as a screening test to predict injuries in professional male soccer.

Background: Little is known about the rate and pattern of injuries in international volleyball competition. Objective: To describe the risk and pattern of injuries among world-class players based on data from the The International Volleyball Federation (FIVB) Injury Surveillance System (ISS) (junior and senior, male and female). Methods: The FIVB ISS is based on prospective registration of injuries by team medical staff during all major FIVB tournaments (World Championships, World Cup, World Grand Prix, World League, Olympic Games). This paper is based on 4-year data (September 2010 to November 2014) obtained through the FIVB ISS during 32 major FIVB events (23 senior and 9 junior). Results: The incidence of time-loss injuries during match play was 3.8/1000 player hours (95% CI 3.0 to 4.5); this was greater for senior players than for junior players (relative risk: 2.04, 1.29 to 3.21), while there was no difference between males and females (1.04, 0.70 to 1.55). Across all age and sex groups, the ankle was the most commonly injured body part (25.9%), followed by the knee (15.2%), fingers/thumb (10.7%) and lower back (8.9%). Injury incidence was greater for centre players and lower for liberos than for other player functions; injury patterns also differed between player functions. Conclusions: Volleyball is a very safe sport, even at the highest levels of play. Preventive measures should focus on acute ankle and finger sprains, and overuse injuries in the knee, lower back and shoulder.

IntroductionHead injuries represent a concern in skiing and snowboarding, with traumatic brain injuries being the most common cause of death.AimTo describe the mechanisms of head and face injuries among World Cup alpine and freestyle skiers and snowboarders.MethodsWe performed a qualitative analysis of videos obtained of head and face injuries reported through the International Ski Federation Injury Surveillance System during 10 World Cup seasons (2006–2016). We analysed 57 head impact injury videos (alpine n=29, snowboard n=13, freestyle n=15), first independently and subsequently in a consensus meeting.ResultsDuring the crash sequence, most athletes (84%) impacted the snow with the skis or board first, followed by the upper or lower extremities, buttocks/pelvis, back and, finally, the head. Alpine skiers had sideways (45%) and backwards pitching falls (35%), with impacts to the rear (38%) and side (35%) of the helmet. Freestyle skiers and snowboarders had backwards pitching falls (snowboard 77%, freestyle 53%), mainly with impacts to the rear of the helmet (snowboard 69%, freestyle 40%). There were three helmet ejections among alpine skiers (10% of cases), and 41% of alpine skiing injuries occurred due to inappropriate gate contact prior to falling. Athletes had one (47%) or two (28%) head impacts, and the first impact was the most severe (71%). Head impacts were mainly on snow (83%) on a downward slope (63%).ConclusionThis study has identified several characteristics of the mechanisms of head injuries, which may be addressed to reduce risk.

Background Post traumatic arthritis and avascular necrosis of the femoral head are common complications after operatively treated acetabular fractures. This may cause severe disabilities for the patient, necessitating a total hip arthroplasty. Even though an arthroplasty may provide good symptomatic relief, the long-term results are more uncertain and no consensus exists according to preferred prosthetic designs. With this cohort study, we aimed to investigate the medium to long term arthroplasty survival and clinical results of total hip arthroplasty after operatively treated acetabular fractures. Methods We included 52 patients treated with a secondary total hip arthroplasty at a median of 2.4 (0.1–14.1) years after an operatively treated acetabular fracture. The median age was 54 (11–82) years. Cemented arthroplasty was used for 33 patients, 10 patients had an uncemented arthroplasty and 9 patients received a hybrid arthroplasty. Average follow up was 8.0 (SD 5.0) years. Results Ten-year revision free arthroplasty survival was 79%. Uncemented arthroplasties had a significantly worse 10-year survival of 57%. Arthroplasties performed at a centre without a pelvic fracture service also had a significantly worse 10-years survival of 51%. Cox regression showed similar results with an 8-fold increase in risk of revision for both uncemented arthroplasties and operations performed at a non-pelvic trauma centre. Conclusion Total hip arthroplasty secondary to an operatively treated acetabular fracture provides good symptomatic relief. These patients are, however, complex cases and are probably best treated at specialist centres with both pelvic trauma surgeons and arthroplasty surgeons proficient in complex revisions present. Reduced survival for uncemented compared to cemented total hip arthroplasty after operatively treated acetabular fractures. Clarke-Jenssen J, Westberg M, Røise O, Storeggen SAØ, Bere T, Silberg I, Madsen JE. Injury. 2017 Nov;48(11):2534-2539. © 2017. This manuscript version is made available under the CC-BY-NC-ND 4.0 license.

