Categorising sports injuries in epidemiological studies: the subsequent injury categorisation (SIC) model to address multiple, recurrent and exacerbation of injuries

Training Load and Fatigue Marker Associations with Injury and Illness: A Systematic Review of Longitudinal Studies

Background

Coaches, sport scientists, clinicians and medical personnel face a constant challenge to prescribe sufficient training load to produce training adaption while minimising fatigue, performance inhibition and risk of injury/illness.

Objective

The aim of this review was to investigate the relationship between injury and illness and longitudinal training load and fatigue markers in sporting populations.

Methods

Systematic searches of the Web of Science and PubMed online databases to August 2015 were conducted for articles reporting relationships between training load/fatigue measures and injury/illness in athlete populations.

Results

From the initial 5943 articles identified, 2863 duplicates were removed, followed by a further 2833 articles from title and abstract selection. Manual searching of the reference lists of the remaining 247 articles, together with use of the Google Scholar ‘cited by’ tool, yielded 205 extra articles deemed worthy of assessment. Sixty-eight studies were subsequently selected for inclusion in this study, of which 45 investigated injury only, 17 investigated illness only, and 6 investigated both injury and illness. This systematic review highlighted a number of key findings, including disparity within the literature regarding the use of various terminologies such as training load, fatigue, injury and illness. Athletes are at an increased risk of injury/illness at key stages in their training and competition, including periods of training load intensification and periods of accumulated training loads.

Conclusions

Further investigation of individual athlete characteristics is required due to their impact on internal training load and, therefore, susceptibility to injury/illness.

Risk and Protective Factors for Middle- and Long-Distance Running-Related Injury

BACKGROUND

Despite a rapidly growing body of research, a systematic evidence compilation of the risk and protective factors for middle- and long-distance running-related injury (RRI) was lacking.

OBJECTIVES

Our objective was to compile the evidence about modifiable and non-modifiable training-related and behavioral risk and protective factors for middle- and long-distance RRI.

METHODS

We searched five databases (PubMed, CINAHL, MEDLINE, SPORTDiscus, and PsycINFO) for the dates 1 January 1970 to 31 December 2015, inclusive, for original peer-reviewed articles. The eligible designs were cross-sectional, case-control, longitudinal observational studies, and randomized controlled trials involving runners competing at distances from ≥800 m to ≤42.2 km. Outcomes were any specific and/or general RRI, and exposures included training-related and behavioral factors. We extracted authors and date, study design, injury type(s), descriptors and comparators for each exposure, and results and measures of association from the selected studies. Methodological quality was independently appraised using two separate checklists: a modified checklist for observational study designs and the Physiotherapy Evidence Database (PEDro) scale for randomized controlled trials.

RESULTS

Among 73 articles eligible for inclusion, 19 (26.0%) and 30 (41.0%) were of high or satisfactory methodological quality, respectively. As a non-modifiable exposure, a history of previous injury was found to be associated with an increased risk of both general and specific RRI. In terms of modifiable exposures, irregular and/or absent menstruation was found to be associated with an increased risk of stress fracture development, whereas the use of oral contraceptives was found to be associated with a decreased risk. High clinical, methodological, and statistical heterogeneity meant it was not feasible to estimate a pooled effect size across similar studies.

CONCLUSIONS

A history of previous injury was associated with an increased risk of both general and specific RRI. The use of oral contraceptives was found to be associated with a decreased risk of skeletal stress fracture. Conversely, irregular and/or absent menstruation was associated with an increased risk. The varied effect directions and/or a number of statistically insignificant results associated with the majority of factors hindered our ability to draw any definitive conclusions about their relationship to RRI risk.

Reporting Multiple Individual Injuries in Studies of Team Ball Sports: A Systematic Review of Current Practice

Background

To identify and prioritise targets for injury prevention efforts, injury incidence studies are widely reported. The accuracy and consistency in calculation and reporting of injury incidence is crucial. Many individuals experience more than one injury but multiple injuries are not consistently reported in sport injury incidence studies.

Objective

The aim of this systematic review was to evaluate current practice of how multiple injuries within individuals have been defined and reported in prospective, long-term, injury studies in team ball sports.

Data Sources

A systematic search of three online databases for articles published before 2016.

Study Selection

Publications were included if (1) they collected prospective data on musculoskeletal injuries in individual participants; (2) the study duration was >1 consecutive calendar year/season; and (3) individuals were the unit of analysis.

Data Extraction

Key study features were summarised, including definitions of injury, how multiple individual injuries were reported and results relating to multiple injuries.

