Classification of Prevention in Sports Medicine and Epidemiology

Secondary injury prevention reduces hamstring strain and time-loss groin injury burdens in male professional football

OBJECTIVES

This study aimed to assess the effectiveness of a systems-based secondary injury prevention intervention aimed at early detection and management of hamstring strain injury (HSI) and time-loss groin injury in an Australian male professional football club.

DESIGN

Prospective cohort study.

SETTING

Australian male professional football club.

PARTICIPANTS

Data were collected from male professional football players (n = 73) from a single football club.

MAIN OUTCOME MEASURES

Unilateral knee flexion and side-lying hip adduction maximum voluntary isometric contractions were monitored routinely in-season, two days post-match (≥40 h [h]) during a three-season intervention period. Strength reductions greater than the tests' minimal detectable change percentage prompted intervention. HSI and time-loss groin injury burdens were calculated per 1000 player hours and compared with those from an immediately preceding two-season control period, to assess the effectiveness of the intervention.

RESULTS

Across the intervention period, there was a decrease in HSI (4.98 days absence/1000 h (19.8%) decrease) and time-loss groin injury burdens (0.57 days absence/1000 h (49.1%) decrease) when compared with the control period.

CONCLUSIONS

A systems-based secondary injury prevention intervention shows preliminary positive findings in reducing HSI and time-loss groin injury burdens within a male professional football club, compared with usual care only.

Lower HAGOS subscale scores associated with a longer duration of groin problems in football players in the subsequent season

Introduction

Groin injuries represent a considerable problem in football. Although the Adductor Strengthening Programme reduced groin injury risk, players can still experience groin symptoms throughout the season. This study aimed to determine whether preseason Copenhagen Hip and Groin Outcome Score (HAGOS) and a history of previous injury can identify individuals at risk of having a longer duration of groin problems the subsequent season, using an 'any physical complaint' definition of injury.

Methods

Preseason HAGOS score and weekly groin problems were registered with the Oslo Sports Trauma Research Center Overuse questionnaire during one full season in 632 male semiprofessional adult players.

Results

The prognostic model showed a decreased number of weeks with groin problems for each increase in HAGOS score for 'groin-related quality of life' (QOL) (IRR=0.99, p=0.003). A 10-point higher 'QOL' score predicted 10% fewer weeks of groin problems. Additionally, previous hip/groin injury was associated with a 74% increase in the number of weeks with symptoms (p<0.001).

Conclusion

The HAGOS questionnaire applied preseason can detect players at risk of getting more weeks with groin problems the following season. The 'QOL' subscale seems to be the superior subscale for estimating subsequent groin problem duration. While HAGOS appears promising in identifying players at risk, previous groin injury is the most robust indicator, showing a substantial 74% increase in weeks with symptoms.

Injury and illness in short-course triathletes: A systematic review

BACKGROUND

Determining the incidence and prevalence of injury and illness in short-course triathletes would improve understanding of their etiologies and therefore assist in the development and implementation of prevention strategies. This study synthesizes the existing evidence on the incidence and prevalence of injury and illness and summarizes reported injury or illness etiology and risk factors affecting short-course triathletes.

METHODS

This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies reporting health problems (injury and illness) in triathletes (all sexes, ages, and experience levels) training and/or competing in short-course distances were included. Six electronic databases (Cochrane Central Register of Controlled Trials, MEDLINE, Embase, APA PsychINFO, Web of Science Core Collection, and SPORTDiscus) were searched. Risk of bias was independently assessed by 2 reviewers using the Newcastle-Ottawa Quality Assessment Scale. Two authors independently completed data extraction.

RESULTS

The search yielded 7998 studies, with 42 studies eligible for inclusion. Twenty-three studies investigated injuries, 24 studies investigated illnesses, and 5 studies investigated both injuries and illnesses. The injury incidence rate ranged 15.7-24.3 per 1000 athlete exposures, and the illness incidence rate ranged 1.8-13.1 per 1000 athlete days. Injury and illness prevalence ranged between 2%-15% and 6%-84%, respectively. Most injuries reported occurred during running (45%-92%), and the most frequently reported illnesses affected the gastrointestinal (7%-70%), cardiovascular (14%-59%), and respiratory systems (5%-60%).

CONCLUSION

The most frequently reported health problems in short-course triathletes were: overuse and lower limb injuries associated with running; gastrointestinal illnesses and altered cardiac function, primarily attributable to environmental factors; and respiratory illness mostly caused by infection.

Universal prevention through a digital health platform reduces injury incidence in youth athletics (track and field): a cluster randomised controlled trial

OBJECTIVES

To examine whether universal prevention via a digital health platform can reduce the injury incidence in athletics athletes aged 12-15 years and if club size had an influence on the effect of the intervention.

METHODS

This was a cluster randomised trial where young athletics athletes were randomised through their club following stratification by club size into intervention (11 clubs; 56 athletes) and control (10 clubs; 79 athletes) groups. The primary endpoint was time from baseline to the first self-reported injury. Intervention group parents and coaches were given access to a website with health information adapted to adolescent athletes and were encouraged to log in and explore its content during 16 weeks. The control group continued training as normal. Training exposure and injury data were self-reported by youths/parents every second week, that is, eight times. The primary endpoint data were analysed using the log-rank test. Cox proportional hazards regression was used to analyse the second study aim with intervention status and club size included in the explanatory models.

RESULTS

The proportion of completed training reports was 85% (n=382) in the intervention group and 86% (n=545) in the control group. The injury incidence was significantly lower (HR=0.62; χ²=3.865; p=0.049) in the intervention group. The median time to first injury was 16 weeks in the intervention group and 8 weeks in the control group. An interaction effect between the intervention and stratification factor was observed with a difference in injury risk between athletes in the large clubs in the intervention group versus their peers in the control group (HR 0.491 (95% CI 0.242 to 0.998); p=0.049).