Background There is limited knowledge on the injury rate and injury pattern in the different disciplines among elite snowboarders. Objective The aim of this study was to describe and compare the injury rate and injury pattern among the different International Ski Federation (Federation Internationale de Ski, FIS) World Cup (WC) snowboard disciplines. Methods We conducted retrospective interviews with FIS WC snowboard athletes at the end of each season in the period 2007–2012, to register all acute injuries sustained during training or competition during the competitive season requiring attention by medical personnel. To calculate the exposure, we obtained information from result lists from the FIS competition database for all WC competitions for each of the interviewed athletes. Results We registered a total of 574 injuries among 1432 athletes, accounting for an overall injury rate of 40.1 injuries/100 athlete/season. A total of 171 injuries occurred during the FIS WC competitions, corresponding to 6.4 injuries/1000 runs. During competition, injury risk was highest in snowboard cross with 11.9/1000 runs, followed by 6.3 in halfpipe, 3.6 in big air and 2.8 in parallel giant slalom/parallel slalom (PGS/PSL). Snowboard cross also had the highest risk of severe injuries (>28 days absence). No differences in injury risk were detected between male and female snowboarders. The most commonly injured body part was the knee (17.8%), followed by the shoulder/clavicle (13.4%) and head/face (13.2%). The risk of knee injury (the most common injury type) and head injury was significantly higher in snowboard cross and halfpipe compared to PGS/PSL. Conclusions The risk of injuries was higher in snowboard cross than in halfpipe, big air and PGS/PSL. The most commonly injured body part was the knee. Prevention of snowboard injuries among elite snowboarders should focus on knee injuries, severe injuries and snowboard cross athletes.

We have limited insight into how injuries occur in professional ski racing. The aim of this study was to describe the injury situations in World Cup alpine skiing. Injuries reported through the International Ski Federation Injury Surveillance System for three consecutive World Cup seasons (2006-2009) were obtained on video. In total, 69 injuries and 124 runs of matched controls were analysed by five experts to evaluate the skiing situation, skier behavior, as well as piste-related factors. A chi-square test (95% CI, P ≤ 0.05) was used to examine whether there was a difference between course sections regarding where the injury situation occurred. The skier was most frequently turning (n = 55) or landing from a jump (n = 13) at the time of injury. Most of the injuries to the head and upper body (96%) resulted from crashes, while the majority of knee injuries (83%) occurred while the skier was still skiing. Gate contact contributed to 30% of the injuries, while 9% occurred at contact with safety nets/material. Almost half of the injuries (46%) occurred in the final fourth of the course. A particular concern was the high contribution of inappropriate gate contact and the high-energy impacts to the body when crashing. Language: en

BackgroundAnkle injuries are prevalent in elite volleyball and suggested to result from player contact at the net. Traditionally, ankle sprains are thought to happen in a plantarflexed position, but case studies suggest plantarflexion may not be involved.AimDescribe the injury situations and mechanisms of ankle injuries in world-class volleyball based on systematic video analysis of injuries reported through the Fédération Internationale de Volleyball (FIVB) Injury Surveillance System.MethodsVideos of 24 injuries from major FIVB tournaments were included for analysis (14 men, 10 women). Five analysts reviewed the videos to determine specific situations and mechanisms leading to injuries.ResultsThe majority of injuries occurred during two volleyball situations, blocking (n=15) and attacking (n=6). Injuries to blockers were the result of landing on an opponent (n=11) or teammate (n=4). Attacking injuries most frequently occurred when a back-row player landed on a front-row teammate (n=4 of 6). When landing on an opponent under the net, the attacker landed into the opponent’s court in 11 of 12 situations but without violating the centre line rule. Injuries mostly resulted from rapid inversion without any substantial plantarflexion.ConclusionsThe majority of injuries occur while blocking, often landing on an opponent. The attacker is overwhelmingly to blame for injuries at the net secondary to crossing the centre line. Injuries while attacking often result from a back-row player landing on a front-row teammate. Landing-related injuries mostly result from rapid inversion with the absence of plantarflexion.

