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Background: The aim of the study was to estimate differences in bioelectrical activity between rectus femoris (RF) and vastus medialis (VM) muscles of each lower limb. Material/Methods: 29 female and 18 male adult subjects participated in the study. Each subject performed the following quadriceps contractions with each lower limb: concentric, isometric, eccentric and 30-sec. long maximal voluntary isometric contraction. 3 parameters were obtained in surface electromyography (SEMG): mean RMS amplitude (RMS), mean percentage value of maximal voluntary contraction (%MVC) and mean frequency (MF). Results: RF occurred to have a lower percentage activity (-28.43%) and absolute amplitude (- 36.57%) value than VM during all three basic forms of contraction against gravity. Except the RMS values for concentric contraction, all the mentioned parameters were significantly different. In contrast, RF had a higher MF rate than VM. Differences were at the mean level of 22.57% for all activities. Conclusions: There are no differences in SEMG of quadriceps muscle between both lower limbs. VM and RF differ from each other in RMS, %MVC and MF during all types of studied contractions.
Background: The aim of the study was to determine the level of maintaining body balance in a handstand among gymnasts at the stage of directed and championship training and to prove a relationship with the sports result, taking into account the difficulty and the quality of exercises. Material/Methods: The study involved boys aged 11–12 years systematically training gymnastics (G1, n = 20) and 12 experienced gymnasts aged 18–26 years with an accomplished international class (G2, n = 12). Both groups comprised top athletes classified at the national and the international level.The study was conducted prior to the apparatus trial, on the day preceding competition in an official sports tournament. The trial of maintaining the body balance in a handstand was carried out in a closed room after about a 10-minute warm-up. Results: An analysis of the tests showed significant differences in the level of maintaining the body bal-ance in a handstand. The largest one was reported in Area 95, whose field in experienced athletes was less than half the size (X = 8.16cm² ±8.06cm²) of the younger group ( X = 19.81cm² ±8.74cm²). Conclusions: The study of correlations of the body balance in a handstand with the level of sports prepara-tion has shown that the level of this specific to artistic gymnastics skill plays a big role in shap-ing sports mastery both among young gymnasts with a few years’ experience and among ex-perienced athletes with the international class.
Background: There is a lack of peak power (PP) estimation for young gymnasts; therefore, the purpose was to derive a new regression equation predicting young gymnasts’ PP and to validate and compare it with the previously published ones. Material/Methods: In the study, eighty young male gymnasts (age = 10.9 ±1.98 years; body mass = 33.5 ±7.45 kg) performed a countermovement jump on a force platform. Then, ¼ of the subjects were randomly assigned to a validation group and the rest served to develop a new linear regression equation using their body mass and vertical jump height (VJH). Results: In comparison, PP estimated by the new equation (1439.8 ±479.3 W) showed no significant (p > 0.05) differences with the actual PP (1400.8 ±542.8 W), whereas other previously published ones were different (p < 0.05). The developed new equation looked as follows: PP [W] = 73.81 x VJH [cm] + 34.66 x body mass [kg] -1617 (r2 = 0.75). Conclusions: According to a small systematic bias (38.97 W), the new equation can be used to predict PP of young gymnastic groups. The newly developed equation fits better the actual performance of gymnasts than the previous published ones.
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