The impact of strength exercises of involved in sports activities and not involved in sports activities 11-13 year old children quadriceps muscle thickness and function

The subject of research: changes of quadriceps muscle strength, thickness and thigh volume applying strength exercises. The problem of research: research shows that the involvement of majority of Lithuanian schoolchildren in sports activities is insufficient. Lack of physical activity has an adverse effect on their growth and maturity. Scientists, who have studied the issue of physical activity of children in Lithuania, envisage obviously declining trends of physical activity. Research data show that physical activity of more than 20% of boys and over 40% of girls in Lithuania is sufficient. Physical activity is an integration of active movements of muscles and joints (Mickeviciene et al., 2006). Biological maturity is one of the important factors determining a physiological respond of an organism to exercises. The objective of the research: to assess the impact of strength exercises on the thickness and function of quadriceps muscle of involved in sports activities and not involved in sports activities 11 – 13 year old children. Objectives: 1. To assess of quadriceps muscle thickness, strength and thigh volume between the teenagers involved and not involved in sports activities prior to and after the application of strength exercises. 2. To compare the results of quadriceps muscle thickness, strength and thigh volume between the children of different gender. 3. To assess the quadriceps muscle strength, thickness and thigh volume on the study dominant and non-dominant leg. 4. To assess the relationship between quadriceps muscle thickness, strength and thigh volume. Hypothesis: Hope that the strength exercises will have a positive impact of quadriceps muscle thickness and strength and thigh volume increase. 7 Conclusions: 1. After application of strength exercises the increase in thigh volume, quadriceps muscle thickness and strength was statistically significant (p0.05) in the group not involved in sports activities. 2. Thigh volume between the genders in both groups did not show statistically significant difference (p>0.05); muscle strength of boys was statistically significantly higher (p0.05) prior to and after the application of strength exercises. 4. The closest correlation was between the quadriceps muscle thickness and thigh volume as well as between the quadriceps muscle strength and thickness. Relation between the quadriceps muscle strength and thigh volume was average or week