Results

Of the 71 publications included, half did not specifically indicate multiple individual injuries; those that did were largely limited to reporting recurrent injuries. Eight studies reported the number/proportion of athletes with more than one injury, and 11 studies presented the mean/number of injuries per athlete.

Conclusions

Despite it being relatively common to collect data on individuals across more than one season, the reporting of multiple injuries within individuals is much more limited. Ultimately, better addressing of multiple injuries will improve the accuracy of injury incidence studies and enable more precise targeting and monitoring of the effectiveness of preventive interventions.

Electronic supplementary material

The online version of this article (doi:10.1007/s40279-016-0637-3) contains supplementary material, which is available to authorized users.

Fundamentals of Sports Analytics

Recently, the importance of statistics and analytics in sports has increased. This review describes measures of sports injury and fundamentals of sports injury research with a brief overview of some of the emerging measures of sports performance. We describe research study designs that can be used to identify risk factors for injury, injury surveillance programs, and common measures of injury risk and association. Finally, we describe measures of physical performance and training and considerations for using these measures. This review provides sports medicine clinicians with an understanding of current research measures and considerations for designing sports injury research studies.

Application of a Simple Surveillance Method for Detecting the Prevalence and Impact of Overuse Injuries in Professional Men's Basketball

The aim of this study was to use the Oslo Sports Trauma Research Center (OSTRC) Overuse Injury Questionnaire to record overuse injuries over a single season for a men's professional basketball team to (a) assess the prevalence and severity of overuse injuries and (b) determine the efficacy of this method in identifying overuse injuries in comparison with the team physiotherapist's detection of these injuries. Thirteen athletes from a men's professional basketball team participated in this study. The self-reported, OSTRC injury questionnaire was used to record overuse conditions of the ankle, knee, and lower back over an entire 24-week season. Standard time-loss injury registration methods were also used to record overuse conditions by the physiotherapist. Overuse injury rates per 1,000 hours of athlete exposure and average weekly prevalence of overuse injuries were calculated using the results of the questionnaire. A total of 183 overuse conditions were identified by the questionnaire, whereas only 28 overuse conditions were identified by the physiotherapist. The team's average weekly prevalence of all overuse conditions was 63% (95% confidence interval [CI]: 60-66), with the highest prevalence of injury affecting the lower back (25.9% [95% CI: 19.7-32.1]). The overuse injury rate per 1,000 hours of athlete exposure was 6.4. The OSTRC overuse injury questionnaire captures many more overuse injuries in basketball than standard time-loss methods. The prevalence of lower back injuries is higher than that previously reported in basketball. This additional method of overuse injury surveillance may more accurately quantify the overuse injury problem in basketball and aid earlier intervention and management of these conditions.

Design of ProjectRun21: a 14-week prospective cohort study of the influence of running experience and running pace on running-related injury in half-marathoners

BACKGROUND

Participation in half-marathon has been steeply increasing during the past decade. In line, a vast number of half-marathon running schedules has surfaced. Unfortunately, the injury incidence proportion for half-marathoners has been found to exceed 30% during 1-year follow-up. The majority of running-related injuries are suggested to develop as overuse injuries, which leads to injury if the cumulative training load over one or more training sessions exceeds the runners' load capacity for adaptive tissue repair. Owing to an increase of load capacity along with adaptive running training, the runners' running experience and pace abilities can be used as estimates for load capacity. Since no evidence-based knowledge exist of how to plan appropriate half-marathon running schedules considering the level of running experience and running pace, the aim of ProjectRun21 is to investigate the association between running experience or running pace and the risk of running-related injury.

METHODS

Healthy runners using Global Positioning System (GPS) watch between 18 and 65 years will be invited to participate in this 14-week prospective cohort study. Runners will be allowed to self-select one of three half-marathon running schedules developed for the study. Running data will be collected objectively by GPS. Injury will be based on the consensus-based time loss definition by Yamato et al.: "Running-related (training or competition) musculoskeletal pain in the lower limbs that causes a restriction on or stoppage of running (distance, speed, duration, or training) for at least 7 days or 3 consecutive scheduled training sessions, or that requires the runner to consult a physician or other health professional". Running experience and running pace will be included as primary exposures, while the exposure to running is pre-fixed in the running schedules and thereby conditioned by design. Time-to-event models will be used for analytical purposes.

DISCUSSION

ProjectRun21 will examine if particular subgroups of runners with certain running experiences and running paces seem to sustain more running-related injuries compared with other subgroups of runners. This will enable sport coaches, physiotherapists as well as the runners to evaluate their injury risk of taking up a 14-week running schedule for half-marathon.

