Context: The modified side-bridge exercise is designed for some special situations in which it is impossible to tolerate the compressive load on the side supported during the side bridge, such as in the older people with a hip or knee replacement and even in athletes with shoulder pain. Objectives: To examine the effects of 3 modified side-bridge exercises on the spinal stability muscles compared with traditional side-bridge (TSB) exercises for healthy men. Design: The effects of different exercises on the muscle activities of the external oblique (EO), internal oblique (IO), and quadratus lumborum (QL) during TSB exercise, both legs lift on side lying (BLLS), torso lift on a 45° bench while side lying (TLBS), and wall side bridge (WSB) were analyzed with the 1-way repeated-measures analysis of variance. Setting: This study was conducted in a university hospital laboratory. Participants: A total of 20 healthy men were recruited for this study. Interventions: The participants performed TSB, BLLS, TLBS, and WSB in a random order. Main Outcome Measures: Surface electromyography measured the muscle activity of the EO, IO, and QL. A 1-way repeated-measures analysis of variance assessed the statistical significance of the EO, IO, and QL muscle activity. When there was a significant difference, a Bonferroni adjustment was performed. Results: BLLS and TLBS showed similar effects to TSB in the EO, IO, and QL muscle activity, whereas WSB showed significantly less QL muscle activity than TSB (P < .05). Moreover, TLBS was significantly greater in the muscle activity of QL and EO than WSB (P < .05). Conclusion: BLLS and TLBS may be effective rehabilitation techniques to activate EO, IO, and QL in patients who are unable to perform TSB as spine stability exercises.