Reducing musculoskeletal injury and concussion risk in schoolboy rugby players with a pre-activity movement control exercise programme: a cluster randomised controlled trial

Sport-Related Concussions in High School Athletes: A Comprehensive Update

PURPOSE OF REVIEW

Sport-related concussions (SRC) in high school athletes are a growing public health concern, with recent advancements in epidemiology, pathophysiology, diagnosis, management, and prevention. We concisely summarize SRC in high school athletes, emphasizing current research and clinical implications.

RECENT FINDINGS

Athletes are at significant risk of SRCs, with incidence varying by sport, sex, and competitive setting. Advances in pathophysiology highlight the role of metabolic disruption, inflammation, and axonal injury. Updated diagnostic tools, such as SCAT6, aid clinical evaluation, while advanced neuroimaging and biomarkers remain investigational. Return-to-sport/learn protocols emphasize a gradual, stepwise return. Preventative measures, including policy changes, neuromuscular training, and protective equipment, have reduced SRC incidence. Comprehensive SRC management includes recognition and removal from play followed by a structured return to sport/learning. Future research directions include biomarker validation, optimized prevention strategies, and long-term outcome assessment to reduce the burden of SRC in adolescent athletes.

Prevalence of Chronic Traumatic Encephalopathy in Athletes With Repetitive Head Impacts: A Systematic Review and Meta-Analysis

Chronic traumatic encephalopathy (CTE) is a neurodegenerative disorder associated with repetitive head impacts (RHI), which is commonly observed in athletes participating in contact sports. This systematic review and meta-analysis aimed to provide a clearer elucidation of the prevalence, risk factors, and potential outcomes of CTE in athletes. Through a comprehensive search of PubMed, EMBASE, Web of Science, and Google Scholar (January 2015 to July 2024), we ultimately included eight eligible studies with a low risk of bias involving 1000 former contact sports athletes diagnosed by neuropathological methods. Data were analyzed in a random-effects meta-analysis. The results indicated that the pooled prevalence of CTE in contact sport athletes was 53.7% (95% CI: 37.6-69.5, I2 = 93.7%). Subgroup analyses revealed that rugby players exhibited the highest prevalence at 64.7% (95% CI: 48.5-79.5, I2 = 0%), followed by American football players at 53.0% (95% CI: 33.2-72.4, I2 = 92.9%). By participation level, the prevalence was estimated at 44.1% (95% CI: 29.6-59.1, I2 = 84.5%) in amateur athletes and 72.8% (95% CI: 50.9-90.5, I2 = 91.6%) in elite athletes. Notably, the suicide rate among individuals diagnosed with CTE was 39.0% (95% CI: 12.7-69.0, I2 = 94.4%), and the pooled prevalence of CTE in non-suicidal athletes was 30.1% (95% CI: 6.9-60.4, I2 = 97.8%). These findings reveal the high prevalence of CTE in contact sport athletes exposed to RHI, especially at elite-level competition, and emphasize suicide as a potential outcome. Further studies should incorporate more female athletes to comprehensively assess the risk factors, outcomes, and effective prevention strategies for CTE.

Is It All in Your Head? Placebo Effects in Concussion Prevention

Sports-related concussions (SRCs) are a major health issue in athletes of varying ages, ability levels, and sports. Concerns over the short- and long-term consequences of SRCs have incentivized a wealth of products and policies aimed at reducing SRC risk. Research suggesting the effectiveness of such interventions at reducing SRCs has facilitated their adoption by sports organizations and, in some cases, product commercialization. However, the body of SRC mitigation research is almost entirely devoid of placebo or sham groups, which raises important questions about the true clinical effectiveness of these interventions. This Current Opinion explores the plausibility of placebo effects within the scope of SRC prevention, describes why the lack of placebo/sham groups in the current body of literature is problematic, and provides recommendations for including placebo/sham groups in future SRC research.

What do coaches want? Exploring the preferences of youth rugby union coaches for education in the implementation of injury prevention programmes

OBJECTIVE

To explore youth Rugby Union coaches' preferences for education and support in the implementation of injury prevention programmes (IPPs).

METHODS

Twelve Rugby Union coaches involved with youth teams participated in five online focus groups. Conventional content analysis was used to determine preferences initially from transcripts, and thereafter main categories, generic categories and sub-categories.

RESULTS

Coach preferences were organised into three main categories: 'formal/non-formal learning', 'informal learning', and 'intrapersonal considerations'. The generic categories of 'logistics', 'content' and 'resources' featured substantially in coach preferences for education. Coaches prefer live structured group workshops in the pre-season period, which focus on the development of implicit knowledge. To do this, coaches prefer practical opportunities for coaching within the education session. In support of this education, coaches want resources (both physical and video) which assist in session planning.

CONCLUSIONS

The preferences of youth Rugby Union coaches towards IPP education and support are similar to that of other coaching domains. A live practical workshop held in the pre-season is preferred, although facilitator preferences varied. A mismatch is evident between coach preferences for IPP education and what is currently being offered through NGB coach education therefore further exploration of NGB perspectives is warranted.

Efficacy of exercise interventions on prevention of sport-related concussion and related outcomes: a systematic review and meta-analysis

OBJECTIVE

To review the efficacy of exercise interventions on sport-related concussion (SRC) incidence, as well as on linear and rotational head accelerations, and isometric neck strength and to assess reporting completeness of exercise interventions using the Consensus on Exercise Reporting Template (CERT).

DESIGN

Systematic review and meta-analysis, according to the Prisma in Exercise, Rehabilitation, Sport medicine and SporTs science guidelines.

DATA SOURCES

Six databases (MEDLINE, Embase, CINAHL, Scopus, Web of Science CC and SPORTDiscus) were searched up to 26 June 2023.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Randomised controlled trials (RCTs), cluster RCTs or quasi-experimental studies, evaluating exercise interventions on SRC incidence, linear and rotational head accelerations, and/or isometric neck strength in male and/or female athletes of any age, and/or in a healthy general population.

RESULTS

A total of 26 articles were included. A large effect size was observed for resistance training (RT) on isometric neck strength (standardised mean difference (SMD) 0.85; 95% CI 0.57 to 1.13; high-quality evidence). Non-significant effect sizes were observed for neuromuscular warm-up programmes on SRC incidence (risk ratio 0.69; 95% CI 0.39 to 1.23; low-quality evidence), or for RT on linear head acceleration (SMD -0.43; 95% CI -1.26 to 0.40; very low-quality evidence) or rotational head acceleration (SMD 0.08; 95% CI -0.61 to 0.77; low-quality evidence). No studies assessed the impact of RT on SRC incidence. CERT scores ranged from 4 to 16 (out of 19) with median score of 11.5 (IQR 9-13).

CONCLUSION

RT increases isometric neck strength, but the effect on SRC incidence is unknown. More adequately powered and rigorous trials are needed to evaluate the effect of exercise interventions on SRC incidence, and on linear and rotational head accelerations. Future studies should follow CERT guidelines, as the included interventions were generally not reported in sufficient detail for accurate replication.

PROSPERO REGISTRATION NUMBER

CRD42023435033.

A systematic review and network meta-analysis on the effectiveness of exercise-based interventions for reducing the injury incidence in youth team-sport players. Part 1: an analysis by classical training components

OBJECTIVES

The primary purposes were (a) to estimate the pooled effects of injury prevention programs (IPPs) on reducing overall and some specific body regions (lower extremity, thigh, knee, and ankle) injury incidence rates (IIRs) and (b) to compare the effects of single- and multi-component IPPs on mitigating injury risk in youth team sport athletes. A secondary objective was to explore the individual effects of different components on these IIRs.

MATERIALS AND METHODS

Searches were performed up to 15 January 2024 in PubMed, Web of Science, SPORTDiscus, and Cochrane Library. Eligible criteria were: exercise-based interventions evaluated against a control group, overall IIRs were reported, and youth (≤19 years old) team sport players. Two reviewers extracted data and assessed trial quality using the Consolidated Standards of Reporting Trials (CONSORT) statement, the Physiotherapy Evidence Database Scale (PEDro), and a risk of bias tool (Cochrane Back and Neck Group). Pooled effects were calculated by Frequentist random effects pairwise and network meta-analyses.

RESULTS

Twenty-one studies were included. IPPs reduced overall, lower extremities, thigh, knee, and ankle IIRs by an average of approximately 35%. Most of the IPPs demonstrated statistically significant risk mitigation effects for overall and lower extremity injuries compared to control group. Interventions comprised exclusively of strength ([IRR = 0.3 [95%CI = 0.10-0.93]) and flexibility (IRR = 0.49 [95%CI = 0.36-0.68]), as well as those including stability exercises, were the most effective measures for reducing injuries in youth team sports.

CONCLUSIONS

The implementation of current IPPs in training sessions for several weeks has shown to be an effective strategy for reducing the risk of injury in youth team sport athletes by one-third. Indirect evidence suggests that strength, flexibility, and stability might be exercise components with the highest risk mitigation effects; however, more research is crucial to confirm our estimates with direct evidence.

