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