For debate: consensus injury definitions in team sports should focus on missed playing time

Ankle sprain, concussion, and anterior cruciate ligament injuries are common and burdensome in sub-elite female Australian football players

OBJECTIVES

To describe the epidemiology of injuries in sub-elite female Australian Football (AF).

DESIGN

Prospective cohort.

METHODS

424 athletes were tracked across a 12-match season. Injury characteristics (location, severity, mechanism) were reported. Injury incidence (injuries per 1000 h) and injury burden (days absent per 1000 h) were calculated. Severity was considered as the number of days missed between injury onset and return to full training. Incidence was compared using incidence rate ratios, and severity using a Mann-Whitney U test.

RESULTS

Total injury incidence was 10.8 (95 % confidence interval [CI] = 9.0, 12.8) injuries per 1000 h. Match incidence was 34.6 (95 % CI = 28.0, 42.4) injuries per 1000 h. Ankle sprain injuries (2.2 per 1000 h, 95 % CI = 1.4, 3.1) and concussion (1.6 per 1000 h, 95 % CI = 1.0, 2.5) injuries were the most frequent, followed by anterior cruciate ligament (ACL) injuries (0.9 per 1000 h, 95 % CI = 0.4, 1.6). ACL (40.4 days per 1000 h, 95 % CI = 36.9, 44.1), ankle sprain injuries (31.4 per 1000 h, 95 % CI =28.4, 34.7), and concussion (19.9 per 1000 h, 95 % CI = 17.5, 22.5) injuries were also the most burdensome. There were 78 mild, 34 moderate, and 21 severe injuries. ACL injuries were the most severe injury (56.0 [77.0] in-season days missed).

CONCLUSIONS

This research describes the first large-scale injury profile of sub-elite female AF, reporting time-loss measures of incidence and burden for many injury types. Ankle sprain injuries, concussions, and ACL injuries are common and burdensome, and should be prioritised for prevention.

Definitions and surveillance methods of running-related injuries: A scoping review

Inconsistent and restricted definitions of injury have contributed to limitations in determining injury rates and identifying risk factors for running-related injuries (RRIs). The aim of this scoping review was to investigate the definitions and surveillance methods of RRIs. A systematic electronic search was performed using PubMed, Scopus, SPORTDiscuss, MEDLINE, and Web of Science databases. Included studies were published in English between January 1980 and June 2023 which investigated RRIs in adult running populations, providing a definition for a general RRI. Results were extracted and collated. 204 articles were included. Three primary criteria were used to define RRIs: physical description, effect on training and medical intervention, while three secondary criteria are also associated with definitions: cause/onset of injury, location, and social consequences. Further descriptors and sub-descriptors form these criteria. The use of Boolean operators resulted in nine variations in definitions. Inconsistency is evident among definitions of RRIs. Injury definitions seem to be important for two main reasons: firstly, determining accurate injury rates, and secondly, in research examining risk factors. For the latter, definitions seem to be very limited, only capturing severe injuries and failing to recognise the full development process of RRIs, precluding the identification of conclusive risk factors. A potential two-approach solution is the initial use of a broad definition acting as a gatekeeper for identifying any potential injury, and follow-up with an extensive surveillance tool to capture the specific consequences of the varying severity of RRIs.

Umbrella review of musculoskeletal injury burden in dancers: implication for practice and research

BACKGROUND

Dancers are susceptible to injury. Nevertheless, injury epidemiology research in dancers is inconsistent. Furthermore, ballet dancing has dominated the huge body of reviews analyzing the epidemiology of musculoskeletal injuries in a variety of artistic dance forms, making it challenging to acquire a thorough, comprehensive, and understandable reporting of the available data.

PURPOSE

The overview and reanalysis of dancers' musculoskeletal pain and injury load across artistic dance forms.

STUDY DESIGN

Systematic review of systematic reviews and meta-analysis.

METHODS

A search was conducted online for literature written in English using PubMed and Google Scholar (2012-2021). The data gathered was then analyzed using predetermined qualifying criteria.

RESULTS

12 reviews were determined to be qualified, the majority of which had moderate to low confidence and raised concerns about bias based on JBI-URARI and ROBIS. The prevalence of dance-related musculoskeletal injuries ranged from 26% to 84% in any artistic dancers and 42% to 343% in ballet dancers. The incidence was less than 5 per 1000 dance hours in both groups, with lower extremities and back being the commonly reported sites. Reviews themselves stated that the quality of the reviews was often poor. Due to the study's heterogeneity and methodological inconsistency, data pooling and meta-analysis were not possible.

CONCLUSION

The current review emphasizes the gaps and restrictions in the dance epidemiology literature that make it challenging to quantify and report a single overall injury rate for dancers. These results underline the need for better primary investigations and evidence synthesis. As injury epidemiology is a critical component of the overall injury-prevention puzzle, there is a need for standardization in future research, particularly with active and prospective injury surveillance, injury classification, injury evaluation, and injury reporting.

LEVEL OF EVIDENCE

Systematic Review, Level III.

The incidence and burden of injury in male adolescent community rugby union in Australia

OBJECTIVES

To describe the incidence, location, mechanism and burden of injury in community male adolescent rugby.

METHODS

A prospective cohort injury surveillance study using sports trainers to record 'any physical complaint' over three seasons (2018/2019/2021) in 979 U13-U17 community male rugby union players.

RESULTS

One hundred and fifty-two time-loss injuries (27.6/1000 hours) with an associated burden of 2313 days (419.7 days/1000 hours), 169 non-time loss medical attention (30.1/1000 hours) and 813 physical complaints (147.5/1000 hours) were recorded from 5511.7 exposure hours (matches 3932.5 hours, training 1579.2 hours). Time-loss injury incidence was highest in U16 (45/1000 hours) and lowest in U17 (16.6/1000 hours), with U17 significantly lower than U16 and U15 age-grades (p < 0.05). Injury burden was greatest in U13 (561.4 days/1000 hours), and significantly higher than U15 and U17 (p < 0.05). Collectively, injury incidence was greatest for the head/neck (11.8/1000 hours), bruise/contusions were most common (8.7/1000 hours) and concussion (4.5/1000 hours) accounted for the greatest injury burden (102 days/1000 hours). Being tackled was the most observed injury mechanism (10.0/1000 hours). Forwards had significantly higher incidence in mild injury (p < 0.01). The total burden (p < 0.001) associated with mild (p < 0.001) and moderate injuries (p < 0.001) was significantly higher in forwards, as was the burden of being tackled (p < 0.001), collisions (p < 0.001), trunk (p < 0.001) and lower limb (p < 0.01) injury locations. In contrast, ruck-related injury burden was greater in backs (p < 0.001).

CONCLUSION

This study showed age-grade and positional differences in incidence and burden of injury in community adolescent rugby union. The rate of non-time loss relative to time-loss injury and muscle strain injury in U13-U14s suggests further research into injury risk and maturation in rugby is needed.

The impact of concussion on subsequent injury risk in elite junior Australian football athletes

OBJECTIVES

Concussion increases injury risk. However, this has not been investigated in junior Australian football and it is unknown whether the location, severity, and mechanism of subsequent injuries differ after concussion vs. non-concussion injury.

DESIGN

Prospective cohort.

METHODS

1455 elite adolescent male Australian footballers were tracked across seven seasons to determine whether subsequent injury risk was greater after concussion compared to non-concussion index injury using multilevel survival analysis. Mixed-effects logistic regression compared location and mechanism. Mixed-effects Poisson regression compared severity.

