title: Cross-sectional investigation of indices of isokinetic leg strength in youth soccer players and untrained individuals.
abstract: In this cross-sectional study, the differences in the isokinetic peak torque of the knee joint muscles (dominant and non-dominant) were investigated in three groups of youths (n=45; age, 14.9+/-1.1 years) with different soccer training backgrounds. Significant main effects were observed for training background on the functional hamstrings to quadriceps ratios for knee flexion (H(CON):Q(ECC) ratio; F(2,42)=4.023, P=0.025) and extension (H(ECC):Q(CON) ratio; F(2,42)=8.53, P<0.001) at 4.32 rad/s. Post hoc tests indicated that both ratios were significantly different between conventionally trained players compared with resistance-trained players and controls (mean+/-SD; H(ECC):Q(CON) ratio, dominant limb; 0.91+/-0.10; 1.04+/-0.12; 1.10+/-0.22; non-dominant limb; 0.89+/-0.09; 1.05+/-0.19; 1.06+/-0.15; H(CON):Q(ECC) ratio, dominant limb; 0.36+/-0.06; 0.34+/-0.07; 0.30+/-0.08; non-dominant limb; 0.33+/-0.05; 0.32+/-0.08; 0.28+/-0.07). Results suggest that the muscle-loading patterns experienced in youth soccer may alter the reciprocal balance of strength about the knee under high-velocity conditions. The findings also indicate that these balances may be improved by incorporating resistance training into the habitual exercise routines of youth soccer players.
authors.affiliation: Faculty of Sport, Health and Social Care, University of Gloucestershire, Gloucestershire, UK.
authors.forename: J
authors.initials: J
authors.lastname: Iga
authors.forename: K
authors.initials: K
authors.lastname: George
authors.forename: A
authors.initials: A
authors.lastname: Lees
authors.forename: T
authors.initials: T
authors.lastname: Reilly
mesh_terms: D000293:Adolescent; D054874:Athletic Performance; D001696:Biomechanical Phenomena / Q000502:physiology; D003430:Cross-Sectional Studies; D006801:Humans; D007866:Leg; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D055070:Resistance Training; D012916:Soccer; D019415:Torque; D006113:United Kingdom