CONCLUSIONS

A protective effect against injury through universal access to health information adapted for adolescent athletes was observed in youth athletics athletes. The efficacy of the intervention was stronger in large clubs.

TRIAL REGISTRATION NUMBER

NCT03459313.

The Assessment, Management and Prevention of Calf Muscle Strain Injuries: A Qualitative Study of the Practices and Perspectives of 20 Expert Sports Clinicians

Background

Despite calf muscle strain injuries (CMSI) being problematic in many sports, there is a dearth of research to guide clinicians dealing with these injuries. The aim of this study was to evaluate the current practices and perspectives of a select group of international experts regarding the assessment, management and prevention of CMSI using in-depth semi-structured interviews.

Results

Twenty expert clinicians working in elite sport and/or clinician-researchers specialising in the field completed interviews. A number of key points emerged from the interviews. Characteristics of CMSI were considered unique compared to other muscle strains. Rigor in the clinical approach clarifies the diagnosis, whereas ongoing monitoring of calf capacity and responses to loading exposure provides the most accurate estimate of prognosis. Athlete intrinsic characteristics, injury factors and sport demands shaped rehabilitation across six management phases, which were guided by key principles to optimise performance at return to play (RTP) while avoiding subsequent injury or recurrence. To prevent CMSI, periodic monitoring is common, but practices vary and data are collected to inform load-management and exercise selection rather than predict future CMSI. A universal injury prevention program for CMSI may not exist. Instead, individualised strategies should reflect athlete intrinsic characteristics and sport demands.

Conclusions

Information provided by experts enabled a recommended approach to clinically evaluate CMSI to be outlined, highlighting the injury characteristics considered most important for diagnosis and prognosis. Principles for optimal management after CMSI were also identified, which involved a systematic approach to rehabilitation and the RTP decision. Although CMSI were reportedly difficult to prevent, on- and off-field strategies were implemented by experts to mitigate risk, particularly in susceptible athletes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40798-021-00364-0.

Improving Clinical Utility of Real-World Prediction Models: Updating Through Recalibration

ABSTRACT

Bullock, GS, Shanley, E, Thigpen, CA, Arden, NK, Noonan, TK, Kissenberth, MJ, Wyland, DJ, and Collins, GS. Improving clinical utility of real-world prediction models: updating through recalibration. J Strength Cond Res XX(X): 000-000, 2022-Prediction models can aid clinicians in identifying at-risk athletes. However, sport and clinical practice patterns continue to change, causing predictive drift and potential suboptimal prediction model performance. Thus, there is a need to temporally recalibrate previously developed baseball arm injury models. The purpose of this study was to perform temporal recalibration on a previously developed injury prediction model and assess model performance in professional baseball pitchers. An arm injury prediction model was developed on data from a prospective cohort from 2009 to 2019 on minor league pitchers. Data for the 2015-2019 seasons were used for temporal recalibration and model performance assessment. Temporal recalibration constituted intercept-only and full model redevelopment. Model performance was investigated by assessing Nagelkerke's R-square, calibration in the large, calibration, and discrimination. Decision curves compared the original model, temporal recalibrated model, and current best evidence-based practice. One hundred seventy-eight pitchers participated in the 2015-2019 seasons with 1.63 arm injuries per 1,000 athlete exposures. The temporal recalibrated intercept model demonstrated the best discrimination (0.81 [95% confidence interval [CI]: 0.73, 0.88]) and R-square (0.32) compared with original model (0.74 [95% CI: 0.69, 0.80]; R-square: 0.32) and the redeveloped model (0.80 [95% CI: 0.73, 0.87]; R-square: 0.30). The temporal recalibrated intercept model demonstrated an improved net benefit of 0.34 compared with current best evidence-based practice. The temporal recalibrated intercept model demonstrated the best model performance and clinical utility. Updating prediction models can account for changes in sport training over time and improve professional baseball arm injury outcomes.

Epidemiology of injuries sustained in professional Australian netball: A three season cohort study

OBJECTIVES

To report the medical attention and time-loss injury epidemiology of Australia's premier netball competition.

DESIGN

Descriptive epidemiological study.

METHODS

One-hundred and nineteen players in the Suncorp Super Netball league were under surveillance during three consecutive seasons (2017-2019), inclusive of pre-, in-, and post- season phases. Medical attention injuries were recorded by medical personnel, and additionally sub-categorised according to time loss. Injury incidence rates (IIR) and injury burden were calculated per 365 player contract days, with differences between season and season phase IIRs compared using negative binomial generated incidence rate ratios (IRR).

RESULTS

Eight hundred and sixty-six medical attention injuries and 393 time-loss injuries were recorded. The majority of the players had multiple (≥2) medical attention (n = 92; 77.3%) and time-loss (n = 75, 63.0%) injuries reported. The ankle (n = 181; 20.9%), knee (n = 136; 15.7%) and foot (n = 98; 11.3%) were the body sites with the most frequently reported medical attention injuries. Overall, there was a comparable injury incidence rate between the pre-season and in-season periods (IRR = 1.13, 95%CI = 0.98-1.30, p = 0.0842), although variation in the injury burden was identified. Ankle tendon injuries (23.5 days absence) and knee joint injuries (44.9 days absence) the most burdensome injuries in the pre-season and in-season periods respectively.

CONCLUSIONS

Lower limb injuries are the most frequent in professional level netball. Knee and ankle injuries are the most burdensome overall, however the type of injuries with a high burden vary between pre- and in-season periods. Time-loss, non-time loss and subsequent injuries are prominent in professional level netball.

