Risk factors for injury in child and adolescent sport: a systematic review of the literature

Health promotion expectations and perceptions of sport club participants

To develop health promotion (HP) in sports clubs (SCs), stakeholders need to know the HP expectations of sports participants. However, the literature does not provide information on these aspects, which exacerbates the difficulty for SCs to provide an environment, activities and organization that promote health and to play the role entrusted to them in the integration of vulnerable populations. To fill this gap, this study explores the HP expectations and perceptions of sports participants, with a particular focus on ethnocultural characteristics, and documents participants' understanding of HP. A descriptive qualitative study comprising semi-structured interviews was carried out with 22 French and Quebec sports participants. Because they have little experience with HP in their SC, participants do not seem to have many expectations of their SC in terms of HP. Nevertheless, they felt that SCs can play an important role in health and suggested several themes and types of action, such as seminars on nutrition, activities outside the SC to develop cohesion or health monitoring. Sports participants from ethnocultural minorities seem to appreciate the programs designed to integrate them. There is a predominantly physical conception of health and the contribution of SCs to health, and the relationship between the types of health determinants (economic, environmental, organizational and social) and health is not clear. This study shows that the idea of a health-promoting SC appeals to SC participants, but this approach has not yet taken root in this setting or in society as a whole.

Balance performance of healthy young individuals in real versus matched virtual environments: a systematic scoping review

Background

Due to technological advancements and the development of consumer-oriented head mounted displays (HMDs), virtual reality (VR) is used in studies on balance performance and balance trainability more and more frequently. Yet, it may be assumed that balance performance is affected by the physical characteristics of the HMD (e.g., weight) as well as by the virtual visual environment. Moreover, it has been shown that balance is age-dependent with children and adolescents showing worse performances compared to young adults, which may also affect their balance performance in virtual environments.

Objectives

The present systematic scoping review aims to provide an overview on the current evidence regarding balance performance of healthy, young individuals (6–30 years) in real and matched virtual environments.

Methods

A systematic literature search in the electronic databases PubMed, Web of Science, and SPORTDiscus (from their inception date to February 2024) resulted in 9,554 studies potentially eligible for inclusion. Eligibility criteria were: (i) investigation of healthy, young individuals (6–30 years), (ii) balance assessment in the real and a matched virtual environment, (iii) use of a fully immersive HMD, (iv) reporting of at least one balance parameter. A total of 10 studies met the predefined inclusion criteria and were thus included in this review. All studies were conducted with healthy, young adults (19–30 years).

Results

Five studies assessed static balance, four studies quantified dynamic balance, and one study measured static as well as dynamic balance performance. In healthy young adults, static balance performance was similar with and without VR during simple standing tasks (e.g., two-legged stance), but worse in VR during more challenging tasks (e.g., one-legged stance). Concerning dynamic balance, four out of five studies reported worse performance in VR, while one study did not find differences between visual environments. Most importantly, none of the studies investigating healthy children (6–12 years) and/or adolescents (13–18 years) met the predefined inclusion criteria.

Conclusion

In healthy young adults, balance performance seems to be affected by VR only during challenging static (e.g., one-legged stance) as well as during dynamic balance tasks. The underlying causes remain unclear, but factors such as perceived presence in VR, a shift in sensory organization and/or perceptual distortion may play a role. Of particular importance is the finding that there is a void in the literature on the influence of VR on balance performance of healthy children and adolescents.

Head Contact and Suspected Concussion Rates in Youth Basketball: Time to Target Head Contact Penalties for Prevention

OBJECTIVE

To compare game events, head contact (HC) rates, and suspected concussion incidence rates (IRs) in boys' and girls' youth basketball.

DESIGN

Cross-sectional.

SETTING

Canadian club basketball teams (U16-U18).

PARTICIPANTS

Players from 24 boys' and 24 girls' Canadian club basketball teams during the 2022 season.

ASSESSMENT OF RISK FACTORS

Recorded games were analyzed using Dartfish video analysis software to compare sexes.

MAIN OUTCOME MEASURES

Poisson regression analyses were used to estimate HCs [direct (HC1) and indirect (HC2)], suspected concussion IRs, and IR ratios (IRRs). Game event, court location, and HC1 fouls were reported.

RESULTS

Division 1 HC rates did not differ between boys (n = 238; IR = 0.50/10 player-minutes; 95% confidence interval [CI], 0.43-0.56) and girls (n = 220; IR = 0.46/10 player-minutes; 95% CI, 0.40-0.52). Division 2 boys experienced 252 HCs (IR = 0.53/10 player-minutes; 95% CI, 0.46-0.59); girls experienced 192 HCs (IR = 0.40/10 player-minutes; 95% CI, 0.35-0.46). Division 2 boys sustained higher HC1 IRs compared with Division 2 girls (IRR = 1.42; 95% CI, 1.15-1.74). Head contacts, rates did not differ between boys and girls in either Division. Suspected concussion IRs were not significantly different for boys and girls in each Division. Head contacts occurred mostly in the key for boys and girls in each Division. Despite illegality, HC1 penalization ranged from 3.9% to 19.7%. Head contact mechanisms varied across Divisions and sexes.

CONCLUSIONS

Despite current safety measures, both HCs and suspected concussions occur in boys' and girls' basketball. Despite the illegality and potential danger associated with HC, only a small proportion of direct HCs were penalized and therefore targeting greater enforcement of these contacts may be a promising prevention target.

Pilot study of a health promotion intervention in sports clubs

Sports clubs (SCs) are an ideal setting for promoting health. However existing health promotion (HP) interventions in SCs mainly target a single health behavior and men who do sports, and evaluations of such interventions provides little information about their deployment. To overcome these limitations, the PROSCeSS intervention was co-constructed based on the theoretical model of the health-promoting SC and multi-level, multi-determinant health strategies. The aim of this pilot study was to evaluate the deployment of the PROSCeSS intervention and identify the factors influencing its deployment. A qualitative study, using recordings of meetings, email and telephone exchanges, and interviews with project leaders of fourteen SC, was carried out. Although a low number of SCs had completed the intervention, they all considered that they have a role to play in helping their members maintain good health. Their ability to develop HP activities and to implement the intervention was influenced by the resources available, the support they received from their sports federation, and the ability of each project leader to get involved in the intervention. The SCs that deployed the intervention implemented several strategies enabling them to integrate health into the organizational, social, economic, and environmental habits of the SCs and to develop new HP activities, such as adapted sports activity sessions and activities to teach members about first aid, nutrition, and good practices for warming up. This study highlights the importance of understanding the specificities of the contexts in which HP interventions are deployed. Having led to a reworking of the intervention steps and the development of an appropriate evaluation design, it also highlights the essential role of pilot studies in the development and evaluation of interventions.

Is There an Association Between Injury History and Lower Extremity Joint Injury During Canada Games Competition?

Background

Injuries during elite level competition like the Canada Games, occur frequently and injury history is one of the strongest predictors of future injury; however, this association is unknown in the Canada Games.

Purpose

To determine the association between injury history and incidence of lower extremity joint injury during Canada Games competition.

Methods

Data from the 2009 - 2019 Canada Games (8710 male and 8391 female athletes) competitions were de-identified by the Canada Games Council for analysis. Injury data were cleaned and categorized for previous injury and injury type and location. Injury history was self-reported and included concussion, major surgical procedure, neck and back, trauma to joint or bone, and trauma to ligament or tendon. Injury from the Canada Games competitions were categorized to include ankle, knee, hip, and patellofemoral joint injuries. Chi-Square (χ2 ) test of independence determined association between injury history and incidence of lower extremity joint injury during Canada Games competition. IBM SPSS (Version 26) was used for statistical analysis (p-value < 0.05).

Results

Four hundred and seventy-five ankle, 503 knee, 253 hip, and 106 patellofemoral joint injuries were reported during 10 years of Canada Games competitions. There were significant associations between history of neck and back injuries with ankle injuries and knee injuries, history of trauma and overuse of ligament or tendon with hip injuries and history of trauma or overuse of joint or bone with patellofemoral joint injuries.

Conclusion

These findings support previous literature suggesting that injury history is associated with future injury.

Level of Evidence

3.

