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Injury and illness surveillance, and epidemiological studies, are fundamental elements of concerted efforts to protect the health of the athlete. To encourage consistency in the definitions and methodology used, and to enable data across studies to be compared, research groups have published 11 sport-specific or setting-specific consensus statements on sports injury (and, eventually, illness) epidemiology to date. Our objective was to further strengthen consistency in data collection, injury definitions and research reporting through an updated set of recommendations for sports injury and illness studies, including a new Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist extension. The IOC invited a working group of international experts to review relevant literature and provide recommendations. The procedure included an open online survey, several stages of text drafting and consultation by working groups and a 3-day consensus meeting in October 2019. This statement includes recommendations for data collection and research reporting covering key components: defining and classifying health problems; severity of health problems; capturing and reporting athlete exposure; expressing risk; burden of health problems; study population characteristics and data collection methods. Based on these, we also developed a new reporting guideline as a STROBE Extension-the STROBE Sports Injury and Illness Surveillance (STROBE-SIIS). The IOC encourages ongoing in- and out-of-competition surveillance programmes and studies to describe injury and illness trends and patterns, understand their causes and develop measures to protect the health of the athlete. Implementation of the methods outlined in this statement will advance consistency in data collection and research reporting. Funding Agencies|International Olympic Committee

ObjectiveTo compare concussion rates (CRs) over one academic year in high school athletes with and without a COVID-19 infection prior to concussion.MethodsIllness and concussion were prospectively reported for male and female high school athletes across six states over one academic year in the Players Health Rehab surveillance system. Concussion was truncated to 60 days following recovery and return to sport from COVID-19. CRs were estimated per 1000 athletes per academic year and stratified by those who tested positive for COVID-19 infection (with COVID-19) and those who did not (no COVID-19). Poisson regression analyses estimated rate ratio (RR) of concussion controlling for state, gender and an offset of the log athlete participation (with COVID-19 and no COVID-19).ResultsOf 72 522 athletes, 430 COVID-19 infections and 1273 concussions were reported. The CR was greater in athletes who reported COVID-19 (CR=74.4/1000 athletes/year, 95% CI 49.6 to 99.3) compared with those who did not (CR=17.2, 95% CI 16.3 to 18.2). Athletes with recent COVID-19 had a threefold higher rate of concussion (RR=3.1, 95% CI 2.0 to 4.7).ConclusionAthletes returning from COVID-19 had higher CRs than those who did not experience COVID-19. This may be related to ongoing COVID-19 sequelae or deconditioning related to reduced training and competition load during the illness and when returning to sport. Further research is needed to understand the association of recent COVID-19 infection and concussion in order to inform preventive strategies.

ObjectivesResearch evidence is commonly compiled into expert-informed consensus guidelines intended to consolidate and distribute sports medicine knowledge. Between 2003 and 2018, 27 International Olympic Committee (IOC) consensus statements were produced. This study explored the policy and practice impact of the IOC Statements on athlete health and medical team management in two economically and contextually diverse countries.MethodsA qualitative case study design was adopted. Fourteen face-to-face interviews were conducted with purposively selected interviewees, seven participants from Australia (higher economic equality) and seven from South Africa (lower economic equality), representing their national medical commissions (doctors and physiotherapists of Olympic, Paralympic and Youth teams). A framework method was used to analyse interview transcripts and identify key themes.ResultsDifferences across resource settings were found, particularly in the perceived usefulness of the IOC Statements and their accessibility. Both settings were unsure about the purpose of the IOC Statements and their intended audience. However, both valued the existence of evidence-informed guidelines. In the Australian setting, there was less reliance on the resources developed by the IOC, preferring to use locally contextualised documents that are readily available.ConclusionThe IOC Statements are valuable evidence-informed resources that support translation of knowledge into clinical sports medicine practice. However, to be fully effective, they must be perceived as useful and relevant and should reach their target audiences with ready access. This study showed different contexts require different resources, levels of support and dissemination approaches. Future development and dissemination of IOC Statements should consider the perspectives and the diversity of contexts they are intended for.

ObjectiveTo evaluate the effectiveness of a junior high school-based sports injury prevention programme to reduce injuries through neuromuscular training (NMT).MethodsThis was a cluster randomised controlled trial. Students were recruited from 12 Calgary junior high schools (2014–2017). iSPRINT is a 15 min NMT warm-up including aerobic, agility, strength and balance exercises. Following a workshop, teachers delivered a 12-week iSPRINT NMT (six schools) or a standard-of-practice warm-up (six schools) in physical education classes. The definition of all recorded injuries included injuries that resulted in participants being unable to complete a sport and recreation (S&R) session, lost time from sport and/or seek medical attention. Incidence rate ratios (IRRs) were estimated based on multiple multilevel Poisson regression analyses (adjusting for sex (considering effect modification) and previous injury, offset by S&R participation hours, and school-level and class-level random effects were examined) for intent-to-treat analyses.Results1067 students (aged 11–16) were recruited across 12 schools (6 intervention schools (22 classes), 6 control schools (27 classes); 53.7% female, 46.3% male). The iSPRINT programme was protective of all recorded S&R injuries for girls (IRR=0.543, 95% CI 0.295 to 0.998), but not for boys (IRR=0.866, 95% CI 0.425 to 1.766). The iSPRINT programme was also protective of each of lower extremity injuries (IRR=0.357, 95% CI 0.159 to 0.799) and medical attention injuries (IRR=0.289, 95% CI 0.135 to 0.619) for girls, but not for boys (IRR=1.055, 95% CI 0.404 to 2.753 and IRR=0.639, 95% CI 0.266 to 1.532, respectively).ConclusionThe iSPRINT NMT warm-up was effective in preventing each of all recorded injuries, lower extremity injuries and medically treated S&R injuries in female junior high school students.Trial registration numberNCT03312504

ObjectivesThe objective of this study is to evaluate the effect of policy change disallowing body checking in adolescent ice hockey leagues (ages 15–17) on reducing rates of injury and concussion.MethodsThis is a prospective cohort study. Players 15–17 years-old were recruited from teams in non-elite divisions of play (lower 40%–70% by division of play depending on year and city of play in leagues where policy permits or prohibit body checking in Alberta and British Columbia, Canada (2015–18). A validated injury surveillance methodology supported baseline, exposure-hours and injury data collection. Any player with a suspected concussion was referred to a study physician. Primary outcomes include game-related injuries, game-related injuries (>7 days time loss), game-related concussions and game-related concussions (>10 days time loss).Results44 teams (453 player-seasons) from non-body checking and 52 teams (674 player-seasons) from body checking leagues participated. In body checking leagues there were 213 injuries (69 concussions) and in non-body checking leagues 40 injuries (18 concussions) during games. Based on multiple multilevel mixed-effects Poisson regression analyses, policy prohibiting body checking was associated with a lower rate of injury (incidence rate ratio (IRR): 0.38 (95% CI 0.24 to 0.6)) and concussion (IRR: 0.49; 95% CI 0.26 to 0.89). This translates to an absolute rate reduction of 7.82 injuries/1000 game-hours (95% CI 2.74 to 12.9) and the prevention of 7326 injuries (95% CI 2570 to 12083) in Canada annually.ConclusionsThe rate of injury was 62% lower (concussion 51% lower) in leagues not permitting body checking in non-elite 15–17 years old leagues highlighting the potential public health impact of policy prohibiting body checking in older adolescent ice hockey players.

In 2020, the IOC proposed a universal methodology for the recording and reporting of data for injury and illness in sport. Para sport is played by individuals with impairment, and they have a unique set of considerations not captured by these recommendations. Therefore, the aim of this addendum to IOC consensus statement was to guide the Para sport researcher through the complexities and nuances that should be taken into consideration when collecting, registering, reporting and interpreting data regarding Para athlete health. To develop this translation, experts in the field of Para sports medicine and epidemiology conducted a formal consensus development process, which began in March 2020 with the formation of a consensus group that worked over eight phases, incorporating three virtual consensus meetings to finalise the translation. This translation is consistent with the IOC consensus statement, yet provides more detailed Para athlete specific definitions and recommendations on study population, specifically, diagnostic and eligible impairment categorisation and recording of adaptive equipment, and defining and classifying health problems in the context of Para sport. Additionally, recommendations and Para athlete specific examples are described with regards to injury mechanism, mode of onset, injury and illness classification, duration, capturing and reporting exposure and risk. Finally, methods and considerations are provided to cater to the varied needs of athletes with impairment with respect to data collection tools. This harmonisation will allow the science to develop and facilitate a more accurate understanding of injury and illness patterns for tailoring evidence-informed prevention programmes and enabling better planning of medical services for Para sport events.