A systematic review and network meta-analysis on the effectiveness of exercise-based interventions for reducing the injury incidence in youth team-sport players. Part 2: an analysis by movement patterns

The objectives of this network meta-analysis were: (a) to estimate and compare the pooled effects of some injury prevention programs (IPPs) whose exercise-based components were categorized using a movement pattern-specific taxonomy on reducing overall and some specific body regions (lower extremity, thigh, knee, and ankle) injury incidences in youth team sport athletes and (b) to explore the individual effects of these components on the injury incidence rates (IIRs) previously mentioned. Searches were performed in PubMed, Web of Science, SPORTDiscus, and Cochrane Library. Eligible criteria were: exercise-based interventions comprised of exercises involving athletic motor skill competencies and evaluated against a control group, overall IIRs were reported, and youth (≤19 years old) team sport players. For the current analysis, a taxonomy based on movement patterns was employed for exercise component identification (upper body pushing and pulling; lower body concentric and eccentric; core; mechanics; acceleration; and lower body stability). Pooled effects were calculated by frequentist random effects pairwise and network meta-analyses. Nineteen studies were included. Most of the IPPs exhibit risk reduction when compared to their control groups on overall, lower extremity, and ankle injuries. Interventions comprised of lower body concentric and eccentric, core, mechanics, and lower body stability exercises were the most effective measures for reducing these injuries. None of the IPPs demonstrated to be effective for reducing thigh injuries, and contradictory results were found for knee injuries. Individual analysis at component level revealed that the lower body (bilateral and unilateral, concentric, and eccentric) component was the only one associated with a significant reduction on overall injuries. Indirect evidence suggests that interventions incorporating lower body concentric and eccentric, core, mechanics, and lower body stability exercises might be the most effective for reducing overall, lower extremity, and ankle injuries in youth team sports.

Perceptual Response Training for Reduction of Injury Risk Among High School Girls' Soccer Players

Background/Objectives: Neural processes involved in visual detection, decision-making, and motor plan execution are believed to play a key role in the avoidance of sport-related injuries, but very little evidence exists to guide the development of training activities for the optimization of brain function. Immersive virtual reality provides a means to precisely measure the amount of time that elapses from visual stimulus presentation to the initiation of a motor response (i.e., perceptual latency) or its completion (i.e., response time). Methods: The median value of a metric quantifying both the speed and accuracy (i.e., the rate correct per second of response time) of 50 high school female soccer players was used to assign those who exhibited suboptimal performance to a training program. Training sessions required less than 5 min and the number of sessions completed over a 7-week period ranged from 3 to 13 (median = 5). Results: Among 42 players available for follow-up assessment at 8 weeks after the first practice session (training n = 19; comparison n = 23), the results of regression-discontinuity analyses demonstrated statistically significant differences (p < 0.05) for metrics representing fast/accurate movement initiation (i.e., the rate correct score for perceptual latency, p = 0.016) and across-trial consistency (i.e., perceptual latency variability, p = 0.027). From the first practice session to the end of the soccer season, 12 injuries were sustained by 10 players (four concussions and eight musculoskeletal injuries). A time-to-event analysis demonstrated strong associations with perceptual latency variability ≥ 0.143 (Hazard Ratio = 15.43, p = 0.011) and a lifetime history of at least one concussion (Hazard Ratio = 8.84, p = 0.008). Conclusions: The strong association of movement initiation consistency with the avoidance of concussion or musculoskeletal injury suggests that the training program may have a highly beneficial far-transfer effect.

Effect of supervision and athlete age and sex on exercise-based injury prevention programme effectiveness in sport: A meta-analysis of 44 studies

We aimed to evaluate the influence of supervision, athlete age and sex and programme duration and adherence on exercise-based injury prevention programme effectiveness in sport. Databases were searched for randomized controlled trials evaluating exercise-based injury prevention programme effectiveness compared to "train-as-normal". A random effects meta-analysis for overall effect and pooled effects by sex and supervision and meta-regression for age, intervention duration and adherence were performed. Programmes were effective overall (risk ratio (RR) 0.71) and equally beneficial for female-only (0.73) and male-only (0.65) cohorts. Supervised programmes were effective (0.67), unlike unsupervised programmes (1.04). No significant association was identified between programme effectiveness and age or intervention duration. The inverse association between injury rate and adherence was significant (β=-0.014, p = 0.004). Supervised programmes reduce injury by 33%, but there is no evidence for the effectiveness of non-supervised programmes. Females and males benefit equally, and age (to early middle age) does not affect programme effectiveness.

Instrumented mouthguards in elite-level men's and women's rugby union: characterising tackle-based head acceleration events

Objectives

To examine the propensity of tackle height and the number of tacklers that result in head acceleration events (HAEs) in elite-level male and female rugby tackles.

Methods

Instrumented mouthguard data were collected from women (n=67) and men (n=72) elite-level rugby players from five elite and three international teams. Peak linear acceleration and peak angular acceleration were extracted from HAEs. Propensities for HAEs at a range of thresholds were calculated as the proportion of tackles/carries that resulted in an HAE exceeding a given magnitude for coded tackle height (low, medium, high) and number of tacklers. Propensity ratios with 95% CIs were calculated for tackle heights and number of tacklers.

Results

High tackles had a 32.7 (95% CI=6.89 to 155.02) and 41.2 (95% CI=9.22 to 184.58) propensity ratio to cause ball carrier HAEs>30 g compared with medium tackles for men and women, respectively. Low tackles had a 2.6 (95% CI=1.91 to 3.42) and 5.3 (95% CI=3.28 to 8.53) propensity ratio to cause tackler HAEs>30 g compared with medium tackles for men and women, respectively. In men, multiple tacklers had a higher propensity ratio (6.1; 95% CI=3.71 to 9.93) than singular tacklers to cause ball carrier HAEs>30 g but a lower propensity ratio (0.4; 95% CI=0.29 to 0.56) to cause tackler HAEs>30 g. No significant differences were observed in female tacklers or carriers for singular or multiple tacklers.

Conclusion

To limit HAE exposure, rule changes and coaching interventions that promote tacklers aiming for the torso (medium tackle) could be explored, along with changes to multiple tackler events in the male game.

High school rugby coaches' knowledge and opinions of concussion in Kwa-Zulu Natal province in South Africa: an ecological cross-sectional study

BACKGROUND

Concussions in Rugby Union are common with an increased risk to adolescent players. Coaches are key to injury prevention and a greater understanding of their knowledge and sentiments may guide future initiatives. There is a lack of data on rugby coaches, especially in South Africa. This study aimed to investigate the knowledge and opinions of high school rugby coaches regarding concussion management.

METHODS

This cross-sectional study of 37 high school rugby coaches in South Africa, was conducted via a self-reported questionnaire. Concussion knowledge was scored for correct answers only with closed-question scaling methods to measure the importance of items of concussion management using a graphical rating scale. An attitude scale (Likert) was used to assess self-reported opinions and behaviours. Associations were calculated for participant characteristics and overall concussion injury knowledge.

RESULTS

More participants showed good overall knowledge of ≥ 75% (n = 22, 59% vs. n = 15, 40%), especially those with greater coaching experience (p = 0.021). Player welfare was perceived more important than player performance (185 vs. 164), with concussion prevention most important (184 of 185). Appealing characteristics of an injury prevention programme were the improvement of player skill (173, SD ± 0.75, mean 4.68), being adaptable (171, ± 0.86, 4.62), and being completed in the warm-up (167, ± 0.93, 4.51). The biggest perceived barriers were duration (138, ± 1.59, mean 3.73), effort (130, ± 1.56, 3.51), compliance and lack of knowledge (both 127, ± 1.68, 3.43).

CONCLUSION

These results support the implementation of ongoing concussion education for rugby coaches and identify areas for promoting awareness and knowledge of concussion injury prevention, identification, and specific management of younger athletes. Appealing characteristics and barriers are highlighted and may allow for improved implementation and adherence to concussion prevention programmes.

Effectiveness of exercise-based sports injury prevention programmes in reducing injury rates in adolescents and their implementation in the community: a mixed-methods systematic review

OBJECTIVE

Despite evidence supporting the efficacy of sport injury prevention programmes (SIPPs) in adolescents, implementation of SIPPs in community settings is low. This review aims to synthesise and integrate evidence on the efficacy of exercise-based SIPPs in reducing injury rates in adolescents with implementation strategies for such programmes in the community.

DESIGN

A systematic review with meta-analysis, narrative synthesis and meta-aggregation was conducted, followed by a convergent segregated approach to integrate the findings. Sensitivity and subgroup analyses were conducted. Study appraisal was performed using Joanna Briggs Institute Critical Appraisal Checklists and Mixed Methods Appraisal Tool.

DATA SOURCES

Literature search of nine databases was carried out to identify studies in English from January 2012 to December 2022.

ELIGIBILITY CRITERIA

Included were randomised controlled trials (RCTs), qualitative or mixed-methods studies. Population included adolescents (10-19 years). Interventions included SIPPs. Outcomes were injury rate and rate ratio (IRR). Phenomena of interest were facilitators and barriers to the implementation of SIPPs.

RESULTS

23 studies were included for analysis. Meta-analysis for 16 RCTs showed a protective effect of SIPP (IRR 0.63, 95% CI 0.53 to 0.74, p<0.00001) in adolescents. Meta-aggregation of seven qualitative/mixed-method studies revealed four sets of synthesised findings that impact implementation namely players' perceptions and beliefs, coaches as key facilitators, organisational support and characteristics of the SIPP.

CONCLUSION

Implementation of SIPPs provides a 37% risk reduction in adolescents but requires targeting key stakeholders through a top-down multifaceted approach for its efficacy to be translated. Future research should investigate the effectiveness of SIPPs and implementation strategies in adolescents in community settings.

Best practices for the dissemination and implementation of neuromuscular training injury prevention warm-ups in youth team sport: a systematic review

OBJECTIVE

To evaluate best practices for neuromuscular training (NMT) injury prevention warm-up programme dissemination and implementation (D&I) in youth team sports, including characteristics, contextual predictors and D&I strategy effectiveness.

