Association Between Psychological Stress, Anxiety, and Cervical Muscle Activity: A Surface Electromyographic Study

Abstract

Background: Psychological stress and anxiety are common psychosocial factors that can influence
neuromuscular function and contribute to the development of musculoskeletal disorders, particularly in the
cervical region. Increased muscle tension associated with emotional distress may lead to neck discomfort,
fatigue, and functional limitations. Surface electromyography (sEMG) provides an objective method for
evaluating muscle activation and offers valuable insight into the physiological effects of psychological stress
on cervical musculature.
Objective: To investigate the relationship between psychological stress, anxiety, and cervical muscle activity
using surface electromyography in healthy adults.
Methods: An experimental study was conducted among 60 participants aged 18–40 years. Psychological
stress and anxiety were assessed using the Perceived Stress Scale (PSS) and Beck Anxiety Inventory (BAI),
respectively. Surface electromyographic recordings of the upper trapezius and sternocleidomastoid muscles
were obtained during three experimental conditions: resting, stress induction, and recovery. A standardized
mental arithmetic task was used to induce psychological stress. Descriptive statistics and paired comparisons
were used to analyze changes in muscle activity across different conditions.
Results: The study included 32 males (53.3%) and 28 females (46.7%). Mean EMG activity increased from
7.6 ± 1.4 μV during the resting phase to 17.5 ± 2.9 μV during the stress phase. During recovery, EMG activity
decreased to 10.4 ± 1.9 μV but remained elevated compared with baseline values. Mean BAI scores decreased
from 16.8 ± 9.3 to 12.0 ± 6.3, while mean PSS scores decreased from 20.2 ± 8.6 to 14.5 ± 7.1. These findings
indicate a significant increase in cervical muscle activation during psychological stress and incomplete
neuromuscular recovery following stress exposure.
Conclusion: Psychological stress and anxiety significantly influence cervical muscle activity, resulting in
increased activation of the upper trapezius and sternocleidomastoid muscles. Surface electromyography
provides objective evidence of the association between psychological distress and neuromuscular responses.
The findings highlight the importance of incorporating psychological assessment and stress-management
strategies into physiotherapy practice for the prevention and management of stress-related cervical
dysfunction.