Opis: Objective: To investigate associations between running speeds and contraction times in 8- to 13-year-old children.
Method: This longitudinal study analyzed tensiomyographic measurements of vastus lateralis and biceps femoris muscles’ contraction times and maximum running speeds in 107 children (53 boys, 54 girls). Data were evaluated using multiple correspondence analysis.
Results: A gender difference existed between the vastus lateralis contraction times and running speeds. The running speed was less dependent on vastus lateralis contraction times in boys than in girls. Analysis of biceps femoris contraction times and running speeds revealed that running speeds of boys were much more structurally associated with contraction times than those of girls, for whom the association seemed chaotic.
Conclusion: Joint category plots showed that contraction times of biceps femoris were associated much more closely with running speed than those of the vastus lateralis muscle. These results provide insight into a new dimension of children’s development.Ključne besede: children, tensiomyography, running speed, contraction time, skelet muscle, motor developmentObjavljeno: 13.07.2017; Ogledov: 132; Prenosov: 21 Celotno besedilo (454,48 KB)
Opis: Biceps femoris is a major propulsor muscle in sprinting and its contraction time negatively correlates to the running speeds of adults. Our aim was to compare age and gender-related correlations between vastus lateralis and biceps femoris contraction times and running speeds during a longitudinal study of 9- to 14-year old children. On a yearly basis we conducted vastus lateralis and biceps femoris tensiomyographic measurements of muscle contraction time and maximal running speeds measured during 7 meter sprints with flying starts using photocells in 107 children (53 boys). Vastus lateralis contraction time was not correlated with the running speed. However, biceps femoris contraction time was negatively correlated with the running speed only in boys after the age of 12.9 years (Pearson r ranges from -0.391 to -0.426; p < 0.002). It was concluded that biceps femoris contraction time is far less correlated with running speed than in adult athletes (Pearson r = -0.60); however, the correlation is gender and age-specific. It seems that the knee flexor and hip extensor, biceps femoris, is not as yet the major determinant of running speed in 9- to 14-year old children at that age.Ključne besede: skeletal muscles, biceps femoris, vastus lateralis, tensiomyography, pediatricsObjavljeno: 21.07.2017; Ogledov: 223; Prenosov: 12 Celotno besedilo (604,33 KB)