DESIGN

Systematic review.

DATA SOURCES

Seven databases were searched.

ELIGIBILITY

The literature search followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

INCLUSION CRITERIA

participation in a team sport, ≥70% youth participants (<19 years), D&I outcomes with/without NMT-related D&I strategies. The risk of bias was assessed using the Downs & Black checklist.

RESULTS

Of 8334 identified papers, 68 were included. Sport participants included boys, girls and coaches. Top sports were soccer, basketball and rugby. Study designs included randomised controlled trials (RCTs) (29.4%), cross-sectional (23.5%) and quasi-experimental studies (13.2%). The median Downs & Black score was 14/33. Injury prevention effectiveness (vs efficacy) was rarely (8.3%) prioritised across the RCTs evaluating NMT programmes. Two RCTs (2.9%) used Type 2/3 hybrid approaches to investigate D&I strategies. 19 studies (31.6%) used D&I frameworks/models. Top barriers were time restrictions, lack of buy-in/support and limited benefit awareness. Top facilitators were comprehensive workshops and resource accessibility. Common D&I strategies included Workshops with supplementary Resources (WR; n=24) and Workshops with Resources plus in-season Personnel support (WRP; n=14). WR (70%) and WRP (64%) were similar in potential D&I effect. WR and WRP had similar injury reduction (36-72%) with higher adherence showing greater effectiveness.

CONCLUSIONS

Workshops including supplementary resources supported the success of NMT programme implementation, however, few studies examined effectiveness. High-quality D&I studies are needed to optimise the translation of NMT programmes into routine practice in youth sport.

Neck strength alone does not mitigate adverse associations of soccer heading with cognitive performance in adult amateur players

OBJECTIVES

Soccer heading is adversely associated with neurocognitive performance, but whether greater neck strength or anthropometrics mitigates these outcomes is controversial. Here, we examine the effect of neck strength or anthropometrics on associations of soccer heading with neurocognitive outcomes in a large cohort of adult amateur players.

METHODS

380 adult amateur league soccer players underwent standardized measurement of neck strength (forward flexion, extension, left lateral flexion, right lateral flexion) and head/neck anthropometric measures (head circumference, neck length, neck circumference and neck volume). Participants were assessed for heading (HeadCount) and cognitive performance (Cogstate) on up to 7 visits over a period of two years. Principal components analysis (PCA) was performed on 8 neck strength and anthropometric measures. We used generalized estimating equations to test the moderation effect of each of the three PCs on 8 previously identified adverse associations of 2-week and 12-month heading estimates with cognitive performance (psychomotor speed, immediate verbal recall, verbal episodic memory, attention, working memory) and of unintentional head impacts on moderate to severe central nervous system symptoms.

RESULTS

3 principal components (PC's) account for 80% of the variance in the PCA. In men, PC1 represents head/neck anthropometric measures, PC2 represents neck strength measures, and PC3 represents the flexor/extensor (F/E) ratio. In women, PC1 represents neck strength, PC2 represents anthropometrics, and PC3 represents the F/E ratio. Of the 48 moderation effects tested, only one showed statistical significance after Bonferroni correction, which was not robust to extensive sensitivity analyses.

CONCLUSION

Neither neck strength nor anthropometrics mitigate adverse associations of soccer heading with cognitive performance in adult amateur players.

A Profile of Isometric Cervical Strength in Elite Professional Male Rugby Players

OBJECTIVES: To (1) provide position-specific normative data for isometric cervical muscle strength and endurance in professional, male rugby players and (2) assess the relationship between age, height, weight, and playing position with cervical muscle strength and endurance. DESIGN: Cross-sectional study. METHODS: Professional rugby players completed peak isometric cervical strength testing followed by a test of cervical muscle endurance. Descriptive statistics for continuous variables with strength normalized to body weight were performed. Multiple linear regression was used to estimate associations between strength measurements. RESULTS: In total, 136 players participated including front-row forwards (27%), other forwards (28%), and backs (45%). Front-row forwards had significantly greater peak isometric cervical muscle strength than other position groups, with backs having the lowest strength. Extension produced the highest force for all 3 position groups (429 N ± 104 N), whereas flexion produced the least (275 N ± 65 N). Age was associated with increased isometric cervical muscle strength. There was a statistically significant relationship between peak flexion strength and flexion endurance (P = .003). The average time for the endurance tests were 55.7 (±17.1) seconds and 52.9 (±20.1) seconds for extension and flexion, respectively. Other forwards had lower cervical extension muscle endurance than backs and front-row forwards. CONCLUSIONS: Normative values for peak and endurance isometric strength in professional rugby players illustrate significant differences between playing position. Consider age, body weight, and intraindividual variability when interpreting cervical strength and endurance results. J Orthop Sports Phys Ther 2024;54(3):1-8. Epub 29 January 2024. doi:10.2519/jospt.2024.11830.

Coaches of youth field sports as delivery agents of injury prevention programmes: how are we training the trainers? A scoping review

OBJECTIVE

To systematically map the coach education (CE) component of injury prevention programmes (IPPs) for youth field sports by identifying and synthesising the design, content and facilitation strategies used to address competency drivers and behaviour change.

DESIGN

Scoping review.

DATA SOURCES

PubMed, PsycInfo, EMBASE, CINAHL, SportDiscus and Google Scholar electronic databases were searched using keywords related to IPPs and youth field sports.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies of IPPs in youth field sports, that provided 'train-the-trainer' education to coaches as designated delivery agents.

RESULTS

20 studies from two field sports (soccer/football; n=17, Rugby Union; n=3) fulfilled the eligibility criteria. Eleven CE interventions occurred in the preseason and 18 occurred at one time-point (single day). Five studies cited use of a behavioural change theory or model in the design of their CE, most frequently the Health Action Process Approach model (n=5); and use of behavioural change techniques varied. Twelve of twenty studies (60%) reported some form of ongoing support to coaches following the CE primary intervention concurrent with IPP implementation.

CONCLUSION

CE that occurs on 1 day (one time-point) is most popular for preparing coaches as delivery agents of IPPs in youth field sports. While recognising pragmatic barriers, more expansive in-service training, support and feedback may enhance the effective implementation of IPPs.

TRIAL REGISTRATION NUMBER

https://doi.org/10.17605/OSF.IO/FMHGD.

Match injuries in English schoolboy rugby union

Objective

This study describes the incidence, severity and burden of match injuries in schoolboy rugby union in England, across three age groups: under-13 (U13), under-15 (U15) and under-18 (U18).

Methods

Data regarding 574 24-hour time-loss match injuries and 18 485 player-hours of match exposure were collected from a total of 35 schools (66 teams) in the 2017/18, 2018/19 and 2019/20 seasons. Injury incidence (injuries/1000 hours), severity (mean and median days lost) and burden (days lost/1000 hours) were calculated for each age group, injury region, event, playing position and match period and were compared using Z scores.

Results

The U18 age group had a significantly higher injury incidence (34.6 injuries/1000 hours, 95% CI 31.5 to 38.1) and burden (941 days/1000 hours, 95% CI 856 to 1035) than both the U13 (incidence=20.7 injuries/1000 hours, 95% CI 14.1 to 30.3, p=0.03; burden=477 days lost/1000 hours, 95% CI 325 to 701, p<0.01) and U15 (incidence=24.6 injuries/1000 hours, 95% CI 20.6 to 29.5, p<0.01; burden=602 days lost/1000 hours, 95% CI 503 to 721, p<0.01) age groups, but no significant differences were found between the U13 and U15 age groups. Contact events accounted for 87% of known injury events, with the tackle responsible for 52% (U13), 48% (U15) and 62% (U18) of all injuries. Concussion was the most common injury type in all age groups (U13=4.8 injuries/1000 hours; U15=6.4 injuries/1000 hours; U18=9.2 injuries/1000 hours), but the incidence was not significantly different between age groups.

Conclusion

Injury incidence and burden was higher in U18 than U13 and U15 age groups. Concussions and the tackle are priority areas at all age groups and should be the focus of injury prevention strategies.

Pediatric Sport-Related Concussion: Recommendations From the Amsterdam Consensus Statement 2023

The 6th International Consensus Conference on Concussion in Sport, Amsterdam 2022, addressed sport-related concussion (SRC) in adults, adolescents, and children. We highlight the updated evidence-base and recommendations regarding SRC in children (5-12 years) and adolescents (13-18 years). Prevention strategies demonstrate lower SRC rates with mouthguard use, policy disallowing bodychecking in ice hockey, and neuromuscular training in adolescent rugby. The Sport Concussion Assessment Tools (SCAT) demonstrate robustness with the parent and child symptom scales, with the best diagnostic discrimination within the first 72 hours postinjury. Subacute evaluation (>72 hours) requires a multimodal tool incorporating symptom scales, balance measures, cognitive, oculomotor and vestibular, mental health, and sleep assessment, to which end the Sport Concussion Office Assessment Tools (SCOAT6 [13+] and Child SCOAT6 [8-12]) were developed. Rather than strict rest, early return to light physical activity and reduced screen time facilitate recovery. Cervicovestibular rehabilitation is recommended for adolescents with dizziness, neck pain, and/or headaches for greater than 10 days. Active rehabilitation and collaborative care for adolescents with persisting symptoms for more than 30 days may decrease symptoms. No tests and measures other than standardized and validated symptom rating scales are valid for diagnosing persisting symptoms after concussion. Fluid and imaging biomarkers currently have limited clinical utility in diagnosing or assessing recovery from SRC. Improved paradigms for return to school were developed. The variable nature of disability and differences in evaluating para athletes and those of diverse ethnicity, sex, and gender are discussed, as are ethical considerations and future directions in pediatric SRC research.