Previous Injury and Lower Well-being Increase Injury Risk in Female Adolescent Athletes

Several risk factors for injury have been suggested in female elite athletes. However, there is a lack of prospective studies in young female athletes where multiple risk factors have been studied. The aim of this study was to identify risk factors for injury in female adolescent elite athletes. Substantial injuries were monitored in 222 athletes using the validated Oslo Sports Trauma Research Centre Questionnaire over 20 weeks. Over 20 potential risk factors were explored. Based on a binomial generalized linear mixed model, two significant (p<0.05) risk factors for injury were identified; previous injury within the last 12 months (OR 2.55) and well-being (OR 0.97). An athlete with a previous injury had twice as high a risk of injury (13% vs. 6%) compared to an athlete with no previous injury. Higher perceived well-being was associated with a decreased risk of injury. Based on a prospective design with a large sample of female adolescent elite athletes, investigating over 20 potential risk factors for injury, our results suggest that a previous injury and well-being are risk factors for injury.

Growth-related sports injuries among young male professional football players in the Netherlands: a prospective cohort study concerning injury incidence, severity and burden

OBJECTIVES

To investigate the incidence, type and location of growth-related sports injuries (GRSI) in youth professional football in the Netherlands. Secondary, to gain more knowledge on the injury severity and burden of GRSI.

METHODS

In this prospective, longitudinal cohort study, 813 players aged 10-18 are included. Data collection is performed by instructing the medical staff of six professional football club academies to register GRSI by means of standardized forms. Training and match exposure are registered individually on a weekly basis. Injury incidence was calculated as number of GRSI per 1000 hours, injury severity as the median number of days lost in categories and injury burden as the number of days lost per 1000 hours.

RESULTS

A total of 62 GRSI were documented in the football season 2021-2022. The total incidence of GRSI was 0.62/1000 hours football exposure. Morbus Osgood Schlatter and Morbus Sever were most common types of GRSI, both with incidence rates of 0.22/1000 hours exposure. About 58.3% of the documented GRSI were classified as major (>28 days lost). Within this group, the mean severity was 55 days time-loss to football.

CONCLUSIONS

GRSI are relatively common in youth professional football. The most common types are Morbus Sever and Morbus Osgood Schlatter. Morbus Osgood Schlatter has the highest injury severity and burden compared to other types of GRSI.

Combined hormonal contraceptive use is not protective against musculoskeletal conditions or injuries: a systematic review with data from 5 million females

OBJECTIVE

Assess the association between combined hormonal contraceptives (CHC) use and musculoskeletal tissue pathophysiology, injuries or conditions.

DESIGN

Systematic review with semiquantitative analyses and certainty of evidence assessment, guided by the Grading of Recommendations Assessment, Development and Evaluation approach.

DATA SOURCES

MEDLINE, EMBASE, CENTRAL, SPORTDiscus, CINAHL searched from inception to April 2022.

ELIGIBILITY

Intervention and cohort studies that assessed the association between new or ongoing use of CHC and an outcome of musculoskeletal tissue pathophysiology, injury or condition in postpubertal premenopausal females.

RESULTS

Across 50 included studies, we assessed the effect of CHC use on 30 unique musculoskeletal outcomes (75% bone related). Serious risk of bias was judged present in 82% of studies, with 52% adequately adjusting for confounding. Meta-analyses were not possible due to poor outcome reporting, and heterogeneity in estimate statistics and comparison conditions. Based on semiquantitative synthesis, there is low certainty evidence that CHC use was associated with elevated future fracture risk (risk ratio 1.02-1.20) and total knee arthroplasty (risk ratio 1.00-1.36). There is very low certainty evidence of unclear relationships between CHC use and a wide range of bone turnover and bone health outcomes. Evidence about the effect of CHC use on musculoskeletal tissues beyond bone, and the influence of CHC use in adolescence versus adulthood, is limited.

CONCLUSION

Given a paucity of high certainty evidence that CHC use is protective against musculoskeletal pathophysiology, injury or conditions, it is premature and inappropriate to advocate, or prescribe CHC for these purposes.

PROSPERO REGISTRATION NUMBER

This review was registered on PROSPERO CRD42021224582 on 8 January 2021.

Softball Pitchers' Body Segment Girths Are Associated with Varied Biomechanics at Ball Release of the Pitch

PURPOSE

The purpose of this study was to examine the relationships between pitcher trunk and throwing arm girth with kinematics at ball release of the softball pitch. Softball pitchers can be of various shapes and sizes; however, it is unknown if segment girth might influence pitch biomechanics. Because of the importance of body positioning at ball release of the windmill pitch, this study examined the relationship between segment girth and pitch biomechanics at ball release.

METHODS

Forty-two pitchers volunteered to participate (1.706 ± 0.061 m, 74.98 ± 15.94 kg, 15.5 ± 1.7 yr). Participants' throwing upper arm, chest, waist, and hip girth were measured. Participants then pitched fastballs to a catcher (43 ft) while an electromagnetic motion capture system synced with a force plate and motion analysis software collected kinematic data (sampled at 240 Hz).

RESULTS

Linear regressions revealed that upper arm, chest, and waist girth were associated with throwing arm shoulder horizontal abduction. Greater segment girth was associated with less horizontal abduction at ball release of the pitch.

CONCLUSIONS

Segment girth is related to pitch biomechanics and may influence body positions at crucial softball pitch events such as ball release.

CLINICAL RELEVANCE

Understanding biomechanical differences according to body segment girth is important for safe and optimal player development and performance.

Effects of Rearfoot Eversion on Foot Plantar Pressure and Spatiotemporal Gait Parameters in Adolescent Athletes

BACKGROUND

Foot malalignment can augment the risk of lower-extremity injuries and lead to musculoskeletal disorders. This study aimed to clarify the contribution of rearfoot alignment to plantar pressure distribution and spatiotemporal parameters during gait in healthy adolescent athletes.

METHODS

This retrospective study included 39 adolescent athletes who were divided into the rearfoot eversion and control groups according to a leg heel angle of 7°. A total of 78 legs were analyzed (45 and 33 legs in the rearfoot eversion [women, 53.3%] and control groups [women, 48.5%], respectively). Gait was assessed using an in-shoe plantar pressure measuring system and a wearable inertial sensor.

RESULTS

The foot plantar pressure distribution in the hallux was higher in the rearfoot eversion group than that in the control group (p = 0.034). Spatiotemporal parameters showed that the foot pitch angle at heel strike was significantly larger in the rearfoot eversion group than that in the control group (24.5° vs. 21.7°; p = 0.015). Total sagittal range of motion of the ankle during the stance phase of gait was significantly larger in the rearfoot eversion group than that in the control group (102.5 ± 7.1° vs. 95.6 ± 15.8°; p = 0.020). Logistic regression analysis revealed that plantar pressure at the hallux and medial heel and foot pitch angle at heel strike were significantly associated with rearfoot eversion.

CONCLUSIONS

Our findings suggest that rearfoot eversion affects the gait patterns of adolescent athletes. Notably, leg heel angle assessment, which is a simple and quick procedure, should be considered as an alternative screening tool for estimating plantar pressure and spatiotemporal gait parameters to prevent sports-related and overuse injuries in adolescent athletes.

Tennis Specialization and Consequence of Injury/Illness Following Retirement

(1) Background: There is a lack of literature that examines the impact of early vs. late sport specialization on quality of life after retirement from tennis. Thus, the purpose of this study was to examine the relationship between early specialization in the sport of tennis and health outcomes after retirement from collegiate/professional sport; (2) Methods: Participants were recruited through social media posts, newsletters, and contacts with tennis organizations. Basic demographic and injury information was collected from 157 former tennis players, along with the age of tennis specialization and two questionnaires: the Oslo Sports Trauma Research Center Questionnaire on Health Problems (OSTRC), and the CDC HRQOL-14 "Healthy Days Measure" Questionnaire (HRQOL); (3) Results: Significant differences (F_1,117 = 5.160, p < 0.025) in the specialization age between the low (11.9 ± 4.5 y) and high (9.8 ± 4.1 y) OSTRC groups were found after covarying for the current age. No difference (F_1,72 = 0.676, p < 0.414) was shown among the high (10.9 ± 4.4 y) and low (11.28 ± 4.6 y) HRQOL groups for the specialization age after covarying for the current age. A weak negative correlation was identified between the OSTRC score and specialization age (r = -0.233, p = 0.008), while no significant changes were shown between the specialization age and HRQOL score (r = -0.021, p = 0.857), or between the OSTRC and HRQOL scores (r = 0.146, p = 0.208); (4) Conclusions: Retired tennis players with low injury/illness severity scores specialized in tennis later than those with high injury/illness severity scores, while no differences in the specialization age were noted when the sample was separated into HRQOL groups.

