Biological Maturity Status Research Articles

Biological maturity and relative age effects in German age-group swimming

Relative age effects (RAE) refer to a skewed distribution with an overrepresentation of athletes born close to the selection date. The prevalence of RAE has been repeatedly demonstrated in youth swimming. Additionally, being more mature within an age group is associated with consistent selection advantages. The present study aims to determine (1) the prevalence and magnitude of RAE in youth swimming and (2) the relation to anthropometry and biological maturity status. The study included 650 swimmers (male n = 273, age 11.00 ± 1.27 years; female n = 377, age 11.00 ± 1.25 years). The dates of birth were split into four birth quartiles (Q). The maturity status was assessed using equations to estimate the age of peak height velocity (APHV). χ2 tests and analysis of variance (ANOVA) were used for statistical analyses. The χ2 tests have shown significant RAE with medium effect sizes (ES; p < 0.001, 0.18 < V < 0.20) for male and female athletes. Also, the results have shown significant RAE with medium effect sizes (ES; p < 0.001, 0.18 < V < 0.20). ANOVA has not revealed significant differences regarding body height, body mass, and APHV between the four birth quartiles for both sexes, except for body mass in female athletes (p = 0.037). The findings indicate that maturity status and anthropometry influence RAE in youth swimming. It can be assumed that relatively younger swimmers can counteract their disadvantage only by similar anthropometric and maturity-related characteristics to the relatively older swimmers, which significantly impacts talent identification and development of swimmers.

Assessment of Performance in Youth Soccer Players: Should We Consider the Maturation Status?

The influence of biological maturity status on talent identification and development in youth soccer has been debated extensively. Alternative methods have thus recently emerged to estimate maturity status, such as the Pubertal Development Scale (PDS), but their relationship with physical capabilities of young soccer players still needs to be determined. The present study investigated the relationships of different PDS-derived pubertal status measures, chronological age, and relative age with selected performance variables in youth soccer. Sixty-one male soccer players were assessed for physical capabilities using field tests for sprinting, vertical jumps (countermovement jump, CMJ), intermittent high-intensity endurance, and repeated sprint ability. Chronological age was defined as the number of days since birth, and relative age was defined in terms of age quarters. PDS-derived measures of puberal status, otherwise, were determined as an average PDS score, a PDS category score, and a pubertal category. Chronological age, relative age, and measures of pubertal status were scarcely related (p > 0.05) to selected measures of soccer performance. Significant correlations were only found between different measures of pubertal status and the variable "work" in the CMJ test (range r = 0.33-0.36; p < 0.01) and between chronological age and CMJ height (r = -0.297; p = 0.02). The present results suggest that physical performance of young soccer players is poorly related to chronological age, relative age, and pubertal status. Potential effects of biological maturity status on physical capabilities may not be easily identifiable in a group of young soccer players narrowed in terms of chronological age and training status.

Maturity Status and Relative Age of Elite Taekwondo Youth Competitors-Case Study on Croatian National Team.

This study examines the maturity status and relative age effect in elite youth taekwondo Croatian National Team athletes. Measurements of biological age, maturity offset, and body composition were taken from a sample of 17 junior athletes. Differences in maturity status were observed among athletes of the same chronological age, with variations in sitting height and age at peak height velocity. Male athletes generally exhibited higher values in body height, percentage of body fat, muscle mass, and total body water. No significant relative age effect was found. These findings highlight the importance of considering individual biological age and maturity status for talent development and training program adjustments. Further research involving athletes from different countries is recommended to validate these results and enhance the understanding of youth taekwondo athlete development.

Reference Values of Physical Performance in Handball Players Aged 13-19 Years: Taking into Account Their Biological Maturity.