Acute effects of an isometric neck warm-up programme on neck performance characteristics and ultrasound-based morphology

OBJECTIVE

Athletic performance can be enhanced immediately after an isometric warm-up, a phenomenon termed post-activation performance enhancement (PAPE). While isometric warm-ups can improve lower extremity sprint and jump performance, neck-specific isometric warm-ups need development and validation for mild traumatic brain disorders and neck pain. This study examined acute effects of isometric warm-ups on neck performance and morphology.

METHODS

Arm 1: Twenty-six adults (13 M:13F) completed neck performance testing before and after a 10-minute neck isometric warm-up or stationary bike (sham) between two visits. Testing included visual-motor reaction time, peak force, rate of force development, force steadiness, and force replication/proprioception measured by a 6-axis load cell. An inclinometer assessed range-of-motion. Paired t-tests and two-way ANOVA examined effects of neck/bike warm-up and interaction effects, respectively. Arm 2: 24 adults (11 M:13F) completed ultrasound scans of cervical muscles: before 20-minute rest (sham), and before/after a 5-min neck isometric warm-up. Longus colli cross-sectional area and sternocleidomastoid/upper trapezius thickness and stiffness, and cervical extensors thickness was assessed. One-way ANOVA compared morphological values at sham, before, and after warm-up. Significance was set at p < 0.05.

RESULTS

Isometric neck warm-up increased rate of force development in flexion (p = 0.022), extension (p = 0.001-0.003), right lateral flexion (p = 0.004-0.032), left lateral flexion (p = 0.005-0.014), while peak force improved only in left lateral flexion (p = 0.032). Lateral flexion range-of-motion increased after neck warm-up (p = 0.003-0.026). Similarly, longus colli cross-sectional area (p = 0.016) and sternocleidomastoid thickness (p = 0.004) increased.

CONCLUSIONS

Increased neck performance characteristics and morphology are likely due to PAPE effects of isometric neck warm-up. For coaches and athletes, simple isometric contractions could be added to existing warm-ups to reduce prevalence, incidence, and severity of mild traumatic brain injuries and neck pain.

Differences in injury and concussion rates in a cohort of Canadian female and male youth Rugby Union: a step towards targeted prevention strategies

OBJECTIVE

To examine differences in match and training musculoskeletal injury and concussion rates and describe mechanisms of concussion while considering previous playing experience in female and male Canadian high school Rugby Union ('rugby') players.

METHODS

A 2-year prospective cohort study was completed in a high school league (n=361 females, 421 player-seasons; n=429 males, 481 player-seasons) in Calgary, Canada over the 2018 and 2019 rugby playing seasons. Baseline testing was completed at the start of each season and injury surveillance and individual player participation through session attendance was documented to quantify individual-level player exposure hours. Injury incidence rates (IRs) and incidence rate ratios (IRRs) were calculated using Poisson regression, offset by player exposure hours and clustered by team.

RESULTS

Overall match IR for females was 62% higher than males (overall IRR=1.62, 95% CI: 1.20 to 2.18) and the overall training IR was twice as high for females (overall IRR=2.15, 95% CI: 1.40 to 3.32). The female match concussion IR was 70% higher than the males (concussion IRR=1.70, 95% CI: 1.08 to 2.69). Females had a 75% greater tackle-related IR compared with males (IRR=1.75, 95% CI: 1.20 to 2.56). Additionally, female tacklers had a twofold greater rate of injury compared with male tacklers (IRR=2.17, 95% CI: 1.14 to 4.14). Previous playing experience was not associated with tackle-related injury or concussion IRs.

CONCLUSION

The rate of injury and concussion was significantly higher in females within this Canadian high school cohort. These results emphasise the need for development, implementation and evaluation of female-specific injury and concussion prevention strategies to reduce injury and concussion in female youth rugby.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

Efficacy of a Neuromuscular Warm-up Program in Reducing the Risk of School Sports Injury among Chinese Children: A Cluster Randomized Controlled Trial

Background

Children who participate in sports have reduced cardiovascular risk, obesity, and type 2 diabetes. However, sports participation also comes with an inherent risk of sports-related injuries.

Purpose

To examine the efficacy of a school-based neuromuscular warm-up program (NWP) in reducing the risk of school sports injury (SSI) in children and the impact of different levels of compliance on the effectiveness of the program.

Study Design

Randomized controlled trial; Level of evidence, 1.

Methods

A total of 421 students from grades 4 to 6 at a single school (age range, 9-14 years) were randomized by grade to an intervention group and a control group. The intervention group participated in a 13-week simplified (8-minute) NWP designed to reduce SSI risk. The control group participated in a standard warm-up of the same length and duration. Exposure, compliance, and injury data were collected via a weekly form. The primary injury outcome was all SSIs. Secondary outcomes included injuries from physical education (PE) and non-PE class, upper and lower extremity injuries, other location injuries, and time-loss injuries. A Poisson regression model using an intent-to-treat analysis was performed to estimate the incidence rate ratio (IRR) for all injuries in the intervention group compared with the control group. To examine the influence of level of compliance, we divided the intervention group into low compliance (participation 1-2 times/wk) and high compliance (participation >2 times/wk) then compared the difference on injury rates (IRs) between these groups and the control group.

Results

There were significant differences between the intervention and control groups regarding all SSIs (IRR, 0.47; 95% CI, 0.23-0.96; P = .038), PE class injuries (IRR, 0.37; 95% CI, 0.14-0.99; P = .048), and other location injuries (IRR, 0.20; 95% CI, 0.05-0.82; P = .025). The compliance analysis revealed that although the low-compliance group was able to reduce the risk of SSIs (IR, 4.43; 95% CI, 2.49-6.37) compared with the control group (IR, 7.60; 95% CI, 5.61-9.59), the high-compliance group produced a better effect in reducing the SSI risk (IR, 1.80; 95% CI, 0.04-3.56).

Conclusion

The simplified NWP used in this study was efficacious in the reduction of SSIs in children.

Registration

ChiCTR2100043875 (Chinese Clinical Trial Registry; http://www.chictr.org.cn).

Epidemiology of International Match Injuries in Scottish Rugby: A Prospective Cohort Study

Fifteen-a-side rugby union ("rugby") is a full-contact sport played separately by men and women, with large injury incidences reported previously. Context specific injury surveillance fulfils governing bodies' duty of care to understand risks to player welfare, yet no contemporary match injury epidemiology studies exist for international players in Scotland. The current study therefore aimed to describe the incidence, severity, burden and nature of match injuries sustained by Scotland's men's and women's national teams. A prospective cohort study of injuries recorded in matches across the 2017/18 and 2018/19 seasons was undertaken, with injury and exposure definitions in line with the international consensus for injury surveillance in rugby. Injury incidence was 120.0 (men) and 166.7/1,000 player match hours (women), injury severity was 12.0 (median) and 31.2 days (mean) for men, and 11.0 (median) and 30.2 days (mean) for women. Injury burden was 3,745 (men) and 5,040 days absence/1,000 player match hours (women). Concussion was the most common specific injury for men (22.5/1,000 hours) and women (26.7/1,000 hours). No statistical differences were found for incidence or severity measures between sexes. Injury incidence was greater than recent Rugby World Cup studies. High incidences of concussion reinforces the need for prevention strategies targeting this injury.

Concussion Rehabilitation and the Application of Ten Movement Training Principles

Concussion awareness continues to grow in all aspects of healthcare, including the areas of prevention, acute care, and ongoing rehabilitation. Most of the concussion research to date has focussed on the challenges around screening and diagnosing what can be a complex mix of brain impairments that overlay with additional pre-existing comorbidities. While we expect further progress in concussion diagnosis, progress also continues to be made around proactive rehabilitation, with the emergence of interventions that can enhance the recovery process, maximise function and independence with a return to study, work, and play. Traditionally, optimal multimodal assessments of concussion have treated the physical, cognitive, and psychological domains of brain injury separately, which supports diagnosis, and informs appropriate follow-up care. Due to the complex nature of brain injury, multimodal assessments direct care toward professionals from many different disciplines including medicine, physiotherapy, psychology, neuropsychology, ophthalmology, and exercise physiology. In addition, these professionals may work in different fields such as sports, neurorehabilitation, vestibular, musculoskeletal, community, vocational, and general practice clinical settings. Rehabilitation interventions for concussions employed in practice are also likely to use a blend of theoretical principles from motor control, cognitive, and psychological sciences. This scale of diversity can make information dissemination, collaboration, and innovation challenging. The Ten Movement Training Principles (MTPs) have been proposed as a usable and relevant concept to guide and support clinical reasoning in neurorehabilitation. When applied to concussion rehabilitation, these same 10 principles provide a comprehensive overview of key rehabilitation strategies for current and future practice. Future collaborations can use these training principles to support clinical and research innovations including the rapid rise of technologies in this growing field of rehabilitation practice.

Injury Rates, Mechanisms, Risk Factors and Prevention Strategies in Youth Rugby Union: What's All the Ruck-Us About? A Systematic Review and Meta-analysis

BACKGROUND

Rugby Union is a collision team sport played globally. Despite this, significant concerns have been raised regarding the sport's safety, particularly in youth players. Given this, a review of injury rates, risk factors and prevention strategies is required across different youth age groups as well as in males and females.