Clinical Prediction Models in Sports Medicine: A Guide for Clinicians and Researchers

SYNOPSIS

Participating in sport carries inherent risk of injury. Clinicians execute high-level clinical reasoning and decision making to support athletes to achieve the best outcomes. Accurately diagnosing a problem, estimating prognosis, or selecting the most suitable intervention for each athlete is challenging. Clinical prediction models are tools to assist clinicians in estimating the risk or probability of a health outcome for an individual by using data from multiple predictors. Although common in general medical literature, clinical prediction models are rare in sports medicine. The purpose of this article was to (1) describe the steps required to develop and validate (ie, evaluate) a clinical prediction model for clinical researchers, and (2) help sports medicine clinicians understand and interpret clinical prediction model studies. Using a case study to illustrate how to implement clinical prediction models in practice, we address the following issues in developing and validating a clinical prediction model: study design and data, sample size, missing data, selecting predictors, handling continuous predictors, model fitting, internal and external validation, performance measures, reporting, and model presentation. Our work builds on initiatives to improve diagnostic and prognostic clinical research, including the PROGnosis RESearch Strategy (PROGRESS) series of papers and textbook and the Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis (TRIPOD) statement. J Orthop Sports Phys Ther 2021;51(10):517-525. doi:10.2519/jospt.2021.10697.

Training in spikes and number of training hours correlate to injury incidence in youth athletics (track and field): A prospective 52-week study

OBJECTIVES

The aim was to describe the annual incidence and types of musculoskeletal injuries, and to examine factors associated with injury risk.

DESIGN

A 52-week prospective study in Swedish youth athletics aged 12-15 years.

METHODS

Data on exposure to training and injury were collected from parents/caregivers and youth athletes using a web-survey system.

RESULTS

A total of 101 (86%) youth athletes participated. Fifty-four (53%) of the athletes reported one new injury. Girls were at higher risk of sustaining an injury than boys (p = 0.048). Ninety-one percent of the new injuries were non-traumatic and 85% occurred in the lower extremities. Injuries to the front thigh represented 20% of the injuries. Cox proportional hazard regression analyses showed a six-fold increased risk for a first injury for athletes reporting use of spikes and training <6 h every two weeks (hazard ratio, 6.1; 95% confidence interval, 1.2-31.3) compared to athletes training <6 h using no spikes. Athletes training 6 h or more reporting use or no use of spikes had an eight-fold increase injury risk (p < 0.01).

CONCLUSIONS

Almost half of the youth athletes experienced a new injury and girls had a higher risk compared to boys. Nine out of ten injuries were related to overuse. An interesting observation was the high incidence of injuries to the quadriceps muscle complex. The study identified a correlation with training hours and an interaction with track spikes and risk of injury that needs further attention.

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.

Preseason weight-bearing ankle dorsiflexion in male professional football players with and without a history of severe ankle injury: A novel analysis in an English Premier League club

OBJECTIVES

Ankle injuries are common in professional football and have profound player/team/club consequences. The weight-bearing lunge-test (WBLT) assesses ankle dorsiflexion range-of-motion in football primary/secondary injury prevention and performance contexts. Data for uninjured and previously ankle-injured players in the English Premier League (EPL) is not available. This study analysed WBLT measurements (cm) within and between uninjured and previously severe ankle-injured players (injured-stiff group, injured-lax group) in one EPL club.

DESIGN

Cross-sectional.

SETTING

Preseason.

PARTICIPANTS

Forty-nine players (age 22.9 ± 4.6 yr; height 181.6 ± 5.2 cm; mass 77.7 ± 7.6 kg).

MAIN OUTCOME MEASURES

Prevalence (%) of previous unilateral severe ankle injury (USAI). Side-to-side (right/left, dominant/nondominant, injured/uninjured) WBLT comparisons at group-level (t-test [within-group]; Welch's ANOVA [between-group]; effect sizes [within-/between-group]) and individual-level (limb symmetry index [%]; absolute-asymmetry [%]).

RESULTS

Prevalence of USAI was 38.7%. There were no statistically-significant side-to-side differences for within-/between-group comparisons. Effect sizes: just-below-large (injured-stiff) and extremely-large (injured-lax) for within-group injured-side/uninjured-side comparisons; just-below-medium (injured-lax) to just-above-medium (injured-stiff) for injured-side comparisons to uninjured players. Absolute-asymmetries: uninjured players, 15.4±13.2%; injured-stiff, 21.8±33.6%; injured-lax 20.4±13.6%.

CONCLUSIONS

Over one-third of players had previous USAI. Effect sizes indicate substantial within-group side-to-side differences and less substantial between-group differences. Across groups, some players had absolute-asymmetries that may elicit concern in ankle primary/secondary injury prevention and performance contexts.

Determinants of Sports Injury in Young Female Swedish Competitive Figure Skaters

Introduction: Although figure skating attracts several hundred thousand participants worldwide, there is little knowledge about physical health and sports injuries among young skaters. The present study aimed to describe the health status of a geographically defined Swedish population of licensed competitive figure skaters and to examine injury determinants.

Methods: All licensed competitive skaters in the southeastern region of Sweden were in April 2019 invited to participate in a cross-sectional study using an online questionnaire. Multiple binary logistic regression was used for the examination of injury determinants. The primary outcome measure was the 1-year prevalence of a severe sports injury episode (time loss >21 days). The secondary outcome measure was the point prevalence of an ongoing injury. The determinants analyzed were age, skating level, relative energy deficiency indicators, and training habits.

Results: In total, 142 (36%) skaters participated, 137 (96%) girls [mean (SD) age: 12.9 (SD 3.0) years]. Participating boys (n = 5) were excluded from further analysis. The 1-year prevalence of a severe sports injury episode was 31%. The most common injury locations for these injuries were the knee (25%), ankle (20%), and hip/groin (15%). In the multiple model, having sustained a severe injury episode was associated with older age (OR 1.2, 95% CI 1.1–1.4; p = 0.002) and an increased number of skipped meals per week (OR 1.1, 95% CI 1.0–1.3; p = 0.014). The point prevalence of an ongoing injury episode was 19%. The most common locations were the knee (24%), ankle (24%), and foot (24%). Having an ongoing injury episode was associated with older age (OR 1.4, 95% CI 1.2–1.7; p < 0.001) and an increased number of skipped meals per week (OR 1.1, 95% CI 1.0–1.3; p = 0.049).