RESULTS

Of 1455 athletes, 632 were injured and included in subsequent-injury analysis. There were no differences in injury incidence after a concussion compared to upper- (hazard ratio = 1.0, 0.6 to 1.9, P = 0.892; trivial effect) and lower (hazard ratio = 1.1, 0.6 to 1.9, P = 0.810; trivial effect) index injury, or in location. Subsequent injuries were more likely to be contact-based after a non-concussion injury than concussion (odds ratio = 4.6, 1.3 to 16.0; P = 0.017; large effect). There was no difference in subsequent injury severity after lower- (3.4 ± 3.0 missed matches; incidence rate ratio = 1.4, 0.9 to 2.1; P ≤ 0.117; small effect) and upper-limb injuries (3.4 ± 3.1 missed matches; incidence rate ratio = 1.4, 0.9 to 2.2; P = 0.189; small effect) compared to concussion (2.4 ± 2.0 missed matches).

CONCLUSIONS

Subsequent injury risk, severity, and location in junior Australian football are similar following concussion compared to non-concussion index injuries, although contact injuries are less likely.

Does changing the Functional Movement Screen composite score threshold influence injury risk estimation in junior Australian football players?

This study aimed to identify whether a revised lower Functional Movement Screen (FMS) composite score threshold would be associated with a greater injury risk for junior athletes than the common threshold of≤14. This prospective cohort study included tracking of 809 elite junior male Australian football players for injuries that resulted in a missed game. All athletes completed pre-season FMS testing and a 12-month self-reported retrospective injury questionnaire. Analyses examined the relationship between composite score thresholds of≤14, ≤13, and≤12 and the risk of injury. The relationship between prospective injury and the common composite threshold score of ≤ 14 was dependent on the presence of a recent injury history (relative risk [RR] = 1.45, p = 0.004) in comparison to no recent injury history (RR = 0.98, p = 0.887). Scoring≤12 in the presence of a recent injury history had the greatest diagnostic accuracy but only a trivial increase in injury risk (RR = 1.59, p = 0.001, sensitivity = 0.35, specificity = 0.80, negative and positive likelihood ratios = 0.81 and 1.75). Whilst some small statistical relationships existed between prospective injury and the FMS composite score thresholds, all three thresholds were not associated with a clinically meaningful relationship with prospective injury and were no more effective than retrospective injury for determining athletes at risk of injury.

Comparison of injury profiles between elite Australian male and female cricket players

OBJECTIVES

This study presents seven seasons of injury surveillance data for both elite Australian male and female cricket players, revealing injury statistics and allowing for comparison between sexes.

DESIGN

Retrospective cohort.

METHODS

Participants were elite Australian male and female cricket players who were contracted to play for a national and/or state/territory team and/or T20 franchise between 2015-16 and 2021-22 (7 seasons). Injury data was recorded in Cricket Australia's Athlete Management System database and combined with match data. The STROBE-SIIS statement was used as the relevant guideline for this study.

RESULTS

Data for 1345 male player seasons and 959 female player seasons revealed sex-related differences in the injury incidence rates and prevalence. Males had higher incidence (average 136 vs 101 injuries per 1000 match days) and prevalence of match time-loss injuries (average 10.4% vs 6.5% players unavailable). However, the overall incidence of all medical attention injuries were similar between sexes (Incidence Rate Ratio (IRR) 0.9, 95%CI 0.8-1.0). The most frequent match time-loss injuries for males were hamstring strains (7.4 new injuries per 100 players per season), side and abdominal strains (5.5), concussion (5.0), lumbar stress fractures (4.3), and wrist and hand fractures (3.9). The most frequent match time-loss injuries for females over the 7 seasons were hamstring strains (3.1), concussion (2.3), quadriceps strains (2.4) and shin/foot/ankle stress fractures (2.0). The IRR of medical attention injuries for males compared to females was higher for lumbosacral stress fractures (IRR 2.3), elbow and forearm injuries (1.5), and concussion (1.4), and lower for lower leg, foot, and ankle stress fractures (0.6), shoulder and upper arm injuries (0.7), and quadriceps strains (0.6).

CONCLUSIONS

Robust long-term injury surveillance enabled the injury profiles of elite Australian male and female cricket players to be understood and compared. Males had a higher incidence and prevalence of match time-loss injuries, likely reflecting a higher match exposure.

Injury characteristics in Norwegian male professional football: A comparison between a regular season and a season in the pandemic

The Coronavirus Disease-19 (COVID-19) pandemic forced the Norwegian male premier league football season to reschedule, reducing the fixture calendar substantially. Previous research has shown that a congested match schedule can affect injury rates in professional football. Therefore, we aimed to investigate whether the Norwegian premier league teams suffered more injuries in the more match congested 2020 season than in the regular 2019-season. We invited all teams having participated in both seasons to export their injury data. Only teams that used the same medical staff to register injuries in both seasons were included, and to maximize data comparability between seasons, we applied a time-loss injury definition only. Seven of 13 teams agreed to participate and exported their injury data. Both seasons had 30 game weeks, but the 2020 season was 57 days shorter than the 2019 season. The match injury incidence did not differ significantly [incidence rate ratio 0.76 (0.48-1.20; p = 0.24) in the 2020 season compared to the 2019 season. Furthermore, we found no differences in the number of injuries, days lost to injury, matches missed to injury, or injury severity. We could not detect any differences between the two seasons, suggesting the congested match calendar combined with the safety measures in the 2020 season can be a safe alternative in future seasons.

The Incidence, Cost, and Burden of Concussion in Women's Rugby League and Rugby Union: A Systematic Review and Pooled Analysis

Background

The extent of concussion injury in the rugby codes for women is unclear.

Objective

Our aim was to review all published studies reporting concussion injuries from match and training participation in rugby codes and report the pooled data estimates for rugby league and union concussion injury epidemiology.

Methods

We conducted a systematic literature analysis of concussion in rugby league and rugby union for published studies from January 1990 to July 2021. Data from 16 studies meeting the inclusion criteria were extracted for women’s concussion injuries and were subsequently pooled. Costs from Accident Compensation Corporation (ACC) data were attributed to the results to provide cost estimates.

Results

The pooled analysis match injury incidence of women’s concussion was higher for rugby league (10.3 per 1000 match hours) than rugby 15 s (2.8 per 1000 match hours) or rugby 7 s (8.9 per 1000 match hours). There was a fourfold difference in the pooled incidence of concussion in women’s rugby league (risk ratio [RR] 4.53, 95% confidence interval [CI] 1.8–11.3]; p = 0.0001) when compared with rugby 15 s. There was also a ninefold higher risk of a concussion during match participation compared with training participation for women’s rugby 15 s (RR 9.3, 95% CI 1.29–66.78; p = 0.0070). The total estimated costs for the concussions reported were NZ$1,235,101. For rugby 7 s, the pooled concussive injury burden was 33.2 days.

Conclusions

Our pooled analysis clarified the extent of concussion injury and the possible associated costs at several levels of the game for women’s rugby codes. The pooled mean days lost because of concussions was 33 days. As this was considerably longer than the 7- to 10-day expected timeframe outlined in the Concussion in Sport Consensus statement, these guidelines need to be updated to include sex-specific differences.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40279-022-01645-8.

The association between Y-balance test scores, injury, and physical performance in elite adolescent Australian footballers

OBJECTIVES

Identify how modified Lower-Quarter Y-Balance Test (mYBT-LQ) and Upper-Quarter Balance Test (mYBT-UQ) scores relate to injury risk and measures of physical performance in elite adolescent Australian Football (AF) athletes.

DESIGN

Prospective cohort study.

