Muscle Fatigue Assessment during Flexion – Extension Movements Curriculum: Electromagnetism and Bioengineering Author

Muscle fatigue represents a complex phenomenon encompassing various causes, mechanisms and forms of manifestation. Continuous monitoring of local muscle fatigue during performance of certain work is possible by measuring myoelectric activity of particular muscles by the method of surface electromyography. Biochemical and physiological changes in muscles during fatiguing contractions are reflected also in properties of myoelectric signals recorded on the surface of the skin above the muscle. It is well know that the spectral analysis of surface myolelectric signals, through the mean and median frequency values, is a valuable tool for the quantification of the electrical manifestations of muscle fatigue. Specifically, it has been demonstrated that during an isometric muscle contraction the power spectrum of the signal is progressively scaled towards the power lower frequencies. Although important results have been obtained in the past by assessing fatigue under static conditions, fatigue assessment during dynamic tasks is here taken into consideration because are likely more relevant to daily functions and clinical applications. In particular, the dynamic conditions were controlled by an isokinetic machine that allowed to compare the electrical manifestations of muscle fatigue during concentric and eccentric contractions. The purpose the our study is to evaluate the isokinetic principle in rehabilitation through time-frequency analysis to understand of muscle behavior during two modalities of contraction. Doctoral School on Engineering Sciences Università Politecnica delle Marche