Conclusion: One-third of young female Swedish competitive figure skaters had sustained a severe injury episode during the past year, and a fifth reported an ongoing episode. Older age and an increased number of skipped meals per week were associated with a sports injury episode. Long-term monotonous physical loads with increasing intensity and insufficient energy intake appear to predispose for injury in young female figure skaters. Further examination of injury determinants among competitive figure skaters is highly warranted.

Assessing parents, youth athletes and coaches subjective health literacy: A cross-sectional study

OBJECTIVES

The aim was to describe levels of subjective Health Literacy (HL), and to examine possible differences in prevalence proportions between sexes, age groups and level of educations among youth athletes and their mentors (coaches, parents/caregivers) in Swedish Athletics.

DESIGN

Cross-sectional.

METHODS

Data on subjective HL were collected using the Swedish Communicative and Critical Health Literacy (S-CCHL) instrument for mentors and for youth the School-Aged Children (HLSAC) instrument. Questions assessing mentors' literacy on sports injury and return to play were also included.

RESULTS

The surveys were completed by 159 (91%) mentors and 143 youth athletes (87%). The level of S-CCHL was sufficient in 53% of the mentors. Of youth athletes, 28% reported a high level of HL and the item with least perceived high HL (21%) was critical thinking. Ninety-four percent of the mentors believed that it is quite possible to prevent injuries in athletics and 53% perceived having a very good knowledge about how to prevent injuries. Forty-six percent of the mentors perceived having a very good knowledge of return to sport criteria.

CONCLUSIONS

The level of health literacy was low with about half of the mentors and one out of three youth athletes having adequate HL levels. Only half of the mentors stated having a good knowledge of various injury prevention strategies. To reduce health consequences in youth sport and enable talent development more work is needed to understand the facilitators and barriers for the uptake of various health promotion and injury prevention strategies.

Sport and exercise participation in time of Covid-19-A narrative review of medical and health perspective

Coronavirus outbreak during 2020 brought enormous challenges for the world of sport and exercise. Much debated lockdown finished with the first wave in most countries and the “new normal” was the new beginning for professional and recreational sport activities. The aim of this narrative review is to acknowledge the most important medical and health aspects of sport and exercise participation until COVID‐19 pandemic is resolved. Management of existing crisis creates numerous opportunities for medical advances. Remote testing, tele‐health, field laboratories, continuous follow‐up of professional athletes, technological advances and artificial intelligence in new sporting environment using multidisciplinary, and systematic approach can be now thoroughly evaluated and defined for the best SEM practices. Sports and exercise medicine expertise in prevention can have a decisive role in dealing with ongoing and future pandemics.

Can Neurocognitive Function Predict Lower Extremity Injuries in Male Collegiate Athletes?

The purpose of this study is to demonstrate whether neurocognitive evaluation can confirm the association between neurocognitive level and postural control and to analyze the relationship between neurocognitive level and acute musculoskeletal injury in male non-net sports athletes. Seventy-seven male non-net sports athletes participated in this study. The Standardized Assessment of Concussion (SAC), Landing Error Scoring System (LESS), Balance Error Scoring System (BESS), and Star Excursion Balance Test (SEBT) were used for testing; we collected data related to injury history for six months after testing. Pearson's correlation analysis, logistic regression, and the independent sample t-test were used for statistical analysis. The correlation between SAC and SEBT results was weak to moderate (p < 0.05). Eleven of the seventy-seven participants experienced acute lower limb injuries. SAC, LESS, BESS, and SEBT results have no effect on the occurrence of acute lower extremity injuries (p > 0.05) and were not statistically different between the injured and non-injured groups (p > 0.05). Therefore, using the SAC score alone to determine the risk factor of lower extremity injuries, except in the use of assessment after a concussion, should be cautioned against.

"Does isometric exercise improve leg stiffness and hop pain in subjects with Achilles tendinopathy? A feasibility study"

BACKGROUND

In Achilles tendinopathy (AT) the ability to store and recycle elastic energy during ground contact phase is often altered. A measure of this function is represented by leg stiffness (LS). Immediate responses in LS following therapeutic intervention have not been examined.

OBJECTIVE

The aim of this paper was to examine the feasibility of the protocol in participants with AT.

DESIGN

Single cohort feasibility study.

PARTICIPANTS

Adults with persistent AT pain, symptoms on palpation and less than 80 points on the Visa-A questionnaire.

INTERVENTION

heavy isometric exercise sequence in plantarflexion.

OUTCOME MEASURES

Feasibility was assessed by evaluating: the willingness of participants to enroll into the study, the number of eligible participants, the recruitment rate, adherence to the intervention, the drop-out rate, the tolerability of the protocol. LS, reactive strength index, pain and rate of perceived effort were secondary outcomes.

RESULTS

22 AT were eligible for data collection and 19 entered the statistical analysis. The intervention was well tolerated, no withdrawals. Pain scores were low during both the intervention and the assessment. Immediate improvements in LS and pain were recorded.

CONCLUSIONS

The isometric exercise protocol was feasible. Future research should investigate its effectiveness.

Strength and Power Training in Rehabilitation: Underpinning Principles and Practical Strategies to Return Athletes to High Performance

Injuries have a detrimental impact on team and individual athletic performance. Deficits in maximal strength, rate of force development (RFD), and reactive strength are commonly reported following several musculoskeletal injuries. This article first examines the available literature to identify common deficits in fundamental physical qualities following injury, specifically strength, rate of force development and reactive strength. Secondly, evidence-based strategies to target a resolution of these residual deficits will be discussed to reduce the risk of future injury. Examples to enhance practical application and training programmes have also been provided to show how these can be addressed.

