Abstract
Strength is an important component of fitness in health and disease because weak muscles may markedly limit a person's physical fitness and daily physical abilities. Testing of isokinetic strength provides an objective approach in diagnostics and simpler quantification of muscular strength and endurance in children and adolescents.
Nevertheless, in this field there are many gaps dealing with its manifestation among youths.The purpose of the study was to compare knee extensors and flexors strength in non-sporting children and detect its differences with respect to gender, contraction velocity and lower limb dominancy.The group of non-sporting children (n = 43, boys: n = 25, age = 11.5+-0.2 years, height =157.0+-7.3cm, weight = 52.8+-13.2 cm, girls: n = 18, age = 11.6+-0.4 years, height =155.7+-6.0cm, weight = 53.8+-13.6 cm) was tested on the isokinetic dynamometer Cybex at five velocities (60, 120, 180, 240, 300 o.s-1) for the dominant (DL) and non-dominant leg (NL) during the knee flexion and extension in concentric contraction. Three-way Mixed-design ANOVA (2x2x5) with two between subject effect (age (A), laterality (L)) and one within subject effect (angular speed) was used for evaluation of PT differences between the factors.Strength of knee extensors (PTE) and flexors (PTF) was significantly different depending on angular speed (PTE: F2.4;195.6 = 434.7, p<0.01, η2 = 0.84 or PTF: F2.8;226.3 = 168.9 p<0.01, η2 = 0.67 respectively).
The levels of PTE and PTF were significantly different in all tested velocities (p<0.01). Gender had a significant effect on the level of both PTE (F1;82 = 4.05, p<0.05, η2 = 0.05) and PTF (F1;823 = 11.33, p<0.01, η2 = 0.12).
Knee flexors and extensors strength is dependent on contraction velocity. The boys of this age group achieved significantly higher values of PT in comparison to the girls.
In any of the groups, no difference between the dominant and non-dominant limb was detected.