The purpose of this research is to utilizing the Tetrax$^{(R)}$ balance measuring instrument in order to analyze the postural balance of males and females in their 30 s diagnosed with chronic lower back pain who have followed a 12-week rehabilitation exercise program. The research also examines the effects on any change in back pain level. In terms of the variables in this research, postural balance (left/right, front/back, postural balance) and pain level change (0~100 mm) were measured. Pre-/post-experimental differences were assessed using the paired-t test. In addition, to identify any gender gap, we set the preliminary scores as a covariate and ran the Analysis of Covariance. Statistical significance (a) herein was set at 0.05. As a result of this research experiment, the left/right, front/back, and overall postural balance were found to increase in both the male and female cases, but with no statistical significance or gender gap. However, both males and females showed a significant decrease in their back pain levels. These findings demonstrate the necessity of continuing clinical research based on the Tetrax$^{(R)}$ equipment for scientific evaluation of the effects of rehabilitation exercises on chronic lower back pain patients and their balancing ability.