Injuries across a pre-professional ballet and contemporary dance tertiary training program: A retrospective cohort study

OBJECTIVES

The study aims to analyse the incidence of medical attention injuries, subsequent injuries, and the median time to injury, across tertiary ballet and contemporary dance training programs.

DESIGN

Retrospective cohort.

METHODS

Consenting ballet and contemporary dance students completing the third/final year of two tertiary programs were included. The three-year programs consisted of six semesters. Access was granted to onsite physiotherapy notes, timetables, and academic enrolment. Injury was defined as requiring medical attention. Injury and exposure data were extracted, injuries coded for location and tissue, and subsequent injuries, occurring after an initial index injury, categorised. Mean, standard deviation, range, injury incidence, risk and rate ratios, proportions and Kaplan-Meier curves were calculated to report participant characteristics, and injury patterns across three years of the dance program.

RESULTS

All 17 students (mean age=20.7 years; standard deviation=1.32) from one program consented to participate, of which all were injured across the three-year program, with 2.71 (95% confidence interval: 2.22, 3.20) injury incidence rate per 1000h, and increasing injury incidences seen across the program. The most injured site and tissue were the ankle (17.65%) and muscle (23.53%) respectively. 74.86% of subsequent injuries were different (affecting a different location and tissue), and 4.88% reinjuries (affecting the same location, tissue, and structure after recovery). The median time to the first injury was seven weeks in the first semester, and later in subsequent year levels.

CONCLUSIONS

Increasing injury incidences were seen across the program. Most subsequent injuries were different from previous injuries in this cohort. Future research should use exposure measures beyond hours (i.e. intensity) and consider subsequent injuries.

Developing web-based health guidance for coaches and parents in child athletics (track and field)

The aim of this study was to develop athletics health guidance (AHG) aimed at supporting coaches and parents involved in organized child athletics by providing practical advice and tools for the management of the most common health problems experienced in athletics by the 12- to 15-year olds. The study used participatory action research (PAR) and an established health service guideline development procedure modified to fit AHG development in child athletics. A sequential process consisting of four steps with associated subgoals was employed. The collected data were structured according to the AHG development steps and analyzed using qualitative methods. The most common health concern identified was injuries related to growth and overuse. No randomized controlled studies investigating injury prevention programs or any existing concepts/guidelines in child athletics were found that could be used in the development of the AHG. A requirements document was instead defined in a nominal group process and used for the AHG development. The areas included in the final AHG were as follows: training youth athletes, growth and puberty, recovery, injury prevention, injuries and illnesses, mental illness, safe sport, and anti-doping. The evidence regarding health issues in child athletics is limited, indicating that actions to support good health in the sport are currently based essentially on best practice. The long-term aim of the AHG and associated website is to systematically create and introduce conditions that can bridge the "know-do gap" and provide coaches and parents with easy-to-access and up-to-date knowledge in the field of child athlete health in athletics.

Subsequent Injury Risk Is Elevated Above Baseline After Return to Play: A 5-Year Prospective Study in Elite Australian Football

BACKGROUND

The risk of sustaining a subsequent injury is elevated in the weeks after return to play (RTP) from an index injury. However, little is known about the magnitude, duration, and nature by which subsequent injury risk is increased.

PURPOSE

To quantify and describe the risk of injury in a 12-week period after RTP from an index injury in Australian football players.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Injury data were collected from 79 players over 5 years at 1 Australian Football League club. Injuries were classified with the Orchard Sports Injury Classification System and by side of the body. Furthermore, injury severity was classified as time loss (resulting in ≥1 matches being missed) or non-time loss (no matches missed). Subsequent injury was categorized with the SIC-2.0 model and applied to the data set via an automated script. The probability of a time loss subsequent injury was calculated for in-season index injuries for each week of a 12-week period after RTP via a mixed effect logistic regression model.

RESULTS

Subsequent injury risk was found to be highest in the week of RTP for both time loss injuries (9.4%) and non-time loss injuries (6.9%). Risk decreased with each week survived after RTP; however, it did not return to baseline risk of participation (3.6%).

CONCLUSION

These findings demonstrate that athletes returning to play are at an increased risk of injury for a number of weeks, thus indicating the requirement for tertiary prevention strategies to ensure that they survive this period.

Epidemiology of elite sprint kayak injuries: A 3-year prospective study

OBJECTIVES

To analyse the characteristics of injuries sustained by elite sprint kayak athletes, to investigate relationships between initial and subsequent injuries, and to examine injury differences between male and female athletes.

DESIGN

Descriptive epidemiology study.

METHODS

Data from 63 athletes (37 male, 26 female) of the Australian national sprint kayak squad were prospectively collected over three continuous years (September 2014-August 2017). All medical attention injuries were recorded irrespective of time-loss and modality of training. Descriptive analyses were performed, and frequency comparisons across genders assessed with chi squared tests.

RESULTS

Forty-nine athletes (78%) sustained 146 injuries (median=2, interquartile range=1-4, range=0-12). Most injuries were to the upper limb (48%), with the shoulder being the most common body site injured (27%). Thirty-one athletes (49%) sustained at least one subsequent injury, equating to 97 subsequent injuries. The majority (68%) of subsequent injuries occurred at a different site and nature to previous injuries. Male athletes were more likely to sustain an injury than remain injury free compared to female athletes (Chi²₍₁₎=6.75, p=0.009), but there was no difference between males and females who thereafter sustained a subsequent injury (Chi²₍₁₎=0.84, p=0.359).

CONCLUSIONS

Injury occurrence is common in sprint kayak, with many athletes experiencing more than one injury. Small variations in injury characteristics exist between male and female athletes in sprint kayak. This study identifies upper limb and trunk, and joint and muscle injuries as the most prevalent sprint kayak injuries, providing a focus for the development of future injury prevention strategies.