METHODS

Pre-season mYBT-LQ, mYBT-UQ, and physical performance measures (speed, jump height, and agility) were obtained in 257 elite adolescent male AF athletes. Injury status was tracked across the 18-game season to determine the relationship between mYBT scores and injury risk based on time-to-event analysis. Cross-sectional analysis of mYBT-LQ scores and performance measures determined the relationships between these variables.

RESULTS

There were no significant associations between injury risk and any single mYBT parameter. However, athletes with high posteromedial asymmetry and good agility performance (top 25% of the cohort) had moderately increased injury risk with and tended to without a previous injury history (Hazard Ratio = 3.26 [95% Confidence Interval: 1.01, 10.54; p = 0.048] and 2.69 [95% Confidence Interval = 0.92, 7.82; p = 0.069], respectively). There were significant correlations between faster agility times and higher composite limb-length normalised mYBT-LQ (r = -0.210; CI = -0.324, -0.090), limb-length normalised average posteromedial reach score (r = -0.227; CI = -0.340, -0.108), and limb-length normalised average posterolateral reach score (r = -0.250: CI = -0.361, -0.132).

CONCLUSION

In isolation, the mYBT is not useful for identifying injury risk in junior AF athletes, and only small correlations between mYBT-LQ and physical performance variables were identified. However, high mYBT-LQ posteromedial asymmetry is associated with increased injury risk for athletes with good agility performance. This should be considered within athlete preparation programs.

Despite maintaining a high daily training availability, a quarter of athletes start the season injured and three quarters experience injury in an Australian State Academy of Sport

OBJECTIVES

To 1) investigate the incidence, prevalence, burden and characteristics of injuries; and 2) explore the frequency of physiotherapy and medical servicing for elite sports academy athletes over a 12-month season.

DESIGN

Prospective cohort study.

METHODS

Medical attention and time-loss injuries were prospectively recorded by Physiotherapy and Medical (Sports Physician) staff for 94 athletes (72.3% females). The number of linked physiotherapy and medical servicing appointments was also recorded. Injury incidence rates (IIR), point and period prevalence, and injury burden were calculated and compared by athlete gender, sport, and categorisation (performance level) using incidence rate ratios (IRR).

RESULTS

The number of injuries reported was 193 in 71 (75.5%) athletes. The IIR was 2.1 (95%CI: 1.8 to 2.4) injuries per 365 days, with no gender difference observed (IRR: 1.1, 0.8 to 1.4). The injury burden was 43.5 (95%CI: 37.8 to 50.1) days absent per 365 days. More than one-quarter (point prevalence, 26.6%) of athletes commenced the season with an injury. In-season injury risk was 2.5 fold greater in athletes who started the season with an injury compared to athletes who started the season without an injury (IRR: 2.5, 1.9 to 3.4). The majority (81.2%) of the 1164 appointments recorded were physiotherapy, with an overall 4.3:1.0 physiotherapy to medical appointment ratio.

CONCLUSIONS

One in four athletes began the elite pathway season with a pre-existing injury, while also demonstrating a 2.5 fold greater risk of subsequent injury in the scholarship period. Sports should not assume their athletes are uninjured at the beginning of their scholarship. Injury profiles, and physiotherapy and medical servicing varied across sports. To reduce health as a barrier in the successful transition of talented young athletes to elite athletes, injury management strategies at the commencement of recruitment and throughout the scholarship should be prioritised in the development pathway.

The burden of injury in field hockey: A secondary analysis of prospective cohort data

Most studies report injuries based upon their incidence rate, or the number of injuries which occur in a sport per unit of time. While this is recommended across numerous consensus statements on reporting injury data in sport, it may be of benefit to consider injury burden also. Reporting injuries as the duration of injury per 1000 exposure hours highlights those injuries which will likely cause greater disruption within a team. Therefore, the primary aim of this study was to report the burden of injury in field hockey. This secondary analysis of epidemiological data employed two methods of data collection: self-reported through an online reporting software, and through contact with the team physiotherapist. Athletes reported injury-related symptoms for 4170 days in total, giving rise to an injury burden of 121.0/1000 h, of which 61.4/1000 h were days lost through injury. Injuries to the hamstring, as well as muscle strain injuries, caused the most significant injury burden in athletes (22.6 and 35.8/1000 h respectively). Reporting injuries as the duration of injuries per 1000 hours highlights those injuries which cause the most significant disruption within a squad. Future injury prevention strategies in field hockey should prioritize the injuries which are most burdensome.

Injury surveillance in elite field hockey: a pilot study of three different recording techniques

Objective

In field hockey, injuries are assessed by various recording techniques leading to a heterogenic collection of poorly comparable injury data.

Methods

Injury data were prospectively collected at the 2016 Men’s Hockey Junior World Cup using the match injury reports (MIRs), video injury clips provided by the Fédération Internationale de Hockey, and daily medical reports (DMRs). A pilot study comparing injury type, mechanism, location on the field, injured body part and overall injury incidence among the different injury recording techniques was performed.

Results

MIRs and video injury clips were completely available for analysis. DMRs were returned from 11 out of 16 teams (69%). In total, MIRs yielded 28, video analysis 36, and DMRs 56 injuries. Overall injury rate varied between 24.8 and 57.9 injuries per 1000 player match hours. The majority of injuries affected the lower limbs by all three methods (41.7–61.2%) and were mainly caused by having been hit by the ball (20.4–50%) or stick (11.1–28.6%). Reports of concussions during competition were incoherent between MIR (2 cases) and DMR (no cases). The DMR was the only method to record overuse injuries (16.1%), injuries in training (12.5%), and time-loss injuries of one or two days (12.5%) or of three or more days (14.3%).

Conclusion

Injury data vary substantially between the MIR, DMR and injury video recording technique. Each recording technique revealed specific strengths and limitations. To further advance injury research in field hockey, the strengths of each recording technique should be brought together for a synergistic injury assessment model.

The Incidence and Risk Factors for Injuries in Girls Volleyball: A Prospective Study of 2072 Players

CONTEXT

Girls high school volleyball is very popular across the United States. There is limited prospective data regarding the incidence and risk factors of time loss (TL) and non-time loss (NTL) injuries sustained in this population.

OBJECTIVES

To estimate the incidence and describe the characteristics of injuries (TL and NTL) sustained in a girls' high school volleyball season.

DESIGN

Descriptive epidemiology study.

SETTING

Convenience sample of 78 high school interscholastic volleyball programs.

PATIENTS OR OTHER PARTICIPANTS

High school volleyball players participating during the 2018 interscholastic season.

MAIN OUTCOME MEASURES

TL and NTL injury rates, proportions, rate ratios, and with 95%CI.

RESULTS

A total of 2,072 girls enrolled in the study with 468 subjects (22.5%) sustaining 549 injuries (NTL=28.4%, TL=71.6%) for an overall injury rate of 5.31 [4.89, 5.79] per 1000 AEs. The competition injury rate was greater than the practice injury rate for all injuries (IRR: 1.19, [1.00, 1.41]) and TL injuries (IRR: 1.31, [1.07, 1.60]). Players with a previous musculoskeletal injury had a higher rate of TL than NTL injuries (IRR; 1.36 [1.12, 1.65]). Ankle injuries accounted for the greatest proportion of TL injuries (n=110, 28%), while the greatest proportion of NTL injuries occurred in the hand/fingers (n=34, 22%). Moreover, ligament sprains accounted for 40% of TL injuries (n=156), whereas muscle/tendon strains (n=79, 51%) accounted for over half of all NTL injuries.

