Purpose : The purpose of this study is to examine the influence of a core stability exercise program using Swiss Ball on muscle activity, muscle thickness, maximum muscular strength, and pain in the trunk region during a 6-weeks program involving participants who have lower back pain. Methods : A total of 21 males between the ages of 20 and 33 years old were divided into 3 Swiss Ball exercise groups. Group 1 performed isometric exercises, group 2 performed isotonic exercises, and group 3 performed mixed exercises. Measurements were taken prior to starting the exercise program and after completing the program at the 6-week period using ME6000 to measure muscle activity and VAS to measure pain reduction. Comparisons were made using a paired t-test and ANOVA on SPSS 10.0. Results : There was a statistically significant effect in muscle activity for group 1 and group 3. Secondly, there was a statistically significant effect in pain reduction for group 1, group 2, and group 3. Conclusion : We found that isometric exercises performed by group 1 were effective in improving muscle activity and pain reduction.