The trapezius muscle uniquely lacks adaptive process in response to a repeated moderate cognitive stressor

The aim of this study was to examine the adaptive process of muscular responses in healthy subjects over two repeated exposures to the same moderate cognitive stressor. The electromyographic (EMG) activity of the flexor pollicis brevis, biceps brachii, triceps brachii, trapezius, gastrocnemius and soleus muscles was recorded in 35 males during video-recorded Stroop color-word interference tests. The results showed lower EMG activity in all muscles during the second exposure to the stressful task, but not in the trapezius muscle. These findings could help to the understanding of the role of stressful situations in the development of musculoskeletal disorders.

► We examine the adaptive process of muscular responses over two repeated exposures to the same stressor. ► During the second stressful task, similar level of trapezius EMG activity has been found. ► Lower EMG activity in the other muscles has been found. ► These findings could help in understanding the role of psychological stress in musculoskeletal disorders.