Subsequent Injuries Are More Common Than Injury Recurrences: An Analysis of 1 Season of Prospectively Collected Injuries in Professional Australian Football

BACKGROUND

It is known that some people can, and do, sustain >1 injury over a playing season. However, there is currently little high-quality epidemiological evidence about the risk of, and relationships between, multiple and subsequent injuries.

PURPOSE

To describe the subsequent injuries sustained by Australian Football League (AFL) players over 1 season, including their most common injury diagnoses.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Within-player linked injury data on all date-ordered match-loss injuries sustained by AFL players during 1 full season were obtained. The total number of injuries per player was determined, and in those with >1 injury, the Subsequent Injury Classification (SIC) model was used to code all subsequent injuries based on their Orchard Sports Injury Classification System (OSICS) codes and the dates of injury.

RESULTS

There were 860 newly recorded injuries in 543 players; 247 players (45.5%) sustained ≥1 subsequent injuries after an earlier injury, with 317 subsequent injuries (36.9% of all injuries) recorded overall. A subsequent injury generally occurred to a different body region and was therefore superficially unrelated to an index injury. However, 32.2% of all subsequent injuries were related to a previous injury in the same season. Hamstring injuries were the most common subsequent injury. The mean time between injuries decreased with an increasing number of subsequent injuries.

CONCLUSION

When relationships between injuries are taken into account, there is a high level of subsequent (and multiple) injuries leading to missed games in an elite athlete group.

INJURY INCIDENCE, DANCE EXPOSURE AND THE USE OF THE MOVEMENT COMPETENCY SCREEN (MCS) TO IDENTIFY VARIABLES ASSOCIATED WITH INJURY IN FULL-TIME PRE-PROFESSIONAL DANCERS

BACKGROUND/PURPOSES

Prospective studies utilizing standardized injury and exposure measures are needed to consolidate our knowledge of injury incidence and associated risk factors for musculoskeletal injury amongst pre-professional dancers. The purpose of this study was to investigate the injury incidence amongst pre-professional dancers attending a fulltime training school in New Zealand. The secondary purposes of this study were to investigate the relationship between dance exposure and injury risk, and the relationship between risk factors (specifically the MCS outcome scores) and injury risk.

METHODS

A prospective cohort study of 66 full-time pre-professional dancers was undertaken over one full academic year (38 weeks), included 40 females (mean age 17.78 yrs, SD 1.18) and 26 males (mean age 18.57yrs, SD 1.72). Injury surveillance included both reported and self reported injury data. Dancers were screened using the MCS in the first week of term one.

RESULTS

Eighty-six per cent of dancers sustained one or more injuries. Fifty-nine per cent of all injuries were time-loss. The injury incidence rate was 2.27 per 1000 hours of dance exposure (DEhr) and 3.35 per 1000 dance exposures (DE). There was a significant association between the total number of injuries and total DE per month (B=0.003, 95% CI 0.001 - 0.006, p=0.016). Dancers who had a MCS score < 23 were more likely to be injured than those who scored ≥23 (B = -0.702, 95% CI = -1.354 - -0.050, p=0.035).

CONCLUSION

Injury prevalence and incidence was comparable with other international cohorts. The number of dance exposures was more highly associated with injury risk than the hours of dance exposure. The MCS may be a useful tool to help identify dancers at risk of injury.

LEVEL OF EVIDENCE

Level 3b, Prospective Longitudinal Cohort Study.

How should we categorise self-reported data on subsequent injuries?

Classifying subsequent injuries is of high importance in injury epidemiology since a previous injury has been reported to increase the risk of a new injury or increase the risk of a more severe injury. Multiple reports have shown that self-reported data provide an extensive view of an injury problem and add valuable information to the understanding of the athlete's health. The purpose of this study was to display a method that can be used to facilitate classification of subsequent injuries and to discuss challenges faced when categorising subsequent injuries based on self-reported data. The suitability of a new model for Subsequent Injuries Adjusted for Self-reported data (SIAS model) was demonstrated with sport injury data from a cohort of 101 adolescent elite track & field athletes, followed over 52 weeks. A total number of 71 subsequent injuries were identified. Of all subsequent injuries, recurrent injuries represented 69.0% (n = 49) and 31.0% (n = 22) were classified as new injuries. The majority of subsequent injuries (n = 60, 84.5%) occurred after athletes had recovered from a previous injury. Of all subsequent injuries, 15.5% (n = 11) represented injuries where athletes had not fully recovered from a previous injury. Application of the SIAS model allows for classification of subsequent injuries based on self-reported data on the recovery level of the athletes, the injury onset and injury type. The developed SIAS model follows the consensus recommendations of injury definition, injury classification and is an attempt to increase the understanding of the complex relationship of subsequent injuries in self-reported data sets.

