Purpose The aim of this study was to investigate the effects of strengthening the foot arch on the paretic side on lower limb muscle activity, balance, and gait in individuals with stroke. Methods A total of 34 stroke individuals were selected from a single medical institution and divided into study and control groups, with 17 participants in each group. One participant from the study group and two participants from the control group dropped out, resulting in a final analysis of 31 participants. Both groups underwent their respective interventions three times a week for 6 weeks, with each session lasting 30 minutes. The study group received foot arch strengthening intervention on the paretic side, while the control group received general physical therapy. The effects of the study intervention were evaluated using the following measurements: navicular drop test (NDT), weight distribution ratio (WDR), and surface electromyography (sEMG). Balance was assessed using the limit of stability (LOS), Berg balance scale (BBS), and functional reach test (FRT). Gait evaluation was performed using the 10meter walk test (10MWT), measuring gait velocity, cadence, and step length. Results The results of the NDT, WDR, sEMG, LOS, BBS, FRT, 10MWT demonstrated significant differences between pre and post intervention. Additionally, there were significant differences observed between the study and control groups in terms of WDR, LOS, and gait speed. Conclusion These findings demonstrate that strengthening the foot arch on the paretic side is an effective intervention for improving lower limb muscle activity, balance, and gait in individuals with stroke.