Background Despite the widespread use of periodic health evaluation (PHE) to detect and prevent injury and illness in athletes, its effectiveness in detecting health conditions and relevant risk factors is still debated. Aim To assess health conditions detected by a comprehensive PHE in professional male football players and evaluate their consequences for participation clearance. Methods A total of 558 professional football players in Qatar completed a PHE prior to the 2013 or 2014 seasons: history, general medical (including blood test), cardiovascular (12-lead ECG and echocardiography) and a musculoskeletal examination, including a specific test battery targeting lower extremity strength and flexibility. On the basis of the PHE, players were either cleared or not cleared for participation. Results In 533 players (95.5%), at least one health condition was detected requiring treatment or follow-up. Vitamin D deficiency or insufficiency (≤30 ng/mL) was the most common medical condition (n=499, 89.4%), followed by hepatitis B non-immunity or infection (n=164, 29.4%). Cardiac screening identified 48 players (8.6%) with one or more abnormal findings (ECG (n=19, 3.4%) and echocardiography (n=14, 2.5%)). Musculoskeletal conditions were observed in 180 players (32.3%); injuries to or strength deficits of the hip/groin and thigh accounted for the largest proportion. Medical clearance was temporarily not given in 69 players (12.4%), while further examinations were being conducted. One player was disqualified from competitive football. Conclusions PHE revealed a high prevalence of health conditions requiring treatment or follow-up in professional footballers; however, only 12.4% of conditions impacted on final clearance for participation.

Background In the International Ski Federation (FIS), World Cup (WC) snowboard cross (SBX) and ski cross (SX), the injury incidence in individual qualifi cation runs versus fi nal runs in heats of four athletes is unknown. Objective To investigate the injury incidence in individual qualifi cation runs versus fi nal runs of SBX and SX. Methods Injuries were recorded by the FIS injury surveillance system (FIS ISS) through retrospective athlete interviews at the end of each season during four WC seasons (2006–2010). A total of 713 athletes (345 SBX and 368 SX) were interviewed. Time-loss injuries occurring during SBX and SX competitions were included. Injury incidence was expressed as the relative injury rate (per 1000 runs). Results For SBX, the injury incidence per 1000 runs in fiwas 12.1 vs 6.1 in qualifi cations (RR 1.9, 95% CI 1.1–3.5). The injury incidence was 12.9 in fiand 4.4 in qualifi cations (RR 2.9, 95% CI 1.4–6.2) for SBX males and 10.5 vs 9.3 (RR 1.1, 95% CI 0.5–2.8) for females. For SX, the injury incidence in fiwas 12.4 and 9.2 in qualifi cations (RR 1.4, 95% CI 0.8–2.3). The injury incidence for SX males was 13.6 in fivs 8.8 in qualifi cations (RR 1.5, 95% CI 0.8–3.1) and10.8 vs 9.8 (RR 1.1, 95% CI 0.5–2.6) for females. Conclusion The injury incidence was signifi cantly higher in firuns compared with qualifi cation runs in SBX for males. For SBX females and in SX, no signifi cant differences were found.

Background Snowboard cross (SBX) became an official Olympic sport in 2006. This discipline includes manoeuvring several obstacles while competing in heats. It is common for the riders to collide, making this sport both exciting and at risk of injuries. Although a recent study from the 2010 Olympic Games has shown that the injury risk was high, little is known about the injury mechanisms. Objective To qualitatively describe the injury situation and mechanism of injuries in World Cup Snowboard Cross. Study design Descriptive video analysis. Methods Nineteen video recordings of SBX injuries reported through the International Ski Federation Injury Surveillance System for four World Cup seasons (2006 to 2010) were obtained. Five experts in the field of sports medicine, snowboard and biomechanics performed analyses of each case to describe the injury mechanism in detail (riding situation and rider behaviour). Results Injuries occurred at jumping (n=13), bank turning (n=5) or rollers (n=1). The primary cause of the injuries was a technical error at take-off resulting in a too high jump and subsequent flat-landing. The rider was then unable to recover leading to fall at the time of injury. Injuries at bank turn was characterised by a pattern where the rider in a balanced position lost control due to unintentional contact with another rider. Conclusion Jumping appeared to be the most challenging obstacle in SBX, where a technical error at take-off was the primary cause of the injuries. The second most common inciting event was unintentional board contact between riders at bank turning.