Can motor proficiency testing predict sports injuries and sports-induced bleeds in people with haemophilia?

INTRODUCTION

Predicting the risk of sports injuries and sports-induced bleeds (SIBs) in people with haemophilia (PWH) may support clinical counselling.

AIM

To assess the association between motor proficiency testing and sports injuries and SIBs and to identify a specific set of tests for predicting injury risk in PWH.

METHODS

In a single centre, prospective study male PWH aged 6-49 playing sports ≥1x/week were tested for running speed and agility, balance, strength and endurance. Test results below -2Z were considered poor. Sports injuries and SIBs were collected for 12 months while 7 days of physical activity (PA) for each season was registered with accelerometers. Injury risk was analysed according to test results and type of physical activity (%time walking, cycling, running). Predictive values for sports injuries and SIBs were determined.

RESULTS

Data from 125 PWH (mean [± SD] age: 25 [± 12], 90% haemophilia A; 48% severe, 95% on prophylaxis, median factor level: 2.5 [IQR 0-15]IU/dl) were included. Few participants (n = 19, 15%) had poor scores. Eighty-seven sports injuries and 26 SIBs were reported. Poor scoring participants reported 11/87 sports injuries and 5/26 SIBs. The current tests were poor predictors of sports injuries (Range PPV: 0%-40%), or SIBs (PPV: 0%-20%). PA type was not associated with season (activity seasonal p values > .20) and type of PA was not associated with sports injuries or SIBs (Spearman's rho < .15).

CONCLUSION

These motor proficiency- and endurance tests were unable to predict sports injuries or SIBs in PWH, potentially due to few PWH with poor results and low numbers of sports injuries and SIBs.

Prevalence and pattern of traumatic orofacial injuries in Kabaddi players in Delhi-NCR region

BACKGROUND/AIM

Contact-sports are known to have higher risk of orofacial injuries due to the bodily contact with other players or equipment. Kabaddi is a traditional contact-sport of India that has gained an international recognition. There is a paucity of data regarding prevalence of traumatic dental and orofacial injuries among the Kabaddi players. Hence this study aimed to assess the prevalence, distribution and pattern of orofacial injuries among the Kabaddi players of Delhi and NCR region.

MATERIAL AND METHODS

This observational cross-sectional study was designed as per the best practices of epidemiology and reported as per the STROBE guidelines. The sample size was calculated as 440 and comprised of 10-18 years old players of either gender. Cluster random sampling was performed and the information was collected by one-calibrated evaluator by using a self-designed proforma. The injuries were classified as per standard criteria and the description of each episode was recorded. Statistical analysis was performed using the Statistical software-STATA-version-14(StataCorpLLC,Texas,USA).

RESULTS

Total of 393 players were included in the study (Males-295, Females-98) with majority of them between 15 and 18 years of age. The prevalence of traumatic episode was 49.11% and the prevalence orofacial-trauma was 44.02%.The frequency of extraoral-injuries was higher when compared to the intraoral injuries, with orbit(26.67%) being the commonest-site. Most of the players had not received adequate emergency treatment in the first incident which had improved in the second.

CONCLUSIONS

The prevalence of traumatic orofacial injuries in 10-18 years old Kabaddi players of Delhi-NCR region was found to be 44.02% while the prevalence of traumatic episodes was 49.11%. The prevalence of dental injuries was 5.1%. Majority of the players perceived that Kabaddi can lead to orofacial-injuries.

Injury Pathology in Young Gymnasts: A Retrospective Analysis

Gymnastics has a history of high injury incidence rates. However, little is known about the injury pathology in young gymnasts. The purpose of this study was to fill gaps in the literature by providing insight into the injury pathology in gymnasts aged 6 to 17 years. This study was retrospective in design, where injury data were collected using a Qualtrics questionnaire and distributed via social media. The findings revealed that the most common injury site was the lower limb (60.5%), in particular, the ankle/foot (49%) and knee (27%). Overuse injuries and sprains were most prevalent among the lower limb (25% and 18.4%, respectively), and gymnasts seemed to have a tendency to train through injury with modifications to training. In conclusion, lower limb joint sprain and overuse injuries accounted for the majority of injuries in youth gymnasts. These injuries were more frequently reported in girls in the years associated with peak height velocity and beyond.

The burden of injuries according to maturity status and timing: A two-decade study with 110 growth curves in an elite football academy

Injuries have a negative impact on the development of football players. Maturation is a potential risk factor for football injuries but available data on this topic provide limited evidence due to methodological shortcomings. The aim of this study was to describe the injury burden of male academy football players according to growth curve-derived maturity status and timing. Injury and growth data were collected from 2000 to 2020. Longitudinal height records for 110 individual players were fitted with the Super-Imposition by Translation and Rotation model to estimate age at peak height velocity (PHV). Players were clustered according to maturity status (pre-, circa-, post-PHV, or adults) and timing (early, on-time, late maturers). Overall and specific injury burdens (days lost/player-season) and rate ratios for comparisons between groups were calculated. Overall injury burden increased with advanced maturity status; pre-PHV players had 3.2-, 3.7-, and 5.5-times lower burden compared with circa-PHV, post-PHV, and adult players, respectively. Growth-related injuries were more burdensome circa-PHV, while muscle and joint/ligament injuries had a higher impact post-PHV and in adults. Further, in the pre-PHV period, late maturers showed lower burden of overall, growth-related, anterior inferior iliac spine osteochondrosis, and knee joint/ligament injuries compared with on-time maturers. In adult players, however, injuries were less burdensome for early maturers than on-time and late maturers. In addition, joint/ligament injuries of adult late maturers were 4.5-times more burdensome than those of early maturers. Therefore, monitoring maturity seems crucial to define each player's maturation profile and facilitate design of targeted injury prevention programmes.Highlights Injury burden is significantly lower in football players at pre-peak height velocity (PHV). Growth-related injuries are most burdensome circa-PHV, while muscle and joint/ligament injuries are more burdensome post-PHV and especially in adults.Before PHV, growth-related and knee joint/ligament injuries have lower burden in players who mature late than those who mature on-time. Adult late maturers have greater burden of overall and joint/ligament injuries than early maturers.Football academies should regularly assess the maturity status and timing of young football players, as the impact of injuries varies with maturation status and timing.Management of the maturity-related injury risk profile, in combination with other relevant factors (training load, neuromuscular and biomechanical factors, physiotherapy, coaching, communication, psychosocial factors …), might help improve the success of player development programmes and protect the health of young football players.

Who Does Not Respond to Injury Prevention Warm-up Programs? A Secondary Analysis of Trial Data From Neuromuscular Training Programs in Youth Basketball, Soccer, and Physical Education

OBJECTIVES: To identify factors associated with nonresponse to neuromuscular training (NMT) warm-up programs among youth exposed to NMT warm-ups. METHODS: This is a secondary analysis of youth (aged 11-18 years) in the intervention groups of 4 randomized controlled trials in high school basketball, youth community soccer, and junior high school physical education. Youth who were exposed to NMT and who sustained an injury during the study were considered nonresponders. Odds ratios (ORs) were based on generalized estimating equations logistic regression controlling for clustering by team/class and adjusted for age, weight, height, balance performance, injury history, sex, and sport (soccer/basketball/physical education). RESULTS: A total of 1793 youth were included. Youth with a history of injury in the previous year had higher odds (OR = 1.64; 95% CI: 1.14, 2.37) of injury during the study, and females were more likely (OR = 1.67; 95% CI: 1.21, 2.31) to sustain an injury than males who were participating in NMT. Age was not associated with the odds of sustaining an injury (OR = 1.10; 95% CI: 0.93, 1.30). Soccer players benefited most from greater adherence, with 81% lower odds of injury (OR = 0.19; 95% CI: 0.06, 0.57) when completing 3 NMT sessions a week compared with 1 session per week. CONCLUSION: Factors associated with nonresponse to an NMT warm-up program were female sex, history of injury during the previous 12 months, and lower weekly NMT session adherence in some sports (soccer). J Orthop Sports Phys Ther 2023;53(2):94-102. Epub: 9 December 2022. doi:10.2519/jospt.2022.11526.