OBJECTIVE

The objective of this systematic review (SR) and meta-analysis was to investigate injury and concussion rates, risk factors and primary prevention strategies in youth rugby.

METHODS

To be included, studies were required to report either rates, risk factors or prevention strategies in youth rugby and to have a randomised controlled trial, quasi-experimental, cohort, case control, or ecological study design. Exclusion criteria included non-peer-reviewed grey literature, conference abstracts, case studies, previous systematic reviews and studies not written in English. Nine databases were searched. The full search strategy and list of sources are available and pre-registered on PROSPERO (Ref: CRD42020208343). Each study was assessed for risk of bias using the Downs and Black quality assessment tool. Meta-analyses were conducted using a DerSimonian Laird random effect model for each age group and sex.

RESULTS

Sixty-nine studies were included in this SR. The match injury rates (using a 24-h time-loss definition) were 40.2/1000 match hours (95% CI 13.9-66.5) in males and 69.0/1000 match hours (95% CI 46.8-91.2) in females. Concussion rates were 6.2/1000 player-hours (95% CI 5.0-7.4) for males and 33.9/1000 player-hours (95% CI: 24.1-43.7) for females. The most common injury site was lower extremity (males) and the head/neck (females). The most common injury type was ligament sprain (males) and concussion (females). The tackle was the most common event associated with injury in matches (55% male, 71% females). Median time loss was 21 days for males and 17 days for females. Twenty-three risk factors were reported. The risk factors with the strongest evidence were higher levels of play and increasing age. Primary injury prevention strategies were the focus of only eight studies and included law changes (n = 2), equipment (n = 4), education (n = 1) and training (n = 1). The prevention strategy with the most promising evidence was neuromuscular training. The primary limitations included a broad range of injury definitions (n = 9) and rate denominators (n = 11) used, as well as a limited number of studies which could be included in the meta-analysis for females (n = 2).

CONCLUSION

A focus on high-quality risk factor and primary prevention evaluation should be considered in future studies. Targeting primary prevention and stakeholder education remain key strategies in the prevention, recognition and management of injuries and concussions in youth rugby.

Prevention strategies and modifiable risk factors for sport-related concussions and head impacts: a systematic review and meta-analysis

OBJECTIVES

To evaluate prevention strategies, their unintended consequences and modifiable risk factors for sport-related concussion (SRC) and/or head impact risk.

DESIGN

This systematic review and meta-analysis was registered on PROSPERO (CRD42019152982) and conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

DATA SOURCES

Eight databases (MEDLINE, CINAHL, APA PsycINFO, Cochrane (Systematic Review and Controlled Trails Registry), SPORTDiscus, EMBASE, ERIC0 were searched in October 2019 and updated in March 2022, and references searched from any identified systematic review.

ELIGIBILITY CRITERIA

Study inclusion criteria were as follows: (1) original data human research studies, (2) investigated SRC or head impacts, (3) evaluated an SRC prevention intervention, unintended consequence or modifiable risk factor, (4) participants competing in any sport, (5) analytic study design, (6) systematic reviews and meta-analyses were included to identify original data manuscripts in reference search and (7) peer-reviewed. Exclusion criteria were as follows: (1) review articles, pre-experimental, ecological, case series or case studies and (2) not written in English.

RESULTS

In total, 220 studies were eligible for inclusion and 192 studies were included in the results based on methodological criteria as assessed through the Scottish Intercollegiate Guidelines Network high ('++') or acceptable ('+') quality. Evidence was available examining protective gear (eg, helmets, headgear, mouthguards) (n=39), policy and rule changes (n=38), training strategies (n=34), SRC management strategies (n=12), unintended consequences (n=5) and modifiable risk factors (n=64). Meta-analyses demonstrated a protective effect of mouthguards in collision sports (incidence rate ratio, IRR 0.74; 95% CI 0.64 to 0.89). Policy disallowing bodychecking in child and adolescent ice hockey was associated with a 58% lower concussion rate compared with bodychecking leagues (IRR 0.42; 95% CI 0.33 to 0.53), and evidence supports no unintended injury consequences of policy disallowing bodychecking. In American football, strategies limiting contact in practices were associated with a 64% lower practice-related concussion rate (IRR 0.36; 95% CI 0.16 to 0.80). Some evidence also supports up to 60% lower concussion rates with implementation of a neuromuscular training warm-up programme in rugby. More research examining potentially modifiable risk factors (eg, neck strength, optimal tackle technique) are needed to inform concussion prevention strategies.

CONCLUSIONS

Policy and rule modifications, personal protective equipment, and neuromuscular training strategies may help to prevent SRC.

PROSPERO REGISTRATION NUMBER

CRD42019152982.

Consensus statement on concussion in sport: the 6th International Conference on Concussion in Sport-Amsterdam, October 2022

For over two decades, the Concussion in Sport Group has held meetings and developed five international statements on concussion in sport. This 6th statement summarises the processes and outcomes of the 6th International Conference on Concussion in Sport held in Amsterdam on 27-30 October 2022 and should be read in conjunction with the (1) methodology paper that outlines the consensus process in detail and (2) 10 systematic reviews that informed the conference outcomes. Over 3½ years, author groups conducted systematic reviews of predetermined priority topics relevant to concussion in sport. The format of the conference, expert panel meetings and workshops to revise or develop new clinical assessment tools, as described in the methodology paper, evolved from previous consensus meetings with several new components. Apart from this consensus statement, the conference process yielded revised tools including the Concussion Recognition Tool-6 (CRT6) and Sport Concussion Assessment Tool-6 (SCAT6, Child SCAT6), as well as a new tool, the Sport Concussion Office Assessment Tool-6 (SCOAT6, Child SCOAT6). This consensus process also integrated new features including a focus on the para athlete, the athlete's perspective, concussion-specific medical ethics and matters related to both athlete retirement and the potential long-term effects of SRC, including neurodegenerative disease. This statement summarises evidence-informed principles of concussion prevention, assessment and management, and emphasises those areas requiring more research.

Injury-Reduction Programs Containing Neuromuscular Neck Exercises and the Incidence of Soccer-Related Head and Neck Injuries

CONTEXT

Concern is growing among soccer players, coaches, and parents regarding head and neck injuries, including concussion, particularly from heading a ball. Thus, we need to explore soccer-specific head injury risk-reduction initiatives. One such initiative is to condition the neck musculature of young players by adding neuromuscular neck exercises to existing injury-reduction exercise programs.

OBJECTIVE

To investigate the effect of neuromuscular neck exercises completed as part of an injury risk-reduction exercise program on the incidence of soccer-related head and neck injuries in adolescent soccer players.

DESIGN

Prospective cohort study.

SETTING

Two sports high schools and 6 soccer clubs during the 2021 soccer season.

PATIENTS OR OTHER PARTICIPANTS

A total of 364 male and female soccer players, aged 12 to 18 years.

INTERVENTION(S)

Members of 1 sports high school and 2 soccer clubs performed neuromuscular neck exercises as part of an injury-reduction program during training (neck training group). Members of another sports high school and 4 soccer clubs performed an injury-reduction program but without neck exercises (comparison group).

MAIN OUTCOME MEASURE(S)

Self-reported injury data were collected from each player at the end of the season and used to calculate incidence rate ratios (IRRs) with 95% CIs.

RESULTS

In total, 364 players completed the study, including 146 players in the neck training group and 218 players in the comparison group. Despite players in the neck training group being less likely to self-report a concussion (IRR = 0.23; 95% CI = 0.03, 1.04) and pain on heading a ball (IRR = 0.62; 95% CI = 0.34, 1.07), only a lower incidence of possible concussive events (IRR = 0.38; 95% CI = 0.14, 0.90; P < .05) was significant.

CONCLUSIONS

Integrating neuromuscular neck exercises into injury-reduction exercise programs has the potential to reduce the risk of adolescent soccer players sustaining a possible concussive event, concussion, or pain on heading a ball.

Soft-shell headgear in rugby union: a systematic review of published studies

Objectives

To review the rate of soft-shell headgear use in rugby union, consumer knowledge of the protection potential of soft-shell headgear, incidence of concussion reported in rugby headgear studies, and the capacity of soft-shell headgear to reduce acceleration impact forces.

Design

A systematic search was conducted in July and August 2021 using the databases SPORT Discus, PubMed, MEDLINE, CINAHL (EBSCO), Scopus, and Science Direct. The review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The protocol for this systematic review was registered on PROSPERO (registration number: CRD42021239595).

Outcome measures

Rates of headgear use, reports of estimated protection of headgear against head injury, incidence of concussion and magnitude of impact collisions with vs. without headgear, impact attenuation of headgear in lab studies.

Results

Eighteen studies were identified as eligible: qualitative (N = 4), field (N = 7), and lab (N = 7). Qualitative studies showed low rates of headgear use and varying understanding of the protection afforded by headgear. Field studies showed negligible association of headgear use with reduced impact magnitude in headgear vs. non-headgear cohorts. Lab studies showed increased energy attenuation for thicker headgear material, poorer performance of headgear after repetitive impacts and increased drop heights, and promising recent results with headgear composed of viscoelastic polymers.

Conclusions

Rates of adoption of soft-shell headgear remain low in rugby and any association between its use and reduction in acceleration impact forces remains unclear. Lab results indicating improved impact attenuation need to be validated in the field. Further headgear-related research is needed with youth and female rugby players.

The association between size and symmetry of the lumbar multifidus muscle, and injuries in adolescent rugby union players

OBJECTIVES

This study aimed to investigate the association between size and symmetry of the lumbar multifidus muscle, and season injuries in adolescent rugby union players.

