Experimentally Induced Stress Validated by EMG Activity

Abstract

Experience of stress may lead to increased electromyography (EMG) activity in specific muscles compared to a non-stressful situation. The main aim of this study was to develop and validate a stress-EMG paradigm in which a single uncontrollable and unpredictable nociceptive stimulus was presented. EMG activity of the trapezius muscles was the response of interest. In addition to linear time effects, non-linear EMG time courses were also examined. Taking into account the hierarchical structure of the dataset, a multilevel random regression model was applied. The stress paradigm, executed in N = 70 subjects, consisted of a 3-minute baseline measurement, a 3-minute pre-stimulus stress period and a 2-minute post-stimulus phase. Subjects were unaware of the precise moment of stimulus delivery and its intensity level. EMG activity during the entire experiment was conform a priori expectations: the pre-stimulus phase showed a significantly higher mean EMG activity level compared to the other two phases, and an immediate EMG response to the stimulus was demonstrated. In addition, the analyses revealed significant non-linear EMG time courses in all three phases. Linear and quadratic EMG time courses were significantly modified by subjective anticipatory stress level, measured just before the start of the stress task. Linking subjective anticipatory stress to EMG stress reactivity revealed that subjects with a high anticipatory stress level responded with more EMG activity during the pre-stimulus stress phase, whereas subjects with a low stress level showed an inverse effect. Results suggest that the stress paradigm presented here is a valid test to quantify individual differences in stress susceptibility. Further studies with this paradigm are required to demonstrate its potential use in mechanistic clinical studies.

Impact of early life adversity on EMG stress reactivity of the trapezius muscle

“…[26] In this paradigm, an anticipatory stress effect is generated by inducing both a distinct cognitive stressor and a physical painful stimulus. The anticipatory stress effect is mediated by an increase in electromyographic activity (EMG activity) of the trapezius muscle during the prestimulus phase.…”

“…The anticipatory stress effect is mediated by an increase in electromyographic activity (EMG activity) of the trapezius muscle during the prestimulus phase. [26] …”

“…Consequently, multilevel random regression was used. [33] In addition, it has been shown that EMG activity measured during a stress experiment comprises nonlinear time effects, [26] which can be modeled by multilevel regression. In order to approach the naturalistic effects expected to be present in anticipatory muscle activity, it was decided to include a linear, exponential, and quadratic time effect in the analyses.…”

Facial and Shoulder Electromypgraphic Response to Heat Stimulation at Distinct Intensity Levels

“…Studying muscle reactivity to external painful stimulation seems to be a reasonable approach to get pain-related information rather than stress-related information due to any other circumstances. This statement is supported by the work of Luijcks and colleagues [11]. They assessed Trapezius EMG activity in the context of an unpredictable and uncontrollable noxious (thus, somehow painful) stimulation.…”

Efeitos do programa Mindfulness (versão adaptada) sobre a qualidade de vida em uma população universitária

“…Sua ação pode afetar ainda a saúde mental e resultar em ansiedade, estresse pós traumático (PTSD), depressão e burn-out -exaustão causada pelo excesso de trabalho e sobrecarga. (Luijcks et al, 2014).…”