CONCLUSIONS

While the majority of injuries sustained by adolescent girls' volleyball athletes were TL in nature, nearly a third of all injuries were NTL injuries. Injury characteristics differed widely between TL and NTL injuries. Understanding the most common types and characteristics of injury among high school volleyball players is critical for the development of effective injury prevention programs.

Does load management using the acute:chronic workload ratio prevent health problems? A cluster randomised trial of 482 elite youth footballers of both sexes

BACKGROUND

The acute:chronic workload ratio (ACWR) is commonly used to manage training load in sports, particularly to reduce injury risk. However, despite its extensive application as a prevention intervention, the effectiveness of load management using ACWR has never been evaluated in an experimental study.

AIM

To evaluate the effectiveness of a load management intervention designed to reduce the prevalence of health problems among elite youth football players of both sexes.

METHODS

We cluster-randomised 34 elite youth football teams (16 females, 18 males) to an intervention group (18 teams) and a control group (16 teams). Intervention group coaches planned all training based on published ACWR load management principles using a commercially available athlete management system for a complete 10-month season. Control group coaches continued to plan training as normal. The prevalence of health problems was measured monthly in both groups using the Oslo Sports Trauma Research Centre Questionnaire on Health Problems.

RESULTS

The between-group difference in health problem prevalence (primary outcome) was 1.8%-points (-4.1 to 7.7 %-points; p=0.55) with no reduction in the likelihood of reporting a health problem in the intervention group (relative risk 1.01 (95% CI 0.91 to 1.12); p=0.84) compared with the control group.

CONCLUSIONS

We observed no between-group difference, suggesting that this specific load management intervention was not successful in preventing health problems in elite youth footballers.

TRIAL REGISTRATION NUMBER

ISRCTN18177140.

Jumper's Knee: A Prospective Evaluation of Risk Factors in Volleyball Players Using a Novel Measure of Injury

OBJECTIVES

To examine potential intrinsic risk factors that may contribute to the onset of jumper's knee in elite level-male volleyball players.

DESIGN

Prospective Cohort Study.

SETTING

Varsity and National team volleyball gymnasiums.

PARTICIPANTS

Sixty elite adult male volleyball players from Canada.

ASSESSMENT OF RISK FACTORS

Players completed a series of risk factor assessments at the commencement of their seasons, including vertical jump (cm), ankle dorsiflexion range (degrees), dynamic balance (normalized distance reached; cm), dynamic knee alignment (degrees), and landing mechanics (degrees).

MAIN OUTCOME MEASURE

Self-reported knee problems, captured via short message service.

RESULTS

Knee problem prevalence was 75% [95% confidence intervals (CIs): 62.2-84.6] and the incidence rate for substantial injuries over the study period was 30 injuries/100 players/season (95% CI: 19.5-43.1). No risk factor was found to significantly predict the future occurrence of developing jumper's knee. The odds ratios were close to unity (range: 0.94-1.07) with narrow confidence intervals and P > 0.05.

CONCLUSIONS

A more sensitive capture of overuse knee problems did not result in the identification of distinct risk factors for the development of jumper's knee. These findings highlight a lack of available methodology to accurately assess risk factors for overuse injuries.

Epidemiology of injuries in senior men's field hockey: A two-season prospective observational injury surveillance study

Determining the rate and severity of injuries incurred through sport is accepted as the primary step towards designing, implementing and evaluating injury prevention programmes. The aim of this study was to determine the injury incidence rate and characteristics of male field hockey athletes participating in the Irish Hockey League. Athletes from eight field hockey teams were assigned to an online reporting system, where they logged injuries as they were incurred. Injuries were defined as any physical complaint. Coaches and physiotherapists were contacted weekly to corroborateinjuries. Overall 323 injuries were reported across 34,449 exposure hours, giving rise to an incidence rate of 9.4/1000 h. On average, athletes sustained one injury over the course of two seasons. Muscle strains, pain and contusions were the most common types of injury, while the hamstring, knee and hip/groin were the most frequently reported locations. While 66.9% of injuries occurred through non-contact mechanisms, contact injuries were also common. Injury recurrences accounted for 16.1% of injuries. In conclusion, the incidence of injury in field hockey is high, occurring from a variety of mechanisms. Future injury prevention strategies should prioritise injuries to the hamstring, knee and ankle, and be specific to particular playing positions.

Factors Influencing the Relationship Between the Functional Movement Screen and Injury Risk in Sporting Populations: A Systematic Review and Meta-analysis

BACKGROUND

Studies investigating the association between the Functional Movement Screen (FMS) and sports injury risk have reported mixed results across a range of athlete populations.

OBJECTIVES

The purpose of this systematic review was to identify whether athlete age, sex, sport type, injury definition and mechanism contribute to the variable findings.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

A systematic search was conducted in October 2018 using PubMed, EBSCOhost, Scopus, EmBase and Web of Science databases. Studies were included if they were peer reviewed and published in English language, included athletes from any competition level, performed the FMS at baseline to determine risk groups based on FMS composite score, asymmetry or pain, and prospectively observed injury incidence during training and competition. Study eligibility assessment and data extraction was performed by two reviewers. Random effects meta-analyses were used to determine odds ratio (OR), sensitivity and specificity with 95% confidence intervals. Sub-group analyses were based on athlete age, sex, sport type, injury definition, and injury mechanism.

RESULTS

Twenty-nine studies were included in the FMS composite score meta-analysis. There was a smaller effect for junior (OR = 1.03 [0.67-1.59]; p = 0.881) compared to senior athletes (OR = 1.80 [1.17-2.78]; p = 0.008) and for male (OR = 1.79 [1.08-2.96]; p = 0.024) compared to female (OR = 1.92 [0.43-8.56]; p = 0.392) athletes. FMS composite scores were most likely to be associated with increased injury risk in rugby (OR = 5.92 [1.67-20.92]; p = 0.006), and to a lesser extent American football (OR = 4.41 [0.94-20.61]; p = 0.059) and ice hockey (OR = 3.70 [0.89-15.42]; p = 0.072), compared to other sports. Specificity values were higher than sensitivity values for FMS composite score. Eleven studies were included in the FMS asymmetry meta-analysis with insufficient study numbers to generate sport type subgroups. There was a larger effect for senior (OR = 1.78 [1.16-2.73]; p = 0.008) compared to junior athletes (OR = 1.21 [0.75-1.96]; p = 0.432). Sensitivity values were higher than specificity values for FMS asymmetry. For all FMS outcomes, there were minimal differences across injury definitions and mechanisms. Only four studies provided information about FMS pain and injury risk. There was a smaller effect for senior athletes (OR = 1.28 [0.33-4.96]; p = 0.723) compared to junior athletes (OR = 1.71 [1.16-2.50]; p = 0.006). Specificity values were higher than sensitivity values for FMS pain.

CONCLUSION

Athlete age, sex and sport type explained some of the variable findings of FMS prospective injury-risk studies. FMS composite scores and asymmetry were more useful for estimating injury risk in senior compared to junior athletes. Effect sizes tended to be small except for FMS composite scores in rugby, ice hockey and American football athletes.

PROTOCOL REGISTRATION

CRD42018092916.

Variability in the identification and reporting of overuse injuries among sports injury surveillance data collectors

Purpose

This study examined variability in identifying and reporting overuse injuries among Certified Athletic Trainers (ATs).

Methods

This cross-sectional study of ATs participating in the National Collegiate Athletic Association's Injury Surveillance Program, utilized a novel online-only survey, consisting of seven hypothetical clinical scenarios representing various clinical presentations including overuse and acute elements. Participants reported clinical opinions regarding the role overuse played in each scenario (major contributor, not a major contributor, not enough information) and probability (0-100%) of classifying each scenario as having an overuse injury mechanism, then completed open-ended questions addressing their decision-making process.