Biological maturity status significantly influences success in handball, impacting an athlete's performance and overall development. This study aimed to examine the anthropometric and physical performance variables concerning age and maturity status, establishing reference values for physical performance among Tunisian players. A total of 560 handball players (309 males and 251 females aged 13-19 years) were categorized based on maturity status: early (n = 98), average (n = 262), and late (n = 200), determined through Mirwald and colleagues' equations. Anthropometric, physical fitness, and physiological data were collected for reference value creation. Our findings revealed significantly higher anthropometric parameters (p = 0.003) in late-maturing athletes compared to their early-maturing counterparts. Post-pubertal athletes showed significantly superior (p = 0.002) jumping ability, change of direction, and aerobic performance compared to their pre-pubertal peers. Additionally, male athletes outperformed females in both fitness (p = 0.001) and aerobic (p = 0.001) performance. A notable age-by-maturity interaction emerged for most performance outcomes (η2 ranging from 0.011 to 0.084), highlighting increased sex-specific differences as athletes progressed in age. Percentile values are provided for males and females, offering valuable insights for coaches and sports scientists to design personalized training programs. Understanding a player's performance relative to these percentiles allows trainers to tailor workouts, addressing specific strengths and weaknesses for enhanced development and competitiveness.

Exploring Growth, Maturity, and Age as Injury Risk Factors in High-Level Youth Football.

Rapid somatic growth and biological maturity status may affect injury patterns in youth football, yet firm conclusions cannot be drawn from the existing research. We aimed to explore growth velocity, maturity, and age as injury risk factors in 95 academy players (11.9-15.0 years), using anthropometric (height and body mass), maturity (skeletal age), injury, and football exposure data collected prospectively over three seasons (2016/17-2018/19). We compared the relative quality of mixed-effects logistic regression models with growth velocity for 223 growth intervals (average 113 days) included as fixed effects and adjusted for age (chronological or skeletal) plus load (hours/week). Associations were considered practically relevant based on the confidence interval for odds ratios, using thresholds of 0.90 and 1.11 to define small beneficial and harmful effects, respectively. We observed harmful effects of older age on overall (OR: 2.61, 95% CI: 1.15-5.91) and sudden onset (1.98, 1.17-3.37) injury risk. Significant associations (p<0.05) were observed for higher body mass change and greater maturity on sudden onset injuries, and for higher hours/week on gradual onset, bone tissue, and physis injuries. Future studies should include larger samples, monitoring athletes from pre-adolescence through maturation, to enable within-subject analyses and better understand the relationship between growth, maturation, and injuries.

Biological maturity vs. relative age: Independent impact on physical performance in male and female youth handball players.

Maturity status and relative age are two of the determining factors in talent development. The aim of the study was to analyze the influence of biological maturity status and relative age on physical performance in young male and female handball players. The sample included 48 males (14.11 ± 1.17 years) and 41 females (14.25 ± 1.64 years) players from one Spanish professional handball academy. Anthropometric data (height, sitting height, body mass and self-reported biological parent heights) and physical performance data (CMJ, DJ, 20 m speed, T-test and throwing velocity) were collected. Biological maturity status was determined as the percentage of predicted adult height, while relative age was estimated in birth quartiles based on biennial age grouping (Q1-Q8). The results showed a positive correlation between maturity status and CMJ in male players (p < 0.01). Differences in CMJ performance according to maturity status were identified (p < 0.05), with higher jump heights being recorded especially in early maturing boys (p < 0.01) and first lines and wings (p < 0.05). The variance in CMJ test scores could be explained by the maturity status by 42.90% in U-15 (p < 0.05) and 72.60% in U-16 male players (p < 0.001). By contrast, no differences were found in girls (p > 0.05). Moreover, no relationships were found between relative age and indices of physical performance (p > 0.05). Overall, maturity status had greater impacts on the tests of physical performance than relative age. Stakeholders should monitor the maturity status of young handball players to avoid physical performance biases that do not allow them to develop their sporting potential.

Bio-banding in handball: Academy players' perceptions based on maturity status and gender.