Application of the subsequent injury categorisation model for longitudinal injury surveillance in elite rugby and cricket: intersport comparisons and inter-rater reliability of coding

BACKGROUND

When an athlete has more than one injury over a time period, it is important to determine if these are related to each other or not. The subsequent injury categorisation (SIC) model is a method designed to consider the relationship between an index injury and subsequent injury(ies).

OBJECTIVE

The primary aim was to apply SIC to longitudinal injury data from two team sports: rugby union and cricket. The secondary aim was to determine SIC inter-rater reliability.

METHODS

Rugby union (time-loss; TL) and cricket (TL and non-time-loss; NTL) injuries sustained between 2011 and 2014 within one international team, respectively, were recorded using international consensus methods. SIC was applied by multiple raters, team clinicians, non-team clinicians, and a sports scientist. Weighted kappa and Cohen's kappa scores were calculated for inter-rater reliability of the rugby union TL injuries and cricket NTL and TL injuries.

RESULTS

67% and 51% of the subsequent injuries in rugby union and cricket respectively were categorised as injuries to a different body part not related to an index injury (SIC code 10). At least moderate agreement (weighted and Cohen kappa ≥0.60) was observed for team clinicians and the non-team clinician for both sports. Including NTL and TL injuries increased agreement between team clinician and non-team clinician, but not between clinician and sports scientist.

CONCLUSION

The most common subsequent injury in both sports was an injury to a different body part that was not related to an index injury. The SIC model was generally reliable, with the highest agreement between clinicians working within the same team. Recommendations for future use of SIC are provided based on the proximity of the rater to the team and the raters' level of clinical knowledge.

Physical Activity Level and Sport Participation in Relation to Musculoskeletal Pain in a Population-Based Study of Adolescents: The Young-HUNT Study

Background:

Prevalence of musculoskeletal pain among adolescents is high, and pain in adolescence increases the risk of chronic pain in adulthood. Studies have shown conflicting evidence regarding associations between physical activity and musculoskeletal pain, and few have evaluated the potential impact of sport participation on musculoskeletal pain in adolescent population samples.

Purpose:

To examine the associations between physical activity level, sport participation, and musculoskeletal pain in the neck and shoulders, low back, and lower extremities in a population-based sample of adolescents.

Study Design:

Cross-sectional study; Level of evidence 4.

Methods:

Data from the Nord-Trøndelag Health Study (Young-HUNT3) were used. All 10,464 adolescents in the Nord-Trøndelag county of Norway were invited, of whom 74% participated. Participants were asked how often they had experienced pain, unrelated to any known disease or acute injury, in the neck and shoulders, low back, and lower extremities in the past 3 months. The associations between (1) physical activity level (low [reference], medium or high) or (2) sport participation (weekly compared with no/infrequent participation) and pain were evaluated using logistic regression analyses, stratified by sex, and adjusted for age, socioeconomic status, and psychological distress.

Results:

The analyses included 7596 adolescents (mean age, 15.8 years; SD, 1.7). Neck and shoulder pain was most prevalent (17%). A moderate level of physical activity was associated with reduced odds of neck and shoulder pain (OR = 0.79 [95% CI, 0.66-0.94]) and low back pain (OR = 0.75 [95% CI, 0.62-0.91]), whereas a high level of activity increased the odds of lower extremity pain (OR = 1.60 [95% CI, 1.29-1.99]). Participation in endurance sports was associated with lower odds of neck and shoulder pain (OR = 0.79 [95% CI, 0.68-0.92]) and low back pain (OR = 0.77 [95% CI, 0.65-0.92]), especially among girls. Participation in technical sports was associated with increased odds of low back pain, whereas team sports were associated with increased odds of lower extremity pain. Strength and extreme sports were related to pain in all regions.

Conclusion:

We found that a moderate physical activity level was associated with less neck and shoulder pain and low back pain, and that participation in endurance sports may be particularly beneficial. Our findings highlight the need for health care professionals to consider the types of sports adolescents participate in when evaluating their musculoskeletal pain.

A Sport Fitness Index for Assessment of Sport-Related Injury Risk

OBJECTIVE

To develop and validate a concise survey that will identify athletes who possess elevated injury risk.

DESIGN

Cohort study.

SETTING

National Collegiate Athletic Association Division I athletic program.

PARTICIPANTS

Cohorts of 188 and 146 college athletes who participated during successive academic years.

ASSESSMENT OF RISK FACTORS

The first cohort provided responses to 4 joint-specific outcome surveys that were related to subsequent time-loss injury occurrence. Receiver operating characteristic analysis identified survey items that provided best discrimination, which were combined with a negative life event stress item to create a new 10-item survey. The second cohort provided responses to the new survey, which were converted to a 0 to 100 score.

