Nonspecific chronic low back pain (NSCLBP) is a common condition that has garnered widespread attention, yet its pathogenesis remains unclear. In recent years, the study of the biomechanics underlying the occurrence and progression of this disease, aided by relevant equipment, has become increasingly important. This review focuses on the core function of the lumbar spine - flexion and extension movements - and summarizes the progress made in the research of the biomechanical characteristics of lumbar flexion and extension in NSCLBP both domestically and internationally. Through an in-depth discussion and summary of specific research methods and observation indexes, it was found that patients with NSCLBP exhibit anomalous kinematics, kinetics, surface electromyography records, and other parameters, opening up new avenues for exploring the pathogenesis and scientific prevention and treatment of this condition.