Previous injury, sex and well-being are associated with injury profiles in 422 adolescent elite athletes of age 15-16 years: a 20-week longitudinal study

Background

Adolescent elite athletes have a high injury risk and many risk factors for injury have been suggested. However, there is a lack of prospective studies in adolescent elite athletes of age 15-16 years.

Aim

The aim of the study was to prospectively explore risk factors associated with different injury prevalence profiles in adolescent elite athletes.

Methods

Substantial injury was monitored in adolescent elite athletes (n=422) using the validated Oslo Sports Trauma Research Center Questionnaire over 20 weeks. Athletes were categorised in tertiles based on injury prevalence.

Results

The median substantial injury prevalence for all athletes was 10% (IQR 0%-20%). Compared with the 'no injury' group, previous injury (p<0.001, OR 3.91) and well-being (p<0.001, OR 0.93) were associated with the 'high injury' group, and previous injury (p=0.006, OR 1.96) and being a female athlete (p=0.002, OR 2.08) with the 'low injury' group. A female athlete with a previous injury and low perceived well-being (25th percentile) had a 48% risk (95% CI 36% to 59%) of belonging to the 'high injury' group, compared with 7% (95% CI 4% to 12%) for a male athlete with no previous injury and high well-being (75th percentile).

Conclusion

Medical personnel should be aware of the high injury risk and risk factors for injury in adolescent elite athletes, and closely monitor the rehabilitation post-injury as a previous injury is such a strong risk factor for a new injury.

EPIDEMIOLOGICAL PROFILE OF AMATEUR ATHLETES AT A MEDICAL SCHOOL IN THE CITY OF SÃO PAULO

ABSTRACT Introduction: Epidemiologic data about sports injuries among college athletes in Brazil is scarce. The aim of this study was to analyze the epidemiology of sports injuries in a single center. Methods: We interviewed 262 athletes from 10 different sports retrospectively about injuries sustained in their university careers and whose injuries sustained during one season were monitored prospectively. The characterization of the injuries included data on the location of the injury, type of injury, time of year, injury mechanism, and the moment of the injury during training or a game. Results: In the university history, the incidence of injuries was higher in men (81.5%) than in women (67.8%). Lower limb injuries were the most frequent both in the university history and the season. The sports with the highest injury rate for the season was handball (34.2%) and for the university history was basketball (80.8%). The main injury mechanism was non-contact. The months with the highest incidence of injuries were those at the beginning of the season (53.3%). The most frequent diagnoses were ligament injuries, followed by fractures. Both the presence of a previous injury in the same region and the practice of weight training were predictive factors for injury. Conclusion: College athletes at this center are more likely to suffer injuries during the first months of the season, especially in contact sports involving lower limbs. Level of Evidence III; Study of non-consecutive patients, without uniformly applied “gold” reference standard .

Injuries and Illnesses Across 10 Years of Canada Games Competitions: 2009 - 2019

Background

The Canada Games are a national level competition held every two years alternating between Summer and Winter Games. Participation in elite level athletics, like the Canada Games, have an inherent risk of injury and illness.

Purpose

To analyze the incidence and characteristics of injuries and illnesses during Canada Games competitions from 2009-2019 (primarily) and to understand sex differences in odds of musculoskeletal injury for Summer and Winter Canada Games athletes (secondarily).

Study Design

Descriptive Epidemiology Study.

Methods

Using a retrospective cohort, data were abstracted from medical incident reports generated during Canada Games from 2009 - 2019. Data were coded for body part injured and injury type or illness system; injuries were also categorized as acute or chronic.

Results

Across all 10 years of competition, 3160 injuries reported in 8710 male athletes and 3272 injuries reported in 8391 female athletes. Injury incidence was 362.8 and 389.9 and illness incidence was 47.8 and 64.5 per 1000 male and female athletes, respectively. Female athletes had a 1.12 (95% CI: 1.06; 1.19) greater odds of injury and 1.37 (95% CI: 1.20; 1.57) greater odds of illness compared to male athletes. Overall, injury (399.31 vs. 360.31; p < 0.001) and illness (68.67 vs. 47.30; p < 0.001) incidences were higher in Winter Games, compared to Summer Games, per 1000 athletes. When comparing male and female athletes participating in similar sports, sex specific differences exist in odds of both injury and illness.

Conclusions

Male and female athletes competing in Canada Games competitions demonstrate differences in injury and illness incidence and odds of injury. This suggests a need to examine if additional modifiable risk factors may exist, which could contribute to prevention strategies to reduce injury and illness during Canada Games competition.

Level of Evidence

3.

Ankle Joint Dorsiflexion Reference Values in Non-Injured Youth Federated Basketball Players: A Cross-Sectional Study

(1) Background: The aim of the present study was to establish ankle joint dorsiflexion reference values among youth federated basketball players. (2) Methods: Cross-sectional study. The participants were basketball players who belonged to youth basketball developmental teams (female and male) from under-12 (U12) to under-17 (U17) categories. Ankle joint dorsiflexion range of motion was evaluated with the weight-bearing lunge test through the Leg Motion system. The distance achieved was recorded in centimeters. (3) Results: 693 basketball players who met the eligibility criteria and volunteered to participate were included in the study. The mean (SD) of ankle joint dorsiflexion was 10.68 (2.44) cm and the reference values were: excessive hypomobility < 6.09 (0.54) cm; hypomobility 6.09 (0.88) cm-8.43 (0.77) cm; normal 8.44 (0.77)-13.11 (0.79) cm; hypermobility 13.11 (0.74)-15.44 (0.86) cm; and excessive hypermobility >15.44 (0.86) cm. (4) Conclusions: This study provides ankle joint dorsiflexion reference values in youth basketball players from 12 to under 17 years old.

Softball Pitching Propulsion and Performance Differences According to Body Fat Percentage

Softball pitchers with a high body-fat percentage (bf%) can often be successful, despite the heightened risk of injury associated with high bf%. Given the importance of propulsion during pitching, those with high bf% may have an advantage performance-wise. Therefore, the purpose of this study was to examine the differences in ground reaction force (GRF) development between two groups of pitchers: those with a high-fat percentage (≥32 bf%) and a healthy-fat percentage (<32 bf%). Thirty-two female high-school softball pitchers (1.70±.06 m, 76.09±17.50 kg, 15±1 yrs) completed dual-energy x-ray absorptiometry (DEXA) scans. GRF data were collected during pitch propulsion via a force plate, pitch speed was captured using a radar gun, BMI was calculated from pitcher height and mass, and fat free mass index (FFMI) and fat mass index (FMI) were calculated using DEXA data and pitcher height. Multivariate analysis of variance revealed pitcher group GRFs differed significantly (F_3,30=3.45, p=.030). Univariate follow-up analyses showed healthy bf% pitchers presented greater weight-normalized peak medial GRF (F_1,30=7.17, p=.012). BMI and FFMI were positively associated with pitch speed while bf% and FMI were negatively associated with pitch speed. While pitchers can be successful and carry excess bf%, results indicate potential performance disadvantages associated with having an increased bf%.

Players with high physical fitness are at greater risk of injury in youth football

The aim of this study was to investigate physical fitness, football-specific skills, and their association with injury risk in youth football. Altogether 447 male and female players aged 9-14 years (median 12 years) participated in performance tests and prospective follow-up. The physical fitness tests included five-jump test for distance, 30-m sprint, football-specific figure of eight agility, countermovement jump, and Yo-Yo intermittent endurance test level 1. The football-specific skill tests included dribbling and passing tests. Injuries and exposure were registered during the 20-week follow-up. Our candidate risk factors were low/high level of physical fitness measured with a composite score of physical fitness tests and low/high level of football-specific skills measured with a composite score of dribbling and passing tests. Secondarily, we investigated performance in individual tests and their association with injury risk. During the follow-up, players reported 565 injuries (264 acute and 301 overuse injuries). High level of physical fitness was associated with increased rate of all injuries (age-, sex-, and mean team exposure-adjusted IRR: 1.28, 95% CI: 1.04-1.58). The level of football-specific skills had no influence on the overall injury rate. Burden of overuse injuries, but not acute injuries was significantly higher in most fit players compared with the players in the reference group (IRR: 2.09, 95% CI: 1.04-4.24). In conclusion, most fit players were at greater risk of sustaining injuries in youth competitive football.

