Injury risk is greater in physically mature versus biologically younger male soccer players from academies in different countries

Injury incidence, prevalence, and burden in an Argentinian male youth soccer academy: one-season descriptive study

OBJECTIVE

To prospectively describe the incidence, severity, and burden of injuries in the youth divisions of an Argentinian professional soccer club during a competitive season.

METHODS

Two hundred and twelve male soccer academy players were grouped by age categories and maturity offset as pre-peak height velocity (PHV), circa-PHV and post-PHV. Injury characteristics were recorded as the International Olympic Committee suggests.

RESULTS

A total of 235 time-loss injuries were sustained by 101 different players. The overall injury incidence rate was of 5.8 injuries per 1000 hours (h), with a training and match injury incidence rate of 4.9 and 9.7 injuries per 1000 h, respectively. The prevalence over the season was 47%. Most of the injuries (202) affected the lower limbs (86.6%) and most of them were classified as muscle/tendon injuries (n = 117, 49.8%). Hamstring structural injury was the diagnosis with the highest burden in both circa and post-PHV groups.

CONCLUSIONS

The incidence, prevalence, and injury burden reported in this study would add valuable information to Argentinians' youth soccer institutions. Post-PHV players had higher incidence, severity, and burden compared to circa-PHV. Structural/functional injuries to the muscle/tendon represented the highest burden for type of injuries (41.1 per 1000 h), suggesting a need for implementing preventive measures.

A Risk Tool for Evaluating Overuse Injury and Return-to-Play Time Periods in Youth and Collegiate Athletes: Preliminary Study

BACKGROUND

Overuse injuries in youth athletes are associated with risks, including sports specialization, biological maturation, female sex, and workload measures. As no assessment tool exists to evaluate risk accumulation, we developed a novel risk factor scoring system (Sport Training Assessment of Risk [STAR]) to assess participants' risk of overuse injury and explore association with return-to-play (RTP) time periods.

HYPOTHESIS

(1) STAR will reach an acceptable predictive threshold in the assessment of overuse injury in youth athletes. (2) Higher STAR scores will be associated with increased RTP time periods after injury.

STUDY DESIGN

Longitudinal cohort study.

LEVEL OF EVIDENCE

Level 3.

METHODS

Youth athletes with an injury sustained during competitive sport completed questionnaires. Association of questionnaire variables with injury risk type was evaluated via logistic regression analyses, and unweighted and weighted versions of a total risk score were developed. RTP was defined by physician clearance per electronic medical record review. Mantel-Haenszel chi-square tests and Kendall's rank correlation coefficients were used to assess the relationship between weighted total risk score and RTP time periods. The weighted STAR model was analyzed with receiver operating characteristic (ROC) curves.

RESULTS

The weighted STAR model trended toward an acceptable level of prediction for overuse (nonserious + serious) injury (area under the ROC curve [AUC], 0.66; 95% CI, 0.61-0.71), but was less predictive for serious overuse injury (AUC, 0.63; 95% CI, 0.55-0.71). Weighted total risk score was weakly associated with return to full play (ρ = 0.11; P < 0.01), and potentially with return to modified play (ρ = -0.08; P = 0.04).

CONCLUSION

STAR may be a feasible tool for assessing overuse injury risk and RTP time periods in youth athletes but requires further development, as it did not reach an acceptable predictive threshold in this preliminary study.

CLINICAL RELEVANCE

Clinicians can use STAR to assess overuse injury risk in youth athletes.

Survey of the current practices of German football academies towards biological maturation assessment

OBJECTIVES

This study aimed to examine the importance assigned to assessing and considering biological maturation in thematic areas of player development and provide an overview of current practices in German football academies regarding its consideration in training and competition.

METHODS

An online survey was sent to 56 elite German football academies. A total of 46 responded to the questionnaire (82% response rate). Six participants provided incomplete information resulting in a total of 40 completed surveys in the period from March to May 2022.

RESULTS

Only 20 of participants regularly carried out maturation assessments, despite 95% recognizing its importance for load management, 90% for player development, and 85% for injury prevention. There was no consistent approach to modifying training and competition formats based on maturity status, with a primary focus on gym-based sessions for load management.