MAIN OUTCOME MEASURES

Construct validity was assessed through documentation of time-loss injuries sustained during the preceding 12 months and predictive validity was assessed through prospective documentation of sport-related sprains and strains. Cronbach alpha was calculated to assess internal consistency.

RESULTS

Each of the outcome survey items used to develop the new survey demonstrated much greater specificity than sensitivity. Both the retrospective and prospective receiver operating characteristic (ROC) analyses identified scores of 96 and 88 as cut-points that provided good discrimination between injured and noninjured cases. The area under the curve was 0.69 (P < 0.001) for the retrospective analysis and 0.62 (P = 0.016) for the prospective analysis. Cronbach alpha was 0.89 (90% CI, 0.86-0.91).

CONCLUSIONS

Self-reported effects of previous injury may be one method to efficiently identify athletes who possess elevated injury risk, and subsequently deliver preventive interventions, thereby providing an alternative method to time-intensive functional testing.

The Sports-Related Injuries and Illnesses in Paralympic Sport Study (SRIIPSS): a study protocol for a prospective longitudinal study

BACKGROUND

Paralympic sport provides sporting opportunities for athletes with a disability, with the Paralympic Games as the main event. Participation in sport is, however, associated with a significant risk for sustaining injuries and illnesses. Our knowledge of sports-related injuries and illnesses in Paralympic sport is very limited and there are no large-scale epidemiological cohort studies. The purpose here is to present a protocol for a prospective longitudinal study: The Sports-Related Injuries and Illnesses in Paralympic Sport Study (SRIIPSS).

METHODS/DESIGN

An argument-based method for investigation of design problems was used to structure the study protocol. The primary requirement of the protocol is to allow prospective studies over time and include exposure to both training and competition. To reflect the complexity of Paralympic sport with athletes' pre-existing impairments, use of assistive equipment, pain and other and medical issues, it is required that the data collection system is specifically adapted to Paralympic sport. To allow the collection of data, at the same time as there is limited access to coaches and medical personnel, it is advantageous that data can be collected online directly from the athletes. Based on this a self-report athlete monitoring system will be developed, where the athletes can enter data weekly via their mobile phones or lap-tops. Data will be collected from around 100 Swedish Paralympic athletes for approximately 1 year, which will allow us to i) prospectively estimate the annual incidence of sports-related injuries and illnesses and ii) explore risk factors and mechanisms for sustaining sports-related injuries and illnesses based on athlete exposure and training loads.

DISCUSSION

For effective implementation of injury and illness prevention measures, comprehensive epidemiological knowledge is required. This study will be the first prospective longitudinal self-report study of sports-related injuries and illnesses in Paralympic sport over a longer period of time. The results will eventually contribute to the development of evidence-based preventive measures specifically adapted to Paralympic sport in order to provide safe and healthy sport participation. Thereby, the project will be of relevance for Paralympic athletes at all levels and to the Paralympic Movement.

TRIAL REGISTRATION

The study is registered at ClinicalTrials.gov (Identifier: NCT02788500; Registration date: 22 May 2016).

Hamstring Reinjuries Occur at the Same Location and Early After Return to Sport: A Descriptive Study of MRI-Confirmed Reinjuries

BACKGROUND

Despite relatively high reinjury rates after acute hamstring injuries, there is a lack of detailed knowledge about where and when hamstring reinjuries occur, and studies including imaging-confirmed reinjuries are scarce.

PURPOSE

To investigate the location, radiological severity, and timing of reinjuries on magnetic resonance imaging (MRI) compared with the index injury.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A MRI scan was obtained ≤5 days after an acute hamstring index injury in 180 athletes, and time to return to sport (RTS) was registered. Athletes with an MRI-confirmed reinjury in the same leg ≤365 days after RTS were included. Categorical grading and standardized MRI parameters of the index injury and reinjury were scored by a single radiologist (with excellent intraobserver reliability). To determine the location of the reinjury, axial and coronal views of the index injury and reinjury were directly compared on proton density-weighted fat-suppressed images.

RESULTS

In the 19 athletes included with reinjury, 79% of these reinjuries occurred in the same location within the muscle as the index injury. The median time to RTS after the index injury was 19 days (range, 5-37 days; interquartile range [IQR], 15 days). The median time between the index injury and reinjury was 60 days (range, 20-316 days; IQR, 131 days) and the median time between RTS after the index injury and the reinjury was 24 days (range, 4-311 days; IQR, 140 days). More than 50% of reinjuries occurred within 25 days (4 weeks) after RTS from the index injury and 50% occurred within 50 days after the index injury. All reinjuries with more severe radiological grading occurred in the same location as the index injury.