DESIGN

Prospective longitudinal cohort study.

SETTING

Pre-season assessment of the size (cross-sectional area) of the lumbar multifidus (L2-5) muscles using ultrasound imaging.

PARTICIPANTS

Seventy-one adolescent rugby union players (aged 15-18 years).

MAIN OUTCOME MEASURES

"Time-loss" injuries were recorded during the season and divided into four injury regions (head and neck, upper limb, trunk and lower limb).

RESULTS

Thirty-nine injuries were recorded during the season. Players who sustained an upper limb injury during the season had smaller lumbar multifidus muscles at the L5 vertebral level (effect size = 0.7, p = 0.03) and asymmetry in muscle size at the L2 (p = 0.05) and L5 (p = 0.04) in the pre-season. There was no association between size of the lumbar multifidus muscle and other injuries (p > 0.05).

CONCLUSION

Lumbar multifidus muscle size and symmetry may impact lumbopelvic control which may increase the risk of sustaining an upper limb injury during rugby union. Future research should aim to identify whether lumbar multifidus muscle size is a modifiable risk factor for rugby union injuries to guide future intervention programs.

Effectiveness of a warm-up programme to reduce injuries in youth volleyball players: a quasi-experiment

OBJECTIVES

To establish the effectiveness of the 'VolleyVeilig' programme on reducing injury rate, injury burden and injury severity in youth volleyball players.

METHODS

We conducted a quasi-experimental prospective study over one season of youth volleyball. After randomisation by competition region, we instructed 31 control teams (236 children, average age 12.58±1.66) to use their usual warm-up routine. The 'VolleyVeilig' programme was provided to 35 intervention teams (282 children, average age 12.90±1.59). This programme had to be used during each warm-up before training sessions and matches. We sent a weekly survey to all coaches, collecting data on each player's volleyball exposure and injuries sustained. Multilevel analyses estimated differences in injury rates and burden between both groups, and we used non-parametric bootstrapping to compare the differences in injury numbers and injury severity.

RESULTS

We found an overall reduction in injury rates of 30% for intervention teams (HR 0.72; 95% CI 0.39 to 1.33). Detailed analyses revealed differences for acute (HR 0.58; 95% CI 0.34 to 0.97) and upper extremity injuries (HR 0.41; 95% CI 0.20 to 0.83). Compared with control teams, the intervention teams had a relative injury burden of 0.39 (95% CI 0.30 to 0.52) and a relative injury severity of 0.49 (95% CI 0.03 to 0.95). Only 44% of teams fully adhered to the intervention.

CONCLUSION

We established that the 'VolleyVeilig' programme was associated with reduced acute and upper extremity injury rates and lower injury burden and severity in youth volleyball players. While we advise implementation of the programme, programme updates to improve adherence are needed.

A multidimensional approach to identifying the physical qualities of male English regional academy rugby union players; considerations of position, chronological age, relative age and maturation

Interpreting the physical qualities of youth athletes is complex due to the effects of growth, maturation and development. This study aimed to evaluate the effect of position, chronological age, relative age and maturation on the physical qualities of elite male academy rugby union players. 1,424 participants (n = 2,381 observations) from nine Rugby Football Union regional academies prospectively completed a physical testing battery at three time points, across three playing seasons. Anthropometrics, body composition, muscular power, muscular strength, speed, aerobic capacity and running momentum were assessed. Positional differences were identified for all physical qualities. The largest effect sizes were observed for the associations between chronological age (d = 0.65-0.73) and maturation (d = -0.77 to -0.69) and body mass related variables (i.e. body mass and running momentum). Relative strength, maximum velocity and aerobic capacity were the only models to include two fixed effects with all other models including at least three fixed effects (i.e. position and a combination of chronological age, relative age and maturation). These findings suggest a multidimensional approach considering position, chronological age, relative age and maturation is required to effectively assess the physical qualities of male age grade rugby union players. Therefore practitioners should use regression equations rather than traditional descriptive statistic tables to provide individualised normative comparisons thus enhancing the application of testing results for talent identification and player development.Highlights Practitioners should record and incorporate position, chronological age, relative age and maturation into the physical evaluation of elite academy rugby union players.The regression equations provided within this study offer highly generalisable comparative values that are specific to a players chronological and biological development.Through the use of enhanced player evaluation practitioners will be able to make more informed decisions surrounding talent identification and athlete development.

It Takes Two to Tango: High Rates of Injury and Concussion in Ball Carriers and Tacklers in High School Boys' Rugby

OBJECTIVE

To examine injury and concussion rates, mechanisms, locations, and types of injury in Canadian high school male rugby.

DESIGN

Prospective cohort study.

SETTING

High school male rugby.

PARTICIPANTS

A total of 429 high school players (2018: n = 225, 2019: n = 256) were recruited from 12 teams in 7 schools in Calgary, Canada.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Injury surveillance included baseline questionnaires, weekly exposure, and injury reports. Injuries included those requiring medical attention, resulted in time loss and/or inability to complete a session. Concussion was defined as per the fifth Consensus on Concussion in Sport, and all players with a suspected concussion were referred to a study sport medicine physician.

RESULTS

A total of 134 injuries were captured, leading to an injury incidence rate (IR) of 57.9/1000 hours [95% confidence intervals (CIs): 45.4-73.8]. Median time loss was 6 days (range: 0-90). Injuries to the head were the most common (40%), followed by shoulder (12%) and ankle (10%). The concussion IR was 22.0/1000 hours (95% CIs: 15.9-30.4), which was the most common injury type (38%), followed by sprain (20%) and strain (15%). Sixty-five percent of injuries occurred in the tackle (ball carrier 35%, tackler 30%) and 76% of concussions (ball carrier 41%, tackler 35%).

CONCLUSIONS

The rate of injury and concussion in Canadian youth high school male rugby is high, with tackle-related injuries and concussions the most common. Given this, there is a critical need for implementation of prevention strategies, in particular targeting concussion and the tackle event (eg, neuromuscular, tackle training, and law changes).

Injury Trends for School Rugby Union in Ireland: The Need for Position-specific Injury-prevention Programs

BACKGROUND

Concern has been raised over the injury risk to school Rugby union (Rugby) players and the potential long-term health consequences. Despite the increase in studies for this cohort, the influence of playing position on injury incidence and presentation is unclear.

PURPOSE

To describe the incidence, nature and severity of match injuries for school Rugby in Ireland overall, and as a function of playing position.

STUDY DESIGN

Prospective cohort study.

METHODS

Data were collected from 15 male (aged 16-19 years) school Senior Cup teams across 2 seasons. In total, 339 players participated in season 1, whereas 326 players participated in season 2. Injury data were recorded onto a bespoke online platform. Match exposure was also recorded.

RESULTS

The incidence rate of match injuries (24-hour time loss) was 53.6 per 1000 hours. Across both seasons, 6810 days were lost from play due to injury. Forwards (65.4 per 1000 hours) sustained significantly more (P < 0.05) injuries than backs (40.5 per 1000 hours). The head, shoulder, knee, and ankle were the most common injured body regions; however, forwards sustained significantly more (P < 0.05) head and shoulder injuries than backs. The tackle was responsible for the majority of injuries in both groups. The highest proportion of injuries occurred during the third quarter.

CONCLUSION

Clear differences in injury presentation and incidence were evident when comparing forwards versus backs. The high rate of head and shoulder injuries in the forwards suggest the need for more targeted injury-prevention strategies and further research on education and laws around the tackle event. The spike of injuries in the third quarter suggests that fatigue or inadequate half-time warm-up may be a contributing factor warranting further exploration.

CLINICAL RELEVANCE

This study demonstrates clear differences in injury presentation according to playing position in school Rugby and highlights the need for a more tailored approach to the design and implementation of injury-prevention strategies.

LEVEL OF EVIDENCE

Level 3.

Extended Knee Control programme lowers weekly hamstring, knee and ankle injury prevalence compared with an adductor strength programme or self-selected injury prevention exercises in adolescent and adult amateur football players: a two-armed cluster-randomised trial with an additional comparison arm

OBJECTIVE

To evaluate the preventive efficacy of an extended version of the Knee Control injury prevention exercise programme (IPEP) compared with an adductor strength programme and to a comparison group using a self-selected IPEP in amateur adolescent and adult male and female football players.

METHODS

Two-armed cluster-randomised trial with an additional non-randomised arm. All 251 amateur teams (players 14-46 years) in one regional football district were approached. Teams meeting inclusion criteria were randomised to (1) extended Knee Control or (2) an adductor strength programme. Teams already using an IPEP were allocated to a comparison group and received no new intervention. Players responded to weekly questionnaires about football exposures and injuries during a 7-month season.

RESULTS

Seventeen teams in the extended Knee Control, 12 in the adductor and 17 in the comparison group participated, with 502 players. For the primary outcomes, no difference in injury incidence in three lower-limb injury locations combined (hamstring, knee and ankle) was seen between extended Knee Control and the adductor group, whereas extended Knee Control had 29% lower incidence than the comparison group (incidence rate ratio 0.71, 95% CI 0.52 to 0.98). No between-group differences in groin injury incidence were seen. The weekly injury prevalence rates in the three lower limb locations combined (hamstring, knee and ankle) were 17% lower (prevalence rate ratio (PRR) 0.83, 95% CI 0.69 to 1.00) and 26% lower (PRR 0.74, 95% CI 0.63 to 0.87) in extended Knee Control compared with the adductor and comparison groups, respectively.