ObjectiveTo synthesise the current evidence regarding the risk factors, the injury prevention strategies and the profile of injured skiers and snowboarders in terrain parks (TPs) and half-pipes (HPs).DesignSystematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines.Data sourcesLiterature searches from six electronic databases and manual searches were performed.Eligibility criteria for selecting studiesInclusion criteria were: (1) publication based on original data; (2) injuries sustained in TPs or HPs; (3) recreational skiing or snowboarding injuries; (4) observational or experimental study design with a comparison group.ResultsNo study explored the risk factors in HPs or the prevention strategies in TPs or HPs. From the literature retrieved, there is strong evidence that skiing or snowboarding in a TP is a risk factor for head, neck, back and severe injuries. Two papers assessed the risk factors for injuries in TPs, mainly demonstrating that features promoting aerial manoeuvres or a large drop to the ground were associated with higher feature-specific injury rates. The profile of injured skiers and snowboarders in TPs described in the literature suggested some evidence of associations between factors including activity, sex, skill level, helmet use, age and TP injuries.Summary/conclusionsThis systematic review demonstrates the need for studies identifying the risk factors for injuries to skiers and snowboarders and on interventions to reduce the risk of injury in TPs and HPs. Studies addressing the issue of TP design should be considered.PROSPERO registration numberCRD42016045206.

Since the beginning of the COVID-19 pandemic, there have been a lot of words and phrases that have become part of the daily news such as ‘unprecedented’, ‘cohort’ and ‘the new normal’. We also hear people speaking about how they or their families are adapting to the change. Adaptation can be defined as a process of change or evolution that allows the individual or group to cope with a situation. In sports, we see athletes do this on a continual basis. The demands of training impose physical and mental stress on the body and mind so that there are adaptations, which make the athlete stronger and more resilient. This also happens at an organisational level. Every company, government, sporting organisation, athlete and individual has had to adapt to the new reality. The year 2020 was supposed to be a full year of in-person planning, sport conferences and credentialling exams—not to mention an Olympic Summer Games. Instead, as the world abruptly shut down, Sport Physiotherapy Canada (SPC) had to pivot rapidly. We did what …

In a 2018 editorial, the challenges of bridging the gap between current practice and evidence in sports medicine were highlighted.1 Establishing and perpetuating evidence-based practice is the responsibility of individuals across all disciplines within sports medicine. Clinician–scientists are an important bridge between research and clinical practice because they have a foot in both worlds. Clinicians understand questions that are faced in daily clinical practice and are ideally situated to develop and undertake clinically relevant research.2 There are several key barriers to clinician engagement in research, but Esculier et al 1 argue that a model with more clinician–scientists would avoid clinicians criticising researchers for the lack of clinical applicability of their research and researchers criticising clinicians for not using the latest evidence in their practice. A call to action by the authors included recommendations for greater involvement of clinicians in research design, completion and dissemination; funding clinicians’ research contributions; creating combined clinic and research positions and facilitating organic collaboration between clinicians and scientists through smart working space design.1 Most clinicians learn through private unaccredited courses, rather than from scientific journals or postgraduate university courses.3 While clinicians may strive to enhance their clinical skills through courses, few courses prioritise critical appraisal skills, integration of best evidence into practice and contribution to research through collaboration with researchers. Lander et …

Aim or objective To examine the effectiveness of concussion prevention strategies in reducing concussion risk in sport. Design Systematic review according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines. Data sources Eleven electronic databases searched and hand-search of references from selected studies. Eligibility criteria for selecting studies The following were the study inclusion criteria: (1) contained original human research data; (2) investigated an outcome of concussion or head impact; (3) evaluated a concussion prevention intervention; (4) included sport participants; (5) analytical study designand (6) peer-reviewed. The following were the exclusion criteria: (1) review articles, case series or case studies and (2) not in English. Results The studies selected (n=48) provided evidence related to protective gear (helmets, headgear, mouthguards) (n=25), policy and rule changes (n=13) and other interventions (training, education, facilities) (n=10). Meta-analyses demonstrate a combined effect of a 70% reduction (incidence rate ratio (IRR)=0.3 (95% CI: 0.22 to 0.41)) in concussion risk in youth ice hockey leagues where policy disallows body checking, and the point estimate (IRR=0.8 (95% CI: 0.6 to 1.1)) suggests a protective effect of mouthguards in contact and collision sport (basketball, ice hockey, rugby). Summary/conclusions Highlights include a protective effect of helmets in skiing/snowboarding and the effectiveness of policy eliminating body checking in youth ice hockey. Future research should examine mouthguards in contact sport, football helmet padding, helmet fit in collision sport, policy limiting contact practice in youth football, rule enforcement to reduce head contact in ice hockey and soccer, ice surface size and board/glass flexibility in ice hockey and training strategies targeting intrinsic risk factors (eg, visual training). Systematic review registration PROSPERO 2016:CRD42016039162

BackgroundConcussion is the most common injury in youth ice hockey. Whether mouthguard use lowers the odds of concussion remains an unanswered question.ObjectiveTo determine the association between concussion and mouthguard use in youth ice hockey.MethodsNested case–control design. Cases and controls were identified from two prospective cohort studies using valid injury surveillance methods. Cases were players concussed during a game or practice; controls were players who sustained a non-concussion injury during a game or practice. The primary exposure was mouthguard use at time of injury; mouthguard type (dental custom fit or off the shelf) was a secondary exposure. Physician-diagnosed or therapist-suspected concussion was the primary outcome. Dental injury was a secondary outcome. Multilevel logistic regression with random effect at a team level was used to obtain ORs for the mouthguard effect, adjusted for level of play, age group, position, concussion history, mechanism of injury, cohort, session type and body checking policy.ResultsAmong cases, 236/315 (75%) were wearing a mouthguard at time of injury, while 224/270 (83%) controls were wearing a mouthguard at time of injury. Any mouthguard use was associated with an adjusted OR for concussion of 0.36 (95% CI 0.17 to 0.73). Off-the-shelf mouthguards were associated with a 69% lower odds of concussion (adjusted OR: 0.31; 95% CI 0.14 to 0.65). Dental custom-fit mouthguards were associated with a non-significant 49% lower odds of concussion (adjusted OR: 0.51; 95% CI 0.22 to 1.10). No dental injuries were identified in either cohort.ConclusionMouthguard use was associated with lower odds of concussion. Players should be required to wear mouthguards in youth ice hockey.

ObjectiveTo compare rates of injury and concussion among non-elite (lowest 60% by division of play) Bantam (ages 13–14 years) ice hockey leagues that disallow body checking to non-elite Bantam leagues that allow body checking.MethodsIn this 2-year cohort study, Bantam non-elite ice hockey players were recruited from leagues where policy allowed body checking in games (Calgary/Edmonton 2014–2015, Edmonton 2015–2016) and where policy disallowed body checking (Kelowna/Vancouver 2014–2015, Calgary 2015–2016). All ice hockey game-related injuries resulting in medical attention, inability to complete a session and/or time loss from hockey were identified using valid injury surveillance methodology. Any player suspected of having concussion was referred to a study physician for diagnosis and management.Results49 body checking (608 players) and 33 non-body checking teams (396 players) participated. There were 129 injuries (incidence rate (IR)=7.98/1000 hours) and 54 concussions (IR=3.34/1000 hours) in the body checking teams in games. After policy change, there were 31 injuries (IR=3.66/1000 hours) and 17 concussions (IR=2.01/1000 hours) in games. Policy disallowing body checking was associated with a lower rate of all injury (adjusted incidence rate ratio (IRR)=0.44; 95% CI: 0.27 to 0.74). The point estimate showed a lower rate of concussion (adjusted IRR=0.6; 95% CI: 0.31 to 1.18), but this was not statistically significant.ConclusionPolicy change disallowing body checking in non-elite Bantam ice hockey resulted in a 56% lower rate of injury. There is growing evidence that disallowing body checking in youth ice hockey is associated with fewer injuries.