CONCLUSION

The majority of the hamstring reinjuries occurred in the same location as the index injury, early after RTS and with a radiologically greater extent, suggesting incomplete biological and/or functional healing of the index injury. Specific exercise programs focusing on reinjury prevention initiated after RTS from the index injury are highly recommended.

How do training and competition workloads relate to injury? The workload-injury aetiology model

Injury aetiology models that have evolved over the previous two decades highlight a number of factors which contribute to the causal mechanisms for athletic injuries. These models highlight the pathway to injury, including (1) internal risk factors (eg, age, neuromuscular control) which predispose athletes to injury, (2) exposure to external risk factors (eg, playing surface, equipment), and finally (3) an inciting event, wherein biomechanical breakdown and injury occurs. The most recent aetiological model proposed in 2007 was the first to detail the dynamic nature of injury risk, whereby participation may or may not result in injury, and participation itself alters injury risk through adaptation. However, although training and competition workloads are strongly associated with injury, existing aetiology models neither include them nor provide an explanation for how workloads alter injury risk. Therefore, we propose an updated injury aetiology model which includes the effects of workloads. Within this model, internal risk factors are differentiated into modifiable and non-modifiable factors, and workloads contribute to injury in three ways: (1) exposure to external risk factors and potential inciting events, (2) fatigue, or negative physiological effects, and (3) fitness, or positive physiological adaptations. Exposure is determined solely by total load, while positive and negative adaptations are controlled both by total workloads, as well as changes in load (eg, the acute:chronic workload ratio). Finally, we describe how this model explains the load-injury relationships for total workloads, acute:chronic workload ratios and the training load-injury paradox.

International consensus statement on injury surveillance in cricket: a 2016 update

Cricket was the first sport to publish recommended methods for injury surveillance in 2005. Since then, there have been changes to the nature of both cricket and injury surveillance. Researchers representing the major cricket playing nations met to propose changes to the previous recommendations, with an agreed voting block of 14. It was decided that 10 of 14 votes (70%) were required to add a new definition element and 11 of 14 (80%) were required to amend a previous definition. In addition to the previously agreed 'Match time-loss' injury, definitions of 'General time-loss', 'Medical presentation', 'Player-reported' and 'Imaging-abnormality' injuries are now provided. Further, new injury incidence units of match injuries per 1000 player days, and annual injuries per 100 players per year are recommended. There was a shift towards recommending a greater number of possible definitions, due to differing contexts and foci of cricket research (eg, professional vs amateur; injury surveillance systems vs specific injury category studies). It is recommended that researchers use and report as many of the definitions as possible to assist both comparisons between studies within cricket and with those from other sports.

Sports-related workload and injury risk: simply knowing the risks will not prevent injuries: Narrative review

Training loads contribute to sports injury risk but their mitigation has rarely been considered in a sports injury prevention framework. A key concept behind monitoring training loads for injury prevention is to screen for those at increased risk of injury so that workloads can be adjusted to minimise these risks. This review describes how advances in management of workload can be applied as a preventive measure. Primary prevention involves screening for preparticipation load risk factors, such as low training loads, prior to a training period or competition. Secondary prevention involves screening for workloads that are known to precede an injury developing so that modification can be undertaken to mitigate this risk. Tertiary prevention involves rehabilitation practices that include a graded return to training programme to reduce the risk of sustaining a subsequent injury. The association of training loads with injury incidence is now established. Prevention measures such as rule changes that affect the workload of an athlete are universal whereas those that address risk factors of an asymptomatic subgroup are more selective. Prevention measures, when implemented for asymptomatic individuals exhibiting possible injury risk factors, are indicated for an athlete at risk of developing a sports injury. Seven key indicated risks and associated prevention measures are proposed.

Shedding Light on the Etiology of Sports Injuries: A Look Behind the Scenes of Time-to-Event Analyses

The etiological mechanism underpinning any sports-related injury is complex and multifactorial. Frequently, athletes perceive "excessive training" as the principal factor in their injury, an observation that is biologically plausible yet somewhat ambiguous. If the applied training load is suddenly increased, this may increase the risk for sports injury development, irrespective of the absolute amount of training. Indeed, little to no rigorous scientific evidence exists to support the hypothesis that fluctuations in training load, compared to absolute training load, are more important in explaining sports injury development. One reason for this could be that prospective data from scientific studies should be analyzed in a different manner. Time-to-event analysis is a useful statistical tool in which to analyze the influence of changing exposures on injury risk. However, the potential of time-to-event analysis remains insufficiently exploited in sports injury research. Therefore, the purpose of the present article was to present and discuss measures of association used in time-to-event analyses and to present the advanced concept of time-varying exposures and outcomes. In the paper, different measures of association, such as cumulative relative risk, cumulative risk difference, and the classical hazard rate ratio, are presented in a nontechnical manner, and suggestions for interpretation of study results are provided. To summarize, time-to-event analysis complements the statistical arsenal of sports injury prevention researchers, because it enables them to analyze the complex and highly dynamic reality of injury etiology, injury recurrence, and time to recovery across a range of sporting contexts.