The purpose of this study was to evaluate young male and female handball players' perceptions to the bio-banding concept. The estimated biological maturity status was assessed in a sample of 46 male and 40 female handball players (aged 14.06 ± 1.40 years) who competed in both an annual age-group and bio-banded tournament. To test the players' perception, a post-competition questionnaire was conducted. A series of ANOVA and one-sample t-tests were used in order to examine the differences in perception between the different maturity groups. An inductive thematic analysis of the qualitative data recorded in the open-ended questions was also carried out. The results showed that early-maturing boys enjoyed the bio-banding tournament more than late-maturing (p < 0.05). Conversely, no differences were found in girls (p > 0.05). Interesting conclusions could be drawn from the qualitative analysis of the players' written comments. Furthermore, a greater influence on play and leadership in male late and female early maturers, a greater physical challenge in male early maturers and an opportunity to express themselves technically and tactically in male late and female on-time maturers were observed. Thus, stakeholders must consider the different consequences of bio-banding in order to maximise the athlete's sport development process.

Beyond the coaches eye: Understanding the ‘how’ and ‘why’ of maturity selection biases in male academy soccer

This study explored academy football coaches’ perceptions and experiences of managing individual differences in the maturity timing of male adolescent football players in an English Premier League academy. Using a longitudinal mixed method design, 98 under 12–16 players were assessed for maturity status, growth velocities, and match performance grade. Interviews with nine respective coaches were conducted in parallel. The qualitative and quantitative data were combined to generate a contextualised richer understanding and four archetypal case studies. Findings showed coaches perceive various advantages and disadvantages to players maturing either ahead or in the delay of their peers and had different expectations of performance based upon a players maturity status; biological maturity status and timing had large implications for selection and release decisions. This study highlights the challenges of developing, managing and selecting adolescent players in elite male youth football. Biological maturation confounds talent identification and development, and academy environments need to monitor maturity status and educate coaches and selectors on the complexities and intricacies of individual differences in maturity timing.

Intra-observer reproducibility and inter-observer agreement of Fels skeletal age assessments among male tennis players 8–16 years

BackgroundSkeletal age (SA) is an estimate of biological maturity status that is commonly used in sport-related medical examinations. This study considered intra-observer reproducibility and inter-observer agreement of SA assessments among male tennis players.MethodsSA was assessed with the Fels method in 97 male tennis players with chronological ages (CA) spanning 8.7–16.8 years. Radiographs were evaluated by two independent trained observers. Based on the difference between SA and CA, players were classified as late, average or early maturing; if a player was skeletally mature, he was noted as such as an SA is not assigned.ResultsThe magnitude of intra-individual differences between repeated SA assessments were d = 0.008 year (observer A) and d = 0.001 year (observer B); the respective coefficients of variation were 1.11% and 1.75%. Inter-observer mean differences were negligible (t = 1.252, p = 0.210) and the intra-class correlation coefficient was nearly perfect (ICC = 0.995). Concordance of classifications of players by maturity status between observers was 90%.ConclusionFels SA assessments were highly reproducible and showed an acceptable level of inter-observer agreement between trained examiners. Classifications of players by skeletal maturity status based on assessments of the two observers were highly concordant, though not 100%. The results highlight the importance of experienced observers in skeletal maturity assessments.

Adolescent male soccer players have higher growth rates and risk of injury is associated with biological maturity.

