Muscle activation of a sportsman vs. an untrained man.

abstrakt

angličtina

The presented research is based on the aim to analyse the stimuli of the muscle activity using EMG during repeated simple dynamic physical activity. The purpose of this study is to find out if it is possible to determine differences between a sportsman and an untrained man in the timing of muscle activity of selected muscles during increasing load. Two men took part in the research. The untrained man (MN) was 20 years old, height 180 cm, weight 74 kg, ectomorph, physical activity once a week. Sportsman (MS) was 22 years old, height 177 cm, weight 87 kg, mesomorph, physical training unit concentrated on the development of strength 5 times a week. Research participants performed repeated flexion and extension in the elbow joint on the fitness machine. The arms were supported from the armpit to the elbow on the pad of the machine. Activation of the muscle activity has been tested using EMG on the selected muscles: biceps brachi (BB), brachioradialis (B), trapezius p. descendez (TD), deltoideus p. acromialis (DA) and where BB and B were considered main working muscles and TD and DA secondary muscles. Each research participant performed flexion and extension in elbow at his own speed and rhythm without pauses in between flexion and extension. Both participants performed test for 5, 8 and 12 kg load. Number of repeated activities at every load was 10. Data from 2-9 physical movement cycles was processed and evaluated. In both research participants, performance of movement flexion cycle was always faster than extension at all loads. In a sportsman, time differences between flexion and extension were minimal, on average 5%. In untrained man, these differences were 11.8%. Sportsman was performing flexion and extension significantly faster than the untrained man. At the identical loads (5, 8, 12 kg) in flexion, the time of muscle activations were the same or very similar for BB for both research participants and always longer in MN for B. Differences in the time of activations for secondary muscles were also different. For TD were longer in MS for all loads and for DA longer in MN for 5 and 8 kg load and shorter for 12 kg load. Differences in the activation time were caused especially by a different finishing time. In extension DA and B in MN, partly also TD were activated for a longer time. The time for activation of BB was mostly the same. Differences were caused mainly by the later start of the activation in MS, finishing time caused only minor differences. We found out differences in both research participants in flexion and extension which were specific for the individual muscles. Significantly longer time of activation of all muscles in MN was expected, but it has been proved only for B and DA for both kinds of movements. Differences between participants in the total time of activation at the absolutely same load were expected especially because of the better movement efficiency, adaptation to the power load and movement technique. More effective and therefore shorter activation in the sportsman were expected due to higher efficiency of the neuromuscular system during movement, adaptation and the technique of movement itself but we didn`t prove it for all muscles. Also tendencies in prolonging and shortening the time of activation in relation to increasing load in both research participants demonstrate different characteristics.

EMG, muscle activation, flexion, extension, timing

KORVAS, P.; KOŤOVÁ, M.; HORÁKOVÁ, P.

3. 12. 2015

University of West – Hungary,Szombathely, Hungary

HUngary, Szombathely

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http://xmasconference.com/wp-content/uploads/2015/12/e-Book-of-Abstracts-2015.pdf