Transauricular Vagus Nerve Stimulation for Chronic Whiplash Associated Disorders

Inclusion Criteria: 1. Symptom duration ≥3 months and \<10 years; and 2. Classifiable as WAD grade I (neck pain without physical impairments) or II (neck pain \& impairment such as movement loss and/or tenderness) or III (neck pain \& neurological deficit evident on physical exam); 3. Average pain intensity (over one week) ≥ 4/10; 4. Neck Disability Index score \> 28% (14/50). Exclusion Criteria: 1. WAD IV injury (no neurological deficit, fracture, or dislocation); 2. Concussion symptoms; 3. Patients who have undergone cervical vagotomy; 4. Patients diagnosed with severe bradycardia; 5. Patients with a permanent implanted metallic or electronic device or jewellery at close proximity to the ear tragus; 6. Patients with any active implanted device (including electronic and/or medical devices) e.g. cochlear implant, cerebral shunts, invasive vagus nerve stimulators, or non-active but potentially interacting with the nervous system (e.g., metal implants); 7. Open wounds or rashes, swollen, red, infected, or inflamed areas or skin eruptions (e.g., phlebitis, thrombophlebitis, varicose veins); or cancerous lesions in the area of stimulation 8. Using medications associated with ANS function such as Beta Blockers; 9. Adverse general health factors such as presence of a neurological disorder (e.g., multiple sclerosis), inflammatory condition (e.g., rheumatoid arthritis), cardiovascular disorder (known severe coronary disease or recent myocardial infarction (within 5 years)); metabolic disorder (e.g., diabetes), visual deficit or disease process (e.g. cataracts, double or blurred vision), known or suspected serious spinal pathology (e.g. metastatic disease of the spine), pregnancy, or previous spinal surgery or recurrent treatment for spinal disorders; 10. History of any mental health conditions prior to the MVC, such as bipolar disorder, schizophrenia, anxiety, PTSD or severe depression; 11. People who are unable to complete the questionnaires.