Publications

2024 – Normative Reference Centiles for Sprint Performance in High-Level Youth Soccer Players: The Need to Consider Biological Maturity

Ludwig Ruf,1,2 Stefan Altmann,1,3 Christian Kloss,2 and Sascha Härtel2 1TSG ResearchLab gGmbH, Zuzenhausen, Germany; 2TSG 1899 Hoffenheim, Zuzenhausen, Germany; 3Department for Performance Analysis, Institute of Sports and Sports Science, Karlsruhe Institute of Technology, Karlsruhe, Germany

Pediatric Exercise Science, Volume 36: Issue 4, 2024, P 192–200

https://doi.org/10.1123/pes.2023-0186

Conclusion:  The findings of this study provide a valuable tool to assist the evaluation of sprint performance in relation to biological maturity status (assessed by Sonicbone’s BAUSport) for talent identification purposes in highly trained youth soccer players.

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2024 – Selection-Dependent Differences in Youth Elite Basketball Players’ Relative Age, MaturationRelated Characteristics, and Motor Performance

Daniel Leyhr a , David Rösch a , Sean P.Cumming b , and Oliver Höner a Eberhard Karls University of Tübingen, Germany; b University of Bat UK

Research Quarterly for Exercise and Sport

https://doi.org/10.1080/02701367.2024.2311644

Conclusion: For this purpose, skeletal age assessment by ultrasound diagnostics (By SonicBone) seems promising... Meanwhile, mobile ultrasound devices exist that estimate an individuals’ skeletal age based on three various spots and/or positions of the hand and have been shown to be reasonably accurate when compared to reference diagnostics in comparable settings in soccer .. With only little effort possible maturity-related bias in the performance data can be avoided by simple corrections. As a result, coaches or scouts get an additional view on the players which might put certain players (i.e., late-maturing players) into coaches’ focus which would have been deselected otherwise.

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2023 – “Monitoring Training Load and Responses to Load in Youth Soccer, Special Reference to Biological Maturation” (N=114 from U12 to U17).

By Dr. Ludwig Ruff 

PhD thesis submitted to Saarland University, Germany

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 BAUSport skeletal age as indicators of biological maturity status in youth soccer players.

Methods: Maturity status was determined via percentage of predicted adult height based upon the Khamis-Roche method (somatic maturity) and assessed via the SonicBone BAUSport system (skeletal maturity).

Conclusion: A selection biases towards early maturing players emerged in the U14 – U17 age group. Results confirm the construct-validity of. SonicBone BAUSport system to assess biological maturity status.

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2023 – The Validity of automatic methods for estimating skeletal age in young athletes: a comparison of the BAUSport ultrasound system and BoneXpert with the radiographic method of Fels, Greulich-Pyle, and Tanner-Whitehouse III

  • Sean Cumming PhD, Paediatric Exercise Science, University of Bath, UK
  • Ramon Pi-Rusiñol, MD, Futbol Club Barcelona Medical Services and Barça Innovation Hub, Barcelona Spain.
  • Gil Rodas, MD, Futbol Club Barcelona Medical Services and Barça Innovation Hub, Barcelona Spain.
  • Franchek Drobnic, MD, Futbol Club Barcelona Medical Services and Barça Innovation Hub.
  • Alan D. Rogol, MD, Pediatric Endocrinology, School of Medicine, University of Virginia, Charlottesville, VA USA.

Biology of Sport – Vol. 41 No1, 2024.

Conclusion: The study findings support the use of BAUSport as an alternative, practical and non-invasive method for the estimation of Skeletal Age in young athletes. In comparison to the established methods for estimating Skeletal Age in youth, the BAUSport system performed well and especially in the categorization of youth as advanced, on-time, and delayed in maturation.

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2023 – Assessing biological maturity timing by MRI and coaches’ eye in elite youth soccer players: A comparison between objective and subjective diagnostics utilizing correlation and single case analyses

Daniel Leyhr1,2, Dennis Murr1, Michael Romann3, Katrin Eichler4, Lajos Basten4,5, Thomas Hauser6, Dennis Lüdin3, and Oliver Höner1

1 Institute of Sports Science, Eberhard Karls University Tübingen, Tübingen, Germany… 6 Medical Center, DFB Academy, Frankfurt, Germany

International Journal of Sports Science & Coaching. 

https://journals.sagepub.com/doi/10.1177/17479541231152820

Conclusion (N=93): Although utilizing subjective coach assessments as an alone standing tool to assess a player’s BMT is not recommended in applied practice, its use can be beneficial when applied in addition to common objective diagnostics that are appropriate in daily practical work within youth soccer (e.g., Sonicbone ultrasound-based diagnostics) or in circumstances where objective data are not available