Results

74 ATs (25%) completed the survey. Six of the seven scenarios generated discordance in responses among the participating ATs. Variability in AT decisions involved: the progression of injury, duration of symptoms, and activity at time of injury.

Conclusion

Developing a formalized definition of overuse injury may improve consistency and standardize methods for identifying and reporting overuse injuries within injury research.

Methods may matter in injury surveillance: "how" may be more important than "what, when or why"

To examine if and how adjustments in injury surveillance recording methodology may have influenced injury rates. Injury and exposure data were collected among professional male players from the Qatar Stars League from the 2008-2009 season to the 2017-2018 season. There have been four iterations of our data collection methods. In the first five seasons, participation in the programme was voluntary. For seasons 6-7, additional dedicated researchers were tasked with contacting the medical teams every month. At the start of season 8, an electronic recording method was instituted. In the final two seasons, injury surveillance participation was further boosted by reinforced encouragement from institutional management. Overall injury incidence increased from season 5 to season 8. Severe injuries have fallen steadily, but slightly over the ten seasons, whereas mild injuries increased dramatically from seasons 5 to 8. The current data suggest that along with the standard metrics (e.g. injury incidence, injury burden) we also need to clearly report the methods by which data were collected and verified in as much detail as possible. We suggest that sports medicine journals should adopt minimum reporting standards and perhaps checklists could be a useful step forward.

What Is Injury in Ice Hockey: An Integrative Literature Review on Injury Rates, Injury Definition, and Athlete Exposure in Men's Elite Ice Hockey

Injuries in men's elite ice hockey have been studied over the past 40 years, however, there is a lack of consensus on definitions of both injury and athlete exposure. These inconsistencies compromise the reliability and comparability of the research. While many individual studies report injury rates in ice hockey, we are not aware of any literature reviews that have evaluated the definitions of injury and athlete exposure in men's elite ice hockey. The purpose of this integrative review was to investigate the literature on hockey musculoskeletal injury to determine injury rates and synthesize information about the definitions of injury and athlete exposure. Injury rates varied from 13.8/1000 game athlete exposures to 121/1000 athlete exposures as measured by player-game hours. The majority of variability between studies is explained by differences in the definitions of both injury and athlete exposure. We were unable to find a consensus injury definition in elite ice hockey. In addition, we were unable to observe a consistent athlete exposure metric. We recommend that a consistent injury definition be adopted to evaluate injury risk in elite ice hockey. We recommend that injuries should be defined by a strict list that includes facial lacerations, dental injuries, and fractures. We also recommend that athlete exposure should be quantified using player-game hours.

Tendon and Ligament Injuries in Elite Rugby: The Potential Genetic Influence

This article reviews tendon and ligament injury incidence and severity within elite rugby union and rugby league. Furthermore, it discusses the biological makeup of tendons and ligaments and how genetic variation may influence this and predisposition to injury. Elite rugby has one of the highest reported injury incidences of any professional sport. This is likely due to a combination of well-established injury surveillance systems and the characteristics of the game, whereby high-impact body contact frequently occurs, in addition to the high intensity, multispeed and multidirectional nature of play. Some of the most severe of all these injuries are tendon and ligament/joint (non-bone), and therefore, potentially the most debilitating to a player and playing squad across a season or World Cup competition. The aetiology of these injuries is highly multi-factorial, with a growing body of evidence suggesting that some of the inter-individual variability in injury susceptibility may be due to genetic variation. However, little effort has been devoted to the study of genetic injury traits within rugby athletes. Due to a growing understanding of the molecular characteristics underpinning the aetiology of injury, investigating genetic variation within elite rugby is a viable and worthy proposition. Therefore, we propose several single nucleotide polymorphisms within candidate genes of interest; COL1A1, COL3A1, COL5A1, MIR608, MMP3, TIMP2, VEGFA, NID1 and COLGALT1 warrant further study within elite rugby and other invasion sports.

Australian Football League Injury Characteristics Differ Between Matches and Training: A Longitudinal Analysis of Changes in the Setting, Site, and Time Span From 1997 to 2016

Background:

Injury surveillance has been used to quantify the scope of the injury burden in Australian football. However, deeper statistical analyses are required to identify major factors that contribute to the injury risk and to understand how these injury patterns change over time.

Purpose:

To compare Australian Football League (AFL) injury incidence, severity, prevalence, and recurrence by setting, site, and time span from 1997 to 2016.

Study Design:

Descriptive epidemiology study.

Methods:

A total of 15,911 injuries and medical illnesses recorded by team medical staff at each club were obtained from the AFL’s injury surveillance system and analyzed using linear mixed models with 3 fixed effects (setting, time span, site) and 1 random effect (club). All types of injuries and medical illnesses were included for analysis, provided that they caused the player to miss at least 1 match during the regular season or finals. Five-season time spans (1997-2001, 2002-2006, 2007-2011, and 2012-2016) were used for comparisons. Incidence rates were expressed at the player level. Recurrences were recoded to quantify recurrent injuries across multiple seasons.

Results:

Compared with training injuries, match injuries had a 2.8 times higher incidence per season per club per player (matches: 0.070 ± 0.093; training: 0.025 ± 0.043; P < .001). Match injuries resulted in 1.9 times more missed matches per club per season (matches: 17.2 ± 17.0; training: 9.1 ± 10.5; P < .001). and were more likely to be recurrences (matches: 11.6% ± 20.0%; training: 8.6% ± 21.8%; P < .001). From the 1997-2001 to 2007-2011 time spans, overall injury severity increased from a mean of 3.2 to 3.7 missed matches (P ≤ .01). For the most recent 2012-2016 time span, injuries resulted in 3.6 missed matches, on average. Hip/groin/thigh injuries had the highest incidence (0.125 ± 0.120) and prevalence (19.2 ± 16.4) rates, and recurrences (29.3% ± 27.9%) were 15% more likely at this site than any other injury site.

Conclusion:

The risks of match injuries are significantly higher than those of training injuries in the AFL. Compared with the 1997-2001 time span, injuries became more severe during the 2007-2011 time span.

Involving research-invested clinicians in data collection affects injury incidence in youth football

It is well established that differences in injury definition and recording methodology restrict comparisons between injury surveillance programmes. There is, however, little documentation of the variation that can exist between data recorders. The aim of this study was, therefore, to explore the effect on reported injuries when team recorders or supervisors are involved in research. Injury data collected prospectively over five seasons for the U16, U17, and U18 age groups in a youth football (soccer) academy were used to compare different recording settings based on the research involvement of the clinicians. A research-invested team physiotherapist reported an 8.8 times greater incidence (P < 0.001) of non-time-loss injuries and a 2.5 times greater incidence (P < 0.001) of minimal injuries (1-3 days lost) compared to a setting where neither the team physiotherapists nor the supervisor relied on the collected data for research purposes. When team physiotherapists were not invested in research themselves but were supervised by a researcher, the incidence of non-time-loss injuries and minimal injuries was 2.5 times (P < 0.001) and 2.0 times greater (P < 0.01) than in the non-invested setting, respectively. However, there were no differences between recording settings for overall incidence of time-loss injuries. The results from this study demonstrate that involving clinicians that are relying on the collected data for research purposes can significantly affect the reported rates of non-time-loss and minimal injuries. Time-loss injuries overall were not affected by research investment, and should therefore be preferred for comparisons between teams and seasons.

Incidence rate and burden of illness at the Pyeongchang 2018 Paralympic Winter Games

Objective

To describe the incidence rate (IR) and illness burden (IB) at the Pyeongchang 2018 Paralympic Winter Games.

