Analysis of Psychological Stress and Muscle Activity Using Electromyography and Stress Test

Stress is a significant contributor to mental and physical health deterioration and has been widely studied through various physiological measures, one of which is electromyography (EMG), especially the trapezius muscle. This study investigates the relationship between psychological stress and muscle activity using EMG. To induce psychological stress, the Mental Arithmetic Test (MAT) with three increasing levels of difficulty was used. Additionally, stress levels were assessed using the Perceived Stress Scale (PSS-10) and Visual Analogue Scale (VAS) in between stress and rest phases. Data analysis involved calculating the correlation between EMG signals, MAT scores, PSS-10 and VAS scores. The Spearman correlation between all shows that EMG RMS weakly correlates with VAS (r = −0.18) and not with MAT scores. VAS moderately correlates with MAT (r = −0.41), and RMS shows a positive link with PSS-10 (r = 0.52), indicating higher perceived stress aligns with increased muscle activity. These findings provide insights into the complex relationship between psychological stress, muscle activity, and perceived stress measures. Increased task difficulty generally raised EMG RMS values, likely due to cognitive load and stress, though RMS sometimes decreased in later, more challenging stages, possibly due to muscle fatigue or cognitive overload. Despite limitations such as individual differences in muscle reactivity and task-related fatigue, these findings highlight EMG's potential as a tool for stress detection, offering insights into physiological responses to cognitive stress. Future research should explore multi-modal approaches, larger samples, and more rigorous control of individual variability to strengthen EMG's application in accurately detecting psychological stress.