Factors Associated with School Sports Injury among Elementary and Middle School Students in Shanghai, China

School sports activity (SSA) is beneficial to gaining and maintaining optimal health among elementary and middle school students but might increase risks for school sports injury (SSI). This cross-sectional study aimed to investigate the incidence and identify risk factors of SSI among Chinese elementary and middle school students in Shanghai. Students in grades 4–5 (elementary) and 7–9 (middle) from three k-12 schools (aged from 9 to 16 years old) in Shanghai selected via the method of cluster random sampling were invited to participate in the study. Information on socio-demography, sleep duration, individual internal and external risk factors, and SSI experiences in the past 12 months was collected. A multivariate logistic regression model was performed to estimate the risk factors of SSI. A total of 1303 participants completed the questionnaires, with an overall SSI incidence rate of 29.5%. Along with boys, elementary school students, and sports team members, students scoring high on internal and external risk factors were at higher risk for SSA. In summary, SSI was prevalent among elementary and middle school students in Shanghai, China, and was associated with several modifiable risk factors. The findings provide insights regarding actions that could be taken to reduce the occurrence of SSI and maximize the benefits of SSA, including improvements in safety education, maintenance of facilities and equipment, and completion of warm-up exercises.

Sex Differences in Pre-Season Anthropometric, Balance and Range-of-Motion Characteristics in Elite Youth Soccer Players

In soccer, injury epidemiology differs between males and females. It is clinically useful to know whether there are between-sex differences in selected characteristics relevant to primary injury risk and injury prevention practices. The purpose of this study was to explore between-sex differences in anthropometric, balance, and range-of-motion characteristics in Spanish elite male and female youth soccer players. This was a pre-season cross-sectional study. Sixty-nine males (age 16.8 ± 0.9 yr; height 175.9 ± 6.8 cm; mass 67.9 ± 6.3 kg) and thirty-seven females (age 17.2 ± 1.7 yr; height 164.0 ± 6.3 cm; mass 59.0 ± 5.8 kg) participated. Anthropometrics (standing/sitting height, bodymass, right/left leg length) and right/left anterior reach test (ART), hip internal/external active range of motion, active knee extension (AKE), and weightbearing lunge test (WBLT) were measured. Between-sex differences were assessed with Bonferroni-corrected Mann−Whitney U tests and Cliff’s delta (d). Between-sex significant differences (p < 0.003, d ≥ 0.50) were observed for anthropometric data and for hip internal rotation. No between-sex significant differences were observed for ART/AKE/WBLT measures. Between-sex significant differences with large effect sizes were identified for anthropometric data and right/left hip internal rotation. The present study adds new data to the literature for young Spanish male and female soccer players. The present findings will help inform clinical reasoning processes and future injury prevention research for elite male and female youth soccer players.

Detection of Neuromuscular Deficits in Movement Pattern among Uninjured Federated Youth Basketball Players: A Cross-Sectional Study

(1) Background: The aim of the present study was to evaluate and to detect neuromuscular deficiencies in static and dynamic tests among federated youth basketball players. (2) Methods: Cross-sectional study with 778 basketball players. Specific tests and trials were conducted to evaluate members of teams from several clubs in male and female from under 12 (U12) to under 17 (U17) categories. The evaluations consisted of static physical measurements and dynamic measurements. (3) Results: 575 players were included in this study. A total of 95% of participants are unable to keep their ankle stable in monopodial loading; 86% present dynamic lower extremity valgus with statistically significant differences between categories (p = 0.004); 94% are unable to keep the pelvis stable when performing a single-leg squat; 93% are unable to keep their trunk stable when performing the same movement. During landing, 96% present dynamic lower extremity valgus. The thighs of 92% do not reach parallel (peak of jump). (4) Conclusions: The most frequent neuromuscular deficits in federated youth basketball players are related to instability, the most frequent being ankle instability, followed by lumbo-pelvic instability, dynamic postural instability and dynamic knee valgus. Deficits in jumping/landing technique are also very frequent in all the items analyzed (jumping, landing and plyometrics). The performed tests, which mostly showed a poor performance by the sample, can be indicative of injury probability.

Maternal Pre-Pregnancy Nutritional Status and Physical Activity Levels and a Sports Injury Reported in Children: A Seven-Year Follow-Up Study

Objective: Our aim was to analyze dose–response associations between maternal pre-pregnancy body mass index and physical activity levels with childhood sports injury rates. Methods: Participants included pre-pregnant mothers (n = 4811) and their children at the age of 7 years (n = 3311). Maternal anthropometry (height, weight, and body mass index), time spent in physical activity, and education level were recorded. All sports injuries were defined as injuries reported in the past year by the children at the age of 7 years. Results: Children whose mothers were overweight/obese in the pre-pregnancy period were 2.04 (OR = 2.04, 95% CI = 1.12–3.71) times more likely to report a sports injury at the age of 7 years. Underweight mothers exhibited a 74% decrease in the odds of their children reporting a sports injury at follow-up (OR = 0.26, 95% CI = 0.10–0.68). Finally, an increase in maternal physical activity across the last three quartiles was associated with a lower odds of sports injuries. Conclusions: The risk of reporting a sports injury was greater for children whose mothers were overweight/obese in the pre-pregnancy period. However, there was a lower risk with both maternal underweight status and increasing minutes of physical activity.

The performance of body mass component indices in detecting risk of musculoskeletal injuries in physically active young men and women

BACKGROUND

Body composition indices can be related to musculoskeletal injuries (MI), particularly in physically active groups. However, little is known about the accuracy of these diagnoses as potential predictors of musculoskeletal injuries. Therefore, this study aims to indicate the cut-off points of relative body mass (BMI), fat mass index (FMI), skeletal muscle mass (SMI), and muscle to fat ratio (MFR) and establish its reliability in injury prediction for physically active men and women.

METHODS

The sample included 119 physically active individuals aged 23.72 ± 1.12 (66 men body height 1.79 ± 0.07 (m); body weight 80.51 ± 9.85 (kg) and 53 women body height 1.67 ± 0.08 (m); body weight 62 ± 10.72 (kg)), students at university of physical education in Poland. The participants' physical activity was measured with the International Physical Activity Questionnaire (IPAQ). The relevance of body mass index (BMI), fat mass index (FMI), skeletal muscle mass index (SMI), and muscle to fat ratio (MFR) in detecting injury risk was examined. Musculoskeletal injuries during 1 year before examination were registered using a self-reporting questionnaire. The areas under the curve (AUC) and Youden Index in the receiver operating characteristic curve (ROC) were calculated.

RESULTS

The cut-off points used to classify the indices among men were BMI = 24.38; FMI = 3.74; SMI = 16.40; MFR = 3.70; and for women BMI = 20.90; FMI = 4.17; SMI = 8.96; MFR = 1.67. Results suggested the greatest reliability in the prediction of musculoskeletal injuries among men had BMI (AUC = 0.623; Youden = 0.30) and SMI (AUC = 0.608; Youden = 0.23) whereas among women, MFR (AUC = 0.628; Youden = 0.29) and FMI (AUC = 0.614; Youden = 0.32).

CONCLUSION

BMI and SMI are the most appropriate indices to predict the risk of musculoskeletal injury in physically active men, whereas in women, MFR and FMI are more reliable. These results indicate that the indices with more muscle mass meaning are better in predicting injury among men. In contrast, indices with a higher contribution of fat are better for women. It indicates sex differentiation of injury risk conditions. Men should focus on developing muscle mass, whereas women should reduce body fat to decrease injury risk. However, widespread use seemed to be limited to the specific examined group. Therefore, cut-off points should be used with caution, and calculated values should be verified and confirmed in subsequent studies.