CONCLUSION

No difference in injury incidence was seen between the extended Knee Control and the adductor programme whereas extended Knee Control reduced injury incidence by nearly one-third compared with a self-selected IPEP. Players in extended Knee Control had lower injury prevalence compared with an adductor or self-selected IPEP.

TRIAL REGISTRATION NUMBER

NCT04272047; Clinical trials.

Movement retraining programme in young soccer and rugby football players: A feasibility and proof of concept study

INTRODUCTION

Movement screening to identify abnormal movement patterns can inform development of effective interventions. The primary objective of this study was to evaluate the feasibility of using a movement screening tool in combination with a tailored movement control retraining programme in young soccer and rugby football players. A secondary objective was to investigate changes in movement control patterns post-intervention, to provide proof of concept (PoC) for movement retraining.

METHODS

52 male amateur players, including 34 soccer players (mean age 15 ± 2 years) and 18 rugby players (mean age 15 ± 1 years) participated. They were screened for movement control ability using a shortened version of the Hip and Lower Limb Movement Screening (Short-HLLMS) and completed an eight-week movement control retraining programme. Evaluation of feasibility included consent from players invited, adherence, attendance at the exercise sessions, drop-out and adverse events. Short-HLLMS total score and The Copenhagen Hip and Groin Outcome Score (HAGOS) were analysed to provide PoC for retraining movement control.

RESULTS

feasibility outcomes were favourable. Significant statistical changes occurred post-intervention in the Short-HLLMS total score (paired-samples t-test) and in three HAGOS subscales (symptoms, physical function in daily living and in sport and recreation) (Wilcoxon-Signed Rank Test) in both groups.

CONCLUSIONS

Feasibility of using the Short-HLLMS in combination with a movement control retraining programme in soccer and rugby players was promising. The data provided PoC for the potential application of a shortened version of the HLLMS to evaluate changes in movement control and to inform targeted motor control programmes.

Injuries in Canadian high school boys’ collision sports: insights across football, ice hockey, lacrosse, and rugby

Background

Collision sport participation rates among high school youth in Canada are high. While participation is beneficial for physical and mental well-being, the rates of injury in these sports are high.

Aims

This study aims to compare injury rates and profiles across four common youth collision sports (ice hockey, tackle football, lacrosse, rugby).

Methods

Data from a cross-sectional questionnaire of 2029 high school youth were used to identify male collision sport participants to be included in this secondary analysis (n = 360).

Results

Of the 2029 students who completed the questionnaire, 360 participated in collision-based sports [Ages: 14 (5%), 15 (41%), 16 (25%), 17 (26%), 18 (3%)]. The rates of injury ranged from 12.7 injuries/100 participants/year (rugby) to 33.1 injuries/100 participants/year (ice hockey). Concussion rates ranged from 12.4 (football) to 15.8 (ice hockey) concussions/100 participants/year. Similarities existed in the profile of injuries between sports, with most injuries occurring due to contact with another player (range 57.0% to 87.5%). Injuries to the head (33.3%), wrist/hand (16.0%), shoulder (12.8%), and knee (12.0%) were the most prevalent injury type. Substantial differences in previous playing experience existed between sports.

Discussion

The high rate of injury and concussion reported across each of these sports highlights the need for the introduction of primary prevention strategies in these sports aimed to reduce the risk of injury.

Evaluation of an injury prevention programme (Prep-to-Play) in women and girls playing Australian Football: design of a pragmatic, type III, hybrid implementation-effectiveness, stepped-wedge, cluster randomised controlled trial

INTRODUCTION

Due to the increase in participation and risk of anterior cruciate ligament (ACL) injuries and concussion in women's Australian Football, an injury prevention programme (Prep-to-Play) was codesigned with consumers (eg, coaches, players) and stakeholders (eg, the Australian Football League). The impact of supported and unsupported interventions on the use of Prep-to-Play (primary aim) and injury rates (secondary aim) will be evaluated in women and girls playing community Australian Football.

METHODS AND ANALYSIS

This stepped-wedge, cluster randomised controlled trial will include ≥140 teams from U16, U18 or senior women's competitions. All 10 geographically separated clusters (each containing ≥14 teams) will start in the control (unsupported) phase and be randomised to one of five dates (or 'wedges') during the 2021 or 2022 season to sequentially transition to the intervention (supported Prep-to-Play), until all teams receive the intervention. Prep-to-Play includes four elements: a neuromuscular training warm-up, contact-focussed football skills (eg, tackling), strength exercises and education (eg, technique cues). When transitioning to supported interventions, study physiotherapists will deliver a workshop to coaches and player leaders on how to use Prep-to-Play, attend team training at least two times and provide ongoing support. In the unsupported phase, team will continue usual routines and may freely access available Prep-to-Play resources online (eg, posters and videos about the four elements), but without additional face-to-face support. Outcomes will be evaluated throughout the 2021 and 2022 seasons (~14 weeks per season).

PRIMARY OUTCOME

use of Prep-to-Play will be reported via a team designate (weekly) and an independent observer (five visits over the two seasons) and defined as the team completing 75% of the programme, two-thirds (67%) of the time.

SECONDARY OUTCOMES

injuries will be reported by the team sports trainer and/or players. Injury definition: any injury occurring during a football match or training that results in: (1) being unable to return to the field of play for that match or (2) missing ≥ one match. Outcomes in the supported and unsupported phases will be compared using a generalised linear mixed model adjusting for clustering and time. Due to the type III hybrid implementation-effectiveness design, the study is powered to detect a improvement in use of Prep-to-Play and a reduction in ACL injuries.

ETHICS AND DISSEMINATION

La Trobe University Ethics Committee (HREC 20488) approved. Coaches provided informed consent to receive the supported intervention and players provided consent to be contacted if they sustained a head or knee injury. Results will be disseminated through partner organisations, peer-reviewed publications and scientific conferences.

TRIAL REGISTRATION NUMBER

NCT04856241.

Statistical analysis considerations within longitudinal studies of physical qualities in youth athletes: A qualitative systematic methodological review

Background

The evaluation of physical qualities in talent identification and development systems is vital and commonplace in supporting youth athletes towards elite sport. However, the complex and dynamic development of physical qualities in addition to temporal challenges associated with the research design, such as unstructured data collection and missing data, requires appropriate statistical methods to be applied in research to optimise the understanding and knowledge of long-term physical development.

Aim

To collate and evaluate the application of methodological and statistical methods used in studies investigating the development of physical qualities within youth athletes.

Methods

Electronic databases were systematically searched form the earliest record to June 2021 and reference lists were hand searched in accordance with the PRISMA guidelines. Studies were included if they tested physical qualities over a minimum of 3 timepoints, were observational in nature and used youth sporting populations.

Results

Forty articles met the inclusion criteria. The statistical analysis methods applied were qualitatively assessed against the theoretical underpinnings (i.e. multidimensional development, non-linear change and between and within athlete change) and temporal challenges (i.e. time variant and invariant variables, missing data, treatment of time and repeated measures) encountered with longitudinal physical testing research. Multilevel models were implemented most frequently (50%) and the most appropriately used statistical analysis method when qualitatively compared against the longitudinal challenges. Independent groups ANOVA, MANOVA and X2 were also used, yet failed to address any of the challenges posed within longitudinal physical testing research.

Conclusions

This methodological review identified the statistical methods currently employed within longitudinal physical testing research and addressed the theoretical and temporal challenges faced in longitudinal physical testing research with varying success. The findings can be used to support the selection of statistical methods when evaluating the development of youth athletes through the consideration of the challenges presented.

Players', parents' and staffs' perceptions of injury prevention exercise programmes in youth rugby union

Background and aim

Despite evidence of their efficacy, there is no widespread adoption of injury prevention exercise programmes (IPEPs) among young players and coaches in community rugby union. The purpose of this study was to (1) analyse the knowledge and perceptions of injury prevention and IPEPs among staff, parents and players in youth rugby union and (2) explore the facilitators and barriers to implementation of IPEPs. With this contextual information, tailored implementation strategies can be created.

Methods

Participants completed an online survey addressing knowledge and perceptions of injury risk, injury prevention practices and a rugby-specific IPEP. Community rugby union players aged 14-18 years, their parents and staff were invited to participate, including school-based and development squads competing at a national level.

Results

Surveys were completed by 18 staff members, 72 parents and 56 players. Staff, parents and players believe that the risk of injury in youth rugby union is high and that injury prevention is important. The perceived role in injury prevention and availability of allied health staff, particularly strength and conditioning coaches, was apparent in this sample. Reported barriers to completion of IPEPs related to time, resources, awareness of the programme and end-users' attitudes or motivations. Leadership, the use of role models and the structure and routine provided by an IPEP were considered facilitative.

Conclusions

These findings inform future implementation strategies for IPEPs in this setting, including the need to provide practical solutions, education and considering the role of allied health staff in facilitating such programmes.

Effectiveness of the Activate injury prevention exercise programme to prevent injury in schoolboy rugby union

OBJECTIVE

The efficacious Activate injury prevention exercise programme has been shown to prevent injuries in English schoolboy rugby union. There is now a need to assess the implementation and effectiveness of Activate in the applie setting.

METHODS

This quasi-experimental study used a 24-hour time-loss injury definition to calculate incidence (/1000 hours) and burden (days lost/1000 hours) for individuals whose teams adopted Activate (used Activate during season) versus non-adopters. The dose-response relationship of varying levels of Activate adherence (median Activate sessions per week) was also assessed. Player-level rugby exposure, sessional Activate adoption and injury reports were recorded by school gatekeepers. Rate ratios (RR), adjusted by cluster (team), were calculated using backwards stepwise Poisson regression to compare rates between adoption and adherence groups.

