ISSN: 1899-1955
Human Movement
Current issue Articles in Press Archive Special Issues About the journal Editorial board Instructions for Reviewers Journal's Reviewers Ethical standards and procedures Abstracting and indexing Contact Instructions for authors
Editorial System
Submit your Manuscript
SCImago Journal & Country Rank
vol. 23
Review paper

Asymmetries of isokinetic strength and flexibility in young soccer players: a systematic review

Sarah Ramos
1, 2
Marcelo Corso
Amanda Brown
1, 3
Roberto Simão
Ingrid Dias

School of Physical Education and Sports, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
Medical Department, Club de Regatas Vasco da Gama, Rio de Janeiro, Brazil
Graduate Program in Clinical Medicine, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
Hum Mov. 2022;23(4):21-33
Online publish date: 2022/02/21
View full text Get citation
PlumX metrics:
The study aim was to review the isokinetic strength assessment protocols, the obtained peak torque (PT) values, and the hamstring/quadriceps ratio (H/Q); review the unilateral evaluation protocols and normative values for flexibility; and verify the existence of asymmetries between the limbs, muscle imbalances, or bilateral differences (BD) in the strength and flexibility of young soccer players.

The PRISMA model was used. Searches were conducted in PubMed, SciELO, and LILACS, divided into soccer, isokinetic, and flexibility. Inclusion criteria: articles with a sample of young elite male soccer players with an average age less than 20 years; isokinetic strength assessment: presentation of values for absolute PT and/or H/Q ratio; flexibility assessment: use of unilateral tests for the hip flexion movement. The quality and risk of bias in each study were also analysed.

In the isokinetic strength, a symmetrical pattern was observed for PT and the H/Q ratio between the limbs and divergent results for BD. Regarding flexibility, it was possible to verify a tendency towards an asymmetry of flexibility, with a more flexible dominant than non-dominant leg. Evaluation protocols and normative values were proposed for the tests of isokinetic strength and flexibility.

Imbalances for the H/Q ratio, asymmetries, and BD for isokinetic strength and flexibility are not natural aspects of the modality and should be avoided in young soccer players. The monitoring of these characteristics and the use of interventions to restore a symmetrical pattern have become essential since the beginning of sports life.


athletes, muscle strength dynamometer, muscle strength, range of motion, side-to-side differences

Quick links
© 2023 Termedia Sp. z o.o.
Developed by Bentus.