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Assessment of skeletal age in youth female soccer players: Agreement between Greulich‐Pyle and Fels protocols

journal contribution
posted on 24.11.2021, 16:35 by Diogo V Martinho, Manuel J Coelho‐e‐Silva, João Valente‐dos‐Santos, Cláudia Minderico, Tomás G Oliveira, Inês Rodrigues, Jorge Conde, Lauren SherarLauren Sherar, Robert M Malina
OBJECTIVE: The purpose of the study was to evaluate the agreement between the Fels and Greulich-Pyle methods for the assessment of skeletal age (SA) in female youth soccer players. METHODS: The sample included 441 Portuguese players 10.08-16.73 years of age who regularly participated in organized and competitive soccer. Standardized radiographs of the left hand-wrist were obtained and analyzed by an experienced examiner. SA was estimated with the Fels and Greulich-Pyle (GP) methods. Differences between SA and chronological age (CA) were used to define skeletal maturity groups: late, average and early maturing. In addition to descriptive statistics, Cohen's kappa and Lin concordance correlation coefficients were used to evaluate agreement between methods. RESULTS: Intraindividual differences in SA based on the two methods varied between 0.10 to 1.47 years among age groups with larger mean differences at older ages. Agreement of maturity classifications between methods was 74% at younger ages (under-13: kappa = 0.48; under-14: kappa = 0.39; Lin CCC = 0.68) and declined with increasing CA (under-17: 19% agreement; kappa = 0.001; Lin CCC = 0.11). About 19% of the total sample was skeletally mature with the Fels method and an SA was not assigned; in contrast, no players were skeletally mature with the GP method. CONCLUSIONS: GP SAs were systematically lower than Fels SAs among female soccer players. Intraindividual variability in SAs between methods was considerable. The findings highlight the impact of method on estimates of maturity status.


CIDAF. Grant Number: FCT (uid/dtp/04213/2020)

Diogo V. Martinho. Grant Number: FCT (SFRH/BD/121441/2016)



  • Sport, Exercise and Health Sciences

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American Journal of Human Biology




AM (Accepted Manuscript)

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© Wiley Periodicals LLC

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This is the peer reviewed version of the following article: MARTINHO, D.V. ... et al, 2021. Assessment of skeletal age in youth female soccer players: Agreement between Greulich‐Pyle and Fels protocols. American Journal of Human Biology, doi:10.1002/ajhb.23591, which has been published in final form at This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.

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Prof Lauren Sherar. Deposit date: 23 November 2021

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