Effects of the Timing of Vagus Nerve Stimulation Combined With Exercise in Chronic Neck Pain

This randomized controlled trial aims to investigate whether the timing of transcutaneous auricular vagus nerve stimulation (taVNS) relative to exercise influences clinical and autonomic outcomes in individuals with chronic neck pain. Participants will be randomly allocated to one of three groups: taVNS applied before exercise, taVNS applied after exercise, or exercise alone. All groups will receive a standardized exercise program designed for chronic neck pain. The intervention will be conducted over a 6- to 8-week period. The effects of the interventions will be evaluated using pain intensity, neck-related disability, sleep quality, heart rate variability, and exercise adherence. The study will determine whether applying taVNS before or after exercise provides additional benefits compared with exercise alone and whether the timing of stimulation influences treatment outcomes.