Development of Surface Electromyography Signal Frequency Analysis to Evaluate Non-contracting Muscle Fatigue

• Main Author: Maslim, Reinaldy
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/43746
• Institution: Institut Teknologi Bandung

The non-invasive nature of surface electromyography (sEMG) has been particularly appealing in areas like prosthesis control and diagnosis of muscle injuries, including muscle strain and fatigue. Methods to evaluate muscle fatigue are becoming attractive nowadays, because it may prevent fatigue-induced injuries, not only prominent among athletes but also among workers doing daily physical exertion. The main causes of skeletal muscle fatigue are isotonic contraction and isometric contraction. The study of EMG signal from fatigued muscle caused by isometric contraction are more favored because of its stationariness and minimal interference from relative movement of the electrodes with the skin, and movement artifacts. This study investigates muscle fatigue in isometric and relaxed state. The sEMG signals are evaluated in the frequency domain in terms of mean frequency (MNF) and median frequency (MDF). The results of this study are expected to be applied in the form of a wearable device that measures sEMG signals in a non-invasive and real-time manner to evaluate muscle fatigue, especially in the isometric condition. The sEMG signals are measured on two healthy male subjects. The first subject was directed for biceps brachii sEMG signal measurement, while the second subject was directed for vastus lateralis and vastus medialis sEMG signal measurement. This study concludes that fatigue in relaxed and isometric muscles are indicated by a decrease in MNF and MDF. The one sample t-tests conducted showed that the MNF and MDF of the fresh muscle and fatigued muscle are significantly different at 95% confidence level in all intervals.