Autonomic and muscular responses and recovery to one-hour laboratory mental stress in healthy subjects
Nilsen, Kristian Bernhard; Sand, Trond; Stovner, Lars Jacob; Leistad, Rune Bang; Westgaard, Rolf Harald
Abstract
Background: Stress is a risk factor for musculoskeletal pain. We wanted to explore stress related
physiology in healthy subjects in order to gain insight into mechanisms of pain development which
may relate to the pathophysiology of musculoskeletal pain disorders.
Methods: Continuous blood pressure, heart rate, finger skin blood flow, respiration, surface
electromyography together with perception of pain, fatigue and tension were recorded on 35
healthy women and 9 healthy men before, during a 60 minute period with task-related low-grade
mental stress, and in the following 30 minute rest period.
Results: Subjects responded physiologically to the stressful task with an increase in trapezius and
frontalis muscle activity, increased blood pressure, respiration frequency and heart rate together
with reduced finger skin blood flow. The blood pressure response and the finger skin blood flow
response did not recover to baseline values during the 30-minute rest period, whereas respiration
frequency, heart rate, and surface electromyography of the trapezius and frontalis muscles
recovered to baseline within 10 minutes after the stressful task. Sixty-eight percent responded
subjectively with pain development and 64% reported at least 30% increase in pain. Reduced
recovery of the blood pressure was weakly correlated to fatigue development during stress, but
was not correlated to pain or tension.
Conclusion: Based on a lack of recovery of the blood pressure and the acral finger skin blood flow
response to mental stress we conclude that these responses are more protracted than other
physiological stress responses.