Background: New regulations for ski equipment were implemented prior to the 2012/2013 season in the International Ski Federation (FIS) alpine World Cup (WC). Objective: To investigate the effect of the new ski regulations on the rate and pattern of injuries by comparing data before (2006-12) and after (2012-15) the implementation. Methods: Injuries were recorded based on the FIS Injury Surveillance System (FIS ISS) through retrospective interviews at the end of each of the nine WC seasons (2006-15). All acute injuries occurring during the competitive season that required medical attention were registered. Injury incidence was expressed as the absolute injury rate (injuries per 100 athletes per season) and as the relative injury rate (injuries per 1000 runs). Exposure was calculated based on the official result lists. Results: The absolute injury rate was lower in the three seasons after the new ski regulations compared to the six seasons before (risk ratio (RR) 0.74, 95% CI 0.63 to 0.87). This was also the case for the relative injury rate (RR 0.76, 95% CI 0.59 to 0.98). However, these changes were only evident for male skiers, not for females. There was a lower absolute injury rate for upper body injuries after the new ski regulations (RR 0.56, 95% CI 0.43 to 0.77), while no difference was found for lower extremity injuries (RR 0.84, 95% CI 0.70 to 1.01). Conclusion: We found a lower rate of injuries in the three seasons after the new ski regulation compared to the six seasons before. However, the ability to draw conclusions on the effects of the equipment change in subgroups of sex, discipline or body part is restricted by limited statistical power.

Background The IOC encourages international federations to establish systematic athlete injury and illness surveillance programmes. Objective To describe pattern of injuries and illnesses during the 24th Men9s Handball World Championship 2015 by implementing the IOC injury and illness surveillance protocol. Methods The medical staff of participating teams (n=24) were requested to report all new injuries and illnesses during matches and/or training on a daily basis throughout the event (15 January to 1 February, 2015). Exposure (number of player-hours) during all matches was calculated for all players (n=384) and for each of the 4 player positions (wing, back, line and goalkeeper). Results Medical staff of all teams submitted 96.7% (n=325) of the daily report forms. In total, 27.1% of the players were injured, and of the 132 injuries reported, 40% were time-loss injuries. The total incidence of injuries was 104.5 per 1000 player-hours. The highest risk of injury was found among line players, and more injuries occurred during the first half of the matches. The most frequent injury location was the ankle, followed by the thigh, knee and head/face. The majority of injuries were contusion, sprain or strain. In total, 10.9% of the players were affected by an illness during the event. Of the 42 cases recorded, 31 (73.8%) were reported as respiratory tract infection. Conclusions The risk of injury in handball is high among Olympic sports. Preventive measures should focus on contusions, ankle sprains, and thigh muscle strains, as well as measures aimed to reduce upper respiratory tract infections.

Background There are limited data on injuries in World Cup (WC) telemark skiing. Objective To describe the injury incidence and injury pattern seen among WC telemark skiers during the competitive season. Methods We interviewed all WC athletes (or their coach, if the athlete was not present) at the end of five winter seasons from 2008 until 2013. All acute injuries occurring in the competitive season that required the attention of medical personnel were registered. Exposure was calculated based on the official International Ski Federation (FIS) results database. Results 149 acute injuries were registered during 565 WC skier seasons. The absolute injury incidence was 26.4 injuries per 100 athletes per season (95% CI 22.1 to 30.6), higher for females than males (risk ratio (RR) 1.49, 95% CI 1.07 to 2.08). During the FIS WC competitions, 69 injuries were registered, corresponding to a relative incidence of 8.2 injuries per 1000 runs (95% CI 6.3 to 10.1). The most frequently injured body part was the knee (21%) followed by the hand-fingerthumb (20%), ankle (13%) and shoulder/clavicle (13%). The absolute risk of knee and shoulder/clavicle injuries was higher for females versus males (RR for knee injuries 2.72, 95% CI 1.35 to 5.51; RR for shoulder/ clavicle injuries 2.55, 95% CI 1.06 to 6.14). No differences were detected in the injury incidence between disciplines. Conclusions Female telemark skiers are at 1.5 times greater risk of injury than male skiers. The most commonly injured body part was the knee. The risk of knee and shoulder/clavicle injuries was higher for female athletes than for male athletes.

Background Handball is a contact sport with a high prevalence of acute injuries. Injuries often occur during high-speed movements involving several players, making it difficult to describe the exact mechanism of injury. Objective Describe the mechanisms of injury in elite male handball. Design Prospective video analysis. Setting During the men´s handball world championship 2015, 132 injuries were reported through on-site injury surveillance by team medical staff. Based on the injury reports, two operators accessed the videos of each game and identified the specific injury situations using video analysis software (ProzoneHANDBALL v.1.0.0.14, ProzoneSports, Leeds, UK). Video analysis A total of 97 injury videos were identified; 42 were excluded, as the injury situation was not visible. Five handball experts performed an individual analysis of the 55 included videos based on a specific form developed to describe the injury situations and causes, followed by a consensus meeting. Main Outcome Measurements The form included variables related to the playing situation, landing situation, action of attacker and defender at time of injury and localization of tackle/hit. Results The most common injury location was the head and face (n=17, 31%), followed by the ankle (n=6, 11%). The most frequent injury cause was opponent contact (n=27, 49%), followed by landing trauma subsequent to opponent contact (n=8, 15%). The injuries were equally distributed between attackers (n=29, 53%) and defenders (n=26, 47%), but time-loss injuries (49%) were more common among attackers (68%). The most frequent playing action performed by injured attackers was a jump shot (n=9, 31%); tackles were most often to their throwing arm (n=7, 30%). Conclusions Acute injuries in elite male handball are equally distributed between attackers and defenders. However, attackers sustain more severe injuries. The most frequent injury causes are direct opponent contact and landing trauma after opponent contact.

