Nonspecific chronic low back pain ( NSCLBP) is a common disease that has generated widespread attention, yet its pathogenesis remains unclear. In recent years, more and more attention has been paid to biomechanical mechanism of the occurrence and development of NSCLBP aided by relevant equipment. This review focused on core function of lumbar spine, i. e. flexion and extension movements, and summarized the progress on biomechanical characteristics of NSCLBP during lumbar flexion and extension both domestically and internationally. Through an in-depth discussion and summary of specific research methods and observationindexes, anomalous signs of kinematics, kinetics, surface electromyography were found in patients with NSCLBP, which opened up new ideas for exploring pathogenesis of NSCLBP and its scientific prevention and treatment.