CONCLUSION

The survey results highlight limited implementation of maturation assessment and training modification based on maturity status in German elite youth football academies. Despite recognizing the importance of load monitoring, reporting to parents, and long-term player development in considering biological maturation, practices are not widespread. The predominant use of the maturity offset method suggests an opportunity to improve accuracy by exploring alternative measurement methods and increasing assessment frequency. Moreover, a lack of established procedures for incorporating maturity status into training and competition exists, hindering comprehensive consideration of biological maturation and injury risk prevention. Further research is needed to understand the reasons for inconsistent approaches in maturation assessment and load modification during training and competition.

Is Biobanding the Future of Youth Sport Participation?

Traditionally, sports participation has been based on the chronological age of the individual with year of birth determining participation grouping. However, grouping by chronological age can result in individuals who are nearly a full year different in age competing within the same age group. Moreover, during the pubertal years, age grouping may provide physical (size) advantage to early maturers and disadvantage to late maturers. These advantages/disadvantages could impact talent selection, psychosocial aspects of sport participation, technical and tactical skill development, competitiveness, and injury risk. Biobanding is an alternative method for determining sport participation categorization and uses factors of growth and/or maturation, rather than traditional chronological age, for grouping athletes. Implementation of biobanding in sports may be advantageous to both early and late-maturing athlete development.

Sports Injury Surveillance Systems: A Scoping Review of Practice and Methodologies

Background: Injury prevention/reduction strategies are driven by data collected through injury surveillance systems. The aim of this review was to describe injury surveillance systems that are used for ongoing surveillance in either a professional or amateur sporting environment. This was an update to a review done in 2015 to determine the gaps in injury surveillance. Methods: A systematic search process of five databases (MEDLINE, CINAHL, EMBASE, SCOPUS and ProQuest) was used to discover published research that presented methodological data about the injury surveillance systems implemented by clubs and organisations for ongoing surveillance. Inclusion criteria centred on the population under surveillance and the ongoing nature of that activity. Data extracted and summarised included the level of athlete under surveillance, the data collection mechanism and the personnel involved, the injury definitions applied and the date and country of origin to provide a comprehensive picture of the systems. Results: A total of 21 systems were documented as being used in ongoing injury surveillance, with 57% of these exclusively in the professional/elite landscapes and 33% at the amateur level. Surveillance systems cater for one sport per athlete entry so there is a gap in research for multi-sport athletes at the amateur level, especially where there is no early specialisation in a multi-sport participation environment. Conclusions: Research in this area will lead to a better understanding of subsequent injury risk for multi-sport athletes who have a higher athlete exposure than single-sport athletes.

IOC consensus statement on elite youth athletes competing at the Olympic Games: essentials to a healthy, safe and sustainable paradigm

With the pronounced ongoing growth of global youth sports, opportunities for and participation of youth athletes on the world sports stage, including the Olympic Games, are expected to escalate. Yet, adolescence is a vulnerable period of development and inherently dynamic, with non-linear and asynchronous progression of physical, physiological, psychological and social attributes. These non-concurrent changes within and between individuals are accompanied by irregular and unpredictable threats and impediments. Likewise, the evident age-based criteria and conventional path for those youth athletes deemed eligible candidates for the Olympic Games are not well or consistently defined. Furthermore, the unstructured and largely varying policies and practices across the sporting International Federations specific to youth participation underscore the need to establish a contemporary universal paradigm that would enable elite youth athletes to navigate an individualised healthy pathway to personal, athletic and sport success. First, we reviewed and summarised key challenges facing elite youth athletes and the relevant evidence fundamental to facilitating and supporting central aspects of health and well-being, while empowering safe, sustainable and positive engagement during athletic and personal advancement and competition. Second, we developed and present a modern elite youth athlete model that emphasises a child-centred, practical framework with corresponding guidelines and recommendations to protect health and well-being while safely and favourably managing international sport competition. Our proposed evidence-informed paradigm will enable and support individualised pathways for healthy, well-rounded and sustainable positive engagement while achieving sport success for youth contending or aiming to compete at world-class international sporting events.