Background Ankle sprains are the most prevalent injury in volleyball and it is suggested they result from player contact at the net. Traditionally, ankle sprains are thought to happen in a plantarflexed position, but case studies suggest plantarflexion may not be involved. Objective To describe the injury situations and mechanisms for ankle injuries in elite volleyball based on systematic video analyses. Design Descriptive video analysis. Setting National teams participating in major Federation Internationale de Volleyball (FIVB) senior-level tournaments. Material All acute ankle injuries with subsequent time-loss (n=32) reported through the (FIVB) Injury Surveillance System (ISS) 2010–2014. Of these, video footage of 24 injuries was available for analysis. Assessment of Risk Factors Injury situation variables included playing situation, player positions, and center line infringement. Variables examining injury mechanisms included lower extremity (ankle, knee, hip) joint positions at first contact and the index injury frame, joint movement between initial contact and the index frame, and the relationship between ankle dorsiflexion and supination. Results The majority of injuries occurred during blocking (n=15) and attacking (n=6). Injuries to blockers resulted from landing on an opponent (n=11) or teammate (n=4). Attacking injuries mostly occurred when a backrow player landed on a front row teammate (n=4). When landing on an opponent, the attacker landed into the opponent9s court in 11 of 12 situations compared to 2 situations for the blocker. When landing on another player, the ankle moved into a neutral dorsiflexed position prior to rapid pronation/supination in 15 situations compared to 1 situation of supination in plantarflexion. Conclusions The majority of injuries occur while blocking, often landing on an opponent. The attacker is responsible for injuries at the net secondary to crossing the center line. Landing-related injuries mostly occur with the ankle rapidly supinating in a neutral dorsiflexed position.

Background The Nine Plus screening battery test (9+) is a series of 11 tests, used to assess limitations in fundamental movement patterns assumed to predispose athletes for injury. Objective To examine the association of the 9+ with lower extremity injuries, and to identify the optimal cut-off point for risk screening. Design Prospective cohort study. Setting Professional football league. Participants Male professional football players in Qatar. Interventions The 9+ test was performed prior to the 2013 and 2014 seasons. Time-loss injuries and exposure in training and matches were registered prospectively by club medical staff during 2 consecutive seasons. Univariate and multivariate regression analyses were used to calculate odds ratios (ORs), risk ratios (RR) and 95% confidence intervals (CIs). Receiver operating characteristics (ROC) curves were calculated to determine sensitivity and specificity, and identify the optimal cut-off point for risk assessment. Main Outcome Measurement Lower extremity injuries. Results In total, 363 players completed the 9+ and had injury and exposure registration. There were 527 injuries among 204 players (56.2%) during the 2 seasons; injuries to the thigh were most frequent. There was no association between 9+ total score and the risk of lower extremity injuries (OR, 1.02; 95% CI, 0.98–1.06; P=0.44), even when adjusted for exposure (RR, 1.04; 95% CI, 0.98–1.12; P=0.21) or other factors in a multivariate analysis (OR, 1.04; 95% CI, 0.97–1.06; P=0.60). ROC curve analysis revealed an area under the curve of 0.48 for lower extremity injury. No optimal cut-off point to distinguish between injured and non-injured players could be determined. Conclusions The 9+ total score was not associated with lower extremity injury. The 9+ total score was no better than chance for classifying injured and non-injured players. Therefore, the 9+ test cannot be recommended as a screening tool in this population.

