Introduction: To effectively maintain balance we need a constantly working control system. Muscle spindles in skeletal muscles provide the nervous system with information about changes in muscle length and they are sensitive to vibration applied directly on the muscle belly or to the tendon. Tibialis anterior muscle is the best mechanical source of proprioceptive information during quiet standing. Purpose: We wanted to find out if different frequencies of vibration applied on the belly of tibialis anterior muscle affect movement of centre of pressure during quiet standing in different ways, which was assessed by measuring the movement of centre of pressure. Methods: 32 healthy volunteers of both sexes, aged 18 to 47 years participated in the study. During quiet standing on pressure plate with feet close together, we measured the movement of centre of pressure. We performed five measurements: standing without vibration with eyes open and closed, and then standing with eyes closed for each individual vibration frequency. We applied mechanical vibration to the muscle belly of both tibialis anterior muscles using tactors. Vibrations with frequencies of 30 Hz, 80 Hz and 130 Hz and with amplitude of 0,8–1 mm lasted 80 seconds. The following variables were included in statistical analysis of the data: velocity of centre of pressure, mediolateral and anteroposterior path of centre of pressure and area of centre of pressure according to the method of principal component analysis. In statistical analysis we used the analysis of variance for repeated measurements and Friedman test. Results: Analysis of data about movement of centre of pressure during applied vibrations on the belly of tibialis anterior muscle did not show statistically significant differences between different vibration frequencies. There were also no statistically significant differences with or without applied vibrations with closed eyes. Discussion and conclusion: Based on obtained results we can conclude that vibration of different frequencies applied on the belly of tibialis anterior muscle have no influence on static balance in healthy young adults with eyes closed. Our findings contradict the findings of other researchers that vibrations to the tibialis anterior muscle cause change in body tilt and imbalance, as well as those higher frequencies cause greater body tilt. In the future, simultaneously applied combination of influence of vibrations of larger amplitudes on movement of centre of pressure and body tilt should be examined.
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