The aim of this study was to provide normative values of IS parameters in elite young soccer players. The sample consisted of elite youth soccer players of U16 category (n = 134).
Diagnostics was performed on the isokinetic dynamometer during concentric contractions at an angular speed of 60 o.s-1. We evaluated the following parameters: maximum peak muscle torque of knee extensors (PTE) and flexors (PTF) in the preferred (PL) and non-preferred leg (NL), ipsilateral ratio for both extremities (H:QP and H:QN), bilateral ratio between the knee extensors (QP:QN) and flexors (HP:HN).
Percentile scale and parametric t-test were used to data analysis. Normative values for the observed parameters were as follows: (N.kg-1): PTE-PL: P25 = 2.85, P50 = 3.11, P75 = 3.40, PTE-NL: P25 = 2.89, P50 = 3.06, P75 = 3.30; PTF-PL: P25 = 1.66, P50 = 1.82, P75 = 2.00, PTF-NL: P25 = 1.58, P50 = 1.75, P75 = 3.30.
Bilateral force deficit in knee extensors was (%): P25 = 3.0, P50 = 6.00, P75 = 12.00 and in knee flexors (%): P25 = 4.00, P50 = 8.00, P75 = 13.00. Ipsilateral ratio H:Q was in the preferred leg (%): P25 = 53, P50 = 59.00, P75 = 64.00 and in the non-preferred leg (%): P25 = 51.00, P50 = 58.00, P75 = 63.00.
The players achieved significantly higher PTKF-PL(p<0.01).Results of the study may be used as a portfolio performance related to the comparison of normative values. More attention should be paid to knee flexors and ipsilateral ratio in the non-preferred leg.