Associations between growth, maturation and injury in youth athletes engaged in elite pathways: a scoping review

OBJECTIVE

To describe the evidence pertaining to associations between growth, maturation and injury in elite youth athletes.

DESIGN

Scoping review.

DATA SOURCES

Electronic databases (SPORTDiscus, Embase, PubMed, MEDLINE and Web of Science) searched on 30 May 2023.

ELIGIBILITY CRITERIA

Original studies published since 2000 using quantitative or qualitative designs investigating associations between growth, maturation and injury in elite youth athletes.

RESULTS

From an initial 518 titles, 36 full-text articles were evaluated, of which 30 were eligible for final inclusion. Most studies were quantitative and employed prospective designs. Significant heterogeneity was evident across samples and in the operationalisation and measurement of growth, maturation and injury. Injury incidence and burden generally increased with maturity status, although growth-related injuries peaked during the adolescent growth spurt. More rapid growth in stature and of the lower limbs was associated with greater injury incidence and burden. While maturity timing did not show a clear or consistent association with injury, it may contribute to risk and burden due to variations in maturity status.

CONCLUSION

Evidence suggests that the processes of growth and maturation contribute to injury risk and burden in elite youth athletes, although the nature of the association varies with injury type. More research investigating the main and interactive effects on growth and maturation on injury is warranted, especially in female athletes and across a greater diversity of sports.

Perspectives on the role of nutrition in influencing academy soccer player development and performance: A qualitative case study of key stakeholders from an English category one soccer academy

This study aimed to explore player and stakeholder perceptions of the role of nutrition in influencing the development of male academy soccer players. Semi-structured interviews (28 ± 13 mins in length) were conducted with 31 participants from an English category one academy, including players (Youth Development Phase, YDP: n = 6; Professional Development Phase, PDP: n = 4), parents/guardians (n = 10), coaches (n = 3), sport scientists (n = 3), physiotherapists (n = 3), and catering (n = 2). Via reflexive thematic analysis, data demonstrate an apparent lack of understanding and awareness on the role of nutrition in influencing player development, especially in relation to growth, maturation and reducing injury risk. Players highlighted the influence of their parents on their dietary behaviours, whilst parents also called for education to better support their sons. Notably, players and stakeholders perceived that the daily schedule of an academy soccer player presents as "too busy to eat", especially in relation to before school, and before and after training. The results demonstrate the necessity for the co-creation of player and stakeholder specific nutrition education programmes as an initial step towards positively impacting the nutrition culture associated with the academy soccer environment.

The Genetic Association with Athlete Status, Physical Performance, and Injury Risk in Soccer

The aim of this review was to critically appraise the literature concerning the genetic association with athlete status, physical performance, and injury risk in soccer. The objectives were to provide guidance on which genetic markers could potentially be used as part of future practice in soccer and to provide direction for future research in this area. The most compelling evidence identified six genetic polymorphisms to be associated with soccer athlete status (ACE I/D; ACTN3 rs1815739; AGT rs699; MCT1 rs1049434; NOS3 rs2070744; PPARA rs4253778), six with physical performance (ACTN3 rs1815739; AMPD1 rs17602729; BDNF rs6265; COL2A1 rs2070739; COL5A1 rs12722; NOS3 rs2070744), and seven with injury risk (ACTN3 rs1815739; CCL2 rs2857656; COL1A1 rs1800012; COL5A1 rs12722; EMILIN1 rs2289360; IL6 rs1800795; MMP3 rs679620). As well as replication by independent groups, large-scale genome-wide association studies are required to identify new genetic markers. Future research should also investigate the physiological mechanisms associating these polymorphisms with specific phenotypes. Further, researchers should investigate the above associations in female and non-Caucasian soccer players, as almost all published studies have recruited male participants of European ancestry. Only after robust, independently replicated genetic data have been generated, can genetic testing be considered an additional tool to potentially inform future practice in soccer.