Methods

A total of 567 athletes from 49 countries were monitored for 12 days over the Pyeongchang 2018 Games (6804 athlete days). Illness data were obtained daily from teams with (41 teams, 557 athletes) and teams without (8 teams, 10 athletes) their own medical support, through electronic data capturing systems.

Results

There were 87 illnesses reported, with an illness IR of 12.8 illnesses per 1000 athlete days (95% CI 10.2 to 16.0) and IB of 6.8 days lost per 1000 athlete days (95% CI 3.4 to 13.5). The highest IR was reported for Para snowboard (IR of 19.7 [95% CI 12.0 to 32.2]). Illnesses in the respiratory system (IR of 4.1 [95% CI 2.9 to 5.9]; IB of 1.4 [95% CI 0.6 to 3.0]), skin and subcutaneous system (IR of 2.5 [95% CI 1.5 to 4.1]; IB of 0.6 [95% CI 0.1 to 2.9]), and eye and ocular adnexa (IR of 1.6 [95% CI 0.9 to 3.1]; IB of 0.5 [95% CI 0.1 to 3.3]) were the most common.

Conclusion

This is the first study to report both the IR and IB in this setting. There was a high IR of illness in the new sport of Para snowboard. The respiratory system had both the highest IR and IB.

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.

May 2018 Letters to the Editor-in-Chief

Letters to the Editor-in-Chief of JOSPT as follows: "Regarding 'Unraveling the Mechanisms of Manual Therapy'" with Authors' Response "The Use of a Broad or Narrow Definition of Injury in Dance Surveillance" with Authors' Response J Orthop Sports Phys Ther 2018;48(5):421-424. doi:10.2519/jospt.2018.0201.

Does the Reliability of Reporting in Injury Surveillance Studies Depend on Injury Definition?

Background:

Choosing an appropriate definition for injury in injury surveillance studies is essential to ensure a balance among reporting reliability, providing an accurate representation of injury risk, and describing the nature of the clinical demand.

Purpose:

To provide guidance on the choice of injury definition for injury surveillance studies by comparing within- and between-team variability in injury incidence with >24-hour and >7-day time-loss injury definitions in a large multiteam injury surveillance study.

Study Design:

Cohort study (diagnosis); Level of evidence, 2.

Methods:

Injury data were reported for 2248 professional rugby union players from 15 Premiership Rugby clubs over 12 seasons. Within-team percentage coefficient of variation and mean between-team standard deviation (expressed as a percentage coefficient of variation) in injury incidence rates (injuries per 1000 player match hours) were calculated. For both variables, a comparison was made between >24-hour and >7-day injury incidence rates in terms of the magnitude of the observed effects.

Results:

The overall mean incidence across the population with a >24-hour time-loss injury definition was approximately double the reported incidence with the >7-day definition. There was a 10% higher between-team variation in match injury incidence rates with the >24-hour time-loss definition versus the >7-day definition.

Conclusion:

There was a likely higher degree of between-team variation in match injury incidence rates with a >24-hour time-loss definition than with a >7-day definition of injury. However, in professional sports settings, it is likely that the benefits of using a more inclusive definition of injury (improved understanding of clinical demand and the appropriate and accurate reporting of injury risk) outweigh the small increase in variation in reporting consistency.

The Influence of Injury Definition on Injury Burden in Preprofessional Ballet and Contemporary Dancers

Study Design Cohort study. Background Multiple operational definitions of injury exist in dance research. The influence that these different injury definitions have on epidemiological estimations of injury burden among dancers warrants investigation. Objective To describe the influence of injury definition on injury prevalence, incidence, and severity in preprofessional ballet and contemporary dancers. Methods Dancers registered in full-time preprofessional ballet (n = 85; 77 female; median age, 15 years; range, 11-19 years) and contemporary (n = 60; 58 female; median age, 19 years; range, 17-30 years) training completed weekly online questionnaires (modified Oslo Sports Trauma Research Centre questionnaire on health problems) using 3 injury definitions: (1) time loss (unable to complete 1 or more classes/rehearsals/performances for 1 or more days beyond onset), (2) medical attention, and (3) any complaint. Physical therapists completed injury report forms to capture dance-related medical attention and time-loss injuries. Percent agreement between injury registration methods was estimated. Injury prevalence (seasonal proportion of dancers injured), incidence rates (count of new injuries per 1000 dance-exposure hours), and severity (total days lost) were examined across each definition, registration method, and dance style. Results Questionnaire response rate was 99%. Agreement between registration methods ranged between 59% (time loss) and 74% (injury location). Depending on definition, registration, and dance style, injury prevalence ranged between 9.4% (95% confidence interval [CI]: 4.1%, 17.7%; time loss) and 82.4% (95% CI: 72.5%, 89.8%; any complaint), incidence rates between 0.1 (95% CI: 0.03, 0.2; time loss) and 4.9 (95% CI: 4.1, 5.8; any complaint) injuries per 1000 dance-hours, and days lost between 111 and 588 days. Conclusion Time-loss and medical-attention injury definitions underestimate the injury burden in preprofessional dancers. Accordingly, injury surveillance methodologies should consider more inclusive injury definitions. J Orthop Sports Phys Ther 2018;48(3):185-193. Epub 13 Dec 2017. doi:10.2519/jospt.2018.7542 Level of Evidence Symptom prevalence study, level 1b.

Capture of Time-Loss Overuse Soccer Injuries in the National Collegiate Athletic Association's Injury Surveillance System, 2005-2006 Through 2007-2008

CONTEXT

  Overuse injuries are reported to account for nearly 50% of sports injuries and, due to their progressive nature and the uncertainty regarding date of onset, are difficult to define and categorize. Comparing the capture rates of overuse injuries between injury-surveillance systems and medical records can clarify completeness and determinants of how overuse injuries are represented in injury-surveillance data.

OBJECTIVE

  To estimate the capture rate of time-loss medical-attention overuse injuries in men's and women's soccer in the National Collegiate Athletic Association Injury Surveillance System (NCAA ISS) compared with medical records maintained by certified athletic trainers and assess the differences in completeness of capture and factors contributing to those differences.

DESIGN

  Capture-recapture study.

SETTING

  Fifteen NCAA institutions provided NCAA ISS and medical record data from men's and women's soccer programs from 2005-2006 through 2007-2008.

PATIENTS OR OTHER PARTICIPANTS

  National Collegiate Athletic Association men's and women's soccer players.

MAIN OUTCOME MEASURE(S)

  Time-loss medical-attention overuse injuries were defined as injuries with an overuse mechanism of injury in the NCAA ISS or medical records. Capture rates were calculated as the proportion of total overuse injuries classified as having overuse mechanisms in the NCAA ISS and the NCAA ISS and medical records combined.

RESULTS

  The NCAA ISS captured 63.7% of the total estimated overuse mechanisms of injury in men's and women's soccer players. The estimated proportion of overuse injury mechanisms captured by both the NCAA ISS and medical records was 37.1%. The NCAA ISS captured more overuse injury mechanisms in men's soccer than in women's soccer (79.2% versus 45.0%, χ² = 9.60; P = .002) athletes.

CONCLUSIONS

  From 2005-2006 through 2007-2008, the NCAA ISS captured only two thirds of time-loss medical-attention overuse mechanisms of injury in men's and women's soccer players. Future researchers should consider supplementing injury-surveillance data with a clinical record review to capture the burden of these injuries.