Association between Inter-Limb Asymmetries in Lower-Limb Functional Performance and Sport Injury: A Systematic Review of Prospective Cohort Studies

Background: Inter-limb asymmetry in lower-limb functional performance has been associated with increased risk of sport injury; however, findings are not always consistent. Purpose: To conduct a systematic review on whether inter-limb asymmetry in lower-limb functional performance can predict sport injury. Methods: Four electronic databases (MEDLINE, EMBASE, Web of Science, and SportDiscus) were systematically searched for prospective cohort studies reporting the association between inter-limb asymmetry in lower-limb functional performance and sport injury. Results: A total of 28 prospective cohort studies were included in the analyses. Collectively, the findings were highly inconsistent, and a clear statement on the association between each asymmetry and sport injury was difficult. Conclusions: Highly inconsistent findings make it difficult to create clear recommendations on the relationship between the inter-limb asymmetry in lower-limb functional performance (power, muscle flexibility, and dynamic balance) and sport injury. The influence of potential factors (selection of tests/parameters, participant characteristics, definition of injury, and ways of calculating asymmetry) should be considered when using previous findings.

Vertical Drop Jump Biomechanics of Patients With a 3- to 10-Year History of Youth Sport-Related Anterior Cruciate Ligament Reconstruction

Background

A better understanding of movement biomechanics after anterior cruciate ligament reconstruction (ACLR) could inform injury prevention, knee injury rehabilitation, and osteoarthritis prevention strategies.

Purpose

To investigate differences in vertical drop jump (VDJ) biomechanics between patients with a 3- to 10-year history of youth sport-related ACLR and uninjured peers of a similar age, sex, and sport.

Study Design

Cross-sectional study. Level of evidence III.

Methods

Lower limb kinematics and bilateral ground-reaction forces (GRFs) were recorded for participants performing 10 VDJs. Joint angles and GRF data were analyzed, and statistical analysis was performed using 2 multivariate models. Dependent variables included sagittal (ankle, knee, and hip) and coronal (knee and hip) angles at initial contact and maximum knee flexion, the rate of change of coronal knee angles (35%-90% of the support phase; ie, slopes of linear regression lines), and vertical and mediolateral GRFs (normalized to body weight [BW]). Fixed effects included group, sex, and time since injury. Participant clusters, defined by sex and sport, were considered as random effects.

Results

Participants included 48 patients with a history of ACLR and 48 uninjured age-, sex-, and sport-matched controls (median age, 22 years [range, 18-26 years]; 67% female). Patients with ACLR demonstrated steeper negative coronal knee angle slopes (β = -0.04 deg/% [95% CI, -0.07 to -0.00 deg/%]; P = .025). A longer time since injury was associated with reduced knee flexion (β = -0.2° [95% CI, -0.3° to -0.0°]; P = .014) and hip flexion (β = -0.1° [95% CI, -0.2° to -0.0°]; P = .018). Regardless of ACLR history, women displayed greater knee valgus at initial contact (β = 2.1° [95% CI, 0.4° to 3.8°]; P = .017), greater coronal knee angle slopes (β = 0.05 deg/% [95% CI, 0.02 to 0.09 deg/%]; P = .004), and larger vertical GRFs (landing: β = -0.34 BW [95% CI, -0.61 to -0.07 BW]; P = .014) (pushoff: β = -0.20 BW [95% CI, -0.32 to -0.08 BW]; P = .001).

Conclusion

Women and patients with a 3- to 10-year history of ACLR demonstrated VDJ biomechanics that may be associated with knee motion control challenges.

Clinical Relevance

It is important to consider knee motion control during activities such as VDJs when developing injury prevention and rehabilitation interventions aimed at improving joint health after youth sport-related ACLR.

When Do Individuals Get More Injured? Relationship between Physical Activity Intensity, Duration, Participation Mode, and Injury

The present study examines the association between physical activity (PA) participation modes (i.e., family, friends, club members, and alone), PA volumes (i.e., intensity and duration), gender, and injury. A total of 9000 Koreans aged 10-89 years participated in the Korean Survey of Citizens' Sports Participation project. However, participants who did not respond to a question regarding PA participation modes (n = 2429) and those under 18 years old (n = 489) were excluded from this study. Analysis of variance (ANOVA) was used to compare the groups' characteristics and the association between PA participation modes and injury was demonstrated by conducting multinomial logistic regression analysis. The risk of injury was significantly higher in the friend and club member groups than in the alone group. In addition, PA intensity and gender were critical risk factors of injury, while PA duration showed no significant results. The results indicated a strong association between PA participation modes, PA intensity, gender, and injury, and an interesting finding is that more injuries derived from a higher intensity of PA, not from a longer duration of PA. Therefore, this present study directly documented that considerable attention should be placed on the factors that affect injuries, such as gender and PA intensity, to prevent unpredictable injury and encourage potential participants to exercise with diverse participation modes and appropriate intensity.

Lower extremity energy absorption strategies at different phases during single and double-leg landings with knee valgus in pubertal female athletes

Dynamic knee valgus (DKV) malalignment affects the biomechanical characteristic during sports activities. This cross-sectional study was conducted to evaluate mechanical energy absorption (MEA) strategies at initial contact (IC) and total landing (TL) phases during single-leg landing (SLL), and double-leg landing (DLL). Twenty-eight female athletes with DKV (age 10-14) were invited. MEA analysis of lower extremity joints was done in sagittal and frontal motion planes employing 8 Vicon motion capture cameras and 2 Kistler force plates. Statistical analysis was done using IBM Statistics (version24) by Bivariate Pearson Correlation Coefficient test. Knee extensors MEA during SLL (IC: P = 0.008, R = 0.522/TL: P < 0.001, R = 0.642) and DLL (IC: P < 0.001, R = 0.611/TL: P = 0.011, R = 0.525), and knee abductors during SLL (IC: P = 0.021, R = 0.474) were positively correlated with increased DKV angle. Ankle plantar flexors during SLL (TL: P = 0.017, R = - 0.477) and DLL (TL: P = 0.028, R = - 0.404), and hip extensors during SLL (TL: P = 0.006, R = - 0.5120) were negatively correlated with increased DKV angle. Compensated MEA in knee extensors was correlated with less ankle plantar flexion MEA during SLL (IC: P = 0.027, R = - 0.514/TL: P = 0.007, R = - 0.637) and DLL (IC: P = 0.033, R = - 00.412/TL: P = 0.025, R = - 0.485). These outcomes indicated a knee-reliant MEA strategy in female athletes with DKV during puberty, putting them at higher risks of ACL injuries during landing.

Risk Factors for Non-Contact Lower-Limb Injury: A Retrospective Survey in Pediatric-Age Athletes

Background: Risk factors for non-contact lower-limb injury in pediatric-age athletes and the effects of lateral dominance in sport (laterally vs. non-laterally dominant sports) on injury have not been investigated. Purpose: To identify risk factors for non-contact lower-limb injury in pediatric-age athletes. Methods: Parents and/or legal guardians of 2269 athletes aged between 6–17 years were recruited. Each participant completed an online questionnaire that contained 10 questions about the athlete’s training and non-contact lower-limb injury in the preceding 12 months. Results: The multivariate logistic regression model determined that lateral dominance in sport (adjusted OR (laterally vs. non-laterally dominant sports), 1.38; 95% CI, 1.10–1.75; p = 0.006), leg preference (adjusted OR (right vs. left-leg preference), 0.71; 95% CI, 0.53–0.95; p = 0.023), increased age (adjusted OR, 1.21; 95% CI, 1.16–1.26; p = 0.000), training intensity (adjusted OR, 1.77; 95% CI, 1.43–2.19; p = 0.000), and training frequency (adjusted OR, 1.36; 95% CI, 1.25–1.48; p = 0.000) were significantly associated with non-contact lower-limb injury in pediatric-age athletes. Length of training (p = 0.396) and sex (p = 0.310) were not associated with a non-contact lower-limb injury. Conclusions: Specializing in laterally dominant sports, left-leg preference, increase in age, training intensity, and training frequency indicated an increased risk of non-contact lower-limb injury in pediatric-age athletes. Future research should take into account exposure time and previous injury.