The objective of this study was to ascertain disparities in growth and maturation between male adolescents engaged in soccer and their non-athletic counterparts, as well as to examine the injury features specific to young soccer players. A total of 206 soccer players between the ages of 11-16 years, and 208 non-athletic peers were enrolled. Height, weight, body mass index (BMI), annual growth rate, and skeletal age evaluated using a left handwrist x-ray were determined. Biological and sexual maturation were evaluated using skinfold thickness, body composition, and Tanner stages. The game positions, initial age for playing soccer, the number of games per/ week, the number of sports injuries, date of injury, duration for return to activity, the site, nature, mechanism, and rate of injury were recorded for soccer players. Using an injury card, the characteristics of soccer player injuries were recorded. The mean age of the participants was 13.6 ± 1.5 years. There was no difference in the growth rates between the groups at the ages of 11.0, 12.0, and 15.0 but at the ages of 13.0 and 14.0 years growth rates were higher in the soccer group. The soccer players were taller than the controls. For all Tanner stages, soccer players had a lower BMI and total body fat percentage, as well as a faster growth rate. Injuries occurred at a rate of 39.3% per year among soccer players. The most common being toe injuries, and playing soccer increased the risk of multiple injuries. Additionally, injuries occurred more frequently in soccer players who were taller, heavier, with higher total body fat and/or higher growth rate, and most commonly occurred during Tanner stage 4. Futhermore, Tanner stage 4 had a higher incidence of two or more injuries than the other stages. Adolescent male soccer players have higher growth rates than their non-athletic peers, and their biological maturity status is associated with an increased risk of injury.

The selection advantages associated with advanced biological maturation vary according to playing position in national-level youth soccer.

This study investigated the extent to which biological maturation selection biases existed according to playing position in national-level youth soccer. A total of 159 players from the U13 to U16 age groups in the Football Association of Ireland's national talent pathway and international representative squads had their relative biological maturity status assessed using the Khamis-Roche method for the percentage of predicted adult height at the time of observation. Players were categorised as goalkeeper (GK), central defender (CD), full-back (FB), centre defensive midfielder (CDM), centre midfielder (CM), centre attacking midfielder (CAM), wide midfielder (WM) or centre forward (CF). A series of one-sampled means t-tests were used to examine the degree to which biological maturation selection biases existed across playing positions. A non-parametric Kruskal-Wallis test was used to evaluate inter-positional differences. A small to very large selection bias in favour of early maturing players existed for GK (D = 0.7), CD (D = 1.65), FB (D = 0.49), CM (D = 0.62), WM (D = 0.78), and CF (D = 0.76) (p < 0.05). Maturational selection biases did not exist for CDM or CAM. Moreover, CD were significantly more advanced in maturation compared to FB, CDM and CAM (p < 0.05). This study supports the contention that maturation selection biases exist in youth soccer, but the magnitude of this bias is highly dependent upon playing position. The very strong maturity selection biases at the national level evidenced in this investigation highlight the need for Football Associations to explore strategies, such as futures programmes, to help to retain talented, yet late maturing athletes.

Age-, sex-, and maturity-associated variation in the phase angle after adjusting for size in adolescents.

BackgroundApplied research using the phase angle (PhA) in children and adolescents has increased notably. Using multilevel modeling in a fully Bayesian framework, we examined the relationships between PhA, age, sex, biological maturity status, and body size in 10–16-year-old adolescents.MethodsThe sample comprised 519 adolescents (women, n = 241; men, n = 278) from Campinas, São Paulo, Brazil. Biological maturity status was assessed with self-examination of pubertal development for sexual maturity and maturity offset protocol to estimate age at peak height velocity (PHV) for somatic maturity status. Stature and body mass were measured by anthropometry. Phase angle was calculated based on raw resistance and reactance values (50 kHz frequency) obtained by bioelectrical impedance with the foot-to-hand technology.ResultsThe multilevel regression analysis revealed that boys had significantly higher values of phase angle than girls, adjusting for age group and sexual maturity status. Overall, older and more mature adolescents had higher values of phase angle. When considering aligning variation in the phase angle by distance to estimated PHV (maturity offset), there was a higher association between the phase angle and time before and after predicted age at PHV for boys (r = 0.31, 90% CI: 0.23 to 0.39) than girls (r = 0.2, 90% CI: 0.11 to 0.28). When including body mass in the multilevel models, corresponding changes in the overall body mass mediate most of the influence of the maturity status and age group on the phase angle.ConclusionThe present study demonstrated that the variability in phase angle is related to inter-individual variation in sex, age, and maturity status, as well as differences in body size. Research with adolescents considering phase angle should use multilevel modeling with standardized parameters as default to adjust for the concurrent influence of sex, age, maturity status, and body size.