High quality sports injury research can facilitate sports injury prevention and treatment. There is scope to improve how our field applies best practice methods-methods matter (greatly!). The 1st METHODS MATTER Meeting, held in January 2019 in Copenhagen, Denmark, was the forum for an international group of researchers with expertise in research methods to discuss sports injury methods. We discussed important epidemiological and statistical topics within the field of sports injury research. With this opinion document, we provide the main take-home messages that emerged from the meeting. Funding Agencies|BJSM

Background Preprofessional dancers partake in rigorous training and have high injury prevalence. Attempts to identify risk factors for dance injuries have focused on a diversity of intrinsic and extrinsic factors. Objective To identify and evaluate the evidence examining risk factors for musculoskeletal injury in preprofessional ballet and modern dancers. Methods Fifteen electronic databases were systematically searched to October 2015. Studies selected met a priori inclusion criteria and investigated musculoskeletal injury risk factors in preprofessional (elite adolescent, student, young adult) ballet and modern dancers. Two reviewers independently assessed the quality and level of evidence using the Downs and Black (DB) criteria and a modified Oxford Centre of Evidence-Based Medicine 2009 model, respectively. Results Of 1364 potentially relevant studies, 47 were included and scored. Inconsistent injury definition and methodology precluded meta-analysis. The most common modifiable risk factors investigated were anthropometrics (ie, body mass index, adiposity), joint range of motion (ie, lower extremity), dance exposure (ie, years training, exposure hours) and age. The median DB score across studies was 8/33 (range 2–16). The majority of studies were classified as level 3 evidence and few considered risk factor inter-relationships. There is some level 2 evidence that previous injury and poor psychological coping skills are associated with increased injury risk. Conclusions Because of the lack of high-quality studies, consensus regarding risk factors for musculoskeletal injury in preprofessional dancers remains difficult. There is a need for injury definition consensus and high-quality prospective studies examining the multifactorial relationship between risk factors and injury in preprofessional dance.

Youth have very high participation and injury rates in sport. Sport is the leading cause of injury in youth. Sport injury reduces future participation in physical activity which adversely affects future health. Sport injury may lead to overweight/obesity and post-traumatic osteoarthritis. The objective of the systematic review and meta-analysis was to evaluate the efficacy of injury prevention neuromuscular training strategies in youth sport. Three electronic databases were systematically searched up to September 2014. Studies selected met the following criteria: original data; analytic prospective design; investigated a neuromuscular training prevention strategy intervention(s) and included outcomes for injury sustained during sport participation. Two authors assessed the quality of evidence using Downs and Black (DB) criteria. Meta-analyses including randomised controlled trials only (RCTs) to ensure study design homogeneity were completed for lower extremity and knee injury outcomes. Of 2504 potentially relevant studies, 25 were included. Meta-analysis revealed a combined preventative effect of neuromuscular training in reducing the risk of lower extremity injury (incidence rate ratio: IRR=0.64 (95% CI 0.49 to 0.84)). Though not statistically significant, the point estimate suggests a protective effect of such programmes in reducing the risk of knee injury (IRR=0.74 (95% CI 0.51 to 1.07)). There is evidence for the effectiveness of neuromuscular training strategies in the reduction of injury in numerous team sports. Lack of uptake and ongoing maintenance of such programmes is an ongoing concern. A focus on implementation is critical to influence knowledge, behaviour change and sustainability of evidence informed injury prevention practice.

Background The identification of risk factors for groin injury in sport is important to develop and implement injury prevention strategies. Objective To identify and evaluate the evidence examining risk factors for groin injury in sport. Material and methods Nine electronic databases were systematically searched to June 2014. Studies selected met the following criteria: original data; analytic design; investigated a risk factor(s); included outcomes for groin injury sustained during sport participation. The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines were followed and two independent authors assessed the quality and level of evidence with the Downs and Black (DB) criteria and Oxford Centre of Evidence-Based Medicine model, respectively. Results Of 2521 potentially relevant studies, 29 were included and scored. Heterogeneity in methodology and injury definition precluded meta-analyses. The most common risk factors investigated included age, hip range of motion, hip adductor strength and height. The median DB score across studies was 11/33 (range 6–20). The majority of studies represented level 2 evidence (cohort studies) however few considered the inter-relationships between risk factors. There is level 1 and 2 evidence that previous groin injury, higher-level of play, reduced hip adductor (absolute and relative to the hip abductors) strength and lower levels of sport-specific training are associated with increased risk of groin injury in sport. Conclusions We recommended that investigators focus on developing and evaluating preparticipation screening and groin injury prevention programmes through high-quality randomised controlled trials targeting athletes at greater risk of injury.

Dizziness, neck pain and headaches are commonly reported following a sport-related concussion and may persist.1 2 A combination of cervical and vestibular physiotherapy facilitates recovery following sport-related concussion in individuals with ongoing symptoms of dizziness, neck pain and headaches.3 In our randomised controlled trial (RCT), a higher proportion of individuals treated with multimodal physiotherapy were reported to be medically cleared to return to sport (within 8 weeks) than that of individuals who received a control intervention.4 However, the effect of timing of treatment is not currently known. Here we share the results of the second phase of this RCT, which evaluated the efficacy of multimodal physiotherapy and vestibular rehabilitation compared with rest in individuals with persistent symptoms of dizziness, neck pain and/or headaches following a sport-related concussion. Individuals who had already completed an 8-week period of either multimodal physiotherapy …

BackgroundYouth and young adults who participate in sport have an increased risk of knee injury and subsequent osteoarthritis. Improved understanding of the relationship between structural and clinical outcomes postinjury could inform targeted osteoarthritis prevention interventions. This secondary analysis examines the association between MRI-defined osteoarthritis and self-reported and functional outcomes, 3–10 years following youth sport-related knee injury in comparison to healthy controls.MethodsParticipants included a subsample (n=146) of the Alberta Youth Prevention of Early Osteoarthritis cohort: specifically, 73 individuals with 3–10years history of sport-related intra-articular knee injury and 73 age-matched, sex-matched and sport-matched controls with completed MRI studies. Outcomes included: MRI-defined osteoarthritis, radiographic osteoarthritis, Knee Injury and Osteoarthritis Outcome Score, Intermittent and Constant Osteoarthritis Pain, knee extensor/flexor strength, triple-hop and Y-balance test. Descriptive statistics and univariate logistic regression were used to compare those with and without MRI-defined osteoarthritis. Associations between MRI-defined osteoarthritis and each outcome were assessed using multivariable linear regression considering the influence of injury history, sex, body mass index and time since injury.ResultsParticipant median age was 23 years (range 15–27), and 63% were female. MRI-defined osteoarthritis varied by injury history, injury type and surgical history and was not isolated to participants with ACL and/or meniscal injuries. Those with a previous knee injury had 10-fold (95% CI 2.3 to 42.8) greater odds of MRI-defined osteoarthritis than uninjured participants. MRI-defined osteoarthritis was independently significantly associated with quality of life, but not symptoms, strength or function.SummaryMRI-detected structural changes 3– 10 years following youth sport-related knee injury may not dictate clinical symptomatology, strength or function but may influence quality of life.

Background Some snowboarders listen to music on a personal music player and the objective was to determine if listening to music was associated with injury in a terrain park. Methods A case–control study was conducted at a terrain park in Alberta, Canada during the 2008–2009 and 2009–2010 winter seasons. Cases were snowboarders who were injured in the terrain park and presented to either the ski patrol and/or a nearby emergency department (ED). Demographic, environmental and injury characteristics were collected from standardised ski patrol Accident Report Forms, ED medical records and telephone interviews. Controls were uninjured snowboarders using the same terrain park and were interviewed as they approached the lift-line on randomly selected days and times. Multivariable logistic regression determined if listening to music was associated with the odds of snowboard injury. Results Overall, 333 injured cases and 1261 non-injured controls were enrolled; 69 (21%) cases and 425 (34%) controls were listening to music. Snowboarders listening to music had significantly lower odds of injury compared with those not listening to music (adjusted odds ratio (OR) 0.68; 95% CI 0.48 to 0.98). Snowboarders listening to music had significantly higher odds of presenting to the ED versus ski patrol only compared with those not listening to music (adjusted OR 2.09; 95% CI 1.07 to 4.05). Conclusions While listening to music decreased the odds of any injury in the terrain park, it increased the odds of an injury resulting in ED presentation.