INJURIES IN DISC GOLF - A DESCRIPTIVE CROSS-SECTIONAL STUDY

BACKGROUND

Disc golf is rapidly increasing in popularity and more than two million people are estimated to regularly participate in disc golf activities. Despite this popularity, the epidemiology of injuries in disc golf remains under reported.

PURPOSE

The purpose of the present study was to investigate the prevalence and anatomic distribution of injuries acquired through disc-golf participation in Danish disc golf players.

METHODS

The study was a cross-sectional study conducted on Danish disc-golf players. In May 2015, invitations to complete a web-based questionnaire were spread online via social media, and around disc-golf courses in Denmark. The questionnaire included questions regarding disc-golf participation and the characteristics of injuries acquired through disc golf participation. The data was analyzed descriptively.

RESULTS

An injury prevalence of 13.3% (95% CI: 6.7% to 19.9%) was reported amongst the 105 disc-golf players who completed the questionnaire. The anatomical locations most commonly affected by injury were the shoulder (31%) and the elbow (20%). Injuries affecting the players at the time of completion of the questionnaire had a median duration of 240 days (IQR 1410 days), and the majority (93%) had a gradual onset.

CONCLUSIONS

A 13.3% point prevalence of injury was reported. Most injuries occurred in the shoulder and elbow regions, and were gradual in onset. Injuries affecting the players at the time of data collection had median symptomatic duration of 240 days.

LEVELS OF EVIDENCE

3b.

Measuring sports injuries on the pitch: a guide to use in practice

Sports participation is a major ally for the promotion of physical activity. However, sports injuries are important adverse effects of sports participation and should be monitored in sports populations. The purpose of this paper is to review the basic concepts of injury monitoring and discuss the implementation of these concepts in practice. The aspects discussed are: (1) sports injury definition; (2) classification of sports injuries; (3) population at risk, prevalence, and incidence; (4) severity measures; (5) economic costs; (6) systems developed to monitor sports injuries; and (7) online technology. Only with reliable monitoring systems applied in a continuous and long-term manner will it be possible to identify the burden of injuries, to identify the possible cases at an early stage, to implement early interventions, and to generate data for sports injury prevention. The implementation of sports injuries monitoring systems in practice is strongly recommended.

Injury Risk in International Rugby Union: Three-Year Injury Surveillance of the Welsh National Team

BACKGROUND

Within international Rugby Union, only injury rates during the Rugby World Cup have been reported. Therefore, injury rates and types during other international tournaments are unknown.

PURPOSE

To assess the 3-year incidence, severity, nature, and causes of match and training injuries sustained during different international tournaments played by the Welsh national Rugby Union team.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

Injury data for all players (n = 78) selected for 1 national Rugby Union team over a 3-year period were analyzed using the international consensus statement methods. Player height (cm) and mass (kg) were recorded. Tournaments were grouped for comparisons as: autumn tournaments (2012 and 2013), Rugby World Cup (RWC; 2011), Six Nations (2012, 2013, and 2014), and summer tournaments (2012, 2013, and 2014). Injury incidence (injuries/1000 hours), prevalence (% of players unavailable), and severity (days lost) were calculated for each tournament. Injury location, type, and cause of match and training injuries were analyzed.

RESULTS

Match injury incidence was highest during autumn tournaments (262.5/1000 match-hours) and lowest during the RWC (178.6/1000 match-hours). Summer tournaments had the highest training incidence (5.5 injuries/1000 training-hours). Mild injuries were most likely during the RWC (risk ratio [RR], 2.02; 95% CI, 1.26-3.24), while severe injuries were most likely during autumn tournaments (RR, 3.27; 95% CI, 1.70-6.29). Quadriceps hematomas (18.8/1000 match-hours; 95% CI, 11.3-31.1) and concussions (13.8/1000 match-hours; 95% CI, 7.6-24.8) were the most common match injuries, with shoulder dislocations being the most severe (111 mean days lost per injury).