Injuries and Training Practices in Competitive Adolescent Distance Runners: A Retrospective Cross-Sectional Study

Background: Distance running is one of the most popular sports around the world. The epidemiology of running-related injury (RRI) has been investigated in adults, but few studies have focused on adolescent distance runners. Objectives: (1) To provide descriptive epidemiology of RRI (risks, rates, body regions/areas, and severity) and examine the training practices (frequency, volume, and intensity) of competitive adolescent distance runners (13-18 years) in England, and (2) to describe potential risk factors of RRI. Methods: A cross-sectional study design was used. Adolescent distance runners (n = 113) were recruited from England Athletics affiliated clubs. Participants voluntarily completed an online questionnaire between April and December 2018. At the time of completion, responses were based on the participant's previous 12-months of distance running participation. Incidence proportions (IP) and incidence rates (IR) were calculated. Results: The IP for "all RRI" was 68% (95% CI: 60-77), while the IR was 6.3/1,000 participation hours (95% CI: 5.3-7.4). The most commonly injured body areas were the knee, foot/toes, and lower leg; primarily caused by overuse. The number of training sessions per week (i.e., frequency) significantly increased with chronological age, while a large proportion of participants (58%) self-reported a high level of specialisation. Conclusions: RRI is common in competitive adolescent distance runners. These descriptive data provide guidance for the development of RRI prevention measures. However, analytical epidemiology is required to provide better insight into potential RRI risk factors in this specific population.

Noncontact Knee Ligament Injury Prevention Screening in Netball: A Clinical Commentary with Clinical Practice Suggestions for Community-Level Players

Netball is a predominantly female team court-sport which is played worldwide. Netball is becoming more popular in the United States following its countrywide introduction to schools and community centers. A unique characteristic of netball is the footwork rule which restricts players to a one-step landing after catching the ball. Most netball landings are single-leg landings resulting in high vertical ground reaction forces and high skeletal tissue forces. Thus, high-risk landing events that have the biomechanical potential for injury occur frequently. Noncontact knee ligament injuries are common following a knee abduction collapse when landing. Because the consequences of noncontact knee ligament injury are profound, strategies are needed to mitigate the burden of such injury for players, teams, and society. The purpose of this clinical commentary is to demonstrate how theoretical principles, different types of research, and different levels of evidence underpin a rational clinical reasoning process for developing noncontact knee ligament injury prevention screening procedures in netball. The theoretical principles that are discussed in this commentary include injury control, the sequence of prevention, principles of screening in injury prevention, the multifactorial model of injury etiology, complex systems theory, and systems science. The different types of research that are reviewed include descriptive and analytic-observational studies. The different levels of evidence that are discussed include prospective studies, cross-sectional studies, and clinicians' own kinesiological modelling. Subsequently, an integrated approach to the evidence-informed development of noncontact knee ligament injury prevention screening procedures is presented. Clinical practice suggestions include a selection of evidence-informed screening tests that are quickly and easily implemented with netball players in local communities. The need for repeated screening at strategic timepoints across a season/year is explained. Sports physical therapists will find this commentary useful as an example for how to undertake clinical reasoning processes that justify the content of screening procedures contributing to noncontact knee ligament injury prevention in community-level netball.

LEVEL OF EVIDENCE

5.

Influence of State-Level Emergency Planning Policy Requirements on Secondary School Adoption

CONTEXT

Emergency action plans (EAPs) are a critical component in the management of catastrophic sport-related injury. Some state high school athletics associations and state legislation have required that schools develop EAPs, but little research exists on the influence of a statewide policy requirement on local adoption of these policies.

OBJECTIVE

To examine the efficacy of a statewide policy requirement on local adoption of an EAP.

DESIGN

Cross-sectional study.

SETTING

Online questionnaire.

PATIENTS OR OTHER PARTICIPANTS

Secondary school athletic trainers were invited to complete a survey (n = 9642); 1136 completed the survey, yielding an 11.7% response rate.

MAIN OUTCOME MEASURE(S)

Survey responses on the adoption of EAPs along with cardiopulmonary resuscitation and automated external defibrillator (CPR/AED) requirements were cross-referenced with published statewide policies to determine the prevalence of EAP adoption. We evaluated the adoption of emergency action plan components based on the National Athletic Trainers' Association's emergency planning position statement along with CPR/AED requirements to determine component-specific prevalence. We compared the prevalence of EAP and component adoption between states that required EAPs and specific components of EAPs and states without such requirements.

RESULTS

Athletic trainers in states that required adoption of an EAP reported including more components of the emergency planning position statement (mean = 8 ± 4, median = 9) than in states without a requirement (mean = 7 ± 4, median = 8). The adoption of EAP components did not differ between states that required specific components of the EAP versus development of the EAP only. However, schools in states with both EAP and CPR/AED training requirements reported higher rates of CPR/AED training implementation (95.5%) than states that only required CPR/AED training (81.6%, prevalence ratio = 1.10, 95% confidence interval = 1.01, 1.20).

CONCLUSIONS

Based on these data, statewide policy requirements for the development of an EAP may be associated with increasing adoption of EAPs.

Influence of Size and Maturity on Injury in Young Elite Soccer Players

The involvement of pre-adolescents in soccer is becoming more and more frequent, and this growing participation generates some concerns about the potential factors for sports injuries. The purpose of this study was to investigate sports injuries in younger (U9–U11) and older (U12–U13) children playing soccer at an elite level, analyzing potential anthropometric and maturity risk factors. A total of 88 elite soccer players aged 9–13 years were investigated. Weight, stature, and sitting height were measured at the start and at the end of the competitive season, computing the relative growth velocities. Additional body composition parameters were taken during a second survey. Maturity offset was calculated using predictive equations based on anthropometric traits such as years from age at peak height velocity (YPHV). Injuries suffered during the competitive season were recorded. Maturity and some anthropometric characteristics were significantly different according to the presence or absence of injuries among the players. Multiple logistic regression revealed that YPHV, body mass index (BMI), and calf muscle area were the factors most significantly correlated with injuries. Players with increased BMI, with decreased calf muscle area, and who were closer to their peak height velocity, were at a higher risk of injury. Findings showed that a monitoring program of anthropometric characteristics taking into account the maturational stage needs to be developed to prevent injuries.

Motor performance is not related to injury risk in growing elite-level male youth football players. A causal inference approach to injury risk assessment

OBJECTIVE

To identify the causal relation between growth velocity and injury in elite-level youth football players, and to assess the mediating effects of motor performance in this causal pathway.

DESIGN

Prospective cohort study.

METHODS

We measured the body height of 378 male elite-level football players of the U13 to U15 age categories three to four months before and at the start of the competitive season. At the start of the season, players also performed a motor performance test battery, including motor coordination (Körperkoordinationstest für Kinder), muscular performance (standing broad jump, counter movement jump), flexibility (sit and reach), and endurance measures (YoYo intermittent recovery test). Injuries were continuously registered by the academies' medical staff during the first two months of the season. Based on the causal directed acyclic graph (DAG) that identified our assumptions about causal relations between growth velocity (standardized to cm/y), injuries, and motor performance, the causal effect of growth velocity on injury was obtained by conditioning on maturity offset. We determined the natural indirect effects of growth velocity on injury mediated through motor performance.

RESULTS

In total, 105 players sustained an injury. Odds ratios (OR) showed a 15% increase in injury risk per centimetre/year of growth velocity (1.15, 95%CI: 1.05-1.26). There was no causal effect of growth on injury through the motor performance mediated pathways (all ORs were close to 1.0 with narrow 95%CIs).

CONCLUSIONS

Growth velocity is causally related to injury risk in elite-level youth football players, but motor performance does not mediate this relation.

Sports injuries and illnesses at the Lausanne 2020 Youth Olympic Winter Games: a prospective study of 1783 athletes from 79 countries

OBJECTIVE

To describe the injury and illness characteristics among participating athletes during the Lausanne 2020 Youth Olympic Winter Games (YOG 2020), 9-22 January 2020.

METHODS

The daily number of athlete injuries and illnesses were recorded (1) through the reporting of all National Olympic Committee (NOC) medical teams and (2) in the polyclinic and medical venues by the Lausanne 2020 medical staff.

RESULTS

In total, 1783 athletes from 79 NOCs were observed. NOC and Lausanne 2020 medical staff reported 228 injuries and 167 illnesses, equating 11.7 injuries and 8.6 illnesses per 100 athletes over the 14-day period. Injury incidence was highest for snowboard slopestyle (39%), bobsleigh (36%), snowboard big air (29%), ski slopestyle (29%), snowboard cross (24%) and ski cross (21%), and lowest for speed skating, snowboard halfpipe and curling (2%-4%). The highest incidence of illness was recorded for curling (21%), ski mountaineering (15%), snowboard halfpipe (13%), bobsleigh (11%), cross-country skiing (10%) and figure skating (10%). Almost one-third of injuries were expected to result in time loss and 17% of illnesses. Most injuries occurred to the knee (12%) and head (11%), and 64% of illnesses affected the respiratory system. Overall, women suffered more injuries and illness than males.

