Kinesiology, Vol. 47. No. 2., 2015.
Original scientific paper
Lower-extremity side-to-side strength asymmetry of professional soccer players according to playing position
Cassio V. Ruas
; Federal University of Rio Grande do Sul, Brazil, Porto Alegre/RS, Brazil
Lee E. Brown
orcid.org/0000-0001-6269-4616
; California State University, Fullerton, Department of Kinesiology, Fullerton, CA, USA
Ronei S. Pinto
; Federal University of Rio Grande do Sul, Brazil, Porto Alegre/RS, Brazil
Abstract
Previous studies have utilized screening values of 10-15% of lower-extremity side-to-side strength asymmetry in soccer players with conflicting results. The purpose of this study was to determine differences in screening values for side-to-side asymmetry in soccer players according to their playing position, as well as to compare the differences in strength asymmetry between particular playing positions. Seventy-nine Brazilian male professional soccer players (age 26.1±5.3 years; body mass 79.8±14.4 kg; body height 180.4±12.9 cm) were grouped into playing positions of: goalkeepers, side backs, central backs, central defending midfielders, central attacking midfielders, and forwards. They performed maximal knee extension and flexion concentric and knee flexion eccentric actions on their preferred and non-preferred legs at 1.047 rad·s-1. Forwards and goalkeepers had hamstrings concentric peak torque asymmetry (18.0±9.9%) and eccentric peak torque asymmetry (20.1±10.7%) significantly greater than 10% (p<.05). All other playing positions had values less than 15%. Our results indicate that the use of either 10 or 15% asymmetry cut off may result in different conclusions, which may affect decision-making regarding strength ratios. Furthermore, if 10% is used as a
screening value, hamstrings strengthening programs based on bilateral equivalency should be prescribed for goalkeepers and forwards to reduce asymmetry.
Keywords
isokinetic assessment; knee imbalance; peak torque
Hrčak ID:
150545
URI
Publication date:
31.12.2015.
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