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2023 –  The combined effects of growth and maturity status on injury risk in an elite football academy 

Xabier Monasterio1,2,3, Sean P. Cumming3, Jon Larruskain2 , David M. Johnson3 , Susana M. Gil1 , Iraia Bidaurrazaga-Letona1 , Jose A. Lekue1,2, Gontzal Diaz-Beitia1,2, Juan M. Santisteban1,2, Sean Williams3

1 Department of Physiology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain; 2 Medical Services, Athletic Club, Lezama, Spain; 3 Department for Health, University of Bath, Bath, United Kingdom

Biol of Sport. 2024;41(1):235–244

Conclusion:

Practical application – In light of the results above, we recommend academy practitioners to measure players height every 3–4 months to model individual growth curves and estimate growth velocities. In order to monitor maturity status ….. SonBicBone BAUSPORT system (skeletal maturity via ultrasound) could be used to estimate percentage of predicted adult height.

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2023 – “Bone Age Assessment in Children Using Ultrasound Compared to Hand X-ray  (G&P method)”

Conclusion: (N=260, coming soon) – Bone Age estimated by BAUSport is substantially equivalent to physicians’ Bone Age estimates, for both males and females


2022 – Soccer coaches vs. sport science and medicine staff: who can more accurately predict the skeletal age of high-level youth soccer players?

Science and Medicine in Football ;   DOI: 10.1080/24733938.2022.2100461

Ludwig Ruf, Stefan Altmann, Christian Kloss, Sascha Härtel

TSG ResearchLab & TSG 1899 Hoffenheim eV  ;  Karlsruhe Institute of Technology Institute of Sports Science

Conclusion: (N=89, U12 to U16, 12 soccer coaches, 5 sport scientists & medical staff)

Soccer Coaches (SC) were slightly more accurate than the Sports Science and Medicine Staff (SSMS) in prediction of skeletal age (SA). Large Inter-individual variation in SA (up to 5 years within one age group). Moreover, findings suggest that both SC and SSMS equally underestimated and overestimated the SA of early and late maturing players, with poor to moderate inter-rater reliability within age groups… The objective assessment of biological maturity remains an important cornerstone in the routine player monitoring procedure, which might help SC and SSMS alike to optimize talent identification, selection, and development processes.

BAUSport was used as the objective reference for Skeletal Age determination.

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2022 – “Methods for determining growth and biological maturation in junior sports”
Ludwig Ruf, Sascha Hartle et al., 2022, TSG 1899 Hoffenheim Akademie 
TraininGswissenschaft Und -Lehre,  Leistungssport 3/2022, p13

SonicBone (BAUS) can determine the skeletal age using ultrasound. This method was recently validated by independent scientific workgroups as well as in a form of criteria validation against the FELS, G&P and TW2 methods, and also against percentage estimation of adult height method. Many limitations of the traditional X-ray based methods, are overcome by using this ultrasound based BAUS method, so an ongoing and regular assessment of skeletal age in context of growth in sports is made possible”.

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2021 – Construct validity of percentage of predicted adult height (Khamis-Roche method) and  BAUSport skeletal age to assess biological maturity in academy soccer”.

Ludwig Ruf1, Prof. Sean Cumming PhD2, Dr. Sascha Härtel3, Prof. Anne Hecksteden PhD4 , Prof. Barry Drust PhD5, Prof. Tim Meyer PhD6

Annals of Human Biology, 2021, 48(2), 101-109 https://doi.org/10.1080/03014460.2021.1913224

Conclusion: (N=144) The BAUSport TM system provides a reasonable non-invasive indicator of skeletal maturity that is moderately associated with percentage of predicted adult height derived from the Khamis-Roche method.

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2020 – “Biological Maturity Status in Elite Youth Soccer Players: A Comparison of Pragmatic Diagnostics with Magnetic Resonance Imaging”

Daniel Leyhr 1,2 * † , Dennis Murr 1 * † , Lajos Basten3 , Katrin Eichler 3 , Thomas Hauser 4 , Dennis Lüdin5 , Michael Romann5 , Giuseppe Sardo1,4 and Oliver Höner 1

1 Department of Sport Psychology and Research Methods, Institute of Sports Science, Eberhard Karls University of Tübingen, Tübingen, Germany,