Background/aim Concussion is a common injury in sport. Most individuals recover in 7–10 days but some have persistent symptoms. The objective of this study was to determine if a combination of vestibular rehabilitation and cervical spine physiotherapy decreased the time until medical clearance in individuals with prolonged postconcussion symptoms. Methods This study was a randomised controlled trial. Consecutive patients with persistent symptoms of dizziness, neck pain and/or headaches following a sport-related concussion (12–30 years, 18 male and 13 female) were randomised to the control or intervention group. Both groups received weekly sessions with a physiotherapist for 8 weeks or until the time of medical clearance. Both groups received postural education, range of motion exercises and cognitive and physical rest until asymptomatic followed by a protocol of graded exertion. The intervention group also received cervical spine and vestibular rehabilitation. The primary outcome of interest was medical clearance to return to sport, which was evaluated by a study sport medicine physician who was blinded to the treatment group. Results In the treatment group, 73% (11/15) of the participants were medically cleared within 8 weeks of initiation of treatment, compared with 7% (1/14) in the control group. Using an intention to treat analysis, individuals in the treatment group were 3.91 (95% CI 1.34 to 11.34) times more likely to be medically cleared by 8 weeks. Conclusions A combination of cervical and vestibular physiotherapy decreased time to medical clearance to return to sport in youth and young adults with persistent symptoms of dizziness, neck pain and/or headaches following a sport-related concussion. Trial registration number NCT01860755.

Background Snowboarding is a popular albeit risky sport and terrain park (TP) injuries are more severe than regular slope injuries. TPs contain man-made features that facilitate aerial manoeuvres. The objectives of this study were to determine overall and feature-specific injury rates and the potential risk factors for TP injuries. Methods Case–control study with exposure estimation, conducted in an Alberta TP during two ski seasons. Cases were snowboarders injured in the TP who presented to ski patrol and/or local emergency departments. Controls were uninjured snowboarders in the same TP. κ Statistics were used to measure the reliability of reported risk factor information. Injury rates were calculated and adjusted logistic regression was used to calculate the feature-specific odds of injury. Results Overall, 333 cases and 1261 controls were enrolled. Reliability of risk factor information was κ>0.60 for 21/24 variables. The overall injury rate was 0.75/1000 runs. Rates were highest for jumps and half-pipe (both 2.56/1000 runs) and lowest for rails (0.43/1000 runs) and quarter-pipes (0.24/1000 runs). Compared with rails, there were increased odds of injury for half-pipe (OR 9.63; 95% CI 4.80 to 19.32), jumps (OR 4.29; 95% CI 2.72 to 6.76), mushroom (OR 2.30; 95% CI 1.20 to 4.41) and kickers (OR 1.99; 95% CI 1.27 to 3.12). Conclusions Higher feature-specific injury rates and increased odds of injury were associated with features that promote aerial manoeuvres or a large drop to the ground. Further research is required to determine ways to increase snowboarder safety in the TP.

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

Background In this study we describe (1) the implementation of a novel web-based injury and illness surveillance system (WEB-IISS) for use by a team of physicians at multisport events and (2) the incidence and characteristics of injuries and illness in athletes during the London 2012 Paralympic Games. Methods Overall, 3565 athletes from 160 of the 164 participating countries were followed daily over a 14-day period, consisting of a precompetition period (3 days), and a competition period (11 days) (49 910 athletedays). Daily injury and illness data were obtained from teams with their own medical support (78 teams, 3329 athletes) via the WEB-IISS, and without their own medical support through the London Organising Committee of the Olympic Games and Paralympic Games database (82 teams and 236 athletes). Results There were no differences between incidence rates (IR) of injury and illness, or between the precompetition and competition periods. The IR of injury during the competition period was 12.1/1000 athlete-days, with an incidence proportion (IP) of 11.6% (95% CI 11.0% to 13.3%). Upper limb injuries (35%), particularly of the shoulder (17%) were most common. The IR of illness during the competition period was 12.8/1000 athlete-days (95% CI 12.18 to 1421), with an IP of 10.2%. The IP was highest in the respiratory system (27.4%), skin (18.3%) and the gastrointestinal (14.5%) systems. Conclusions During the competition period, the IR and IP of illness and injury at the Games were similar and comparable to the observed rates in other elite competitions. In Paralympic athletes, the IP of upper limb injuries is higher than that of lower limb injuries and non-respiratory illnesses are more common.

Background The incidence and factors associated with illness in Paralympic athletes have not been documented. Aim To determine the factors associated with illness in athletes participating in the London 2012 Paralympic Games. Methods A cohort of 3565 athletes from 160 of the 164 participating countries in the London 2012 Paralympic Games were followed over a 14-day period (precompetition period=3 days, competition period=11 days; 49 910 athlete-days). Daily illness data were obtained from (1) teams with their own medical support who completed a daily illness log (78 teams, 3329 athletes) on a novel web-based system and (2) teams without their own medical support through the local organising committee database (82 teams, 236 athletes). Illness information from all athletes included age, gender, type of sport and the main system affected. Main outcome measurement Incidence rate (IR) of illness (illness per 1000 athlete-days) and factors associated with IR (time period, gender, age and sport). Results The IR of illness was 13.2 (95% CI 12.2 to 14.2). The highest IR of illness was in the respiratory system, followed by the skin, digestive, nervous and genitourinary systems. The IR in the precompetition period was similar to that in the competition period, but the IR was significantly higher in athletics compared with other sports. Age and gender were not independent predictors of illness. Conclusions Illness is common in Paralympic athletes and the main factor associated with higher IR of illness was the type of sport (athletics).

Background The characteristics and incidence of injuries at the Summer Paralympic Games have not previously been reported. A better understanding of injuries improves the medical care of athletes and informs future injury prevention strategies. Objective The objective of this prospective cohort study was to characterise the incidence and nature of injuries during the London 2012 Summer Paralympic Games. Methods Injury information was obtained from two databases. One database was populated from medical encounter forms completed by providers at the time of assessment in one of the medical stations operated by the Organising Committee. The second database was populated daily with information provided by team medical personnel who completed a comprehensive, web-based injury survey. Results The overall injury incidence rate was 12.7 injuries/1000 athlete-days. Injury rates were similar in male and female athletes. The precompetition injury rates in women were higher than those in the competition period. Higher injury rates were found in older athletes and certain sports such as football 5-a-side (22.4 injuries/1000 athlete-days). Overall, 51.5% of injuries were new onset acute traumatic injuries. The most commonly injured region (percentage of all injuries) was the shoulder (17.7%), followed by the wrist/hand (11.4%), elbow (8.8%) and knee (7.9%). Conclusions This is the largest and most comprehensive epidemiological report examining injuries in Paralympic athletes. Injury rates differ according to age and sport. Upper limb injuries are common. The knowledge gained from this study will inform future injury surveillance studies and the development of prevention strategies in Paralympic sport. The Epidemiology of Injuries at the London 2012 Paralympic Games.

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

Objective To evaluate the evidence for rest, treatment, and rehabilitation following sport-related concussion (SRC). Data sources PubMed, CINAHL, PsychInfo, Cochrane Controlled Trials Registers, Health STAR, Sport Discus, EMBASE, Web of Science, and ProQuest. Study selection Articles were included if they met the following criteria: original research, reported SRC as a source of injury, and evaluated the effect of rest or treatment. Data extraction Study design, participants, treatment, outcome measures, and key findings. Data synthesis Three studies met the inclusion criteria for evaluating the effects of rest and twelve for treatment. Low-intensity aerobic exercise may be of benefit. Conclusions The current evidence evaluating the effect of rest and treatment following SRC is sparse. An initial period of rest may be of benefit. Low-level exercise and multimodal physiotherapy may be of benefit for those who are slow to recover. There is a strong need for high level studies evaluating the effects of rest and treatment following SRC.