Effects of tailored advice on injury prevention knowledge and behaviours in runners: Secondary analysis from a randomised controlled trial

OBJECTIVES

To determine whether biweekly tailored advice was more effective than general advice at baseline alone for enhancing evidence-based running-related injury (RRI) prevention knowledge and behaviours in runners.

DESIGN

Randomised controlled trial, blinded statistical analysis, secondary analysis.

SETTING

Recreational running clinics.

PARTICIPANTS

Running clinics were cluster randomised into intervention or control groups. All participants (n = 51) received general RRI prevention advice (baseline), after which the intervention group (n = 31) received additional biweekly tailored advice (weeks 3-11), before all participants completed a Final Questionnaire (week 13).

MAIN OUTCOME MEASURES

Between-group differences in change of evidence-based RRI prevention knowledge and behaviours.

RESULTS

Compared to baseline, the number of correct knowledge responses significantly increased in the intervention group (5.77, 95% CI 4.73, 6.81) and remained unchanged in controls (0.25, 95% CI -1.04, 1.55), outlining a positive effect only in the intervention group (p = 2.06 × 10^-8). The number of correct behaviour responses significantly increased in the intervention group (1.94, 95% CI 0.94, 2.93) however this increase was not significantly greater than controls (p = 0.075).

CONCLUSIONS

Biweekly tailored advice improved RRI prevention knowledge in runners. Further research into the impact of knowledge and behavioural change on RRI occurrence is warranted. ISRCTN 17357362.

Periodic Health Examination and Injury Prediction in Professional Football (Soccer): Theoretically, the Prognosis is Good

In professional soccer and other elite sports, medical and performance screening of athletes (also termed periodic health examination or PHE) is common practice. The purposes of this are: (1) to assist in identifying prevalent conditions that may be a threat to safe participation, (2) to assist in setting benchmark targets for rehabilitation or performance purposes and (3) to assist clinicians in determining which athletes may be at risk of future injury and selecting appropriate injury prevention strategies to reduce the perceived risk. However, when using PHE as an injury prevention tool, are clinicians seeking to identify potential causes of injury or to predict future injury? This Current Opinion aims to examine the conceptual differences between aetiology and prediction of injury while relating these areas to the capabilities of PHE in practice. We also introduce the concept of prognosis—a broader approach that is closely related to prediction—and why this may have greater applicability to PHE of professional athletes.

Comparison of subsequent injury categorisation (SIC) models and their application in a sporting population

Background

The original subsequent injury categorisation (SIC-1.0) model aimed to classify relationships between chronological injury sequences to provide insight into the complexity and causation of subsequent injury occurrence. An updated model has recently been published. Comparison of the data coded according to the original and revised subsequent injury categorisation (SIC-1.0 and SIC-2.0) models has yet been formally compared.

Methods

Medical attention injury data was prospectively collected for 42 elite water polo players over an 8 month surveillance period. The SIC-1.0 and SIC-2.0 models were retrospectively applied to the injury data. The injury categorisation from the two models was compared using descriptive statistics.

Results

Seventy-four injuries were sustained by the 42 players (median = 2, range = 0–5), of which 32 injuries (43.2%) occurred subsequent to a previous injury. The majority of subsequent injuries were coded as occurring at a different site and being of a different nature, while also being considered clinically unrelated to the previous injury (SIC-1.0 category 10 = 57.9%; SIC-2.0 clinical category 16 = 54.4%). Application of the SIC-2.0 model resulted in a greater distribution of category allocation compared to the SIC-1.0 model that reflects a greater precision in the SIC-2.0 model.

Conclusions

Subsequent injury categorisation of sport injury data can be undertaken using either the original (SIC-1.0) or the revised (SIC-2.0) model to obtain similar results. However, the SIC-2.0 model offers the ability to identify a larger number of mutually exclusive categories, while not relying on clinical adjudication for category allocation. The increased precision of SIC-2.0 is advantageous for clinical application and consideration of injury relationships.

Electronic supplementary material

The online version of this article (10.1186/s40621-019-0183-1) contains supplementary material, which is available to authorized users.

Five-Second Squeeze Testing in 333 Professional and Semiprofessional Male Ice Hockey Players: How Are Hip and Groin Symptoms, Strength, and Sporting Function Related?

Background

Hip and groin problems are just as common in ice hockey as they are in soccer. The 5-second squeeze test (5SST) is a valid indicator of hip- and groin-related sporting function (self-reported function) in soccer and is suggested to be interpreted according to a "traffic light" approach in guiding the early identification and management of affected players. It is currently unknown how the 5SST relates to self-reported function and muscle strength in ice hockey players.

Purpose

To investigate correlations between the 5SST result, self-reported function, and hip muscle strength in ice hockey players. A further aim was to investigate the discriminative ability of the "traffic light" approach (numeric rating scale [NRS] score: 0-2 = green, 3-5 = yellow, 6-10 = red) regarding levels of self-reported function and strength.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

Professional and semiprofessional male ice hockey players (N = 333) performed the 5SST and completed the Sport subscale of the Copenhagen Hip and Groin Outcome Score (HAGOS). Bilateral adduction and abduction strength was measured using handheld dynamometry. Associations were estimated using Spearman rank-order correlations, and groups were compared using the Kruskal-Wallis test or analysis of variance. Standardized effect sizes (ESs) for differences in strength (Hedges g) and self-reported function (r) were provided.

Results

The 5SST result was significantly correlated with self-reported function (rho, -0.319; P < .01) and hip muscle strength (rho, -0.157 to -0.305; P < .01). The HAGOS Sport scores differed significantly between all 3 traffic light groups (ES, 0.23-0.33; P ≤ .005). Players with an NRS score >2 (yellow or red light) had lower adduction (ES ≥ 0.75; P < .001) and abduction strength (yellow: ES, 0.30; P = .031) (red: ES, 0.51; P = .058) than players with a green light.