Can we reduce injury risk during the adolescent growth spurt? An iterative sequence of prevention in male academy footballers

Background: The adolescent growth spurt is associated with an increased risk of injury in young athletes.Aim: This study aimed to use an interdisciplinary collaboration between technical coaches, sports scientists, and medical staff to mitigate this risk.Subjects and methods: 77 male academy footballers were followed across two seasons. At-risk players were identified using somatic maturity status and growth rate in stature and the lower limbs, using thresholds of 88% to 92.8% of predicted adult stature, ≥7.2 cm/year, and ≥3.6 cm/year, respectively. During the 2019-20 season, players with symptoms of a growth-related injury or two of three risk factors were included in an intervention strategy that included modified training load, football-specific skills, balance, coordination and landing drills, and an individualised strength program.Results: For players with the three risk factors, there was a significant reduction in the incidence (rate ratio [RR] = 0.14 (5.2 per 1000h → 0.8 per 1000h, p = 0.05) and burden (RR = 0.08 (216 per 1000h → 17 per 1000h, p = 0.02) between the seasons. For players with ≤2 risk factors, there were no significant differences in injury risk between the baseline and intervention seasons.Conclusion: Overall, it may be possible to mitigate injury incidence and burden during the adolescent growth spurt in high-risk athletes.

Growth, maturation and injuries in high-level youth football (soccer): A mini review

Understanding the challenges football (soccer) players face during adolescence is fundamental to avoid disruptions in their development due to injury. This mini review will describe basic concepts of somatic growth and biological maturity, examine data from 53 prospective epidemiological studies on high-level youth football players and discuss how age, growth and maturity may affect the injury patterns observed. Based on the existing evidence, at least every third player sustains an injury during a football season. The thigh (median for studies of boys: 25%, median for girls: 21%), ankle (b: 18%, g: 30%), knee (b: 17%, g: 18%) and hip/groin (b: 14%, g: 10%) are the body parts injured most often, while muscle strains (b: 31%, g: 25%), sprains (b: 20%, g: 27%) and contusions (b: 17%, g: 16%) are the most common injury types. Injury trends are, however, not consistent throughout adolescence, and players' age, maturity status and position relative to peak height velocity (PHV) have shown to influence the number, type and location of injuries sustained. Despite a high volume of observational injury studies published on high-level youth players, girls (7 studies) and settings outside of Europe (included in 23% of studies) are underrepresented and should receive extra attention in the future. Based on the available epidemiological data, tailored injury reduction programmes can be considered in youth football, alongside application of general training principles such as progression, variation and individualization which may be especially important during vulnerable phases such as the adolescent growth spurt.

Playing Position is Associated with Injury Incidence Rate in Male Academy Soccer Players

CONTEXT

It is unclear whether playing position influences injury in male academy soccer players (ASP).

OBJECTIVE

To determine if playing position is associated with injury in ASP.

DESIGN

Descriptive Epidemiology Study.

SETTING

English, Spanish, Uruguayan and Brazilian soccer academies.

PARTICIPANTS

369 ASP from Under 14 (U14) to U23 age groups, classified as 'post-peak height velocity' using maturity offset, and grouped as goalkeepers (GK), lateral defenders (LD), central defenders (CD), lateral midfielders (LM), central midfielders (CM) and forwards (FWD). Additional analysis compared central (CENT) with lateral/forward (LAT/FWD) positions.

MAIN OUTCOME MEASURES

Injuries were recorded prospectively over one season. Injury prevalence proportion (IPP), days missed and injury incidence rate (IIR, injuries per 1000 training/match hours, n=116) were analysed according to playing position.

RESULTS

No association with playing position was observed for any injury type/location regarding IPP (P≥0.089) or days missed (P≥0.235). The IIR was higher in CD than LD for general (9.30 vs. 4.18 injuries/1000h, P=0.009), soft-tissue (5.14 vs. 1.95 injuries/1000h, P=0.026) and ligament/tendon injuries (2.69 vs. 0.56 injuries/1000h, P=0.040). Regarding CENT vs. LAT/FWD, there were no associations with IPP (P≥0.051) or days missed (P≥0.083), but general IIR was greater in CENT than LAT/FWD (8.67 vs. 6.12 injuries/1000h, P=0.047).

CONCLUSIONS

ASP playing position was not associated with IPP or days missed but the higher general, soft-tissue and ligament/tendon IIR in CD suggests this position warrants specific attention regarding injury prevention strategies. These novel findings highlight the importance of including training/match exposure when investigating the influence of playing position on injury in ASP.