Background In 2013, Hockey Canada introduced an evidence-informed policy change delaying the earliest age of introduction to body checking in ice hockey until Bantam (ages 13–14) nationwide. Objective To determine if the risk of injury, including concussions, changes for Pee Wee (11–12 years) ice hockey players in the season following a national policy change disallowing body checking. Methods In a historical cohort study, Pee Wee players were recruited from teams in all divisions of play in 2011–2012 prior to the rule change and in 2013–2014 following the change. Baseline information, injury and exposure data for both cohorts were collected using validated injury surveillance. Results Pee Wee players were recruited from 59 teams in Calgary, Alberta (n=883) in 2011–2012 and from 73 teams in 2013–2014 (n=618). There were 163 game-related injuries (incidence rate (IR)=4.37/1000 game-hours) and 104 concussions (IR=2.79/1000 game-hours) in Alberta prior to the rule change, and 48 injuries (IR=2.16/1000 game-hours) and 25 concussions (IR=1.12/1000 game-hours) after the rule change. Based on multivariable Poisson regression with exposure hours as an offset, the adjusted incidence rate ratio associated with the national policy change disallowing body checking was 0.50 for all game-related injuries (95% CI 0.33 to 0.75) and 0.36 for concussion specifically (95% CI 0.22 to 0.58). Conclusions Introduction of the 2013 national body checking policy change disallowing body checking in Pee Wee resulted in a 50% relative reduction in injury rate and a 64% reduction in concussion rate in 11-year-old and 12-year-old hockey players in Alberta.

Background The objectives of this cohort study were to examine the rate, types, mechanisms and risk factors for injury in female youth (ages 9–17) ice hockey players in the Girls Hockey Calgary Association. Methods The main outcome was ice hockey injury, defined as any injury occurring during the 2008/2009 season that required medical attention, and/or removal from a session and/or missing a subsequent session. Potential risk factors included age group, level of play, previous injury, ice hockey experience, physical activity level, weight, height, position of play and menarche. Incidence rate ratios (IRR) were estimated with Poisson Regression adjusted for cluster (team). Exposure data were collected for every session for each participating player. Results Twenty-eight teams (n=324) from Atom (ages 9–10), PeeWee (11–12), Bantam (13–14) and Midget (15–17) participated with 53 reported injuries. The overall injury rate was 1.9 injuries/1000 player-hours (95% CI 1.4 to 2.7). Previous injury (IRR=2.7, 95% CI 1.7 to 4.3), games (IRR=2.1, 95% CI 1.1 to 4.2), menarche (PeeWee) (IRR=4.1, 95% CI 1.0 to 16.8) were significant risk factors. In Midget, the more elite divisions were associated with a lower injury risk (A-IRR=0.2, 95% CI 0.1 to 0.5) (AAA-IRR=0.5, 95% CI 0.2 to 0.9). Conclusions Injury rates were lower in this study than previously found in male youth and women9s ice hockey populations. Previous injury and game play as risk factors are consistent with the literature. Menarche as a risk factor is a new finding in this study. This research will inform future studies of the development of injury prevention strategies in this population.

Background There is randomised controlled trial (RCT) evidence that neuromuscular training (NMT) programmes can reduce the risk of injury in youth soccer. We evaluated the cost-effectiveness of such an NMT prevention strategy compared to a standard of practice warm-up. Methods A cost-effectiveness analysis was conducted alongside a cluster RCT. Injury incidence rates were adjusted for cluster using Poisson regression analyses. Direct healthcare costs and injury incidence proportions were adjusted for cluster using bootstrapping. The joint uncertainty surrounding the cost and injury rate and proportion differences was estimated using bootstrapping with 10 000 replicates. Results Along with a 38% reduction in injury risk (rate difference=−1.27/1000 player hours (95% CI −0.33 to −2.2)), healthcare costs were reduced by 43% in the NMT group (−$689/1000 player hours (95% CI −$1741 to $234)) compared with the control group. 90% of the bootstrapped ratios were in the south-west quadrant of the cost-effectiveness plane, showing that the NMT programme was dominant (more effective and less costly) over standard warm-up. Projecting results onto 58 100 Alberta youth soccer players, an estimated 4965 injuries and over $2.7 million in healthcare costs would be conservatively avoided in one season with implementation of a neuromuscular training prevention programme. Conclusions Implementation of an NMT prevention programme in youth soccer is effective in reducing the burden of injury and leads to considerable reduction in costs. These findings inform practice and policy supporting the implementation of NMT prevention strategies in youth soccer nationally and internationally.

Objective To determine if there is an association between the risk of all injury or concussion and win–loss records or penalty minutes in competitive youth ice hockey players (ages 11–14). Design, setting, participants This is a secondary data analysis of a 2-year cohort study in Alberta and Quebec on the 2007/2008 (Pee Wee) and 2008/2009 (Bantam) seasons. Main outcome measures Incidence rate ratios (IRRs) were estimated based on Poisson regression for game-related injury and concussion and adjusted for cluster by team. Results A total of 140 teams from Alberta (n=2081) and 137 teams (n=2018) from Quebec were included in the analysis. There were 451 game-related injuries (121 concussions) from Alberta and 280 (62 concussions) from Quebec. For game-related injuries, the IRR between players from teams with more than 50% wins and players with less or equal to 50% wins was 0.78 (95% CI 0.64–0.95) for all injuries, 0.75 (95% CI 0.52–1.08) for concussions, 0.64 (95% CI 0.47–0.88) for injuries resulting in time loss of more than 7 days, and 0.74 (95% CI 0.39–1.40) for concussions resulting in time loss of more than 10 days; adjusting for clustering by team and other important risk factors (ie, province, age, level of play, previous injury, weight and position). There was no association found between the total penalty minutes per game and game-related injury or concussion. Conclusions There was a significant association found between team performance (ie, win/loss/tie record) and injury risk with a 22% lower injury rate and 36% lower injury rate resulting in less than 7 days time loss in Pee Wee and Bantam ice hockey teams winning more than 50% of all season games. Total penalty minutes per game were not associated with injury or concussion rates.

Background Soccer is a leading sport for participation and injury in youth. Objective To examine the effectiveness of a neuromuscular prevention strategy in reducing injury in youth soccer players. Design Cluster-randomised controlled trial. Setting Calgary soccer clubs (male or female, U13–U18, tier 1–2, indoor soccer). Participants Eighty-two soccer teams were approached for recruitment. Players from 60 teams completed the study (32 training (n=380), 28 control (n=364)). Intervention The training programme was a soccer-specific neuromuscular training programme including dynamic stretching, eccentric strength, agility, jumping and balance (including a home-based balance training programme using a wobble board). The control programme was a standardised warm-up (static and dynamic stretching and aerobic components) and a home-based stretching programme. Main outcome measures Previously validated injury surveillance included injury assessment by a study therapist. The injury definition was soccer injury resulting in medical attention and/or removal from a session and/or time loss. Results The injury rate in the training group was 2.08 injuries/1000 player-hours, and in the control group 3.35 injuries/1000 player-hours. Based on Poisson regression analysis, adjusted for clustering by team and covariates, the incidence rate ratios (IRR) for all injuries and acute onset injury were 0.62 (95% CI 0.39 to 0.99) and 0.57 (95% CI 0.35 to 0.91). Point estimates also suggest protection of lower extremity, ankle and knee sprain injuries (IRR=0.68 (95% CI 0.42 to 1.11), IRR=0.5 (95% CI 0.24 to 1.04) and IRR=0.38 (95% CI 0.08 to 1.75)). Conclusions A neuromuscular training programme is protective of all injuries and acute onset injury in youth soccer players.