Traumatic brain injury (TBI) is the leading cause of death in alpine skiing. It has been found that helmet use can reduce the incidence of head injuries between 15% and 60%. However, knowledge on optimal helmet performance criteria in World Cup alpine skiing is currently limited owing to the lack of biomechanical data from real crash situations. Purpose: This study aimed to estimate impact velocities in a severe TBI case in World Cup alpine skiing. Methods: Video sequences from a TBI case in World Cup alpine skiing were analyzed using a model-based image matching technique. Video sequences from four camera views were obtained in full high-definition (1080p) format. A three-dimensional model of the course was built based on accurate measurements of piste landmarks and matched to the background video footage using the animation software Poser 4. A trunk–neck–head model was used for tracking the skier’s trajectory. Results: Immediately before head impact, the downward velocity component was estimated to be 8 m·s-1. After impact, the upward velocity was 3 m·s-1, whereas the velocity parallel to the slope surface was reduced from 33 m·s-1 to 22 m·s-1. The frontal plane angular velocity of the head changed from 80 rad·s-1 left tilt immediately before impact to 20 rad·s-1 right tilt immediately after impact. Conclusions: A unique combination of high-definition video footage and accurate measurements of landmarks in the slope made possible a high-quality analysis of head impact velocity in a severe TBI case. The estimates can provide crucial information on how to prevent TBI through helmet performance criteria and design

Background Traumatic brain injury is the leading cause of death for skiers and snowboarders. Fatal head injuries have also occurred at the International Ski Federation (FIS) World Cup (WC) level. We therefore wanted to describe the risk of head injuries across disciplines and sex among WC skiers and snowboarders. Method We conducted retrospective interviews with FIS WC athletes at the end of seven consecutive seasons (2006–2013) to register injuries sustained during the competitive season. Head injuries were classified as ‘head/face’ injuries and did not include neck or cervical spine injuries. To calculate the exposure, we extracted data from the official FIS website for all WC competitions for each of the athletes interviewed. Results A total of 2080 injuries were reported during seven WC seasons. Of these, 245 (11.8%) were head/face injuries. Of the 245 head/face injuries reported, nervous system injuries/concussions were the most common (81.6%) and 58 of these were severe (23.7%). The injury incidence per 1000 competition runs was higher in freestyle (1.8, 95% CI 1.2 to 2.4) than in alpine skiing (0.9, 95% CI 0.6 to 1.2; risk ratio (RR) 2.05, 95% CI 1.25 to 3.46) and snowboard (1.0, 95% CI 0.6 to 1.3; RR 1.85, 95% CI 1.15 to 2.99). Women had a higher injury incidence (5.8, 95% CI 4.8 to 6.9) versus men (3.9, 95% CI 3.2 to 4.6; RR 1.48, 95% CI 1.15 to 1.90) throughout the season (per 100 athletes). Conclusions The majority of head/face injuries were nervous system injuries/concussions and one in four injuries was severe. Freestyle skiers had the highest overall head injury incidence. Across all disciplines, the injury incidence was higher in women than in men.

Background Although injury risk in Freestyle Ski Cross (SX) is high, little is known about the situations leading up to time-loss injuries. Objective To describe the situations leading up to time-loss injuries in elite Freestyle SX. Study design Descriptive video analysis. Methods Thirty-three video recordings of SX injuries reported through the International Ski Federation Injury Surveillance System for four World Cup seasons (2006/2007 through 2010) were obtained. Five experts in the fields of sport medicine and SX analysed each case to describe in detail the situation leading up to the injury (skiing situation and skier behaviour). Results Injuries occurred in four different skiing situations: jumping (n=16), turning (n=8), jumping and turning (n=7) and rollers (n=2). All injured skiers lost control before time of injury (n=33), due to skier–opponent contact (n=13), technical errors (n=8) or inappropriate strategy (n=8), which led to a fall (n=29). Contact occurred in 21 of 33 cases, usually unintentional at landing or take-off, caused by the opponent (n=11) or injured skier (n=8). The technical error cases (n=8) were dominated by bad jumping technique (n=6) and too much inside lean in turning situations (n=2), while inappropriate course line and bad timing at take off (n=7) dominated the inappropriate strategy cases (n=8). Conclusions We identified four main injury situations in elite SX, dominated by jumping situations. The primary cause of injury was unintentional skier–opponent contact in jumping, bank turning and roller situations. Another common cause of injury was personal errors (inappropriate technique and strategy) at take-off and in turning situations.

