Association between dynamic changes in lumbar back temperature during professional driver training and lumbar muscle endurance: a longitudinal study.

OBJECTIVE: To investigate the dynamic changes in lumbar-back temperature associated with low back pain (LBP) during the training period of professional drivers and its influencing factors, analyze the correlations of infrared thermal imaging parameters with lumbar muscle endurance and LBP symptoms. METHODS: A longitudinal follow-up study was conducted involving 135 male truck driving trainees from a driving school. The follow-up period spanned four months, with four assessment points (T1-T4). Ultimately, 132 trainees (18-30 years; mean 22.6 ± 2.2 years) completed the full follow-up (effective rate: 97.8%). Infrared thermography was employed to measure mean lumbar-dorsal temperature, temperature gradients, Cumulative Heat Alteration (CHA) and Jumpwise Unevenness Estimation (JUE) in the lower back. Concurrently, lumbar muscle endurance tests and physical measurements were conducted, while low back pain symptoms and functional impact were assessed using the Numerical Rating Scale (NRS) and Oswestry Disability Index (ODI). Data were analyzed using repeated measures ANOVA, Pearson/Spearman correlation analysis, and multivariate linear regression, with a significance level of α=0.05. RESULTS: During training, the average lumbar-dorsal temperature initially increased gradually, then stabilized, before showing a marked decrease in the final phase; The lumbar temperature gradient continued to expand, with both group and individual temperature heterogeneity significantly increasing by the training's conclusion (P<0.001). Correlation analysis revealed significant positive correlations between lumbar muscle endurance test duration and both CHA scores (R = 0.2, P = 0.02) and JUE scores (R = 0.25, P = 0.004). After adjusting for confounding factors such as Body Mass Index (BMI), regular physical exercise and muscle percentage, lumbar muscle endurance was the only statistically significant independent factor affecting CHA (P = 0.033) and JUE (P = 0.015). BMI showed a marginal correlation (0.05<P<0.2), and other variables had no independent statistical association. CONCLUSION: During professional driver training, characteristic dynamic changes occur in lumbar-back temperature, and these changes are independently associated with lower back muscle endurance. These metrics provide a non-invasive reference for exploring the relationship between lumbar muscle function and LBP. Targeted lumbar endurance training combined with appropriate BMI management can support lumbar health protection for professional drivers and some sedentary populations.