Conclusion

The 5SST result was significantly correlated with self-reported function as well as hip muscle strength and was able to discriminate between the traffic light levels in ice hockey players. Players with a yellow or red light had reduced adduction and abduction strength compared with players with a green light (NRS score ≤2). Routine 5SSTs may allow the early identification of affected ice hockey players and indicate yellow and red light situations, in which players may benefit from load management and appropriate hip muscle strengthening.

Improvement of Prediction of Noncontact Injury in Elite Australian Footballers With Repeated Exposure to Established High-Risk Workload Scenarios

OBJECTIVES

To assess the effect of multiple high-risk-scenario (HRS) exposures on noncontact injury prediction in elite Australian footballers.

DESIGN

Retrospective cohort study.

METHODS

Sessional workload data (session rating of perceived exertion, global positioning system-derived distance, sprint distance, and maximum velocity) from 1 club (N = 60 players) over 3 seasons were collated; several established HRSs were also defined. Accumulated HRS sessional exposures were calculated retrospectively (previous 1-8 wk). Noncontact injury data were documented. Univariate and multivariate Poisson regression models determined injury incidence rate ratios (IRRs) while accounting for moderating effects (preseason workload volume and playing experience). Model performance was evaluated using receiver operating characteristics (area under curve).

RESULTS

Very low (0-8 sessions: IRR = 5.76; 95% confidence interval [CI], 1.69-19.66) and very high (>15 sessions: IRR = 4.70; 95% CI, 1.49-14.87) exposures to >85% of an individual's maximal velocity over the previous 8 wk were associated with greater injury risk compared with moderate exposures (11-12 sessions) and displayed the best model performance (area under curve = 0.64). A single session corresponding to a very low chronic load condition over the previous week for all workload variables was associated with increased injury risk, with sprint distance (IRR = 3.25; 95% CI, 1.95-5.40) providing the most accurate prediction model (area under curve = 0.63).

CONCLUSIONS

Minimal exposure to high-velocity efforts (maximum speed exposure and sprint volume) was associated with the greatest injury risk. Being underloaded may be a mediator for noncontact injury in elite Australian football. Preseason workload and playing experience were not moderators of this effect.

Lifetime history of sexual and physical abuse among competitive athletics (track and field) athletes: cross sectional study of associations with sports and non-sports injury

OBJECTIVE

To examine associations between lifetime sexual and physical abuse, and the likelihood of injury within and outside sport in athletes involved in competitive athletics.

METHODS

A cross sectional study was performed among the top 10 Swedish athletics athletes using 1 year prevalence of sports and non-sports injuries as the primary outcome measure. Associations with sociodemographic characteristics, lifetime abuse history and training load were investigated. Data were analysed using simple and multiple logistic regression models.

RESULTS

11% of 197 participating athletes reported lifetime sexual abuse; there was a higher proportion of women (16.2%) than men (4.3%) (P=0.005). 18% reported lifetime physical abuse; there was a higher proportion of men (22.8%) than women (14.3%) (P=0.050). For women, lifetime sexual abuse was associated with an increased likelihood of a non-sports injury (OR 8.78, CI 2.76 to 27.93; P<0.001). Among men, increased likelihood of a non-sports injury was associated with more frequent use of alcoholic beverages (OR 6.47, CI 1.49 to 28.07; P=0.013), while commencing athletics training at >13 years of age was associated with a lower likelihood of non-sports injury (OR 0.09, CI 0.01 to 0.81; P=0.032). Lifetime physical abuse was associated with a higher likelihood of sports injury in women (OR 12.37, CI 1.52 to 100.37; P=0.019). Among men, athletes with each parents with ≤12 years formal education had a lower likelihood of sustaining an injury during their sports practice (OR 0.37, CI 0.14 to 0.96; P=0.040).

CONCLUSIONS

Lifetime sexual and physical abuse were associated with an increased likelihood of injury among female athletes. Emotional factors should be included in the comprehension of injuries sustained by athletes.

"Recognize and Remove": A Universal Principle for the Management of Sports Injuries

OBJECTIVE

To identify the locations and types of injury that result in players not being immediately removed from the field of play when injured and to quantify the magnitude of the situation.

DESIGN

Prospective cohort epidemiological study with definitions and procedures compliant with the international consensus statement for studies in rugby.

SETTING

Sevens World Series (SWS) (2008-2016) and Rugby World Cup (RWC) (2007, 2011, 2015).

PARTICIPANTS

Players from 17 countries taking part in the SWS and 22 countries taking part in the RWC.

MAIN OUTCOME MEASURES

Location, type, and mean severity of injury, period of match when the injury occurred and whether players were removed from the field of play when injured.

RESULTS

Injured players (51.5%) in the SWS and 33.1% of injured players in the RWC were immediately removed from the field of play at the time of injury. The percentages of players immediately removed varied from 16.7% for hand fractures (severity: 71 days) to 96.7% for shoulder dislocations/subluxations (severity: 105 days) during the SWS and from 4.5% for shoulder ligament sprains (severity: 25 days) to 65.9% for concussions (severity: 9 days) during the RWC. The percentage of players immediately removed from play when injured was not related to the severity of the injury sustained.

CONCLUSIONS

A high proportion of players continue to play (in the same game) after sustaining an injury although the likelihood of being removed from play is not dependent on injury severity.

Knee flexion not hip extension strength is persistently reduced following hamstring strain injury in Australian Football athletes: Implications for Periodic Health Examinations

OBJECTIVES

Determine whether clinically feasible tests of isometric lower limb strength and range of motion (ROM) in Australian Football (AF) athletes are useful in Periodic Health Examinations to identify persistent deficits following hamstring strain injury (HSI).

DESIGN

Case-control.

METHODS

Thirty-seven male, semi-professional AF athletes (mean±SD; age, 20.2±2.9years; height, 1.7±0.5m; mass, 81±9.2kg) participated, ten athletes (37%) reported HSI within the previous three seasons of competition. Comparisons of pre-season isometric knee flexion and hip extension strength variables (peak force, torque and torque normalised to body mass) and hip, knee and ankle ROM measures were made between athletes with and without past-history of HSI using linear mixed-effect models. A logistic regression evaluated whether any of the outcome measures could differentiate athletes with a past-history of HSI.