CONCLUSION

Injury rates were considerably higher than those previously reported for multiple teams during RWC tournaments. Further investigation of injury rates and risk factors is recommended to accurately gauge their impact within international Rugby Union, particularly with regard to lower limb hematoma, concussion, and shoulder injuries.

A multistate framework for the analysis of subsequent injury in sport (M-FASIS)

Physical activity is beneficial for many aspects of health but is associated with a risk of injury. Studies that assess causal risk factors of injury and reinjury provide valuable information to help develop and improve injury prevention programs. However, the underlying assumptions of analytical approaches often used to estimate causal factors in injury and subsequent injury research are often violated. This means that ineffective or even harmful interventions could be proposed because the underlying analyses produced unreliable or invalid causal effect estimates. We describe an adapted version of the multistate framework [multistate framework for the analysis of subsequent injury in sport (M-FASIS)] that makes investigator choices more transparent with respect to outcome and healing time. In addition, M-FASIS incorporates all previous sport injury analytical frameworks and accounts for injuries or conditions that heal or do not heal to 100%, acute and overuse injuries, illnesses, and competing event outcomes.

OARSI Clinical Trials Recommendations: Design and conduct of clinical trials for primary prevention of osteoarthritis by joint injury prevention in sport and recreation

The risk of post-traumatic osteoarthritis (PTOA) substantially increases following joint injury. Research efforts should focus on investigating the efficacy of preventative strategies in high quality randomized controlled trials (RCT). The objective of these OARSI RCT recommendations is to inform the design, conduct and analytical approaches to RCTs evaluating the preventative effect of joint injury prevention strategies. Recommendations regarding the design, conduct, and reporting of RCTs evaluating injury prevention interventions were established based on the consensus of nine researchers internationally with expertise in epidemiology, injury prevention and/or osteoarthritis (OA). Input and resultant consensus was established through teleconference, face to face and email correspondence over a 1 year period. Recommendations for injury prevention RCTs include context specific considerations regarding the research question, research design, study participants, randomization, baseline characteristics, intervention, outcome measurement, analysis, implementation, cost evaluation, reporting and future considerations including the impact on development of PTOA. Methodological recommendations for injury prevention RCTs are critical to informing evidence-based practice and policy decisions in health care, public health and the community. Recommendations regarding the interpretation and conduct of injury prevention RCTs will inform the highest level of evidence in the field. These recommendations will facilitate between study comparisons to inform best practice in injury prevention that will have the greatest public health impact.

A meta-analysis of injuries in senior men's professional Rugby Union

BACKGROUND

Rugby Union has one of the highest reported incidences of match injuries amongst all professional team sports. The majority of research within this field has focused on elite male cohorts; in this study we present the first meta-analytic review of these data.

OBJECTIVE

The aim of this study was to summarise the incidence and severity of injuries in senior men's professional Rugby Union, and determine the overall effects of level of play, new versus recurrent injuries, playing position, type of injuries, location of injuries, severity of injuries, period of match, and injury incident.

METHODS

Electronic databases were searched using keywords 'Rugby Union' and 'inj*'. Fifteen papers addressing injuries in senior men's professional Rugby Union (from 1995 through September 2012) were included in the review. A maximum of ten of these papers provided incidence data that could be modelled via a Poisson mixed-effects generalised linear model, while up to nine studies provided severity data that could be modelled via a general linear mixed model. Magnitude based inferences were used to assess differences between factors. A descriptive analysis was provided for studies that could not be included in the pooled analysis due to incongruent injury definitions.

RESULTS

The overall incidence of injuries in senior men's professional Rugby Union matches was 81 per 1,000 player hours (95 % CI 63-105), and 3 per 1,000 player hours (95 % CI 2-4) during training. Estimated mean severity for match injuries was 20 days (95 % CI 14-27), and 22 days (95 % CI 19-24) for training injuries. A higher level of play was associated with a greater incidence of injuries in matches, with no clear difference in severity. New injuries occurred substantially more often than recurrent injuries, while the severity of recurrent injuries was, on average, 10 days (95 % CI 4-17) greater than new injuries. Trivial differences were found in injury incidence and severity between forwards and backs. Muscle/tendon and joint (non-bone)/ligament injuries were the two most prevalent injury groups, whereas fractures and bone stress injuries had the highest average severity. The lower limb was the body region with the highest injury incidence, while upper limb injuries were most severe. The third quarter (40-60 min) of matches had the highest injury rate, and injuries most commonly occurred as a result of being tackled.

CONCLUSIONS

This meta-analysis confirms match injury incidence rates in professional Rugby Union can be considered high in comparison with other team sports, but similar to other collision sports. In order to markedly reduce overall injury burden, efforts should target lower-limb injury prevention strategies and technique during contact, as these may render the largest effect.