BACKGROUND: Anterior lumbar lordosis is an important factor in determining flexibility during lifting and movement, and no studies have been reported on the association between anterior lumbar lordosis and lower extremity temperature differences in patients with symptoms reflecting nerve compression in the lower extremity of a herniated lumbar disc. In the present study, we observed the correlation between anterior lumbar curvature and differences in lumbar and lower extremity temperatures in patients with lumbar disc herniation. METHODS: The subjects of this study were 15 patients with confirmed L4-5 lumbar disc herniation and 15 normal subjects as controls. Aged 15 to 45 years, lateral views of the lumbar spine were taken from 30 patients and the difference between the temperature of the lumbar region and lower extremities on the right and left sides of patients with lumbar disc herniation was determined using infrared thermography. Patients with a history of surgical treatment in the lumbar region, patients with low back pain associated with systemic disease (cancer), patients with rheumatism, compression fractures, and patients with neurological abnormalities were excluded. Imaging was performed for each group of patients, and lumbar spine curvature was measured by the PACS system for Cobb’s angle. Measurement of lumbar curvature: the angle of intersection of the extension line drawn backward parallel to the upper edge of the lumbar 1 vertebral body and the extension line parallel to the upper edge of the sacral 1 called vertebral body is called Cobb’s angle. Infrared thermographic tests were performed at the following sites: lumbar erector spinae region (LESR), tibialis anterior region (TAR), anterior ankle region (AAR), calf region (CR), posterior ankle region (APR), and dorsal foot region (FAR), and the difference in mean temperature between the left and right sides was recorded. The data were analyzed by SPSS 12.0 statistical software. The difference between the two groups was analyzed by t-test, and the correlation between lumbar spine curvature and lower limb temperature was analyzed by Persons correlation, and P<0.05 was considered statistically different. RESULTS: The lateral images of the two groups were analyzed by PACS system, and the temperature of the lower extremity was analyzed by infrared thermography. The results showed that compared with the control group, there was a significant difference in the temperature difference between the left and right sides of the lumbar curvature (LLC), LESR, TAR, AAR, and APR in patients with lumbar disc herniation, with a temperature difference of 0.4°C-0.9°C, P<0.05. In the lumbar disc herniation group, LESR, TAR, AAR, CR, APR, and FAR were negatively correlated with LLC. It showed that the temperature difference between LESR, TAR, AAR, CR, APR and FAR on the right and left sides increased with the decrease of lumbar spine curvature. LESR showed a significant negative correlation with LLC in the infrared thermogram. In particular, LESR showed a significant negative correlation with LLC.