Groin Problems in Male Soccer Players Are More Common Than Previously Reported

BACKGROUND

The majority of surveillance studies in soccer have used a time-loss injury definition, and many groin problems result from overuse, leading to gradually increasing pain and/or reduced performance without necessarily causing an absence from soccer training or match play. Thus, the magnitude of groin problems in soccer has probably been underestimated in previous studies based on traditional injury surveillance methods.

PURPOSE

To investigate the prevalence of groin problems among soccer players of both sexes and among male soccer players at different levels of play through a new surveillance method developed to capture acute and overuse problems.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

We registered groin problems during a 6-week period of match congestion using the Oslo Sports Trauma Research Center Overuse Injury Questionnaire. A total of 240 players from 15 teams across different levels of play and from both sexes were included, and they responded to the weekly questionnaire. We calculated the average weekly prevalence of all groin problems and substantial groin problems.

RESULTS

Of the 240 players, 112 male players (59%) and 20 female players (45%) reported at least 1 episode of groin problems. The average weekly prevalence of any groin problem and substantial groin problem for all male players was 29% (range, 23%-32% across different levels) and 10% (7%-13%), respectively. Elite male players had an increased risk of experiencing groin problems (odds ratio: 3.1, 95% CI: 1.5-6.4, P = .03) compared with elite female players. There was no difference in the risk of experiencing groin problems among elite, subelite, and amateur male players. For substantial problems, there was no difference between elite male and elite female players or among levels of play for senior male soccer players.

CONCLUSION

We found a high prevalence of groin problems among male soccer players during a period with match congestion. Time-loss definition as used in previous injury surveillance studies captured only one-third of the male groin problems registered with the new method. Elite male players had 3 times' higher risk of reporting groin problems as compared with elite female players, while playing level did not influence the risk of reporting a groin problem among males.

Descriptive Epidemiology of Non-Time-Loss Injuries in Collegiate and High School Student-Athletes

CONTEXT

  Research on non-time-loss (NTL) injuries, which result in less than 24 hours of restriction from participation, is limited.

OBJECTIVE

  To describe the epidemiology of NTL injuries among collegiate and high school student-athletes.

DESIGN

  Descriptive epidemiology study.

SETTING

  Aggregate injury and exposure data collected from a convenience sample of National College Athletic Association varsity teams and 147 high schools in 26 states.

PATIENTS OR OTHER PARTICIPANTS

  Collegiate and high school student-athletes participating in men's and boys' baseball, basketball, football, lacrosse, soccer, and wrestling and women's and girls' basketball, field hockey, lacrosse, soccer, softball, and volleyball during the 2009-2010 through 2013-2014 and the 2011-2012 through 2013-2014 academic years, respectively, participated. Collegiate student-athletes participating in men's and women's ice hockey were also included.

MAIN OUTCOME MEASURE(S)

  Injury data from the National Collegiate Athletic Association Injury Surveillance Program and the National Athletic Treatment, Injury and Outcomes Network were analyzed. Injury counts, rates per 1000 athlete-exposures (AEs), and rate ratios were reported with 95% confidence intervals (CIs).

RESULTS

  A total of 11 899 and 30 122 NTL injuries were reported in collegiate and high school student-athletes, respectively. The proportion of NTL injuries in high school student-athletes (80.3%) was 1.61 times greater than that of collegiate student-athletes (49.9%; 95% CI = 1.59, 1.63). The NTL injury rate in high school student-athletes (8.75/1000 athlete-exposures [AEs]) was 2.18 times greater than that of collegiate student-athletes (4.02/1000 AEs; 95% CI = 2.13, 2.22). Men's ice hockey (5.27/1000 AEs) and boys' football (11.94/1000 AEs) had the highest NTL injury rates among collegiate and high school athletes, respectively. Commonly injured body parts in collegiate and high school student-athletes were the hip/thigh/upper leg (17.5%) and hand/wrist (18.2%), respectively. At both levels, contusions, sprains, and strains were the most frequent diagnoses. Contact with another player was the most cited injury mechanism (college = 38.0%, high school = 46.3%).

CONCLUSIONS

  Non-time-loss injuries compose large proportions of collegiate and high school sports injuries. However, the NTL injury rate was higher in high school than in collegiate student-athletes. Tracking NTL injuries will help to better describe the breadth of injuries sustained by athletes and managed by athletic trainers.

The financial toll of career-ending concussions in professional hockey

AIM

Several high-profile professional hockey players have retired due to career-ending concussions sustained in the National Hockey League (NHL). We sought to determine the salary cost of career-ending concussions in the NHL.

METHODS

Concussion-induced retirements from 1995 to 2015 were identified using public media sources. The number of missed games due to a player's final concussion was multiplied by per game salary to determine cost.

RESULTS

In total, 35 players were identified: the total cost to teams and insurers of career-ending concussions was US$135,476,777. Half of the total consisted of salaries owing three players with contracts still active in 2015.

CONCLUSION

The financial impact of concussion-induced retirements provides another reason for professional leagues to take measures to better protect their players from concussion.

Training volume and soft tissue injury in professional and non-professional rugby union players: a systematic review

AIM

To investigate the relationship between training volume and soft tissue injury incidence, and characterise soft tissue injury in rugby union players.

DESIGN

A systematic search of electronic databases was performed. The search strategy combined terms covering: training volume and injury, and rugby union, and players of all levels.

DATA SOURCES

Medline, SPORTDiscus, Web of Science, Embase, PubMed.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies were included if they reported: male rugby union players, a clear definition of a rugby union injury, the amount of training volume undertaken by participants, and epidemiological data for soft-tissue injuries including the number or incidence.

RESULTS

15 studies were eligible for inclusion. Overall match and training injury incidence ranged from 3.3 to 218.0 injuries/1000 player match hours and 0.1-6.1 injuries/1000 player training hours, respectively. Muscle and tendon as well as joint (non-bone) and ligament injuries were the most frequently occurring injuries. The lower limb was the most prevalent injury location. Injury incidence was higher in professional rugby union players than non-professional players. Contact events were responsible for the greatest injury incidence. For non-contact mechanisms, running was responsible for the highest injury incidence. Inconsistent injury definitions hindered reliable comparison of injury data. The lack of reporting training volumes in hours per player per week limited the ability to investigate associations between training volume and injury incidence.

CONCLUSIONS

A higher level of play may result in higher match injury incidence. Muscle and tendon injuries were the most common type of soft tissue injury, while the lower limb was the most common location of injury in rugby union players, and running was responsible for the highest injury incidence during non-contact events.

Sports Injury Surveillance Systems: A Review of Methods and Data Quality

BACKGROUND AND AIMS

Data from sports injury surveillance systems are a prerequisite to the development and evaluation of injury prevention strategies. This review aimed to identify ongoing sports injury surveillance systems and determine whether there are gaps in our understanding of injuries in certain sport settings. A secondary aim was to determine which of the included surveillance systems have evaluated the quality of their data, a key factor in determining their usefulness.

METHODS

A systematic search was carried out to identify (1) publications presenting methodological details of sports injury surveillance systems within clubs and organisations; and (2) publications describing quality evaluations and the quality of data from these systems. Data extracted included methodological details of the surveillance systems, methods used to evaluate data quality, and results of these evaluations.

RESULTS

Following literature search and review, a total of 15 sports injury surveillance systems were identified. Data relevant to each aim were summarised descriptively. Most systems were found to exist within professional and elite sports. Publications concerning data quality were identified for seven (47%) systems. Validation of system data through comparison with alternate sources has been undertaken for only four systems (27%).