Poor Reliability of Measurement Instruments to Assess Acute Responses to Load in Soccer Players Irrespective of Biological Maturity Status.

To assess the short-term reliability of measurement instruments to quantify the acute psychophysiological response to load in adolescent soccer players in relation to biological maturity. Data were collected from 108 U12 to U17 soccer players on 2 consecutive weeks (pre, n = 32; at, n = 34; and post, n = 42 estimated peak height velocity). Measurements consisted of the Short Recovery and Stress Scale, a countermovement jump, assessment of leg stiffness, and a submaximal run to assess exercise heart rate and heart rate recovery. Test-retest reliability was assessed with the coefficient of variation (CV) and intraclass correlation coefficient (ICC). Items of the Short Recovery and Stress Scale showed poor reliability across maturity groups (CV = 7.0%-53.5%; ICC = .28 to .79). Only few countermovement jump variables (jump height, concentric impulse, and concentric velocity) possessed good reliability. For most variables of the countermovement jump, reliability was better for the post peak height velocity group followed by at-peak height velocity and prepeak height velocity. Very high levels of reliability across maturity groups were observed for exercise heart rate (CV < 1.8%; ICC > .94), while heart rate recovery was more variable (CV < 16.5%; ICC > .48). Results suggest that the majority of investigated variables have poor reliability, questioning their ability to detect small, yet meaningful changes in acute responses to load in adolescent soccer players.

Effects of Individualized Versus Traditional Power Training on Strength, Power, Jump Performances, and Body Composition in Young Male Nordic Athletes.

This study aimed to examine the effects of individualized-load power training (IPT) versus traditional moderate-load power training (TPT) on strength, power, jump performance, and body composition in elite young Nordic athletes. In a randomized crossover design, 10 young male athletes (ski jumpers, Nordic combined athletes) age 17.5 (0.6) years (biological maturity status: +3.5y postpeak height velocity) who competed on a national or international level performed 5weeks of IPT (4 × 5 repetitions at 49%-72% 1-repetiton maximum [RM]) and TPT (5 × 5 repetitions at 50%-60% 1-RM) in addition to their regular training. Testing before, between, and after both training blocks comprised the assessment of muscle strength (loaded back squat 3-RM), power (maximal loaded back squat power), jump performance (eg,drop-jump height, reactive strength index), and body composition (eg,skeletal muscle mass). Significant, large-size main effects for time were found for muscle strength (P < .01; g = 2.7), reactive strength index (P = .03; g = 1.6), and drop-jump height (P = .02; g = 1.9) irrespective of the training condition (IPT, TPT). No significant time-by-condition interactions were observed. For measures of body composition, no significant main effects of condition and time or time-by-condition interactions were found. Our findings demonstrate that short-term IPT and TPT at moderate loads in addition to regular training were equally effective in improving measures of muscle strength (loaded back squat 3-RM) and vertical-jump performance (reactive strength index, drop jump, and height) in young Nordic athletes.

Does adjusting for biological maturity when calculating child weight status improve the accuracy of predicting future health risk?

