Introduction. The use of classical methods for diagnosing muscle fatigue of physical workers, including dynamometry and electromyography, is often limited due to the complexity of the process, the inability to use them in production, and the subjectivity of the methodology. At the same time, such a method as myotonometry does not have these disadvantages, but the main area of its use at the moment is clinical practice. The aim of study was to determine the possibility of using myotonometry to assess muscle fatigue. Materials and methods. In the course of the study, the biomechanical characteristics of muscles that differ in their depth were evaluated using the "MyotonPro" device (Myoton AS, Estonia). We determined the tone and stiffness of the biceps of the shoulder, the soleus muscle, and the muscle that straightens the back at different periods of time under the influence of maximum load on them. Results. It was found that the studied parameters of these muscles immediately after performing a series of exercises "to failure" statistically significantly increased, and after 30 minutes - again decreased, but did not reach the initial level. Conclusions. The myotonometric study showed objectivity, reliability, repeatability and proved to be one of the most promising modern methods for assessing muscle fatigue, including for solving problems in the field of occupational health.