Despite Good Correlations, There Is No Exact Coincidence between Isometric and Dynamic Strength Measurements in Elite Youth Soccer Players

Research output: Journal contributionsJournal articlesResearchpeer-review

Authors

  • Carl M. Wagner
  • Konstantin Warneke
  • Christoph Bächer
  • Christian Liefke
  • Philipp Paintner
  • Larissa Kuhn
  • Torsten Brauner
  • Klaus Wirth
  • Michael Keiner
Speed strength performances are substantially dependent on maximum strength. Due to their importance, various methods have been utilized to measure maximum strength (e.g., isometric or dynamic) with discussed differences regarding transferability to sport-specific movements dependent upon the testing procedure. The aim of this study was to analyze whether maximum isometric force (MIF) during isometric back squats correlates with maximum strength measurements of the one repetition maximum (1RM) in the squat, with countermovement jump (CMJ) performance, and with drop jump (DJ) performances in elite youth soccer players (n = 16, 18.4 +/- 1.5 [range: 17-23] years old). Additionally, concordance correlation coefficients (CCC, [rho(c)]) between isometric and dynamic measurements were calculated to verify whether one measurement can actually reproduce the results of the other. To improve comprehension, differences between isometric and dynamic testing values were illustrated by providing differences between both testing conditions. For this, the mean absolute error (MAE) and the mean absolute percentage error (MAPE) were calculated. To reach equality in scale, the 1RM measures were multiplicated by 9.81 to obtain a value of N. The 1RM demonstrated correlations of tau = |0.38| to |0.52| with SJ and CMJ performances, while MIF demonstrated correlations of tau = |0.21| to |0.32|. However, the correlations of both 1RM and MIF with the DJ reactive strength index (RSI = jump height/contact time) from different falling heights were of no statistical significance. The data showed significant correlations between both the absolute (tau = |0.54|) and the relative (tau = |0.40|) performances of 1RM and MIF, which were confirmed by CCC of rho(c)= |0.56| to |0.66|, respectively. Furthermore, the MAE and MAPE showed values of 2080.87 N and 67.4%, respectively. The data in this study show that, despite good correlations, there is no exact coincidence between isometric and dynamic strength measurements. Accordingly, both measurements may only represent an estimation of maximal strength capacity and cannot be substituted for each other. Therefore, maximal strength should be tested by using high similarity in the contraction condition, as it is used in the training process to counteract underestimation in strength because of unfamiliarity with the testing condition.
Original languageEnglish
Article number175
JournalSports
Volume10
Issue number11
Number of pages12
DOIs
Publication statusPublished - 10.11.2022

Bibliographical note

Publisher Copyright:
© 2022 by the authors.

Documents

DOI

Recently viewed

Publications

  1. "Stimmiger Auftritt"
  2. Is it really worth it?
  3. Archetypes of Platform-Hosted Crowds
  4. Comment on "nomenclature, Chemical Abstracts Service Numbers, Isomer Enumeration, Ring Strain, and Stereochemistry
  5. Lesetechnik
  6. With a little help from my website. Firm survival and web presence in times of COVID-19 - Evidence from 10 European countries
  7. Das Echo des Propheten Jesaja
  8. Patterns of ecosystem services supply across farm properties: Implications for ecosystem services-based policy incentives
  9. Nachhaltigkeitsethik
  10. Is the wild rabbit (Oryctolagus cuniculus) a threatened species in Spain? Sociological constraints in the conservation of species
  11. What is sustainable agriculture? A systematic review
  12. Palmarum
  13. Vom Abfall zum Einfall
  14. Xenogeneic infection risk: limits to individual right restrictions
  15. Benefits of being ambivalent
  16. Establishment age and wages
  17. Medialization of science as a prerequisite of its legitimization and political relevance
  18. Material and money flows as a means for industry analysis of recycling schemes
  19. "Werde, der du bist"
  20. Zukunft Bologna!?
  21. Governance Challenges at the Interface of Food Security and Biodiversity Conservation
  22. Leveraging Biodiversity Action From Plural Values
  23. Die "Matheasse" in Jena - ein Projekt zur Förderung mathematisch interessierter und (potenziell) begabter Grundschüler
  24. The structure of requests in Irish English and English English
  25. A note on firm age and the margins of imports: first evidence from Germany
  26. Fallstudie
  27. Digital Transformation of Interdisciplinary Engineering Education