Effect of Thread-Embedding Acupuncture at EX-B2 Acupoint on Pain Intensity and Quality of Life in Chronic Low Back Pain

The goal of this clinical trial is to learn whether thread-embedding acupuncture (TEA) is more effective than sham thread-embedding acupuncture in treating adults with chronic low back pain. The study will also evaluate the safety of TEA. The main questions it aims to answer are: * Does TEA reduce pain intensity more effectively than sham TEA? * Does TEA improve quality of life compared with sham TEA? * Does TEA reduce the frequency of bothersome pain episodes? * Does TEA reduce the use of routine and additional (extra) pain medications? * What side effects occur in participants receiving TEA compared with sham TEA? Researchers will compare TEA with sham TEA (a procedure that mimics acupuncture without needle insertion or thread placement) to determine whether TEA provides greater and longer-lasting benefits for chronic low back pain. Participants will: * Receive a single session of TEA or sham TEA * Continue using pain medications as prescribed by their physician * Be evaluated at weeks 2, 4, 6, and 8 after treatment * Complete pain assessments, quality-of-life questionnaires, and reports of pain episodes and medication use * Attend in-person clinic visits at weeks 4 and 8, and receive telephone follow-ups at weeks 2 and 6

Inclusion Criteria: * Male or female participants aged ≥18 years * Subjects with low back pain lasting for at least 3 months (\>12 weeks) * Maximum low back pain intensity within the past 2 weeks of ≥3 on a 0-10 scale, measured using the Numeric Pain Rating Scale (NPRS) or the Face, Legs, Activity, Cry, Consolability (FLACC) scale * Willing to participate in the study until completion and able to provide written informed consent * Receiving pharmacological therapy with a stable analgesic regimen for at least the past 2 weeks, which may include non-opioid analgesics (paracetamol), opioid analgesics (codeine, tramadol, morphine), antidepressants (amitriptyline, duloxetine), anticonvulsants (gabapentin, pregabalin, carbamazepine), and/or muscle relaxants (eperisone, baclofen) Exclusion Criteria: * History of hypersensitivity to acupuncture or thread-embedding acupuncture (TEA), including allergy to stainless steel or polydioxanone threads * History of keloid formation or skin disorders at the planned TEA insertion sites in the low back area * Presence of specific spinal pathology, including fracture, tumor, infection, or severe lumbar spinal stenosis (Schizas grade C or D) requiring surgical intervention * Structural spinal abnormalities (scoliosis or kyphosis) detected on physical examination * History of spinal surgery or current indication for spinal surgery due to severe neurological deficits * Presence of other chronic pain syndromes (fibromyalgia, myofascial pain syndrome, neuropathic pain syndrome, arthritis, chronic pelvic pain, migraine, or chronic tension-type headache) or severe comorbidities (stroke with sensory deficits, Parkinson's disease, end-stage chronic kidney disease, or terminal heart failure) that may affect pain assessment * Presence of cardiac disease, hematologic disorders, or uncontrolled diabetes mellitus * Regular use of systemic steroids, nonsteroidal anti-inflammatory drugs (NSAIDs), antiplatelet agents, anticoagulants, or topical analgesics * Body mass index (BMI) \