Background In ice hockey, body checking is associated with an increased risk of injury. In 2011, provincial policy change disallowed body checking in non-elite Pee Wee (ages 11–12 years) leagues. Objective To compare the risk of injury and concussion between non-elite Pee Wee ice hockey players in leagues where body checking is permitted (2011–12 Alberta, Canada) and leagues where policy change disallowed body checking (2011–12 Ontario, Canada). Method Non-elite Pee Wee players (lower 70%) from Alberta (n=590) and Ontario (n=281) and elite Pee Wee players (upper 30%) from Alberta (n=294) and Ontario (n=166) were recruited to participate in a cohort study. Baseline information, injury and exposure data was collected using validated injury surveillance. Results Based on multiple Poisson regression analyses (adjusted for clustering by team, exposure hours, year of play, history of injury/concussion, level of play, position and body checking attitude), the incidence rate ratio (IRR) associated with policy allowing body checking was 2.97 (95% CI 1.33 to 6.61) for all game injury and 2.83 (95% CI 1.09 to 7.31) for concussion. There were no differences between provinces in concussion [IRR=1.50 (95% CI 0.84 to 2.68)] or injury risk [IRR=1.22 (95% CI 0.69 to 2.16)] in elite levels of play where both provinces allowed body checking. Conclusions The rate of injury and concussion were threefold greater in non-elite Pee Wee ice hockey players in leagues where body checking was permitted. The rate of injury and concussion did not differ between provinces in elite levels, where body checking was allowed.

The health, fitness and other advantages of youth sports participation are well recognised. However, there are considerable challenges for all stakeholders involved— especially youth athletes—in trying to maintain inclusive, sustainable and enjoyable participation and success for all levels of individual athletic achievement. In an effort to advance a more unified, evidence-informed approach to youth athlete development, the IOC critically evaluated the current state of science and practice of youth athlete development and presented recommendations for developing healthy, resilient and capable youth athletes, while providing opportunities for all levels of sport participation and success. The IOC further challenges all youth and other sport governing bodies to embrace and implement these recommended guiding principles.

Objective To determine the association between previous history of concussion and sport-specific skill performance in youth ice hockey players. Design Cross-sectional. Setting Arenas in Calgary, Alberta, Canada over three seasons of play (2012–2015). Participants Five hundred and ninety-six players were recruited from youth hockey teams [525 males and 71 females, aged 11-17, representing elite (upper 30% by division of play) and non-elite (lower 70%)]. Assessment of risk factors Players completed a baseline questionnaire including the number, date of occurrence, and length of recovery following any previous concussions. Outcome measures On-ice skills performance was measured using the Hockey Canada Skills Test (HCST) battery including forward agility weave, forward to backward transition agility, forward/backward speed skate, and a 6-repeat endurance skate Results Previous history of concussion and time since most recent concussion were not associated with any HCST component. Players reporting two or more concussions were faster than those with no history of concussion on forward agility weave with the puck [−7.32 (95% CI: −11.05, −3.59)]. For every additional day of recovery post-concussion, a player’s time was significantly faster on forward agility weave with [−0.11 (95% CI: −0.16, −0.05] and without the puck [−0.08 (95% CI: −0.13, −0.04], transition agility without the puck [−0.01 (95% CI: −0.02, −0.01], and backward speed with [−0.06 (95% CI: −0.1, −0.03)] and without the puck[−0.05 (95% CI: −0.07, −0.03)]. Conclusions Players with a concussion history had similar HCST performance scores to those without. A longer post-concussion recovery was associated with better performance. These results provide reference values which will inform risk assessment and future injury prevention studies. Competing interests None.

Objective To evaluate acute changes in measures of cervical spine, vestibulo-ocular reflex (VOR) function, dynamic balance and tasks of divided attention in elite youth ice hockey players following a sport-related concussion. Study Design Prospective Case series Setting Sport Medicine Centre, Calgary, Alberta, Canada Participants Five hundred and fifty-nine (474 males) elite (AA and AAA) Bantam (13-14 years) and Midget (15-17 years) youth ice hockey players. Outcome measures Clinical measurements including cervical flexor endurance test (CFE), head perturbation test, head thrust test, dynamic visual acuity (DVA) (clinical and computerised), Functional Gait Assessment (FGA) and Walking While Talking (WWTT) test at baseline and acutely following concussion. Main results Sixty-nine of 97 (71%) players completed both baseline and acute post concussion measures for their first concussion and were included in these analyses. Following concussion, neck pain, headache and dizziness increased in 42%, 58% and 40% of participants respectively. After Bonferroni corrections (α=0.00625), using Wilcoxon Signed-Rank Test, cervical spine measures were significantly worse following concussion compared to baseline [cervical flexor endurance test (z=−5.195, p Conclusions Measures of cervical spine function and tasks of divided attention were worse following concussion. However, tests of VOR and dynamic balance were not significantly different than at baseline. Future research to evaluate the mechanism underlying these changes is warranted. Competing interests None.

Objective To determine preseason values on cervical, vestibular and divided attention measures in youth ice hockey players aged 10-14 years Design Cross-Sectional study Setting Sport Injury Prevention Research Centre, Alberta, Canada Participants Youth Ice Hockey players (n=934, age 10-14 years). Outcome measures Numeric pain rating scores for neck pain, headache, dizziness; Cervical flexor endurance test (CFE), cervical flexion rotation test (CFRT), cervical spine strength, head perturbation test, functional gait assessment (FGA), walking while talking test (WWTT), head thrust test and dynamic visual acuity (DVA). Main results Symptoms of neck pain, headaches and dizziness were reported by 17%, 18% and 10% of participants respectively. The median time of CFE was 27.0 seconds (IQR: 19.9, 40.7). CFRT was positive in 52 (6.2%) participants. Median anterolateral cervical spine strength was 8.0 lbs (IQR: 6.1, 10.3) right and 7.8 lbs (IQR: 6.0, 10.1) left. 13% of participants were unable to maintain a stationary head position when an external force was applied. 48% of participants performed less than perfect on the FGA. Time to complete a complex task while walking increased 40 foot walking time by a median of 6.4 seconds (IQR: 4.0, 10.3). Head thrust test was positive in 33 (3.7%) participants. Clinical DVA score was a median of 0.2 logMar (IQR: 0.1, 0.3). Conclusions Symptoms are common at baseline and outcomes on many commonly used clinical tests may be different for healthy 10-14 year olds compared to the adult literature. These findings form an important reference point for the interpretation of post-injury testing. Competing interests None.

Objective The objective of this study was to determine if youth ice-hockey players who perform more moderate and vigorous physical activity (MVPA) during recovery take longer to achieve medical clearance to return to play (RTP). Design Cohort study. Setting Sport Medicine Centre, Alberta, Canada. Participants Thirty youth ice-hockey players [25 males, 5 females, median age 14 years (range 12–17)] presenting to a sport medicine clinic within 4 days (range 2–20 days) of sustaining a sport-related concussion diagnosed by a sport medicine physician. Exposure Participants MVPA during the first three days following their initial appointment was measured using a waist worn Actigraph accelerometer. MVPA was dichotomized into high (≥45 minutes) and low ( Outcome The primary outcome was time (days) to medical clearance to RTP. Results All thirty participants performed at least some MVPA over the first three days, despite physician instruction to initially rest following the concussion. Players performing low levels of MVPA reached medical clearance in a median of 15 days (range: 10–30 days). Players performing high levels of MVPA reached medical clearance in a median of 19 days (range: 12–55 days). The low level MVPA group reached medical clearance significantly sooner than the high activity group (log-rank chi2=5.27, p=0.02). Conclusions More time in MVPA during the first three days after initial assessment is significantly associated with greater time to medical clearance to RTP. Future research is needed to better understand the optimal amount and timing of MVPA for concussion recovery. Competing interests None.