Background In competitive alpine skiing, there is a controversy regarding the sex-related risk of injury. Objective To compare the risk of injury in female versus male World Cup (WC) alpine skiers. Methods Injuries were recorded through the International Ski Federation Injury Surveillance System for six consecutive winter seasons (2006–2012), based on retrospective interviews with athletes from 10 teams at the end of each season. All acute training and competition injuries which required medical attention were recorded. Race exposure was calculated based on the exact number of runs started in the WC for each of the interviewed athletes each season. Results Men had a higher overall rate of injury (relative risk (RR) 1.24, 95% CI 1.05 to 1.47), as well as a higher rate of time-loss injury (RR 1.23, 95% CI 1.03 to 1.48) than women in training and competitions, expressed as injuries/100 athletes/season. These sex differences were even more pronounced during WC races (RR 1.58, 95% CI 1.22 to 2.04 and RR 1.72, 95% CI 1.29 to 2.31, for overall and time-loss injuries, respectively). There was no sex difference in the risk of knee/anterior cruciate ligament (ACL) injuries. Conclusions No previous studies from competitive skiing have reported a significantly higher risk of injuries in men than women. In contrast to recreational skiing and team sports, there was no sex difference in the risk of knee/ACL injuries and prevention efforts should be directed as much towards male as female competitive skiers.

Background: Based on visual video analyses of 20 injury situations, the main mechanism of anterior cruciate ligament (ACL) injury in World Cup alpine skiing, termed the “slip-catch” mechanism, was identified. This situation is characterized by a common pattern in which the inside edge of the outer ski catches the snow surface while turning, forcing the knee into valgus and tibial internal rotation. To describe the exact joint kinematics at the time of injury, a more sophisticated approach is needed. Purpose: To describe the knee and hip kinematics in 2 slip-catch situations utilizing a model-based image-matching (MBIM) technique. Study Design: Descriptive laboratory study. Methods: Two typical slip-catch situations in World Cup alpine skiing reported through the International Ski Federation (FIS) Injury Surveillance System were captured on video with several camera views and high video quality. The injury situations were analyzed using the MBIM technique to produce continuous measurements of knee and hip joint kinematics. Results: Within 60 milliseconds, the knee flexion angle increased rapidly from 26° to 63° in case 1 and from 39° to 69° in case 2. In the same period, we observed a rapid increase in internal rotation of the tibia with a peak of 12° and 9°, respectively. The knee valgus angle changed less markedly in both cases. We also observed a rapid increase of hip flexion as well as substantial hip internal rotation. Conclusion: Knee compression and knee internal rotation and abduction torque are important components of the injury mechanism in a slip-catch situation. Clinical Relevance: Prevention efforts should focus on avoiding a forceful tibial internal rotation in combination with knee valgus.

The authors have recently identified three main mechanisms for anterior cruciate ligament (ACL) injuries among World Cup (WC) alpine skiers, termed as "the slip-catch", "the landing back-weighted" and "the dynamic snowplow". However, for a more complete understanding of how these injuries occur, a description of the events leading to the injury situations is also needed.To describe the skiing situation leading to ACL injuries in WC alpine skiing.Twenty cases of ACL injuries reported through the International Ski Federation Injury Surveillance System (FIS ISS)for three consecutive WC seasons (2006-2009) were obtained on video. Ten experts (9 WC coaches, 1 former WC athlete) performed visual analyses of each case to describe in their own words, factors they thought may have contributed to the injury situation related to different predefined categories: (1) skier technique, (2) skier strategy, (3) equipment, (4) speed and course setting, (5) visibility, snow and piste conditions and (6) any other factors.Factors related to the three categories, namely skier technique, skier strategy, and visibility, snow and piste conditions, were assumed to be the main contributors to the injury situations. Skier errors, technical mistakes and inappropriate tactical choices, were the dominant factors. In addition, bumpy conditions, aggressive snow, reduced visibility and course difficulties were assumed to contribute.Based on this systematic video analysis of 20 injury situations, factors related to skier technique, skier strategy and specific race conditions were identified as the main contributors leading to injury situations.

Background: Limited knowledge exists on injuries among professional alpine skiers. Objective: To describe the risk of injury and the injury pattern among competitive World Cup alpine skiers during the competitive season. Methods: We performed retrospective interviews with all World Cup athletes from 10 nations at the end of the 2006-07 and 2007-08 winter seasons and recorded all acute injuries occurring during the 4.5-month competitive season. If the athlete was not present, we interviewed their coaches or medical personnel. Results: A total of 191 acute injuries were recorded among 521 World Cup alpine skiers. As many as 86 injuries (45%) occurred during World Cup/World Ski Championship competitions, corresponding to an injury rate of 9.8 injuries per 1000 runs (95% confidence interval, 7.8 to 11.9). We found the injury rate to increase with increasing speed (slalom 4.9 injuries per 1000 runs, 95% CI 2.5 to 7.4 - giant slalom 9.2, 5.1 to 13.3 - super-G 11.0, 5.2 to 16.8 - downhill 17.2, 11.6 to 22.7). The most frequently injured body part was knee with 68 injuries (36%) and 37 of these were severe. The overall injury rate was higher in males compared to females, but not for knee injuries. Conclusions: The risk of injury among World Cup athletes in alpine skiing is even higher than previously reported and the knee is the most commonly injured body part and with many severe injuries. Injury rate increased with higher speed and was higher among males compared to females.