RESULTS

Knee flexion peak force, torque and torque normalised to body mass were significantly reduced in athletes with a past-history of HSI (coefficient, 95% CI) (-44.8N, -86.3 to -3.3), (-22.2Nm, -40.5 to -3.7) and (-0.2Nmkg^-1, -0.4 to 0.0) respectively. Knee flexion peak torque normalised to body mass (Nmkg^-1) approached significance as a test was able to differentiate athletes with history of HSI (p=0.068). There were no differences between groups for any hip extension strength or lower limb ROM outcome measures.

CONCLUSIONS

Deficits in isometric peak knee flexion strength persist for up to three seasons following HSI in AF athletes. Isometric knee flexion strength testing may be a clinically feasible option for Periodic Health Examinations and inform tertiary injury prevention strategies.

Monitoring the effect of football match congestion on hamstring strength and lower limb flexibility: Potential for secondary injury prevention?

OBJECTIVES

To investigate the effect of competitive football match congestion on hamstring strength and lower limb flexibility.

DESIGN

Repeated measures.

SETTING

Elite male youth football.

PARTICIPANTS

Fifteen male elite youth football players from the national football association centre of excellence were included (age = 15.81 ±0.65 years, height = 171.95 ±6.89 cm, weight = 65.93 ±7.53 kg).

MAIN OUTCOME MEASURES

Hamstring strength and pain, ankle dorsiflexion, hip extension, knee extension and flexion range of motion.

RESULTS

Hamstring strength was highest at baseline and significantly reduced at 24 (p = 0.001, mean difference -0.19 Nm/Kg, CI₉₅ -0.28, -0.1) and 48 h post-match 1 (p = 0.002, mean difference -0.16 Nm/Kg, CI₉₅ -0.25, -0.07). Strength recovered by match day 2 before significantly reducing again 24 h post-match 2 (p = 0.012, mean difference -0.17 Nm/Kg, CI₉₅ -0.29, -0.04). Pain was lowest at baseline and increased in the post-match periods (p < 0.05) with standardised effect sizes ranging from 0.07 to 0.42. Passive knee flexion range decreased post-match (p < 0.01) with mean differences of 1.5°-2.7°. The other flexibility measures remained unaffected by match play.

CONCLUSION

Isometric hamstring strength and pain can be considered for inclusion in-season to monitor player's post-match hamstring recovery characteristics during congested match fixtures.

Identifying high risk loading conditions for in-season injury in elite Australian football players

OBJECTIVES

To examine different timeframes for calculating acute to chronic workload ratio (ACWR) and whether this variable is associated with intrinsic injury risk in elite Australian football players.

DESIGN

Prospective cohort study.

METHODS

Internal (session rating of perceived exertion: sRPE) and external (GPS distance and sprint distance) workload and injury data were collected from 70 players from one AFL club over 4 seasons. Various acute (1-2 weeks) and chronic (3-8 weeks) timeframes were used to calculate ACWRs: these and chronic load categories were then analysed to determine the injury risk in the subsequent month. Poisson regression with robust errors within a generalised estimating equation were utilised to determine incidence rate ratios (IRR).

RESULTS

Altering acute and/or chronic timeframes did not improve the ability to detect high injury risk conditions above the commonly used 1:4 week ACWR. Twenty-seven ACWR/chronic load combinations were found to be "high risk conditions" (IRR>1, p<0.05) for injury within 7 days. Most (93%) of these conditions occurred when chronic load was low or very low and ACWR was either low (<0.6) or high (>1.5). Once a high injury risk condition was entered, the elevated risk persisted for up to 28 days.

CONCLUSIONS

Injury risk was greatest when chronic load was low and ACWR was either low or high. This heightened risk remained for up to 4 weeks. There was no improvement in the ability to identify high injury risk situations by altering acute or chronic time periods from 1:4 weeks.

A multifactorial evaluation of illness risk factors in athletes preparing for the Summer Olympic Games

OBJECTIVES

Illness can disrupt training and competition performance of athletes. Few studies have quantified the relative contribution of the known medical, behavioural and lifestyle risk factors.

DESIGN

Cross-sectional.

METHODS

Olympic athletes from 11 sports (n=221) were invited to complete questionnaires administered nine months before the Rio 2016 Olympic Games. These included the Depression, Anxiety and Stress Questionnaire (DASS-21), Perceived Stress Scale (PSS), Dispositional Resilience Scale (DRS), Recovery-Stress Questionnaire (REST-Q-52 item), Low Energy in Females Questionnaire (LEAF-Q), a modified Personal and Household Hygiene questionnaire, Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index, and custom-made questionnaires on probiotic usage and travel. An illness (case) was defined as an event which limited training or competition for greater hours in the prior month. Odds ratios and attributable fractions in the population (AFP) were utilised for categorical variables with independent t-tests or Wilcoxon rank-sum for continuous variables.

RESULTS

Eighty-one athletes responded (male, n=26; female, n=55). There were 16 illness cases and 65 controls. Female athletes were at higher odds of illness (OR=9.4, 95%CI 1.3-410, p=0.01, AFP=0.84). Low energy availability (LEAF-Q score ≥8: OR=7.4, 95%CI 0.78-352, p=0.04, AFP=0.76), depression symptoms (DASS-21: depression score >4, OR=8.4, 95%CI 1.1-59, p<0.01; AFP=0.39) and higher perceived stress (PSS: 10-item, p=0.04) were significantly associated with illness.

CONCLUSIONS

Female sex, low energy availability, and mental health are associated with sports incapacity (time loss) due to illness. Low energy availability had high attributable fractions in the population and stands out as a primary association with illness.

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.