title: Relative torque profiles of elite male youth footballers: effects of age and pubertal development.
abstract: This study aimed to establish the effect of age and pubertal development on relative peak torque in youth footballers. One hundred and fifty-seven subjects were arranged into U12-U18 age groups; of these 133 also completed a self-reporting measure of pubertal development (PDS) and were grouped accordingly. Bilateral isokinetic testing included mean peak torque/body weight (PT/BW) and angle of peak torque (AoPT) for reps 2-4 of 5 in concentric quadriceps (CQ), concentric hamstrings (CH) and eccentric hamstrings (EH) at 60 degrees s(-1). Two minutes rest were provided between concentric and eccentric tests for both legs. A significant increase with age was noted for PT/BW in CQ, CH and EH (P<0.05), although POST HOC analyses revealed different patterns of significance dependent upon muscle and type of contraction. Specifically, the U18 s (CQ:2.20 nm/kg, CH:1.39 nm/kg, EH:2.16 nm/kg) were not significantly stronger than the U16 s and U15 s (CQ:2.42/2.29 nm/kg, CH:1.41/1.27 nm/kg, EH:2.22/2.15 nm/kg) even though they had entered full time training. The relationship between EH PT/BW and AoPT showed a weak but significant inverse correlation (P<0.001; R= -0.390 and -0.346 for dominant and non dominant legs). The findings of this study present unique football specific normative and age/PDS group data for PT/BW and AoPT, and the corresponding relationship between these variables.
authors.affiliation: Department of Sport, Health and Exercise Science, University of Hull, Hull, United Kingdom. H.Forbes@hull.ac.uk
authors.forename: H
authors.initials: H
authors.lastname: Forbes
authors.forename: A
authors.initials: A
authors.lastname: Bullers
authors.forename: A
authors.initials: A
authors.lastname: Lovell
authors.forename: L R
authors.initials: LR
authors.lastname: McNaughton
authors.forename: R C
authors.initials: RC
authors.lastname: Polman
authors.forename: J C
authors.initials: JC
authors.lastname: Siegler
mesh_terms: D000293:Adolescent; D000367:Age Factors; D000704:Analysis of Variance; D005080:Exercise Test; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D007866:Leg / Q000502:physiology*; D007869:Leg Injuries / Q000517:prevention & control*; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D011627:Puberty / Q000502:physiology*; D012741:Sexual Maturation; D012916:Soccer / Q000502:physiology*; D013178:Sports Medicine; D013223:Statistics as Topic; D019415:Torque