RESULTS

Individuals in teams adopting Activate had a 23% lower match injury incidence (RR 0.77, 95% CI 0.55 to 1.07), 59% lower training injury incidence (RR 0.41, 95% CI 0.17 to 0.97) and 26% lower match injury burden (95% CI 0.46 to 1.20) than individuals on non-adopting teams. Individuals with high Activate adherence (≥3 sessions per week) had a 67% lower training injury incidence (RR 0.33, 95% CI 0.12 to 0.91) and a 32% lower match injury incidence (RR 0.68, 95% CI 0.50 to 0.92) than individuals with low adherence (<1 session per week). While 65% of teams adopted Activate during the season, only one team used Activate three times per week, using whole phases and programme progressions.

CONCLUSION

Activate is effective at preventing injury in English schoolboy rugby. Attention should focus on factors influencing programme uptake and implementation, ensuring Activate can have maximal benefit.

An 8-Week Neuromuscular Training Program After Concussion Reduces 1-Year Subsequent Injury Risk: A Randomized Clinical Trial

BACKGROUND

Existing data suggest that after concussion, athletes experience an increased risk of subsequent injury. Exploring methods that may reduce injury risk after successful postconcussion return to play may lead to new treatment approaches.

PURPOSE

To examine the efficacy of a neuromuscular training (NMT) intervention on acute sports-related time-loss injury over the subsequent year relative to standard of care.

STUDY DESIGN

Randomized clinical trial; Level of evidence, 1.

METHODS

A total of 27 youth athletes were assessed initially postconcussion (median, 7 days postconcussion; interquartile range [IQR], 5-10) and after return-to-play clearance (median, 40 days postconcussion; IQR, 15-52). After return-to-play clearance, they were randomly assigned to NMT intervention (n = 11; mean ± SD age, 14.7 ± 1.7 years; 36% female) or standard of care (n = 16; mean ± SD age, 15.3 ± 1.8 years; 44% female). The intervention (duration, 8 weeks; frequency, 2 times per week) included guided strength exercises with landing stabilization focus. Standard of care received no recommendations. For the subsequent year, athletes prospectively completed a monthly log of sports-related injuries and organized sports competitions.

RESULTS

During the first year after postconcussion return-to-play clearance, sports-related time-loss injuries were more common among standard of care relative to NMT intervention (75% [95% CI, 48%-93%] vs 36% [95% CI, 11%-69%]). After adjusting for age and sex, the hazard of subsequent injury in the standard-of-care group was 3.56 times (95% CI, 1.11-11.49; P = .0334) that of the NMT intervention group. Sports participation was similar between NMT intervention and standard of care during the year-long monitoring period (hours of organized sports per month; median, 12 [IQR, 2.6-32.1] vs 15.6 [IQR, 3.5-105.9]; P = .55). The age- and sex-adjusted incidence of injuries was 10.2 per 1000 competitive exposures (95% CI, 3.7-28.4) in the standard-of-care group as opposed to 3.4 per 1000 (95% CI, 0.9-13.4) in the NMT intervention group. After adjusting for age and sex, incidence of injuries was higher for standard of care vs NMT intervention (rate ratio, 2.96 [95% CI, 0.89-9.85]; P = .076).

CONCLUSION

Although preliminary, our findings suggest that an NMT intervention initiated after return-to-play clearance may significantly reduce sports-related time-loss injuries over the subsequent year.

REGISTRATION

NCT03917290 (ClinicalTrials.gov identifier).

Characteristics of Plantar Pressure with Foot Postures and Lower Limb Pain Profiles in Taiwanese College Elite Rugby League Athletes

Background: This study aimed to explore the differences in the distributions of plantar pressure in static and dynamic states and assess the possible pain profiles in the lower limb between elite rugby league athletes and recreational rugby players. Methods: A cross-sectional study of 51 college elite rugby athletes and 57 recreational rugby players was undertaken. The arch index (AI) and plantar pressure distributions (PPDs) with footprint characteristics were evaluated via the JC Mat. Rearfoot alignment was examined to evaluate the static foot posture. The elite group’s lower-limb pain profiles were examined for evaluating the common musculoskeletal pain areas. Results: The recreational group’s AI values fell into the normal range, whereas the elite group’s arch type fell into the category of the low arch. Results from the elite group were: (1) the PPDs mainly exerted on the entire forefoot and lateral midfoot regions in static standing, and transferred to the forefoot region during the midstance phase of walking; (2) the static rearfoot alignment matched the varus posture pattern; (3) the footprint characteristics illustrated the features of low-arched, supinated, dropped metatarsal heads and dropped cuboid feet; and (4) the phalanx and metatarsophalangeal joints, and the abductor hallucis and abductor digiti minimi of the plantar plate were common musculoskeletal pain areas. Conclusions: Characteristics of higher plantar loads beneath forefoot and midfoot associated with low-arched supinated feet in bipedal static stance could be the traceable features for the foot diagram of elite rugby league athletes. The limb pain profiles of the elite rugby league athletes within this study echoed the literature on rugby injuries, and reflected the features of metatarsophalangeal joint pains and dropped cuboids. The relationships among the low-arched supinated feet, metatarsophalangeal joint pains and cuboid syndrome are worth further studies.

The Effect of the FIFA 11 + with Added Neck Exercises on Maximal Isometric Neck Strength and Peak Head Impact Magnitude During Heading: A Pilot Study

BACKGROUND

Higher neck strength has been postulated to reduce head impact magnitude during purposeful heading in football.

OBJECTIVES

This pilot trial explored the effect of a neck exercise programme on (1) neck strength and (2) head impact magnitude during heading in male and female adolescent football players.

METHODS

Boys and girls (aged 12-17 years) were randomised by team to the intervention (5 weeks of supervised neuromuscular neck exercises integrated into part 2 of the FIFA 11 + , completed three times per week) or the control group (usual part 2 of the FIFA 11 + , no neck exercises). Outcomes included isometric neck strength and head impact magnitude (peak linear acceleration and peak angular velocity) during standardised heading from a throw-in (at baseline and 6 weeks) plus completion of an evaluation survey by intervention players and coaches.

RESULTS

In total, 52 players (n = 31 intervention; n = 21 control) completed the study. Mixed-model analysis of variance (ANOVA) revealed significant differences in neck strength variables (p < 0.001), peak linear acceleration (p = 0.04) and peak angular velocity (p = 0.04) between the intervention and control groups over time. Intervention players demonstrated increases in mean composite neck strength (53.8% intervention vs 15.6% control) as well as decreases in mean peak linear head acceleration during heading (- 11.8% vs - 5.0%) from baseline to follow-up. Reduction in peak angular velocity was more pronounced in girls (- 27.7%) than boys (- 11.5%) in the intervention group. The addition of neck exercises into part 2 of the FIFA 11 + was feasible and accepted by players and coaches.

CONCLUSION

On average, players who completed neck exercises demonstrated an increase in isometric neck strength and a decrease in head impact magnitude during heading. These exercises were easily incorporated into usual training. Australian New Zealand Clinical Trials Registry (no: ACTRN12619001375145).

Head Games: A Systematic Review and Meta-analysis Examining Concussion and Head Impact Incidence Rates, Modifiable Risk Factors, and Prevention Strategies in Youth Tackle Football

OBJECTIVES

The aims were to (1) examine the rates and mechanisms of concussion and head impact in youth football (high school level or younger); (2) identify modifiable risk factors for concussion and head impact; and (3) evaluate the effectiveness of prevention strategies in tackle football at any level.

METHODS

Nine databases (CINAHL Plus with Full Text; Cochrane Central Register of Controlled Trials; EMBASE; ERIC; Ovid MEDLINE(R) and Epub Ahead of Print, In-Process & Other Non-Indexed Citations and Daily; ProQuest Dissertations & Theses Global Database; PsycINFO; Scopus; and SPORTDiscus with Full Text) were searched using the search strategy focusing on four main concepts: concussion/head impact, tackle football, modifiable risk factors, and primary prevention. Two reviewers completed title, abstract, and full-text screening as well as risk of bias assessment (using the Downs and Black checklist), with a third author available to resolve any disagreements.

MAIN RESULTS

After removing duplicates, 1911 articles were returned. Fifty-eight articles were included in the review and 20 in the meta-analysis. The overall combined rates of concussion (including game and practice-related concussion) based on the meta-analysis were 0.78 concussions/1000 athlete exposures [95% confidence interval (CI) 0.67-0.89] for high school football (ages 13-19) and 1.15 concussions/1000 athlete exposures (95% CI 0.89-1.41) for minor football players (ages 5-15). There is evidence that contact training and practice contact restrictions have reduced the rate of head impacts and concussion. Heads Up Football (an intervention focused on coach education and contact training) has been shown to reduce the rate of concussion by 32% and head impacts by 38% amongst high school football players. Limiting contact practices in high schools to 2 days per week reduced practice head impacts per player-season by 42%, and limiting full contact in practice to 75 min per week in the second week of the season and 60 min in week 3 and beyond resulted in a 54% decrease in the practice-related concussion rate (p = 0.003).

CONCLUSIONS

This review identified a critical need for interventions to address the high rates of concussion and head impact in youth football. To date, contact training and contact restrictions have the strongest evidence supporting their effectiveness at reducing these rates. Future research should use consistent concussion definitions and validated injury surveillance systems, and ensure complete reporting of participant characteristics and sampling details. Prospero ID CRD42020193775.