Objective To determine the value of the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) tool in measuring neurocognitive recovery following concussion. Design Nested case-control. Setting Sport Medicine Centre, Alberta, Canada. Participants Ice hockey players (n=96; 88.5% male, 11-17 years old) following concussion who completed ImPACT at baseline and medical clearance to return to play (RTP) were compared to controls (n=31) matched for age, sex, and testing time interval. Assessment of risk factors Players who sustained a concussion were referred to a study physician for assessment and RTP clearance based on clinical assessment and SCAT2/3. Physicians were blinded to ImPACT scores. Outcome measures ImPACT composite scores were measured (i.?e., verbal memory, visual memory, reaction time, visual motor) at each time interval [i.e., baseline and RTP (cases)/second measurement (controls)]. Between-interval ImPACT reliable change scores (80%CI) were compared. Main results At RTP (Median days since injury: 22, range: 2–84), 43/96 (44.8%) concussed players and 11/31 (35.5%) controls had ≥1 composite scores reliably worse than at baseline. Conditional logistic regression analysis (n=31 matched pairs) did not demonstrate a difference in the odds of having ≥1 reliably worse composite score between concussed and controls [OR=2.00 (95% CI: 0.5–8.0)] or ≥1 reliably better composite score [OR=1.2 (95% CI: 0.37–3.93)]. Conclusions The utility of baseline ImPACT scores in medical decisions to RTP may be limited by the reliability of composite scores in youth populations. Caution is warranted when interpreting ImPACT scores post-concussion on an individual level using baseline performance. Future research including multivariable analyses is warranted in a larger sample. Competing interests Brian Brooks is a co-author of a paediatric memory test for which he receives royalties. No financial interests in ImPACT are declared. None for all other authors.

Objective To evaluate brain adaptation following concussion. Do youth with a history of previous or acute concussion require more ball throws to land on or near a target, when wearing prism glasses (bend light to the left by 15r), than youth with none? Design Cross-sectional study. Setting Sport Injury Prevention Research Centre, Alberta, Canada. Participants Ice hockey players: 21 with acute concussion [(17 males), mean age 13.8 (95% CI: 13.4, 14.2), median number of days since concussion 4 (range 2–11)], 40 reporting previous concussion(s) [(33 males), mean age 13.4 (95% CI: 13.1, 13.7), median number of days since last concussion 620 (range 90–1560)], and 40 with no concussion history [(36 males), mean age 12.9 (95% CI: 12.5, 13.2)]. Independent variable Lifetime concussion history (yes/no) or acute concussion ( Dependent variable Number of throws for brain adaptation. Main results A significant concussion effect was identified across groups [F(2,98)=26.17, p Conclusions Concussion history and acute concussion appears to negatively impact brain plasticity in youth. They do not adapt as well as individuals with no concussion history. Our results support the use of a prism adaptation paradigm for identifying/quantifying short and long-term neurologic impairments in youth following concussion. Competing interests None.

Objective To determine if preseason measures of cervical, vestibulo-ocular function, balance and divided attention change over one year in 10-12 year old ice hockey players. Design Prospective cohort study Setting Sport Injury Prevention Research Centre, Alberta, Canada Participants Youth Ice Hockey players (10-12 years old) who completed cervical, vestibular and divided attention tasks at a preseason assessment during two seasons of play. Outcome measures Numeric pain rating scores (neck pain, headache, dizziness), cervical flexor endurance test (CFE), cervical flexion rotation test (CFRT), anterolateral cervical spine strength, head perturbation test, functional gait assessment (FGA), walking while talking test, head thrust test and dynamic visual acuity (DVA). Main results A total of 193 uninjured youth ice hockey players [95% males; median age 11 (range 10-12) in the first season] completed preseason testing measures in two consecutive seasons (2013-2015). After Bonferroni corrections (α=0.0042), using Wilcoxon Signed-Rank Test, anterolateral neck strength increased (right: z=−5.96, p Conclusions Symptom reports did not differ between two years of play. However, tests of clinical function were different between two seasons of play in youth ice hockey players. These data suggest that developmental and/or maturational changes should be taking into consideration when interpreting these tests in youth. Competing interests None.

Objective To evaluate the association between self-reported physical activity (PA) and concussion incidence in male youth ice hockey players. Design pooled data from three prospective cohort studies. Setting Community ice hockey rinks and sport medicine clinics. Participants PeeWee (ages 11–12), Bantam (ages 13–14), and Midget (ages 15–17) male youth ice hockey players (n=1208). Assesment of risk factors Participants reported six-week physical education and extra-curricular sport participation history upon study entry. Concussion incidence rate ratios [IRRs (95% CI)] associated with 1). total six-week PA volume, and 2). meeting the Canadian PA recommendations of one hour of daily PA (≥42 hours/six weeks) were calculated using multivariable Poisson regression (covariates: age, competition level, concussion history). Models were adjusted for hockey exposure, and cluster by team, study year and city (α Outcome measure Medically-diagnosed concussions during the study period. Main results Total PA volume did not affect concussion incidence in male youth ice hockey players [IRR: 0.996 (95% CI: 0.990–1.003]. Concussion incidence was higher in male ice hockey players who did not meet the PA recommendations versus those who met the PA recommendations amongst PeeWee [IRR: 2.94 (95% CI: 1.29–6.66)] and Bantam [IRR: 2.18 (95% CI: 1.12–3.94)] participants, but not amongst Midget participants [IRR: 1.37 (95% CI: 0.72–2.59)]. There was no evidence of confounding or modification by competition level or concussion history. Conclusions While total PA volume was not associated with concussion risk, PeeWee and Bantam male youth ice hockey players whose six-week PA history was below the PA recommendations were at greater risk of concussion. This research will inform future studies examining the mechanism of this association. Competing interests None.

Objective To examine attention problems in youth ice-hockey players as a risk factor for concussion. Design Secondary analysis of two prospective cohort studies. Setting Ice-rinks and Sport Medicine Centres in two Canadian cities over three ice-hockey seasons (2011/12, 2012/13, 2014/15). Assessment of risk factors Self-report of formal diagnosis of attention or learning disorders were collected on previously validated preseason baseline questionnaires by all participating players. Parents and players completed the Behaviour Assessment System for Children (BASC-2), which includes inattention and hyperactivity scales. Participants 2,364 Canadian ice-hockey players (11–17 years old, 87% male). Outcome measures A previously validated prospective injury surveillance system was used. All suspected concussions were referred to the study physician for confirmation of diagnosis. Concussion risk ratios (RR) were estimated, including stratification by known risk factors. Results One-hundred ninety-two of 2,215 players (9%) self-reported attention and/or learning disorders at baseline. Overall, 256 players (11%) sustained one or more concussions during a season. Players identified as “at-risk” for attention-deficit hyperactivity disorder (ADHD), based on BASC-2 T-scores (inattention and/or hyperactivity scale) greater than 60, had a greater risk of concussion during the season based on child report [RR=1.51 (95% CI 1.13–2.04)] and parent report [2.97 (95% CI 1.65–5.34)]. In players with no history of previous concussion, the RR based on child report was 1.88 (95% CI 1.22–2.90) and based on parent report was 5.03 (95% CI 2.45–10.29). Conclusions Ice-hockey players identified as “at-risk” for ADHD on the basis of baseline BASC-2 scores are at a greater risk of concussion. Competing interests None.

Objective To examine rates of concussion and severe concussion (time loss greater than 10 days) in elite youth ice hockey players. Design Prospective cohort study Setting Alberta, Canada Participants Bantam (13–14 years) and Midget (15–17 years) male and female elite (top 30% by division of play) youth ice hockey players. Assessment of risk factors Participants completed a demographic and medical history questionnaire and clinical test battery at the beginning of the season. A previously validated injury surveillance system was used to document exposure hours and injury during one season of play (8 months). Outcome measures Players with a suspected ice hockey-related concussion were referred to the study sport medicine physicians for assessment. Time loss from hockey participation was documented on an injury report form. Main results Overall, 778 elite youth ice hockey players (659 males, 119 females; aged 13–17 years) participated in this study. In total, 143 concussions occurred. The concussion incidence proportion (IP) was 18 concussions/100 players. The concussion incidence rate (IR) was 1.31 concussions/1000 player-hours (95% CI; 1.09, 1.57). Time loss greater than 10 days was reported in 74% of cases (106/143) and 20% (n=28) had time loss of greater than 30 days. Conclusions Concussion is a common injury in elite youth ice hockey players. In this study population, a large proportion of concussions (74%) resulted in a time loss of greater than 10 days, possibly reflecting more conservative management or longer recovery in youth athletes. Competing interests None.