2 Methods Center, Eberhard Karls University of Tübingen, Tübingen, Germany,

3 Department of Diagnostic and Interventional Radiology, Goethe-University Hospital Frankfurt, Frankfurt, Germany,

4 Deutscher Fußball-Bund, Frankfurt, Germany, 5 Swiss Federal Institute of Sport Magglingen SFISM, Department of Elite Sport, Magglingen, Switzerland

Conclusion: The results suggest that the use of SAUS, (BAUSport) MOMIR, and PAHKR for measuring BMS is more pragmatic in terms of cost and time as compared with MRI diagnostics. Based on a general agreement between these pragmatic diagnostics and the reference method MRI in all three perspectives, the alternative methods can be used to determine BMS among (male) elite youth soccer players

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2020 – “Evaluation of the BAUSport System (By Sonicbone) for Assessing Skeletal Age in Youth”

Dr Sean Cumming, Professor in Paediatric Exercise Science University of Bath, UK

Conclusion: “In comparison to existing methods, the BAUSport method serves as an equally valid and reliable (if not more) measure of skeletal age (as determined by the Fels x-ray based method)”.

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2017 – BONE AGE DETERMINATION BY ULTRASOUND (BAUS) VALIDATION IN BRAZILIAN YOUNG STUDENTS

Santa Casa de São Paulo – School of Medical Sciences Pediatric Endocrinology

 Alvares MA¹; Amaro ML¹; Kochi F²; Sant Ana JP²; Silva TSS¹; Avritchir R³; Kochi C¹; Longui CA¹ Irmandade da Santa Casa de Misericórdia de São Paulo ;

1. Pediatric Endocrinology ; MD; 2. Medical Student; 3. Radiology

Hormone  Research in Paediatrics, Vol. 88, Supp 1, 2017, p 111.

Conclusion: (N=494) “There is a significant positive correlation between BAUS and BARx. BAUS is a safe and practical method of bone age determination, with potential clinical applicability”.

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2017 – Bone Age Assessments by Quantitative Ultrasound (SonicBone) and Hand X-ray Based Methods Are Comparable

Marianna Rachmiel MD1,2, Larisa Naugolni MD1, Kineret Mazor-Aronovitch MD2,3, Nira Koren-Morag PhD4 and Tzvi Bistritzer MD1,2

1 Pediatric Endocrinology Clinic, Assaf Harofeh Medical Center, Zerifin Israel

2 Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel

3 Pediatric Endocrinology Unit, Sheba Medical Center, Tel Hashomer, Israel

4 Department of Epidemiology and Statistics, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel

Conclusion: (N=150) “The radiation-free assessment of bone age in the pediatric population attending endocrine clinics by the BAUS device developed by SonicBone was found to be highly reproducible and comparable to bone age assessed by X-rays based methods with no immediate side effects during usage”.

IMAJ, VOL19, September 2017; Page 2

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2017 – “Evaluating Bone Age and Predicting Young Athletes’ Final Height by a Novel Ultrasound Device (Sonicbone’s BAUSportTM) and their Applications to Talent Selection, Training and Sports Medicine.

Oral presentation by Prof. Yuval Heled PhD at the 8th Asia-Pacific Congress (APCST) on Sports Technology, Tel-Aviv, Israel                                                     

Conclusions: “BAUSportTM can serve as a routine tool for implementation of more scientifically-based programs for training and injury prevention in youth athletes, with better talents selection process for various sports”.

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2016 – “Quantitative Sonometeric (BAUS) Bone Age as a Function of Height and BMI”

Alina German, MD1,  Nira Koren-Morag, PhD2 , Shmuel Levin3 , Prof. Ze’ev Hochberg, MD, PhD4

Conclusion: (N=450) “Shorter and thinner pubertal but not pre-pubertal children have delayed BA as compared to taller and heavier children. ii) The full-length phalanx maturation is affected by height more than the wrist and metacarpals’ epiphyses. iii) The radius-ulna epiphyses are affected by BMI more than the metacarpals and phalanx. iv) These influences have now on to be accounted for in the assessment of a BA.” 

Horm Res Paediatr 2015; 84 P-2-241

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2015 – “On the need for national, racial, or ethnic-specific standards for the assessment of bone maturation“. 

Prof. Ze’ev Hochberg, MD PhD, Eur J Endocrinol. 2015 Sep 28. pii – EJE-15-0673

Conclusion: The notion that genes are the primary determinants of physiognomy, which also includes growth-related traits, has been repeatedly disproved. Based on a fundamental understanding of phenotypic plasticity and an individual’s ability to respond to environmental cues, we do not need ethnic-specific standards for bone maturity.

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