BackgroundThe aim of this study was to assess whether adjusting the weight categorisation of children for their biological maturity status could improve the accuracy of predicting weight status and cardiometabolic risk at age 17.MethodsData from 1525 participants (787 female) from the ALSPAC study were analysed. Participants’ weight status at age 11 was estimated using first standard chronological age and sex adjusted BMI cut-offs, and again using maturity adjusted BMI cut-offs. Each BMI category at age 11 was regressed against cardiometabolic risk score and BMI category at age 17, controlling for sex, ethnicity and socio-economic status.ResultsAt age 11 years, 22% of boys and 46% of girls who were categorised as overweight or having obesity based on chronological age were re-categorised into a lower BMI category after adjusting for biological maturity. Biologically adjusted BMI categories better predicted BMI category at age 17 compared with non-adjusted BMI categories (∆BIC = − 21.69); the odds of having obesity at age 17 were 18.28 times greater with each increase in BMI category at age 11. Adjusted and non-adjusted BMI status at 11 years showed equivalent accuracy in predicting cardiometabolic risk at age 17; the odds ratio of high cardiometabolic risk was 1.85, with heightened risk in boys, particularly early maturers.ConclusionThe traditional method of categorising adolescents into a BMI category may over-predict overweight and obesity, particularly in girls. Adjusting for biological maturity when estimating weight status through calculating adolescents’ BMI classification was equivalent to standard approaches in predicting other cardiovascular risk at age 17.

Multidimensional characteristics of young Brazilian volleyball players: A Bayesian multilevel analysis.

Brazil has been the benchmark for volleyball performance for at least two decades, providing a unique context to examine expertise development. This study examined the variation in body size, functional capacities, motivation for achievement, competitiveness, and deliberate practice of youth volleyball players associated with differences in biological maturity status, chronological age, and accumulated deliberate volleyball practice, adopting a Bayesian multilevel modeling approach. We considered 68 female and 94 male adolescent players (14.2 years, 90% confidence interval: 12.7 to 16.0). Players were grouped by the onset of deliberate volleyball practice as related to biologic maturation milestones [pre-puberty deliberate practice onset (12% of the sample), mid-puberty deliberate practice onset (51% of the sample), and late-puberty deliberate practice onset (37% of the sample). There was substantial variation in body dimensions and functional performance by gender. There was no variation by gender for motivation for deliberate practice and motivation for achievement and competitiveness. The young volleyball players appeared to be highly motivated and committed to deliberate practice, achievement, and competitiveness. Alignment of chronological age, biological maturation, and accumulated training experience allow more in-depth insights into young volleyball players' development, providing sounder support for coaches´ decisions.

Allometric association between physical fitness test results, body size/shape, biological maturity, and time spent playing sports in adolescents.

Regular participation in strength and conditioning activities positively correlates with health-related benefits in sports (team and individual). Maturity offset (MO) is a recognized parameter in fitness outcome assessment. The aims of the present study are to analyze cross-sectional allometric development of motor performances in a sample of adolescents and relate scaled motor performance to the estimated amount and type of physical activity and biological maturity status in 771 subjects aged 14–19 years. Three physical fitness components were evaluated using field tests (standing broad jump, sit-ups, shuttle run). Extra hours of sport after school (EHS) and MO were the covariates. The model to predict the physical performance variables was: Y = a · Mk1 · Hk2 · WCk3 · exp(b · EHS + c · MO) · ε. Results suggest that having controlled for body size and body shape, performing EHS and being an early developer (identified by a positive MO slope parameter) benefits children in physical fitness and motor performance tasks.

Construct validity of percentage of predicted adult height and BAUS skeletal age to assess biological maturity in academy soccer

Background The assessment of biological maturity status plays an important role in talent identification and development programs. Aim To compare age at predicted adult height and BAUS skeletal age as indicators of biological maturity status in youth soccer players using a construct-validity approach. Subjects and methods Participants were 114 players from the U12 to U17 age groups of a professional youth soccer academy. Maturity status was determined via percentage of predicted adult height based upon the Khamis-Roche method (somatic maturity) and assessed via the SonicBone BAUSTM system (skeletal maturity). Convergent and known-groups validity were evaluated between maturity assessment methods and by comparing maturity-related selection biases across age groups. Results Although maturity status indicators were largely interrelated (r = .94, 95%CL 0.91–0.96), concordance (κ = 0.31 to 0.39) and Spearman’s rank-order correlations (ρ = 0.45–0.52) of classification methods were moderate. A selection bias towards early maturing players emerged in the U14 age group which remained relatively consistent through to the U17 age group. Conclusions Results confirm the construct-validity of both methods to assess biological maturity status although further validation relative to established indicators of biological maturity is needed. Furthermore, caution is also warranted when interpreting maturity status classification methods interchangeably given the poor concordance between classification methods.