CONCLUSIONS

This review identified a shortage of ongoing injury surveillance data from amateur and community sport settings and limited information about the quality of data in professional and elite settings. More surveillance systems are needed across a range of sport settings, as are standards for data quality reporting. These efforts will enable better monitoring of sports injury trends and the development of sports safety strategies.

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.

Epidemiology of 3825 injuries sustained in six seasons of National Collegiate Athletic Association men's and women's soccer (2009/2010-2014/2015)

AIM

To describe the epidemiology of National Collegiate Athletic Association (NCAA) men's and women's soccer injuries during the 2009/2010-2014/2015 academic years.

METHODS

This descriptive epidemiology study used NCAA Injury Surveillance Program (NCAA-ISP) data during the 2009/2010-2014/2015 academic years, from 44 men's and 64 women's soccer programmes (104 and 167 team seasons of data, respectively). Non-time-loss injuries were defined as resulting in <24 h lost from sport. Injury counts, percentages and rates were calculated. Injury rate ratios (RRs) and injury proportion ratios (IPRs) with 95% CIs compared rates and distributions by sex.

RESULTS

There were 1554 men's soccer and 2271 women's soccer injuries with injury rates of 8.07/1000 athlete exposures (AE) and 8.44/1000AE, respectively. Injury rates for men and women did not differ in competitions (17.53 vs 17.04/1000AE; RR=1.03; 95% CI 0.94 to 1.13) or practices (5.47 vs 5.69/1000AE; RR=0.96; 95% CI 0.88 to 1.05). In total, 47.2% (n=733) of men's soccer injuries and 47.5% (n=1079) of women's were non-time loss. Most injuries occurred to the lower extremity and were diagnosed as sprains. Women had higher concussion rates (0.59 vs 0.34/1000AE; RR=1.76; 95% CI 1.32 to 2.35) than men.

CONCLUSIONS

Non-time-loss injuries accounted for nearly half of the injuries in men's and women's soccer. Sex differences were found in competition injuries, specifically for concussion. Further study into the incidence, treatment and outcome of non-time-loss injuries may identify a more accurate burden of these injuries.

Training load--injury paradox: is greater preseason participation associated with lower in-season injury risk in elite rugby league players?

AIM

To determine whether players who completed a greater number of planned preseason training sessions were more or less likely to be injured during the competitive season.

METHODS

A cohort of 30 elite rugby league players was prospectively studied during their 17-week preseason and 26-round competitive season. Injuries were recorded using a match time loss definition. Preseason participation was quantified as the number of 'full' training sessions that players completed, excluding modified, rehabilitation or missed sessions. In-season training load variables, collected using global positioning system (GPS) data, included distance covered (m), high-speed distance covered (m) and the percentage of distance covered at high speeds (%). Multilevel logistic regression models were used to determine injury likelihood in the current and subsequent week, with random intercepts for each player. Odds ratios (OR) were used as effect size measures to determine the changes in injury likelihood with (1) a 10-session increase in preseason training participation or (2) standardised changes in training load variables.

RESULTS

Controlling for training load in a given week, completing 10 additional preseason sessions was associated with a 17% reduction in the odds of injury in the subsequent week (OR=0.83, 95% CI=0.70 to 0.99). Increased preseason participation was associated with a lower percentage of games missed due to injury (r=-0.40, p<0.05), with 10 preseason sessions predicting a 5% reduction in the percentage of games missed.

CONCLUSIONS

Maximising participation in preseason training may protect elite rugby league players against in-season injury.

Epidemiology of Overuse Injuries in Collegiate and High School Athletics in the United States

BACKGROUND

Overuse injuries result from microtrauma due to repetitive loading combined with insufficient tissue recovery time and can result in both immediate and long-term time loss from sports.

HYPOTHESIS

Overuse injury rates and patterns differ across college and high school populations, sport, and sex.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

Surveillance data for 16 sports from the National Collegiate Athletic Association's Injury Surveillance System (NCAA ISS; 2004-2005 through 2008-2009) and 14 sports from High School Reporting Information Online (High School RIO; 2006-2007 through 2012-2013) were analyzed. All reported injuries had an injury mechanism of overuse/gradual onset (college) or overuse/chronic (high school). Overuse injury incidence rates were calculated, and rate ratios with 95% CIs were used to compare subgroups.

RESULTS

The rate of overuse injury was 3.28 times higher in college than high school sports (95% CI, 3.12-3.44). The rate of overuse injury among sex-comparable sports was higher in female than male athletes in both populations (college rate ratio, 1.25; 95% CI, 1.16-1.35; high school rate ratio, 1.55; 95% CI, 1.43-1.68). The lower extremity was the most commonly injured body site (college, 69.4%; high school, 70.4%). A larger proportion of overuse injuries among college athletes resulted in time loss of more than 21 days (college, 20.4%; high school, 7.7%) and surgery (college, 5.2%, high school, 2.5%).

CONCLUSION

Overuse injuries can impose a significant burden on college and high school athletes. Interventions addressing prevention of overuse injury are needed.

Definition and usage of the term "overuse injury" in the US high school and collegiate sport epidemiology literature: a systematic review

BACKGROUND

A number of epidemiologic and surveillance-based studies of sports injury provide statistics on, and sometimes discussion of, overuse injuries. However, there is no consensus on the definition of "overuse." Some studies consider "overuse" as a mechanism of injury while others use a diagnosis-based definition.

OBJECTIVE

The objective of this study was to describe variation between studies in the definition and use of the term "overuse."

METHODS

PubMed and SPORTDiscus databases were searched between May and November 2012 to find articles published or online ahead of printing pertaining to US high school or collegiate athletics, which were epidemiologic in nature. Inclusion criteria required that the article present data collected on athlete exposure and provided statistics pertaining to overuse injuries. PRISMA guidelines were adhered to, to the best ability of the authors.

RESULTS

The initial search resulted in 5,182 articles with potential for inclusion. After review of titles or abstracts where appropriate, 232 studies were read in entirety to determine if they were appropriate for inclusion. Of the 35 articles included, 13 used data from the National Collegiate Athletics Association's Injury Surveillance System, 12 used data from the High School Reporting Information Online (RIO) injury surveillance system, and one used data from both of these systems. The remaining nine articles used data from distinct surveillance systems or prospectively collected data. All of these articles included data on overuse injuries, although not all provided definitions for overuse. A major finding from the literature is that the term "overuse" has been used both as a mechanism of injury and as an injury diagnosis (or a category of diagnoses). Specifically, of 35 articles, 14 used "overuse" as a mechanism of injury, seven used it as a category of injury diagnoses, eight used it as both a category of injury diagnoses and a mechanism of injury, and it was unclear in one how the term is used. Only one of the 35 articles provided a biomechanical definition for overuse injuries. Twelve of 35 articles combined "overuse" with other terms such as "chronic," "gradual onset," and "repetitive stress." Use of the term "no contact" was investigated in relation to "overuse." Four of 35 articles define overuse in the context of no contact injuries. Only one of 35 articles define "no contact" as a specific acute mechanism of injury, while all other mentions of "no contact" do not specifically distinguish whether "no contact" was limited to acute injuries only, or has potential to include "overuse" injuries.

CONCLUSION

There is a great deal of inconsistency in the use of the term "overuse" both within and between data sources. This is further complicated by the multiple uses of the term "no contact." We recommend that the term "overuse" only be used in regard to the mechanism of injury in order to enhance interpretation and understanding of the literature regarding overuse injuries and enhance the ability to compare results between studies. We also recommend the adoption of a common working definition of overuse injuries within injury surveillance. This definition should emphasize that overuse injuries are characterized by (1) a mechanism of gradual onset, and (2) an underlying pathogenesis of repetitive microtrauma.