Background: There is limited insight into the mechanisms of anterior cruciate ligament injuries in alpine skiing, particularly among professional ski racers. Purpose: This study was undertaken to qualitatively describe the mechanisms of anterior cruciate ligament injury in World Cup alpine skiing. Study Design: Case series; Level of evidence, 4. Methods: Twenty cases of anterior cruciate ligament injuries reported through the International Ski Federation Injury Surveillance System for 3 consecutive World Cup seasons (2006-2009) were obtained on video. Seven international experts in the field of skiing biomechanics and sports medicine related to alpine skiing performed visual analyses of each case to describe the injury mechanisms in detail (skiing situation, skier behavior, biomechanical characteristics). Results: Three main categories of injury mechanisms were identified: slip-catch, landing back-weighted, and dynamic snowplow. The slip-catch mechanism accounted for half of the cases (n = 10), and all these injuries occurred during turning, without or before falling. The skier lost pressure on the outer ski, and while extending the outer knee to regain grip, the inside edge of the outer ski caught abruptly in the snow, forcing the knee into internal rotation and valgus. The same loading pattern was observed for the dynamic snowplow (n = 3). The landing back-weighted category included cases (n = 4) where the skier was out of balance backward in flight after a jump and landed on the ski tails with nearly extended knees. The suggested loading mechanism was a combination of tibiofemoral compression, boot-induced anterior drawer, and quadriceps anterior drawer. Conclusion: Based on this video analysis of 20 injury situations, the main mechanism of anterior cruciate ligament injury in World Cup alpine skiing appeared to be a slip-catch situation where the outer ski catches the inside edge, forcing the outer knee into internal rotation and valgus. A similar loading pattern was observed for the dynamic snowplow. Injury prevention efforts should focus on the slip-catch mechanism and the dynamic snowplow.

Everything that can be counted does not necessarily count; everything that counts cannot necessarily be counted (Albert Einstein 1879-1955). Alpine ski racing is an Olympic winter sport where athletes ski one by one down the mountain on a demanding course, often in challenging snow and weather conditions. The Athletes must ski as efficiently as possible, as performance is determined by the racing time measured to 0.01 s, but at the same time they have to adapt speed and trajectory to their technical skills and manage risk responsibly. In this issue, Gilgien et al 1 quantify and describe the mechanical characteristics (such as skier speed, turn radius, air drag force, ground reaction force, jump distance and airtime) of World Cup alpine skiing under real race conditions, and interestingly they link these data to the risk of injury. With their biomechanical approach, they add new and valuable information to the field of injury prevention …

Background We have identified that a slip-catch situation is the main mechanism for anterior cruciate ligament (ACL) injuries in World Cup alpine skiing by simple visual inspection of injury videos. This occurs when the skier loses pressure on the outer ski during turning, and while extending the outer knee to regain grip, the inside edge of the outer ski catches abruptly, forcing the knee into valgus and internal rotation. To develop injury prevention methods based on this mechanism, a more precise description is needed. Objective To describe the detailed joint kinematics in a slip-catch situation using a model-based image-matching (MBIM) technique. Design Case study. Setting Men9s World Cup alpine skiing. Methods Video of a slip-catch injury situation in slalom captured with two nearly perpendicular camera views was analyzed using the MBIM method to obtain the time course of knee and hip joint kinematics. Results Knee valgus and internal rotation angle increased by 13° and 13°, respectively, in the last 60 ms before the time of ACL rupture, which was estimated to occur 100 ms after the catching the edge. Knee flexion angle increased by 32° in the last 20 ms from 22° at snow contact to a final position. Hip flexion and adduction angle increased by 18° and 13°, respectively, in the last 20 ms and the hip stayed at approximately 30° of internal rotation in the last 60 ms. Conclusion Abrupt compression, valgus and internal rotation loading seems to be the main mechanism of slip-catch injury situations in ACL injuries in World Cup alpine skiing. The knee loading pattern described from the previous simple visual inspection study matched well with the more detailed analysis using the MBIM technique. Prevention efforts should focus on avoiding valgus and internal rotation loading on the knee.