Characteristics of select and non-select U15 male soccer players.

Baseline characteristics of 31 healthy male U15 soccer players who were classified as select or non-select at the end of the season were compared. Players were 14.4 ± 0.54 years (13.6–15.3 years) at baseline; characteristics included body size, proportions and composition, estimated maturity status, several functional capacities, and coach classifications of potential in the sport. Decisions regarding selection or non-selection were made about two months after baseline. Select and non-select U15 soccer players differed significantly in estimated maturity status, body size, proportions and estimated muscle mass, functional tests related to speed, power and strength, and coach evaluation of potential, specifically tactical skills on offense and skills associated with creativity and decision making. When age and biological maturity status were statistically controlled, select and non-select players differed significantly only on the vertical jump, grip strength, and coach ratings of tactical skills on offense and of creativity and decision making. Results of stepwise discriminant analysis highlighted the importance of coach evaluation of tactical skills associated with offense, and of power and strength in distinguishing select from non-select players. The results highlight the advantages of advanced biological maturity status among adolescent male soccer players and also the importance of coach perceptions of talent. The latter implies a need for further study of the basis of coach perceptions, specifically how they are influenced by and perhaps interact with player characteristics at different ages, and how the perceptions influence playing time and player behaviors and interactions.

Biological Maturity Status in Elite Youth Soccer Players: A Comparison of Pragmatic Diagnostics With Magnetic Resonance Imaging.

The influence of biological maturity status (BMS) on talent identification and development within elite youth soccer is critically debated. During adolescence, maturity-related performance differences within the same age group may cause greater chances of being selected for early maturing players. Therefore, coaches need to consider players' BMS. While standard methods for assessing BMS in adolescents are expensive and time-consuming imaging techniques (i.e., X-ray and MRI), there also exist more pragmatic procedures. This study aimed to evaluate commonly used methods to assess BMS within a highly selected sample of youth soccer players. A total of N = 63 elite male soccer players (U12 and U14) within the German Soccer Association's talent promotion program completed a test battery assessing BMS outcomes. Utilizing MRI diagnostics, players' skeletal age (SAMRI) was determined by radiologists and served as the reference method. Further commonly used methods included skeletal age measured by an ultrasound device (SAUS), the maturity offset (MOMIR), and the percentage of adult height (PAHKR). The relation of these alternative BMS outcomes to SAMRI was examined using different perspectives: performing bivariate correlation analyses (1), modeling BMS as a latent variable (BMSlat) based on the multiple alternative diagnostics (2), and investigating individual differences in agreement (3). (1) Correlations of SAMRI and the further BMS variables ranked from r = 0.80 to r = 0.84 for the total sample and were lower for U12 (0.56 ≤ r ≤ 0.66), and U14 (0.61 ≤ r ≤ 0.74) (2). The latent structural equation modeling (SEM) (R2 = 51%) revealed a significant influence on BMSlat for MOMIR (β = 0.51, p <0.05). The additional contribution of PAHKR (β = 0.27, p = 0.06) and SAUS (β = −0.03, p = 0.90) was rather small (3). The investigation of individual differences between the reference method and alternative diagnostics indicated a significant bias for MOMIR (p <0.01). The results support the use of economical and time-efficient methods for assessing BMS within elite youth soccer. Bivariate correlation analyses as well as the multivariate latent variable approach highlight the measures' usefulness. However, the observed individual level differences for some of the utilized procedures led to the recommendation for practitioners to use at least two alternative assessment methods in order to receive more reliable information about players' BMS within the talent promotion process.