Purpose: The purpose of this study was to examine changes in plantar pressure, balance, and posture by applying the Bruegger exercise using a Thera Band in adults with flexible flat feet, in order to verify the effects of the Bruegger exercise and provide basic data for physical therapy practice. Methods: The study included a total of 26 participants, who were divided into the Bruegger exercise group (13 participants) and the short-foot exercise group (13 participants) as the experimental and control groups, respectively. Each group performed exercises for 30 minutes per day, five times a week, for two weeks, with measurements taken before and after the intervention. The Kolmogorov-Smirnov test was used to verify the normal distribution of each variable, and paired t-tests were used to examine differences in navicular height, plantar pressure, balance ability, and posture before and after the exercise within each group. Independent t-tests were conducted to compare the changes between groups, and the significance level was set at .05 to analyze statistical significance. Results: Both groups showed significant improvements in static plantar pressure and balance, with the experimental group demonstrating greater improvements in both static and dynamic balance. There were no significant differences between the experimental and control groups in any variable. Conclusions: The findings suggest that Brugger's exercise improves plantar pressure distribution and balance in young adults with flexible flat feet. Incorporating functional exercises with Thera Bands strengthens foot muscles, enhancing balance and reducing injury risk. Future research should examine the long-term effects and include a more diverse participant pool.