The 2017 Concussion in Sport Group (CISG) consensus statement is designed to build on the principles outlined in the previous statements1–4 and to develop further conceptual understanding of sport-related concussion (SRC) using an expert consensus-based approach. This document is developed for physicians and healthcare providers who are involved in athlete care, whether at a recreational, elite or professional level. While agreement exists on the principal messages conveyed by this document, the authors acknowledge that the science of SRC is evolving and therefore individual management and return-to-play decisions remain in the realm of clinical judgement. This consensus document reflects the current state of knowledge and will need to be modified as new knowledge develops. It provides an overview of issues that may be of importance to healthcare providers involved in the management of SRC. This paper should be read in conjunction with the systematic reviews and methodology paper that accompany it. First and foremost, this document is intended to guide clinical practice; however, the authors feel that it can also help form the agenda for future research relevant to SRC by identifying knowledge gaps. A series of specific clinical questions were developed as part of the consensus process for the Berlin 2016 meeting. Each consensus question was the subject of a specific formal systematic review, which is published concurrently with this summary statement. Readers are directed to these background papers in conjunction with this summary statement as they provide the context for the issues and include the scope of published research, search strategy and citations reviewed for each question. This 2017 consensus statement also summarises each topic and recommendations in the context of all five CISG meetings (that is, 2001, 2004, 2008, 2012 as well as 2016). Approximately 60 000 published articles were screened by the expert panels for the Berlin …

Background Injury knowledge and beliefs influence uptake of prevention programmes, but the relationship between knowledge, beliefs and adherence remains unclear.Aim To describe injury knowledge and beliefs among youth female soccer coaches and players, and to identify the relationship between these factors, different delivery strategies of the FIFA 11+ programme and adherence.Methods A subcohort analysis from a clusterrandomised controlled trial of 31 female soccer teams (coaches n=29, players (ages 13–18) n=258). Preseason and postseason questionnaires were used to assessknowledge and beliefs. Teams recorded FIFA 11+ adherence during the season.Results At baseline, 62.8% (95% CI 48.4% to 77.3%) of coaches and 75.8% (95% CI 71.5% to 80.1%) of players considered ‘inadequate warm-up’ a risk factor for injury. There was no effect of delivery method (OR=1.1;95% CI 0.8 to 1.5) or adherence (OR=1.0; 95% CI 0.9 to 1.1) on this belief. At baseline, 13.8% (95% CI 1.3% to 26.4%) of coaches believed a warm-up could prevent muscle injuries, but none believed it could prevent kneeand ankle injuries. For players, 9.7% (95% CI 6.1% to 13.3%), 4.7% (95% CI 2.1% to 7.3%) and 4.7% (95% CI 2.1% to 7.3%) believed a warm-up would prevent muscle, knee and ankle injuries, respectively. Years ofplaying experience were negatively associated with high adherence for coaches (OR=0.93; 0.88 to 0.99) and players (OR=0.92; 0.85 to 0.98).Conclusions There were gaps in injury knowledge and beliefs, which differed for coaches and players. Beliefs did not significantly affect adherence to the FIFA 11+, suggesting additional motivational factors should be considered.

Background/aim The risk of injury among Pee Wee (ages 11–12 years) ice hockey players in leagues that allow body checking is threefold greater than in leagues that do not allow body checking. We estimated the cost–effectiveness of a no body checking policy versus a policy that allows body checking in Pee Wee ice hockey. Methods Cost–effectiveness analysis alongside a prospective cohort study during the 2007–2008 season, including players in Quebec (n=1046), where policy did not allow body checking, and in Alberta (n=1108), where body checking was allowed. Injury incidence rates (injuries/1000 player-hours) and incidence proportions (injuries/100 players), adjusted for cluster using Poisson regression, allowed for standardised comparisons and meaningful translation to community stakeholders. Based on Alberta fee schedules, direct healthcare costs (physician visits, imaging, procedures) were adjusted for cluster using bootstrapping. We examined uncertainty in our estimates using cost–effectiveness planes. Results Associated with significantly higher injury rates, healthcare costs where policy allowed body checking were over 2.5 times higher than where policy disallowed body checking ($C473/1000 player-hours (95% CI $C358 to $C603) vs $C184/1000 player-hours (95% CI $C120 to $C257)). The difference in costs between provinces was $C289/1000 player-hours (95% CI $C153 to $C432). Projecting results onto Alberta Pee Wee players registered in the 2011–2012 season, an estimated 1273 injuries and $C213 280 in healthcare costs would be avoided during just one season with the policy change. Conclusion Our study suggests that a policy disallowing body checking in Pee Wee ice hockey is cost-saving (associated with fewer injuries and lower costs) compared to a policy allowing body checking. As we did not account for long-term outcomes, our results underestimate the economic impact of these injuries.

Background Policy allowing body checking (BC) increases injury and concussion risk in youth ice hockey players. Hockey Calgary introduced BC policy change in 2015 that disallows BC at the Bantam (ages 13–14) non-elite level (lowest 60% by division of play). Objective To compare game offensive performance (OP) between non-elite Bantam players playing in a league allowing BC and players in a league not allowing BC. Design Prospective cohort. Setting Arenas in Calgary, Alberta. Participants Non-elite Bantam games were videotaped in Calgary, Alberta during the 2014–15 (n=348 players) and 2015–16 (n=309 players) playing seasons. Assessment of Risk Factors Players from the 2014–15 season played in a league allowing BC, while players from 2015–16 season played in a league where BC was not allowed. Main Outcome Measurements Using Dartfish video analysis software, games were analyzed for OP metrics for the puck carrier using the ice hockey adapted Team Sport Assessment Procedure. These metrics included puck possession (conquered puck from an opponent and received pass from a teammate) and puck outcome (successful shot on goal, lost puck to an opponent, and offensive pass to a teammate). Unadjusted incidence rate-ratios (IRRs), clustered by game, were calculated for each puck action per team game between players in Calgary, Alberta 2014–15 (BC allowed) and 2015–16 (BC not allowed). Results No differences were found in puck possession metrics [conquered puck IRR=1.07 (95% CI: 1.00,1.16), received pass IRR=1.05 (95% CI: 0.93,1.18)] or puck outcome [successful shot IRR=0.97 (95% CI: 0.86,1.10), lost puck IRR=1.07 (95% CI: 0.98,1.18), offensive pass IRR=0.98 (95% CI: 0.86,1.12)]. Conclusions There were no differences found across all OP metrics between a non-elite Bantam league allowing BC and a league not allowing BC. There is no evidence to conclude that offensive performance was negatively nor positively affected by Hockey Calgary9s decision to disallow BC at Bantam non-elite levels.

Background There is a growing body of evidence illustrating the contribution of training load to musculoskeletal injury risk. There is a gap in the literature, however, regarding the impact of training on concussion risk. Objective To evaluate the association between sport-specific participation volume and concussion risk in male youth ice hockey players. Design Cohort study. Setting Community ice rinks and sport medicine clinics (2011–15 hockey seasons). Patients (or Participants) Male Pee Wee (11–12 years old), Bantam (13–14 years old) and Midget (15–17 years old) ice hockey players were eligible. Players were excluded if they reported unhealed injuries at study entry, had missing/systematically incomplete hockey participation exposure data, or if they sustained a concussion but participation volume could not be estimated from the day of injury. Interventions (or Assessment of Risk Factors) Cumulative hockey participation volume (CPHV) was estimated based on participation exposure data reported by team designate. The association between concussion risk and total 7-day and 28-day CHPV was evaluated using multivariable logistic regression [OR (95%CI)]. Models were adjusted for concussion history and cluster by player (α Main Outcome Measurements Medically diagnosed concussion. Results Participants who met the inclusion criteria (n=1235/1990) sustained 34 medically diagnosed concussions. Increased concussion risk was associated with hourly increases in 7-day CHPV [OR=1.16 (95%CI: 1.08–1.25), p Conclusions Increased hockey participation volume was associated with increased concussion risk in male youth ice hockey players. This is the first study to explore the association between training volume and concussion risk. Future research utilizing objective volume measurements and training response tools will be critical to the development of primary concussion prevention strategies that optimize the role of training load.