A questionnaire survey was conducted on the experimental group, which used the far infrared devices, and the control group. A pre-test was first performed to collected data on the subjects’ autonomic nervous systems. An evaluation on their lower back pain was conducted to determine any changes in the autonomic nervous system activity. The research data were analyzed using independent t-tests and paired t-tests. The Bayesian network was used to construct an association model between lower back pain and autonomic nervous activity.