Autonomic Nervous System Dysregulation in People With Chronic Neck Pain

The goal of this observational study is to investigate heart rate variability in different positions and in response to isometric hand-grip test in people with non-specific chronic neck pain as compared with healthy controls. The main questions it aims to answer are: * Do the heart rate variability indices differ between people with non-specific chronic neck pain and healthy controls in supine sitting and standing positions? * Do the heart rate variability indices differ between people with non-specific chronic neck pain and healthy controls when challenged by the isometric hand-grip test?