SENECA - Smart Therapies for Chronic Pain

Inclusion Criteria: * Male or female aged between 30 and 65 years * Indication: chronic myofascial/musculoskeletal back pain * normal function of spinal nerves * Intractable pain for more than 6 months * Patient on oral pharmacotherapy ≤ WHO II with no adequate response or intolerant * Average pain over the last 4 weeks according to the 0-10 numerical pain rating scale ≥ 4 and ≤ 9 at baseline * ODI 20-80 at baseline * Basic digital understanding to work with the patient pain app * Patient understands the therapy and procedures, agrees to its provisions, and gives written informed consent prior to any procedures Exclusion Criteria: * Organic low back pain (trauma, fracture, tumor, infection, severe degenerative spine, documented high-grade spinal stenosis, rheumatologic conditions) * Indication for back surgery * Back surgery within the last 6 months * New analgesics 2 weeks before baseline (paracetamol, NSAIDs, Metamizol, etc.) * Opioid analgesic therapy \> WHO II * New physical therapy modalities for back pain, also TENS, 2 weeks before baseline * History of vagus nerve stimulation or electrical auricular stimulation * History of vasovagal syncope * High BMI \> 35 kg/m² (Obesity Class 2 or higher) * Hemophilia * Autonomic disorders * Advanced stage or poorly controlled diabetes mellitus type I or II * Poorly controlled high blood pressure * Major psychiatric comorbidity (HADS \> 10 on each subscale at baseline) * Other serious clinically relevant co-morbidity * History of arrhythmia, bradycardia, other rhythm disorders or any other clinically significant cardiac anomalies * Infection, eczema, or psoriasis at application site (ear and neck) * Numbed and desensitized skin at the application site (ear and neck) * Chronic drug or alcohol abuse within the last 6 months * Pregnant or nursing female patients * Active implantable device * Open pension request * Currently participating in another clinical trial or participated over the last 3 months * Change in concomitant treatment or medication during the study