CONCLUSION

Overall, injury and illness rates were similar compared with recent YOG. While the rate and characteristics of injury and illness varied between sports, consistent patterns across YOG are emerging. If addressed, changes in highlighted areas of risk could have a positive impact on the health and well-being of these young athletes.

The Effects of Body Mass Index on Softball Pitchers' Hip and Shoulder Range of Motion

Currently it is hypothesized that increased body mass index may contribute to overuse injuries. Thus, if hip or shoulder range of motion is affected by body mass index, pitchers may be placing additional stress on joints as they seek to pitch at maximal velocity. The purpose of this study was to examine if range of motion at the hips and shoulders were related to body mass index classification. A sample of 147 female softball pitchers (17.0±4.2 years; 167.6±11.8 cm; 70.6±17.5 kg; body mass index=24.8±4.7 kg/m ² ) participated. Bilateral hip and shoulder range of motion were assessed. Multivariate analysis of variance results indicated body mass index [Wilks’ Λ =0.742, F=1.722, p=0.014, η ² =0.095] significantly affected range of motion of the shoulder and hip. Post hoc results indicated the underweight group had significantly more range of motion than the obese group in hip internal range of motion on both the throwing side (mean difference=12.39, p=0.005) and glove side (mean difference=11.98, p=0.004). Although body composition is not overly emphasized among softball pitchers, the current study reveals excess weight may inhibit proper mechanics. Coaches, athletic trainers, strength and conditioning personnel, and athletes should acknowledge the role that body composition can play in affecting pitch outcomes.

Enduro World Series (EWS) Mountain Biking Injuries: A 2-year Prospective Study of 2010 Riders

The sport of Enduro is the newest International Cycling Union sanctioned discipline in mountain biking. There are a number of studies reporting mountain biking injury to date however there are none detailing injuries in Enduro. The aim of the present study was to determine the rate, severity and nature of rider injury during the Enduro World Series. Rider injury, and race and practice exposure data were recorded prospectively during 10 events across the 2017 and 2018 seasons. Incorporating 2010 riders (males 90%; females 10%) from 46 countries. 8.9% of riders were injured with mean 12.3 days time-loss per injury. Racing injury incidence was 38.3/1000 hours and practice injury incidence 3.6/1000 hours (p=0.01). The shoulder/clavicle (12.8% of all injuries), hand (9.0%) and head (9.0%) were the most injured locations. Concussion injury was the most frequent diagnosis (7.4%), and shoulder/clavicle fractures caused the greatest burden (442 total days lost). Of those with concussion 28.6% continued racing, and 42.9% reported no time-loss (i. e. time off) post-race. In conclusion, the rate of injury during EWS race events was comparable to Downhill racing. Targeted injury prevention strategies around rider concussion education and rider qualification criteria may help to reduce the risk of injury in Enduro.

Lower limb MSK injuries among school-aged rugby and football players: a systematic review

OBJECTIVE

The objective of this systematic review was to explore the incidence of lower limb musculoskeletal (MSK) injuries sustained by rugby union, rugby league, soccer, Australian Rules and Gaelic football players under 18 years. The review sought to identify the mechanisms and types of injury sustained and to compare between sports.

DESIGN

This systematic review focused on the incidence of lower limb injury in adolescent team sports that involved running and kicking a ball. A literature search of studies published prior to January 2020 was conducted using SportDiscus, Medline and PubMed databases. The Standard Quality Assessment Criteria appraisal tool was used to assess the quality of each article included in the review. Two or more authors independently reviewed all papers.

RESULTS

Sixteen papers met the inclusion criteria; prospective cohort (N=14), retrospective (n=1) and longitudinal (n=1). These studies investigated injuries in rugby union and rugby league (n=10), football (soccer) (n=3), Australian Rules (n=2) and Gaelic football (n=1). There were a total of 55 882 participants, aged 7-19 years old, who reported 6525 injuries. The type, site and mechanisms of injury differed across sports.

SUMMARY

Lower limb injuries were common in adolescent rugby, soccer, Gaelic football and Australian Rules football players, however these studies may not fully reflect the true injury burden where recurrent and overuse injuries have not been considered. There were differences between sports in the mechanisms, types and severity of injury.

Workload a-WEAR-ness: Monitoring Workload in Team Sports With Wearable Technology. A Scoping Review

OBJECTIVES

To (1) identify the wearable devices and associated metrics used to monitor workload and assess injury risk, (2) describe the situations in which workload was monitored using wearable technology (including sports, purpose of the analysis, location and duration of monitoring, and athlete characteristics), and (3) evaluate the quality of evidence that workload monitoring can inform injury prevention.

DESIGN

Scoping review.

LITERATURE SEARCH

We searched the CINAHL, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Embase, HealthSTAR, MEDLINE, PsycINFO, SPORTDiscus, and Web of Science databases.

STUDY SELECTION CRITERIA

We included all studies that used wearable devices (eg, heart rate monitor, inertial measurement units, global positioning system) to monitor athlete workload in a team sport setting.

DATA SYNTHESIS

We provided visualizations that represented the workload metrics reported, sensors used, sports investigated, athlete characteristics, and the duration of monitoring.

RESULTS

The 407 included studies focused on team ball sports (67% soccer, rugby, or Australian football), male athletes (81% of studies), elite or professional level of competition (74% of studies), and young adults (69% of studies included athletes aged between 20 and 28 years). Thirty-six studies of 7 sports investigated the association between workload measured with wearable devices and injury.

CONCLUSION

Distance-based metrics derived from global positioning system units were common for monitoring workload and are frequently used to assess injury risk. Workload monitoring studies have focused on specific populations (eg, elite male soccer players in Europe and elite male rugby and Australian football players in Oceania). Different injury definitions and reported workload metrics and poor study quality impeded conclusions regarding the relationship between workload and injury. J Orthop Sports Phys Ther 2020;50(10):549-563. doi:10.2519/jospt.2020.9753.

LOW BACK PAIN AND INJURY IN BALLET, MODERN, AND HIP-HOP DANCERS: A SYSTEMATIC REVIEW

Background

Low back pain is believed to be a common complaint among dancers; however, a comparison across recent research is needed to support or disprove this assertion across genres.

Purpose

To determine the prevalence of low back pain and low back injury in ballet, modern, and hip-hop dancers through a systematic literature review. A secondary goal was to identify trends amongst dance genres, level of mastery, gender, and age, if possible.

Study Design

Systematic Review of the Literature.

Methods

PRISMA search strategy of terms relating to dance and low back pain was conducted within the Pubmed, MEDLINE, SPORTDiscus, Web of Science, and the archives of the Journal of Dance Medicine and Science databases between November 2017 and March 2018. Inclusion criteria were published articles that addressed low back pain or injury in ballet, modern, or hip-hop dance population. Exclusion criteria included studies relating to specific pathologies or studies that did not report specific dance genre. All included articles were assessed for quality using a modified grading evaluation and a Modified Newcastle-Ottawa Risk of Bias assessment.

Results

Twenty-five ballet articles, five modern, and three hip-hop articles met the inclusion criteria, for a total of 33 articles. Twenty-five of the 33 studies relied on a questionnaire to gather data. Risk of bias results ranged from 3-7/10 and quality of studies ranged from Good I to Limited III. Prevalence of low back pain seems relatively high in ballet dance (range: 20.3%-79% of total dancers are affected). Little research exists on the prevalence of back pain in modern or hip-hop dancers, but hip-hop dancers also seem likely to have low back pain (range: 46.6%-85.7% of total dancers are affected). Low back injuries are also present in ballet (range: 2.1%-88% of total injuries), modern (range: 8.6%-21.6% of total injuries), and hip-hop (range: 26.3%-69.6%).

Conclusion

Ballet dancers seem to be at risk for low back pain or injury independent of gender, age or level of mastery; however, there is not enough evidence to draw any conclusions about modern dancers or hip-hop dancers and their risk for low back pain/injury currently. Future higher-level studies are needed with reduced risk of bias.

Level of Evidence

2a.